Caribbean - Central America Weather

[msbee]

hi Luis yes it is huge....
there go my allergies

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1040 PM AST THU AUG 1 2013

.UPDATE...SOME SHOWERS WITH ISOLATED THUNDERSTORMS WERE NOTED
ACROSS THE COASTAL WATERS...MAINLY OVER THE ATLANTIC WATERS NORTH
OF THE ISLANDS. OTHER SHOWERS MOVED THROUGH THE SOUTHEAST SECTIONS
OF PUERTO RICO LATE THIS EVENING...BUT WERE MOVING QUICKLY. A
SIGNIFICANT AREA OF SAHARAN DUST WAS OVER THE LESSER ANTILLES
LATE TONIGHT. THIS AREA OF SAHARAN DUST WILL APPROACH THE LOCAL
ISLANDS FRIDAY MORNING. THEREFORE...LITTLE SHOWER ACTIVITY IS
EXPECTED. FORECAST REFLECTS THIS SCENARIO...THEREFORE...NO CHANGES
NEEDED AT THIS TIME.

[Macrocane]

It will be interesting to see pictures of the haze especially at sunset. And be careful with your allergies msbee.

The latest HPC Discussion

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
154 PM EDT THU AUG 01 2013

DISCUSSION FROM AUGUST 01/00UTC: DRYING TREND IS ESTABLISHING IN
NORTHWESTERN MEXICO...AS MID/UPPER RIDGE STRENGTHENS ACROSS
WESTERN TEXAS-TAMAULIPAS-NORTHERN VERACRUZ. POTENT RIDGE WILL
SUSTAIN AND GRADUALLY STRENGTHEN SUBSIDENCE INVERSION FAVORING THE
ESTABLISHMENT OF DRIER CONDITIONS AS THE CYCLE PROGRESSES.
CONVECTION WILL CLUSTER ALONG THE SIERRA MADRE OCCIDENTAL AND TO
THE SOUTH OF 20N. EXPECTING ACCUMULATIONS OF 05-10MM/DAY THROUGH
THE CYCLE WITH MAXIMA OF 15MM. TO THE SOUTH OF 20N...ISOLATED TO
SCATTERED DIURNAL CONVECTION WILL PERSIST THROUGH THE CYCLE. A
WEAK MID-LEVEL TROUGH WILL ARRIVE FROM THE EAST INTO DAY 03
LEADING TO A SLIGHT INCREASE IN CONVECTION COVERAGE. EXPECTING
HEAVIEST AMOUNTS ALONG THE SIERRA MADRE DEL SUR WITH ACCUMULATIONS
OF 10-15MM/DAY AND ISOLATED MAXIMA OF 20-30MM.

OVER THE BAHAMAS/CUBA...A STRONG TUTT IS MEANDERING WESTWARD. THE
TUTT IS DEEP AND HAS A STRONG REFLECTION INTO THE MID-LEVELS
ESPECIALLY AROUND THE CLOSED LOW LOCATED JUST TO THE SOUTHEAST OF
GREAT ABACO ISLAND. MID/UPPER CIRCULATION WILL DRIFT INTO CENTRAL
CUBA BY 24 HRS...WEST/CENTRAL CUBA BY 48 HRS...PINAR DEL RIO BY 72
HRS WHILE WEAKENING. MODELS SHOW THIS TROUGH GRADUALLY BECOMING
NEGATIVELY TILTED WITH HEIGHT WHILE PRESSING INTO THE RIDGE TO THE
NORTHWEST. AS A RESULT...AREAS OF DIVERGENCE WILL TEND TO SHIFT
FROM THE EASTERN SIDE TO THE WESTERN SIDE OF THE TROUGH AS EARLY
AS DAY 02. ACCUMULATIONS ON DAY 01 WILL BE LARGEST OVER THE
CENTRAL/NORTHWESTERN BAHAMAS WITH AMOUNTS OF 15-20MM/DAY AND
MAXIMA OF 30-60MM THROUGH 36 HRS. THIS THEN DECREASES TO
05-10MM/DAY AND MAXIMA OF 15MM BY 36-60 HRS...DECREASING FURTHER
AFTERWARDS. ACROSS CUBA THIS IS TO FAVOR RAINFALL AMOUNTS OF
05-10MM/DAY AND ISOLATED MAXIMA OF 20-35MM/DAY THROUGH 36 HRS. BY
36-60 HRS THIS DECREASES TO 05-10MM/DAY AND MAXIMA OF 15MM.

A THIRD TUTT LOW CENTERS AT 25N 55W EXTENDING TO THE SOUTHWEST
INTO THE NORTHEASTERN CARIBBEAN. THIS TUTT WILL MEANDER OVER THE
REGION THROUGH THE CYCLE. THE TUTT IS INDUCING A TROUGH IN THE
EASTERLIES THAT IS MEANDERING WESTWARD AS LOW/MID LEVEL RIDGE OVER
THE CENTRAL ATLANTIC STRENGTHENS. INVERTED TROUGH WILL MEANDER
OVER THE VIRGIN ISLES TO PUERTO RICO BY TODAY. BUT WILL START
LOSING DEFINITION AS IT DECOUPLES FROM THE TUTT ALOFT. THIS WILL
CAUSE THE WAVE FILL SOMEWHAT AND THEN BECOME AN EASTERLY WAVE
ACROSS THE GREATER ANTILLES. MEANWHILE...TUTT AND INDUCED TROUGH
WILL ENHANCE CONVECTIVE DEVELOPMENT ACROSS THE NORTHEAST CARIBBEAN
ISLES. THIS WILL FAVOR RAINFALL AMOUNTS OF 05-10MM/DAY AND
ISOLATED MAXIMA OF 15-20MM/DAY.

A REMARKABLE FEATURE IS UNUSUALLY STRONG AND WIDESPREAD SAHARAN
DUST EVENT ALREADY REACHING THE CENTRAL ATLANTIC. THE STABLE AIR
MASS IS RAPIDLY MIGRATING WESTWARD AS SUBTROPICAL RIDGE BUILDS AND
TRADES STRENGTHEN. RIDGE WILL EXTEND INTO THE BAHAMAS/NORTHEAST
CARIBBEAN BY THE END OF THE WEEKEND. THIS WILL TIGHTEN THE
PRESSURE GRADIENT SUSTAINING A WIND SURGE ACROSS THE ISLAND CHAIN
EXPANDING INTO THE CENTRAL/SOUTHERN CARIBBEAN THROUGH 36-60 HRS.
AT 850 WINDS ACROSS THE LESSER ANTILLES TO EASTERN CARIBBEAN ARE
TO PEAK AT 25-30KT...WHILE OVER THE CENTRAL AND SOUTHERN CARIBBEAN
THEY WILL PEAK AT 45-50KT. THE STRONG WINDS ARE TO ADVECT A
SAHARAN AIR LAYER ACROSS THE TROPICAL ATLANTIC INTO THE CARIBBEAN
LATER THIS WEEK...TO RAPIDLY SPREAD ACROSS THE BASIN.
STRENGTHENING TRADES WIND CAP IS TO SUSTAIN A DRYING TREND ACROSS
THE LESSER ANTILLES/NORTHERN CARIBBEAN ISLES...TO THEN EXPAND
ACROSS THE CENTRAL CARIBBEAN TO PORTIONS OF CENTRAL AMERICA LATER
IN THE CYCLE.

OVER NORTHERN SOUTH AMERICA INTO CENTRAL AMERICA...CONVECTION WILL
BE CLUSTERED ALONG THE ITCZ AND PERTURBATIONS PROPAGATING ALONG
IT. PANAMANIAN LOW IS EXPECTED TO WEAKEN THROUGH THE CYCLE LEADING
TO A DECREASE IN ACCUMULATIONS OVER WESTERN COLOMBIA/PANAMA AND A
SHIFT OF STRONGEST CONVECTION TO THE WEST. TRADE WIND SURGE ACROSS
THE CARIBBEAN WILL INITIALLY ENHANCE LOW-LEVEL CONVERGENCE TO ITS
WEST...AND CYCLONIC VORTICITY TO ITS SOUTH. THIS WILL SUSTAIN
ACTIVE CONVECTION OVER THE SOUTHERN CARIBBEAN-COSTA RICA-NICARAGUA
THROUGH THE CYCLE...AND EASTERN HONDURAS/WESTERN NICARAGUA ON DAY
03. YET...STRONG LOW-LEVEL WINDS WILL START SHEARING OUT
CONVECTION AND MIXING IN DRY AIR MASS TO ITS NORTH/EAST. THIS
SHOULD LIMIT POTENTIAL ACCUMULATIONS. ACROSS WESTERN
COLOMBIA/PANAMA...EXPECTING AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-40MM THROUGH 36 HRS DECREASING AFTERWARDS. THROUGH 36 HRS
ALSO...EXPETING AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 25-50MM OVER
COSTA RICA. ON DAY 02...STRONGEST CONVECTION WILL OCCUR OVER COSTA
RICA/SOUTHERN NICARAGUA/WESTERN PANAMA TO PRODUCE AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-40MM. ON DAY 03...EXPECTING HEAVIEST
FROM SOUTHERN NICARAGUA INTO WESTERN PANAMA WITH AMOUNTS OF
15-20MM/DAY AND MAXIMA OF 25-50MM. FURTHER NORTH OVER THE
CARIBBEAN PLAINS OF HONDURAS AND NICARAGUA EXPECTING AN INCREASE
TO 10-15MM/DAY AND MAXIMA OF 20-30MM.

ACROSS THE GUIANAS...ITCZ CONVECTION AND TROPICAL WAVES WILL LEAD
TO ACCUMULATIONS OF 05-10MM AND MAXIMA OF 15-25MM THROUGH 36 HRS.
ANOTHER PULSE IS EXPECTED ON DAY 03 TO PRODUCE AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-35MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL 24 36 48 60 72 84 96 TYPE
37W 39W 42W 46W 49W 53W 56W 60W TW
55W 58W 61W 65W 69W 73W 76W 80W TW
62W 66W 68W 72W 75W 79W 83W 86W TUTT INDCD/EW
84W 87W 90W 94W 97W 99W 103W 106W TW

TROPICAL WAVE ALONG 37W IS TO ENTER FRENCH GUIANA BY 60-66
HRS...TO MOVE ACROSS SURINAME TO GUYANA THROUGH 72-84 HRS. AS IT
INTERACTS WITH THE ATLANTIC ITCZ THIS IS TO SUSTAIN RAINFALL
AMOUNTS INCREASING TO 10-15MM/DAY AND MAXIMA OF 20-35MM/DAY AHEAD
OF WAVE AXIS.

THE TROPICAL WAVE ALONG 55W CONTINUES TO DAMPEN AS A HIGH
AMPLITUDE RIDGE BUILDS TO THE NORTH ACROSS THE CENTRAL-TROPICAL
ATLANTIC. BY 36-42 HRS THE WEAK PERTURBATION WILL ENTER NORTHERN
GUYANA/NORTHEAST VENEZUELA-SOUTHERN WINDWARD ISLANDS...TO TRIGGER
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM/DAY. SIMILAR
AMOUNTS ARE EXPECTED ACROSS VENEZUELA BY 72-84 HRS.

TUTT INDUCED PERTURBATION ALONG 62W WILL CROSS PUERTO
RICO/USVI/LEEWARDS TODAY SUSTAINING RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM BY 48-60 HRS. WAVE WILL THEN
DETACH FROM TUTT EVOLVING INTO AN EASTERLY WAVE WHILE WEAKENING.
THROUGH 60-72 HRS THIS WILL MOVE INTO EASTERN CUBA PRODUCING
LIGHTER AMOUNTS.

TROPICAL WAVE ALONG 84W CONTINUES TO INTERACT WITH TUTT LOW NEAR
THE BAHAMAS. IT WILL ENHANCE CONVECTION ACROSS EXTREME EASTERN
YUCATAN/WESTERN CUBA PRODUCING AMOUNTS OF 05-10MM/DAY AND MAXIMA
OF 15-25MM. ACROSS COSTA RICA/SOUTHERN NICARAGUA EXPECTING
ACCUMULATIONS OF 15-20MM/DAY AND MAXIMA OF 25-50MM THROUGH 36 HRS.
AS IT ENTERS SOUTHERN MEXICO IT IS TO SUSTAIN RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-30MM/DAY.

ROBINSON...MSJ (JAMAICA)
DAVISON...WPC (USA)
GALVEZ...WPC (USA)

[cycloneye]

Good morning. The hazy conditions have arrived to the Eastern Caribbean with warm and dry weather until it moves out.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
439 AM AST FRI AUG 2 2013

.SYNOPSIS...AT UPPER LEVELS...LOW PRESSURE WILL EXTEND TOWARD THE
AREA OVER THE NEXT SEVERAL DAYS AND THEN STRENGTHEN. ON SUNDAY A
TUTT LOW WILL MOVE SOUTHEAST TOWARD THE LOCAL AREA. ON TUESDAY IT
WILL MOVE INTO THE DOMINICAN REPUBLIC WITH A MODEST 40 TO 50 KNOT
SOUTHERLY JET OVER THE AREA. HIGH PRESSURE RETURNS BY THE END OF
THE WEEK.

AT MID LEVELS...HIGH PRESSURE IN THE CENTRAL ATLANTIC SPLITS NEAR
50 WEST AS LOW PRESSURE FORMS IN THE TROPICAL ATLANTIC. THE HIGH
PRESSURE EXTENDS OVER THE LOCAL AREA UNTIL IT IS GRADUALLY
DISPLACED BY THE WESTWARD MOVING LOW ON 11 AUG. MID LEVELS HAVE
BANDS OF MODEST MOISTURE MOVING THROUGH SATURDAY AND
SUNDAY...TUESDAY AND WEDNESDAY NIGHT.

AT LOWER LEVELS...MOISTURE IS DIMINISHING BUT NOT VANQUISHED AS A
WIND SURGE HEAVILY LADEN WITH SAHARAN DUST MOVES INTO THE AREA
TODAY AND PEAKS SATURDAY. A MID LEVEL VORTICITY MAX WILL MOVE
THROUGH ON SATURDAY AND SUNDAY WITH SUFFICIENT MOISTURE TO
GENERATE SCATTERED SHOWERS THAT PERSIST MUCH OF THE WEEK IN THE
USUAL DIURNAL CYCLE.

&&

.DISCUSSION...OVERNIGHT SHOWERS BROUGHT UP TO ONE HALF INCH TO
NORTHEAST PUERTO RICO AND KEPT THE SKIES ON THE NORTHERN COAST LIT
UP WITH FREQUENT LIGHTNING OVER THE OFFSHORE WATERS. A FEW SHOWERS
WERE ALSO NOTED IN THE CARIBBEAN...BUT ACTIVITY THERE WAS
CONSIDERABLY LESS. THE BACK EDGE OF THE PRECIPITABLE WATER FROM THE
BAND THAT MOVED OVER THE LOCAL AREA...AS SEEN IN THE MIMIC PRODUCT...
APPEARED TO BE APPROACHING RAPIDLY...BUT DURING THE OVERNIGHT
HOURS WAS SEEN TO BE EXTENDING UPSTREAM INTO THE FLOW AS FAR
SOUTHEAST AS GUADELOUPE. THIS WILL EXTEND THE SHOWERS INTO THE
REST OF TODAY EVEN THOUGH MID LEVEL MOISTURE WILL BE DECREASING
SOMEWHAT. FOR THIS REASON SHOWERS AND THUNDERSTORMS ARE EXPECTED
ALONG CONVERGENCE LINES EXTENDING ACROSS PUERTO RICO...MAINLY
NORTH OF THE CORDILLERA CENTRAL DURING THE MID AFTERNOON HOURS. THE
NAM5 MODEL HAS DONE AN EXCELLENT JOB THE LAST 4 TO 5 DAYS IN
FORECASTING THE GOOD SHOWER ACTIVITY THAT HAS OCCURRED ACROSS THE
AREA THAT HAS PROMPTED URBAN AND SMALL STREAM FLOOD
ADVISORIES...AND TODAY IT IS STILL INDICATING SCATTERED SHOWERS
FROM THE LUQUILLO RANGE WEST ACROSS THE COASTAL FOOTHILLS OF
PUERTO RICO.

PSEUDO COLOR IMAGERY FROM METEOSAT-9 SHOWED THE APEX OF THE ARC
OF THE LEADING EDGE OF THE SAHARAN DUST CROSSING THROUGH 58 WEST
AT 01/18Z AND...WITH AN EXTRAPOLATED MOVEMENT OF 8 DEGREES PER
DAY...IT WILL ARRIVE IN SAN JUAN PUERTO RICO AROUND 18Z TODAY. BY
THE END OF THE DAY...DUST WILL COVER ALL OF THE FORECAST AREA
REDUCING VISIBILITIES TO 7 TO 10 MILES...AND LOCALLY LOWER
DEPENDING ON THE SUN ANGLE. NORMALLY THIS WOULD BE SUFFICIENT TO
INHIBIT MOST CONVECTION BUT MOISTURE AND INSTABILITY HAVE BEEN
DIFFICULT TO SUPPRESS. GFS MODEL SOUNDING SHOWS THE LIFTED PARCEL
JUST TOUCHING THE SOUNDING BETWEEN 800-775 MB OR 7-8
KFT...FRIDAY...BUT WITH A MUCH STRONGER CAP ON SATURDAY. THE MODEL
WAS NOT SEEING AN AREA OF MID LEVEL VORTICITY WITH CONVECTION THAT WILL
CROSS OVER THE AREA ON SATURDAY ACCOMPANIED BY A PULSE OF
MOISTURE THAT WILL LAST UNTIL SUNDAY AFTERNOON AND ALLOW SCATTERED
THUNDERSTORMS TO FORM OVER THE WEST DURING THE AFTERNOONS AND
SCATTERED SHOWERS IN ONSHORE FLOW DURING THE EARLY MORNINGS. BY
MONDAY THE UPPER LEVEL LOW THAT HAD BEEN DRIFTING TOWARD THE AREA
WILL HAVE DEEPENED CONSIDERABLY AND DIVERGENCE AND WIND SPEEDS
FROM THE SOUTH SOUTHWEST WILL HAVE INCREASED CONSIDERABLY. BY
06/00Z THE GFS SHOWS 50 KNOTS OVER ARECIBO AT 250 MB...AND...THE
ADDITIONAL VENTILATION THIS SUPPLIES SHOULD AID THUNDERSTORM
FORMATION IN THE DRIER ENVIRONMENT. ACTIVITY MAY INCREASE
OVERNIGHT AS MOISTURE BRIEFLY IMPROVES FROM 1.4 TO 1.7 INCHES OF
PRECIPITABLE WATER. AFTER THE DRIEST PERIOD THIS WEEK ON TUESDAY
NIGHT MOISTURE PEAKS AGAIN ON WEDNESDAY NIGHT FOR THE BEST
MOISTURE SINCE YESTERDAY AND A SERIES OF WEAK TROUGHS FROM AN
AFRICAN EASTERLY WAVE THAT EXITED THE COAST THURSDAY...01 AUG.

DUE TO THE INTENSITY OF THE HEATING AND THE STRENGTH OF THE
CONVERGENCE AND LOCAL WINDS...URBAN AND SMALL STREAM FLOODING
CANNOT BE RULED OUT TODAY OR ANYTIME IN THE NEXT 7 DAYS IN THE
INTERIOR OF PUERTO RICO...NEVERTHELESS ANY FLOODING THAT DOES
OCCUR WILL BE ONLY ISOLATED IN NATURE DUE TO THE WEAKLY CAPPED
NATURE OF THE ATMOSPHERE. THIS DUST EPISODE MAY ALSO INCREASE THE
FREQUENCY OF LIGHTING STRIKES COMING FROM THE THUNDERSTORMS THAT
DO FORM.

&&

.AVIATION...
NO SIGNIFICANT SHRA ACTIVITY IS EXPECTED OVER THE ISLANDS TILL
AFT 02/16Z. THEREFORE...VFR CONDS ARE EXPECTED THROUGH THE NEXT
HOURS. HOWEVER...A DENSE LAYER OF SAHARAN DUST WILL REACH THE TNCM
AND TKPK SITE AROUND THIS MORNING THAT COULD LOWER THE VSBYS.
POSSIBLE HZ CONDS AT TJSJ...TIST...TISX...TJPS...TJMZ AND TJBQ ARE
EXPECTED LATER THIS AFTERNOON. SHRAS AND TSRAS ARE EXPECTED TO
DEVELOP OVER THE INTERIOR OF PUERTO RICO AFT 02/17Z WHERE LCL MVFR
CONDS AND MTN OBSCURATIONS MAY OCCUR VCNTY TJBQ AND TJMZ TIL
02/22Z. LLVL WINDS ESE 10 TO 20 KT...INCRG TO 15 TO 25 KT AFT
02/15Z.

&&

.MARINE...MARINE CONDITIONS WILL REMAIN FAIRLY STEADY THROUGH THE
NEXT 7 TO 10 DAYS WITH UP TO 5 TO 6 FEET IN THE EXPOSED OUTER
WATERS...ESPECIALLY TODAY AND SATURDAY...AND GENERALLY 3 TO 5 FEET
ELSEWHERE EXCEPT IN THE USUALLY PROTECTED AREAS WEST OF THE
ISLANDS. MARINERS WILL SEE MUCH MORE FREQUENT LIGHTNING THAN USUAL
FROM EVENING AND OVERNIGHT THUNDERSTORMS...DUE BOTH TO AN INCREASE
IN SAHARAN DUST AND THE PROXIMITY OF THE TUTT LOW MOVING TO A
POSITION NORTHWEST OF PUERTO RICO BY MONDAY. MARINERS WILL FIND
NAVIGATION USING VISUAL SITING OF OBJECTS MORE THAN 7 MILES AWAY
DIFFICULT TO IMPOSSIBLE DURING THE NEXT 3 TO 5 DAYS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 80 92 78 / 30 20 30 30
STT 90 80 90 79 / 20 20 20 20

[Macrocane]

Big SAL outbreak reaching the Caribbean now:

[Macrocane]

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
114 PM EDT FRI AUG 02 2013

DISCUSSION FROM AUGUST 02/00UTC: DRY WEEKEND EXPECTED IN NORTHERN
MEXICO WHILE MID/UPPER LEVEL RIDGE AND POTENT SUBSIDENCE INVERSION
REMAIN IN PLACE. SEASONAL CONVECTION WILL BE MOSTLY ISOLATED AND
CLUSTER ACROSS THE SIERRA MADRE OCCIDENTAL PRODUCING VERY LIGHT
AMOUNTS. AN SLIGHT INCREASING TREND IN COVERAGE AND INTENSITY IS
EXPECTED EARLY NEXT WEEK.

OVER SOUTHERN MEXICO...MOIST CONVECTION AND RAINFALL WILL
CONCENTRATE TO THE SOUTH OF 20-22N. TROUGH IN THE TRADES CURRENTLY
OVER THE WESTERN YUCATAN PENINSULA-CHIAPAS IS EVOLVING INTO AN
EASTERLY WAVE AND WILL TRANSVERSE SOUTHERN MEXICO THROUGH THE
CYCLE. THIS WILL MODULATE SOMEWHAT DIURNAL CONVECTION SHIFTING
STRONGEST FROM GUERRERO/MICHOACAN TODAY TO JALISCO/NAYARIT ON
SUNDAY. EXPECTING AMOUNTS IN THE 10-15MM/DAY RANGE WITH ISOLATED
MAXIMA OF 20-40MM.

ACROSS CENTRAL AMERICA...CONVECTION WILL BE MODULATED BY THE
INTERACTION BETWEEN TRADE WIND SURGE OVER THE CARIBBEAN BASIN AND
MOISTURE POOL OVER THE SOUTHERN CARIBBEAN...AND MODULATION BY
UPPER TROUGHS AND RIDGES. THE TUTT MEANDERING OVER CUBA/BAHAMAS IS
NOW CENTERING OVER THE GULF OF HONDURAS. THIS IS HELPING TO DRAW
THE ITCZ AND MOISTURE POOL NORTHWARD ACROSS THE SOUTHERN
CARIBBEAN. TUTT WILL GRADUALLY WEAKEN WHILE MID-UPPER RIDGE
ARRIVES FROM THE EAST IN UNISON WITH TRADE WIND SURGE. UPPER RIDGE
WILL VENTILATE CONVECTION IN ITS PERIPHERY AND LOW-LEVEL
CONVERGENCE WILL BE ENHANCED AHEAD OF EASTERLY SURGE...FAVORING
ACCUMULATIONS IN THE CARIBBEAN BASIN OF NICARAGUA AND COSTA RICA.
HOWEVER...MOISTURE WILL REMAIN SOMEWHAT LIMITED AS DRY/STABLE
AIRMASS IS ADVECTED FROM THE EAST AND MIXES IN WITH DEEP MOISTURE
POOL. SURGE WILL SHEAR SOME OF THE STORMS AND ENHANCE ADIABATIC
HEATING TO THE WEST...LIMITING ACCUMULATIONS. THUS EXPECTING A
REACTIVATION OF CONVECTION ESPECIALLY IN EASTERN BASINS...WITH
MODERATE AMOUNTS. THROUGH 36 HRS...EXPECTING HEAVIEST
ACCUMULATIONS OVER COSTA RICA/EASTERN NICARAGUA WITH AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-40MM. ON DAY 02 EXPECTING HEAVIEST
ACROSS EASTERN NICARAGUA/NORTHEASTERN COSTA RICA WITH AMOUNTS
INCREASING TO 15-20MM/DAY AND MAXIMA OF 25-50MM. OVER EASTERN
HONDURAS AND BELIZE/EASTERN GUATEMALA EXPECTING AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM. ON DAY 03 EXPECTING AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-35MM ACROSS COSTA RICA INTO EASTERN
NICARAGUA INTO EASTERN HONDURAS...AND BELIZE/NORTHERN GUATEMALA.

OVER THE BAHAMAS/CUBA...DRIER PATTERN IS ESTABLISHING AS TUTT
REORGANIZES AND LOW-LEVEL TROUGH MOVES NORTHWARD AWAY FROM THE
NORTHERN BAHAMAS. CHANCES FOR SCATTERED DIURNAL STORMS ARE STILL
UP TODAY ACROSS WESTERN CUBA AND THE NORTHERN BAHAMAS. OVER
CUBA...EXPECTING ACCUMULATIONS OF 10-15MM/DAY AND MAXIMA OF
20-35MM. OVER THE BAHAMAS EXPECTING 05-10MM/DAY AND MAXIMA OF
15-20MM. AMOUNTS ARE TO DECREASE AFTERWARDS.

OVER THE CARIBBEAN BASIN...TRADE WIND SURGE AND A THICK SAHARAN
DUST LAYER WILL DOMINATE. THIS WILL LEAD TO DRY CONDITIONS WITH
MOST CONVECTION REMAINING SHALLOW AND ISOLATED. SURGE IS ALREADY
DEVELOPING...WITH WINDS INCREASING TO 20-30KT OVER EASTERN AND
NORTHERN CARIBBEAN LOCATIONS THIS EVENING INTO SUNDAY
AFTERNOON...AND TO 35-50KT ACROSS THE CENTRAL CARIBBEAN FROM THE
GUAJIRA PENINSULA TO SAN ANDRES/NUEVA PROVIDENCIA. AT UPPER
LEVELS...A TUTT IS MEANDERING TO THE NORTHEAST OF THE LEEWARDS.
MODELS NOW HAVE THE TUTT REORGANIZING JUST TO THE WEST OF PUERTO
RICO DURING SUNDAY AND THEN RETROGRESSING. THIS SHOULD ERODE
STRONG SUBSIDENCE INVERSION ALLOWING FOR AN INCREASE IN CONVECTION
INTO EARLY NEXT WEEK.

OVER NORTHERN SOUTH AMERICA CONVECTION WILL BE GREATLY MODULATED
BY TROPICAL WAVES AND INTERACTION WITH THE ITCZ/NET. ON DAY 01
EXPECTING MOST ACTIVE THE VENEZUELAN/COLOMBIAN LLANOS WITH AMOUNTS
OF 10-15MM/DAY AND MAXIMA OF 20-35MM. ON DAY 02 A NEW ROUND OF
ACTIVE CONVECTION WILL DOT MOST OF COLOMBIA. OVER THE ANDES
EXPECTING AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM. ACROSS EJE
CAFETERO/CHOCO/NORTHWESTERN COLOMBIA EXPECTING 15-20MM/DAY AND
MAXIMA OF 25-50MM. ON DAY 03 STRONGEST CONVECTION WILL LIMIT TO
EXTREME NORTHWESTERN COLOMBIA AND PANAMA WITH AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM. ACROSS THE GUIANAS TRANSIENT
DRY PATTERN IS ESTABLISHING. MOST CONVECTION WILL CLUSTER ALONG
THE ITCZ TO AFFECT COASTAL GUYANA AND DELTA AMACURO IN VENEZUELA.
EXPECTING AMOUNTS PEAKING TODAY AT 10-15MM/DAY AND ISOLATED MAXIMA
OF 20-35MM ON DAY 01...DECREASING AFTERWARDS.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL 24 36 48 60 72 84 96 TYPE
42W 45W 47W 50W 53W 57W 60W 63W TW
61W 64W 68W 72W 76W 80W 83W 86W TW
68W 71W 74W 77W 80W 83W 86W 90W EW
89W 92W 95W 98W 101W 104W 107W 109W TW
92W 95W 98W 101W 104W 107W 110W 113W EW

TROPICAL WAVE ALONG 42W IS LIMITED TO THE SOUTH OF 10N UNDER
INFLUENCE OF STRONG RIDGE OVER THE CENTRAL ATLANTIC. WAVE WILL
HOWEVER START AMPLIFYING NORTHWARD LATER IN THE CYCLE AS RIDGE
WEAKENS. WAVE WILL ENTER FRENCH GUIANA BY 42-60 HRS AND THEN
SURINAME/GUYANA BY 60-72 HRS. EFFECTS ON CONVECTION WILL BE
LIMITED.

THE TROPICAL WAVE ALONG 61W IS NOT CONSTRAINED TO THE SOUTHERN
CARIBBEAN/SOUTH AMERICA UNDER INFLUENCE OF DEVELOPING SURGE TO THE
NORTH. THIS WAVE WILL ENHANCE CONVECTION ACROSS THE
VENEZUELAN/COLOMBIAN LLANOS ON DAY 01...MOST OF COLOMBIA ON DAY
02...AND PANAMA/NORTHWESTERN COLOMBIA ON DAY 03.

EASTERLY WAVE ALONG 68W WILL AID CONVECTION ACROSS OVER
HISPANIOLA/TURKS AND CAICOS TODAY AND SOUTHEASTERN CUBA/JAMAICA ON
DAY 02...PRODUCING LIGHT ACCUMULATIONS AS STRONG SUBSIDENCE CAP
DOMINATES.

TROPICAL WAVE ALONG 89W IS EXITING INTO THE PACIFIC WITH LIMITED
EFFECTS IN ACCUMULATIONS OVER THE CONTINENT.

NEWLY DEVELOPED EASTERLY WAVE AT 92W OVER THE GULF OF MEXICO WILL
PROPAGATE WESTWARD THROUGH THE CYCLE. AS IT CROSSES MEXICO...WILL
AID TO CHANGE THE FOCUS OF MOST WIDESPREAD DIURNAL CONVECTION FROM
GUERRERO/OAXACA TO JALISCO/NAYARIT THROUGH THE CYCLE.

ROBINSON...MSJ (JAMAICA)
DAVISON...WPC (USA)
GALVEZ...WPC (USA)

[cycloneye]

The haze really is very thick here with reduced visibilities.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
256 PM AST FRI AUG 2 2013

.SYNOPSIS...TUTT NORTHEAST OF THE AREA WILL RELOCATE OVER
HISPANIOLA BY TUE. SUBEQUATORIAL RIDGE WILL BUILD OVR THE AREA MID
NEXT WEEK. SAL WILL BEGIN TO WEAKEN SUN.

&&

.DISCUSSION...DENSE LAYER OF SAHARAN DUST OVER PR ATTM PER VISUAL
OBS...GOES VIS AND MODIS AOD AND DUST PRODUCTS. SAL WILL CONTINUE
TO INTENSIFY THROUGH SAT WITH H85 TEMPS EXPECTED TO SOAR TO 22C
RESULTING IN VERY HOT AND/OR NEAR RECORD TEMPERATURES SAT. TEMPS
LIKELY TO REACH MID 90S.

ON SUN...SKIES EXPECTED TO BECOME CLEARER AS SAL BEGINS TO
WEAKEN. BY MON...IT APPEARS SAL AND ASSOCIATED INVERSION WILL
WEAKEN SUFFICIENTLY TO ALLOW FOR AFTERNOON SHOWERS AND THUNDERSTORMS
TO DEVELOP ACROSS WRN PR. HOWEVER...STILL LOTS OF MID LEVEL DRY
WHICH SHOULD LIMIT AREAL CVRG OF SHOWERS.

A TROPICAL WAVE WILL REACH THE AREA WED AND GIVE US THE BEST
CHANCE OF PRECIP OVR THE NEXT SEVEN DAYS. THIS IS ABOUT A DAY
FASTER THAN YDAY ATTM. GRADUAL DRYING EXPECTED THU THRU FRI.


&&

.AVIATION...VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES THROUGH
THE FORECAST PERIOD. HOWEVER...A DENSE LAYER OF SAHARAN DUST WILL
CONTINUE TO PREVAIL OVER THE AREA LOWERING VSBYS. LVL WINDS ESE
15 TO 25 KT.

&&

.MARINE...DUST HAZE WILL BE THE ONLY THING SIGNIFICANT TODAY AND
SAT WITH SKIES BECOMING CLEARER SUN. SEAS GENERALLY 3-5 FT AND
WINDS 15-20 KT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 90 78 89 / 0 0 0 0
STT 82 91 82 91 / 10 0 10 0

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1041 PM AST FRI AUG 2 2013

.UPDATE...VERY DRY CONDITIONS ARE EXPECTED TO CONTINUE AS
SAHARAN AIR LAYER DOMINATES THE LOCAL REGION. LATEST NAAPS
AEROSOL MODEL INDICATED LOCAL AREA TOMORROW WILL BE IN MAX DUST
SURFACE CONCENTRATION AROUND 03/18Z...WHICH IS EXPECTED TO CONTINUE
THROUGH SUNDAY MORNING...IMPROVING...SUNDAY AFTERNOON. ALTHOUGH NO
CHANGES TO SHORT TERM GRIDS WERE MADE...LATEST LOCAL WRF
MODEL...SHOWS A LITTLE BIT OF CONVECTION FOR TOMORROW AFTERNOON IN
THE WESTERN INTERIOR AND NORTHWEST SECTIONS OF PUERTO RICO.
THEREFORE...CHANCE OF SOME BRIEF SHOWERS TOMORROW AFTERNOON CANT
BE RULED OUT OVER THE MOUNTAINS SECTIONS OF PUERTO RICO.
ELSEWHERE...VERY DRY AND HOT WEATHER IS EXPECTED.

[cycloneye]

Good morning. The hazy conditions will continue thru the weekend for PR and adjacent islands.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
538 AM AST SAT AUG 3 2013

.SYNOPSIS...AT UPPER LEVELS...A TUTT LOW NORTHEAST OF PUERTO RICO
WILL MOVE WEST SOUTHWEST TOWARD THE BAHAMAS AND STALL ON SUNDAY.
THIS WILL PULL AN UPPER LEVEL JET MAX OF 55 KNOTS OVER CULEBRA AND
VIEQUES ON MONDAY. HIGH PRESSURE WILL RETURN TO THE AREA TUESDAY
THROUGH SATURDAY UNTIL ANOTHER TUTT MOVES IN FROM THE EAST
NORTHEAST OVER NEXT WEEKEND.

AT MID LEVELS...HIGH PRESSURE WILL DOMINATE THE ATLANTIC OVER THE
WEEKEND. A LONG WAVE TROUGH WILL DIG SOUTH FROM MID LATITUDES ON
MONDAY AND INDUCE A LOW NORTH OF HISPANIOLA THAT PERSIST THROUGH
MID WEEK. HIGH PRESSURE RETURNS TO THE WESTERN ATLANTIC LATER IN
THE WEEK.

AT LOWER LEVELS...HIGH PRESSURE SHIFTS NORTH DURING THE UPCOMING
WEEK WITH ONLY A SLIGHT WEAKENING OF THE TRADE WIND FLOW. THE
SAHARAN DUST LAYER WILL CONTINUE OVER THE AREA WEAKENING SLOWLY
TODAY THROUGH MONDAY. A FRAGMENTED TROPICAL WAVE MOVES THROUGH
THE AREA ON WEDNESDAY WITH AN INCREASE IN SHOWER ACTIVITY.

&&

.DISCUSSION...A FEW SMALL SHOWERS MOVED THROUGH THE LOCAL WATERS
AND INTO PUERTO RICO OVERNIGHT...BUT OVERALL CONDITIONS WERE DRY.
SAHARAN DUST CONTINUES OVER THE AREA. THE GFS MODEL SOUNDING SHOWS
A STRONG CAP OF ALMOST 4000 FEET AND 3 DEGREES CELSIUS FOR 03/18Z
AND IT IS EXPECTED THAT THIS WILL CAP ALMOST ALL CONVECTIVE
ACTIVITY TODAY...LIMIT CLOUD COVER AND ALLOW GOOD SOLAR WARMING.
IN FACT...THE MIMIC PRODUCT SHOWS A
BAND OF HIGHER PRECIPITABLE WATER ADVANCING ACROSS THE NORTHERN
LEEWARD ISLANDS AND INTENSIFYING AS IT DOES SO. THIS SHOULD MAKE
IT TO PUERTO RICO BY MAXIMUM HEATING AND CREATE SOME
SHOWERS...MAINLY IN WESTERN PUERTO RICO. OTHERWISE VERY FEW
SHOWERS WILL BE ABLE TO FORM IN PUERTO RICO OR ELSEWHERE TODAY.
SHOWER ACTIVITY WILL INCREASE SUNDAY AND MONDAY AS AN UPPER LEVEL
TUTT LOW MOVES WEST SOUTHWEST AND BRINGS UP A 55 KNOT JET MAX
ACROSS CULEBRA AND VIEQUES. ALTHOUGH SOME DIVERGENCE ALOFT OCCURS
OVER PUERTO RICO ON MONDAY...THE AXIS OF THE BEST DIVERGENCE IS
BETWEEN SAINT JOHN AND SAINT MARTIN ON TUESDAY MORNING. SHOWERS
OVER THE AREA WILL INCREASE WHEN A TROPICAL WAVE MOVES THROUGH THE
AREA ON WEDNESDAY...BUT IT IS SOMEWHAT FRAGMENTED AND WEAK...AND
ACTIVITY SHOULD NOT PRESENT A PROBLEM EXCEPT FOR URBAN AND SMALL
STREAM FLOODING IN ISOLATED AREAS. THE GFS PRESENTS NO OTHER WELL
ORGANIZED SYSTEM DEVELOPING DURING THE NEXT 10 DAYS ALTHOUGH
SEVERAL OTHER WAVES ARE SEEN ROLLING OUT OF AFRICA DURING THE
PERIOD. PRESENTLY DUST AND DRY AIR ARE STILL ROLLING OUT OF AFRICA
AT OUR LATITUDES AND WAVE ACTIVITY THAT MIGHT HAVE FORMED TROPICAL
CYCLONES IS BEING SUPPRESSED.

&&

.AVIATION...VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES THROUGH THE
FORECAST PERIOD. HOWEVER...A DENSE LAYER OF SAHARAN DUST WILL
CONTINUE TO PREVAIL OVER THE AREA LOWERING VSBYS. LLVL WINDS FROM E TO
ESE BETWEEN 10 AND 20 KT.

&&

.MARINE...WINDS AND WAVES ARE LIKELY TO PEAK TODAY ACROSS BOTH
ATLANTIC AND CARIBBEAN WATERS. SEAS DIMINISH THROUGH THURSDAY TO 4
TO 5 FEET IN EXPOSED WATERS.

&&

.CLIMATE...SINCE WINDS ARE EXPECTED TO BE EAST AT THE SURFACE AND THE RECORD
TEMPERATURES FOR THIS DATE IS 95 DEGREES IN SAN JUAN...97 IN
SAINT THOMAS AND 94 IN SAINT CROIX...IT WILL BE QUITE WARM BUT RECORD
TEMPERATURES ARE UNLIKELY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 91 80 89 79 / 0 0 0 10
STT 91 82 91 82 / 10 10 0 10

[cycloneye]

Forecast for some Caribbean Islands

http://www.antiguamet.com/

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
254 PM AST SAT AUG 3 2013

.SYNOPSIS...SAHARAN DUST AND HAZE WILL PREVAIL FOR THE REST OF THE
WEEKEND. SURFACE HIGH PRESSURE TO DOMINATE THE CENTRAL ATLANTIC
FOR THE NEXT SEVERAL DAYS. TUTT LOW TO THE NORTHEAST OF THE LOCAL
AREA WILL MOVE TO THE SOUTHWEST AND POSITION ITSELF TO THE
NORTHWEST OF PUERTO RICO EARLY NEXT WEEK. TROPICAL WAVE EXPECTED
BY MIDWEEK.

&&

.DISCUSSION...FAIR WEATHER WAS OBSERVED TODAY WITH THE EXCEPTION
OF VERY QUICK PASSING LIGHT SHOWERS ACROSS THE LOCAL WATERS AND
EASTERN PUERTO RICO. THESE SHOWERS ONLY LEFT TRACE AMOUNTS OF
RAIN. THE SAHARAN DUST HAS CAUSE HAZY SKIES THROUGH THE LOCAL
ISLANDS AND HAS DECREASED VISIBILITIES A BIT. NAAPS MODEL
INDICATES THAT THE SURFACE DUST WILL PREVAIL THROUGH THE REST OF
THE WEEKEND. IN ADDITION...GFS MODEL SUGGESTS THAT THE
PRECIPITABLE WATER WILL REMAIN AT 1.6 INCHES OR LESS UNTIL EARLY
WEDNESDAY WHEN A TROPICAL WAVE APPROACHES.

AS OF NOW IT LOOKS LIKE WEDNESDAY WILL BE DAY WITH THE BEST
CHANCES OF RAIN AS THE TROPICAL WAVE APPROACHES AND THE TUTT LOW
IS TO OUR NORTHWEST...CAUSING AN INCREASE IN MOISTURE...THETA-E AT
850 MB...AND DIVERGENCE ALOFT.

&&

.AVIATION...VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS. SAHARAN
DUST IS CAUSING SOME HAZY SKIES. WINDS WILL REMAIN FROM EASTERLY
AT 10 TO 15 KNOTS AND GUSTY...DECREASING OVERNIGHT TO AROUND 10
KTS OR LESS.


&&

.MARINE...SEAS ACROSS THE LOCAL WATERS CONTINUE TO RUN AT 6 FEET
OR LESS AND WINDS FM ENE BETWEEN 12-19 KNOTS WITH OCCASIONALLY
HIGHER WINDS GUSTS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 80 89 80 89 / 0 0 10 10
STT 81 91 80 90 / 10 0 10 10

[cycloneye]

Good morning. The hazy conditions will continue today but slowly it will go away ahead of a Tropical Wave that will arrive on Wednesday.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
517 AM AST SUN AUG 4 2013

.SYNOPSIS...AT UPPER LEVELS...THE UPPER LEVEL LOW MOVING WEST SOUTHWEST IS
CONTINUING TO BE FORECAST TO SET UP AN UPPER LEVEL JET OF UP TO 65
KNOTS NORTH OF THE AREA. HIGH PRESSURE RETURNS LATER IN THE
WEEK...BUT LOW PRESSURE MOVES IN FROM THE EAST OVER NEXT WEEKEND.

AT MID LEVELS...WHILE LOW PRESSURE DOMINATES THE TROPICAL
ATLANTIC...HIGH PRESSURE RIDGES INTO THE NORTHEAST CARIBBEAN FROM
THE CENTRAL ATLANTIC MONDAY THROUGH WEDNESDAY. HIGH PRESSURE
CONTINUES ACROSS THE SUB TROPICAL ATLANTIC THROUGH THE BEGINNING
OF NEXT WEEK.

AT LOWER LEVELS...HIGH PRESSURE CONTINUES ACROSS THE SUB TROPICAL
ATLANTIC WITH MODERATE TRADE WIND FLOW. A TROPICAL WAVE WILL MOVE
THROUGH THE AREA ON WEDNESDAY FOLLOWED BY MORE SAHARAN DUST.

&&

.DISCUSSION...VERY LIGHT SHOWERS ACCOMPANIED THE LATEST BAND OF
MOISTURE TO MOVE INTO THE AREA FROM THE EAST NORTHEAST...BUT
MOISTURE IS SHALLOW AND THESE STORMS WERE UNABLE TO BREAK THROUGH
THE STRONG CAPPING. THE 04/00Z SOUNDING WAS EXTRAORDINARY IN THAT
IT HAD A CAP OF 4100 FEET...A LIFTED INDEX OF MINUS 12 AND A CAPE
OF 4356 J/KG. HAD THERE BEEN MORE MOISTURE AND NO CAP...YESTERDAY WOULD
HAVE BEEN A DAY OF STRONG THUNDERSTORMS. THE GFS PAINTS A SIMILAR
PICTURE TODAY...ALTHOUGH STABILITY IS A LITTLE LESS UNSTABLE...SINCE
THE MODEL STILL KEEPS MINUS 9.4 AS THE LIFTED INDEX...BUT THE CAP
IS MUCH WEAKER. WITH MOST OF THE LAYER FROM 850 MB TO 300 MB
GENERALLY DRY AT LESS THAN 50 PERCENT RELATIVE HUMIDITY LITTLE OR
NO CONVECTION IS EXPECTED AGAIN TODAY...WITH THE GREATEST
PROBABILITY IN THE WESTERN INTERIOR. DUST IS EXPECTED TO THIN AT
THE SURFACE...AND CONTINUE TO A LIMITED DEGREE OVERHEAD...BUT
IMPROVEMENT SHOULD BE NOTED TODAY THROUGH TUESDAY. MONDAY
CONTINUES TO BE DRY. SOME MOISTURE MOVES OVER THE AREA AHEAD OF
THE TROPICAL WAVE...AND SHOWER ACTIVITY WILL INCREASE...BUT THE
BEST ACTIVITY OF THE NEXT 5 DAYS IS EXPECTED ON WEDNESDAY.
PRECIPITABLE WATER JUMPS TO 1.9 INCHES AND RIPPLES MOVE THROUGH
THE MID LEVEL FLOW. ON SATURDAY ANOTHER WEAK WAVE MOVES THROUGH.

ALTHOUGH THE GFS BRINGS A STRONG LOW OFF THE COAST OF AFRICA NEXT
WEEKEND IT IMMEDIATELY MOVES IT NORTH OF 20 DEGREES NORTH AND
WEAKENS IT. HENCE AT THIS TIME IT DOES NOT APPEAR TO BE A THREAT
TO THE THE U.S. VIRGIN ISLANDS OR PUERTO RICO. IN FACT MODELS SHOW
NO SIGNIFICANT TROPICAL WEATHER FOR PUERTO RICO OR THE U.S. VIRGIN
ISLANDS THROUGH THE NEXT 15 DAYS.

&&

.AVIATION...MOSTLY VFR CONDITIONS ARE EXPECTED ACROSS THE LOCAL
FLYING AREA THROUGH THE FORECAST PERIOD. HOWEVER...A DENSE LAYER OF
SAHARAN DUST WILL CONTINUE TO PREVAIL OVER THE AREA LOWERING VSBYS.
LLVL WINDS MAINLY FROM THE E BETWEEN 10 AND 15 KT.

&&

.MARINE...MODERATE TRADE WINDS WILL CONTINUE OVER THE AREA. SMALL
CRAFT ADVISORIES ARE OT EXPECTED FOR THE NEXT 7 DAYS ALTHOUGH
STRONGER WINDS WILL BE SEEN SOUTH OF THE LOCAL AREA AND SMALL
CRAFT WILL NEED TO EXERCISE CAUTION IN THE SOUTHERN OUTER
CARIBBEAN WATERS.

&&

.CLIMATE...EAST WINDS WILL NOT PREVENT THE SEA BREEZES ON ANY
COAST TODAY...SO TEMPERATURES ARE NOT EXPECTED TO RISE MUCH ABOVE 90
DEGREES ANYWHERE. THE RECORD FOR THE LUIS MUNOZ MARIN AIRPORT
TODAY IS 93 DEGREES SET IN 2005 AND IT IS NOT EXPECTED TO BE
BROKEN. LIKEWISE FOR THE 94 DEGREE RECORD IN SAINT CROIX OR THE
99 DEGREE RECORD...SET IN 1994 IN SAINT THOMAS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 80 89 79 / 0 10 10 30
STT 90 80 90 80 / 0 10 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
300 PM AST SUN AUG 4 2013

.SYNOPSIS...SAHARAN DUST EXPECTED TO DIMINISH FOR THE NEXT FEW
DAYS. SURFACE HIGH PRESSURE IN THE CENTRAL ATLANTIC IS EXPECTED TO
CONTINUE DOMINATING THE AREA AND THE TUTT TO THE NORTH OF THE
LOCAL AREA WILL CONTINUE TO SLOWLY MOVE TO THE WEST SOUTHWEST FOR
THE NEXT FEW DAYS. RELATIVELY DRY AIR MOVES IN


&&

.DISCUSSION...THE LOCAL AREA REMAINED DRY TODAY WITH ONLY AN
ISOLATED SHOWER OR TWO ACROSS THE SOUTHWESTERN QUADRANT OF PUERTO
RICO IN THE AFTERNOON. OTHERWISE IT REMAINED PARTLY CLOUDY AND
HAZY. SLIGHT IMPROVEMENT IN THE DUST IS EXPECTED TOMORROW AND
TUESDAY...HOWEVER A WEAK TROPICAL WAVE IS EXPECTED TO MOVE OVER
THE AREA ON WEDNESDAY.

PRECIPITABLE WATER VALUES WILL REMAIN RELATIVELY LOW AT AROUND 1.5
INCHES OR SO UNTIL THE TROPICAL WAVE MOVES IN ON WEDNESDAY.
HOWEVER...BECAUSE THERE IS LESS DUST EXPECTED FOR MONDAY AND
TUESDAY...WITH A WEAKER CAP...THERE IS A SLIGHTLY HIGHER CHANCE OF
SHOWERS AND THUNDERSTORMS IN THE AFTERNOONS ACROSS THE INTERIOR
AND WESTERN SECTIONS OF PUERTO RICO. SHOWERS AND THUNDERSTORM
ACTIVITY MAY ALSO INCREASE ON WEDNESDAY WHILE THE WEAK TROPICAL
WAVE PASSES OVER THE AREA.


&&

.AVIATION...PREVAILING VFR CONDS DURG NXT 24 PRD ACROSS LOCAL
FLYING AREA. FEW-ISOLD PASSING -SHRA OVR COASTAL WATERS BTW PR AND
NRN LEEWARDS...WITH MINIMAL OR NO AFTN CONVECTION ANTICIPATED
ACROSS MOST OF THE LOCAL ISLANDS THROUGH 04/23Z. HOWEVER ISOLD
-SHRA/-TSRA WILL REMAIN PSBL DURG OVR WRN PR VCTY TJMZ. LVL WINDS
MAINLY FM E-NE AT 10-20 KTS BLO FL250.

&&

.MARINE...WINDS WILL BE UP TO 17 KNOTS OVERNIGHT AND SEAS UP TO 5
FEET. ALTHOUGH WINDS MAY INCREASE A BIT TOMORROW OVER THE CARIBBEAN
WATERS...SMALL CRAFT ADVISORY CRITERIA IS NOT EXPECTED TO BE MET.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 90 78 89 / 10 10 30 30
STT 79 91 79 89 / 10 30 30 30

[cycloneye]

Good morning. Some showers will move thru PR today but when Tropical Wave arrives on Wednesday is when a more general shower activity is expected.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
525 AM AST MON AUG 5 2013

.SYNOPSIS...UPPER LEVEL TROUGH OVER THE MONA PASSAGE WILL CONTINUE TO
MOVE SLOWLY WEST THROUGH MID WEEK. SURFACE HIGH PRESSURE ACROSS THE
CENTRAL ATLANTIC WILL CONTINUE TO MAINTAIN A MODERATE TRADE WIND
FLOW ACROSS THE LOCAL WATERS OVER THE NEXT FEW DAYS. TROPICAL WAVE
WILL MOVE THROUGH THE AREA ON WEDNESDAY.

&&

.DISCUSSION...SHOWERS HAVE BEEN INCREASING OVERNIGHT AND EARLY
THIS MORNING...AS SURFACE NORTHEAST WIND FLOW BRINGS PATCHES OF
LOW LEVEL MOISTURE ACROSS THE REGION. SHOWERS ARE MOVING
QUICKLY...THEROFRE...LITTLE RAINFALL ACCUMULATIONS HAS BEEN
OBSERVED. FOR TODAY....AN UPPER LEVEL TROUGH LOCATED ACROSS THE
MONA PASSAGE...WILL COMBINE WITH STRONG DAYTIME HEATING AND LOCAL
EFFECTS TO PRODUCE SCATTERED TO NUMEROUS SHOWERS WITH THUNDERSTORMS
MAINLY OVER THE INTERIOR AND SOUTHWEST SECTIONS OF PUERTO RICO
THIS AFTERNOON.

FOR WEDNESDAY...AN INCREASE IN SHOWER AND THUNDERSTORMS ACTIVITY IS
EXPECTED...AS TROPICAL WAVE MOVES ACROSS THE REGION. LATEST
COMPUTER GUIDANCE INDICATED THIS WAVE WILL BRING PLENTY OF
MOISTURE TO THE AREA...AND WILL LINGER THROUGH AT LEAST THURSDAY.
THEREFORE...THE DEVELOPMENT OF SHOWERS WITH THUNDERSTORMS EACH
AFTERNOON OVER THE INTERIOR SECTIONS OF PUERTO RICO ARE LIKELY
MOST OF THIS WEEK. IN THE LONG TERM...UPPER LEVEL RIDGE WILL BUILD
ACROSS THE REGION FROM THE EAST...LIMITING SOMEWHAT THE CHANCES
FOR SHOWERS ACROSS THE REGION. NO SIGNIFICANT WEATHER EVENTS ARE
EXPECTED TO AFFECT THE LOCAL REGION AT THIS TIME.

&&

.AVIATION...MOSTLY VFR CONDITIONS EXPECTED DURING THE NEXT 24 HOURS
ACROSS THE LOCAL FLYING AREA. A FEW ISOLATED PASSING SHOWERS WILL
BE LIKELY ACROSS THE USVI AND NORTH SECTIONS OF PR THROUGH
MID-MORNING. THEN...AFTERNOON SHRA/TSRA WILL DEVELOP OVER THE
INTERIOR AND SW PORTIONS OF PR. BRIEF MVFR CONDS ARE POSSIBLE IN AND
AROUND OF TJPS AND TJMZ AS WELL AS MOUNTAIN OBSCURATIONS OVER THE
WESTERN INTERIOR SECTIONS OF PR. LLVL WINDS WILL CONTINUE FM THE NE
AT 10-15 BLW 5K FT.

&&

.MARINE...SEAS UP TO 4 FEET AND WINDS OF 17 KNOTS OR LESS ARE
EXPECTED OVER THE COASTAL WATERS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 77 89 78 / 10 30 30 30
STT 91 79 89 80 / 10 30 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
249 PM AST MON AUG 5 2013

.SYNOPSIS...ELONGATED TUTT AXIS EXTENDS ACROSS HISPANIOLA AND
THE MONA PASSAGE INTO THE SOUTHWEST ATLANTIC...WILL CONTINUE TO
SLOWLY RETROGRESS WESTWARD AS UPPER RIDGE BUILDS ACROSS THE
NORTHEAST CARIBBEAN. STRONG SURFACE HIGH PRESSURE ACROSS THE
CENTRAL AND NORTHEAST ATLANTIC WILL HELP MAINTAIN PREVAILING
EASTERLIES THROUGH THE MIDDLE OF THE WORK WEEK. A WEAK TROPICAL
WAVE APPROACHING THE LESSER ANTILLES IS FORECAST TO ENTER THE
EASTERN CARIBBEAN LATE TUESDAY AND CROSS THE LOCAL REGION
WEDNESDAY THROUGH EARLY THURSDAY.

&&

.DISCUSSION...THE PROXIMITY OF THE UPPER TROUGH ALONG WITH AVAIL
POCKETS OF MOISTURE AND LOCAL AND DIURNAL EFFECTS WILL LEAD TO
AFTERNOON CONVECTION ACROSS PARTS OF THE INTERIOR AND WEST TO
SOUTHWEST SECTIONS OF PUERTO RICO. SOME OF THESE MAY BE ISOLATED
BUT STRONG AND WILL PRODUCE PERIODS MODERATE TO HEAVY RAINFALL AS
WELL AS GUSTY WINDS AND FREQUENT LIGHTNING IN ISOLATED AREAS.
MOSTLY ISOLATED AFTERNOON SHOWERS WILL REMAIN POSSIBLE ACROSS
PARTS OF THE VIRGIN ISLANDS TODAY. SIMILAR CONDITIONS CAN BE
EXPECTED ON TUESDAY. HOWEVER...BY LATE TUESDAY AND ON WEDNESDAY...
THE PRESENCE OF THE UPPER LEVEL RIDGE ALONG WITH THE TROPICAL
WAVE WILL PROVIDE GOOD UPPER LEVEL VENTILATION AND LOW LEVEL
MOISTURE TO ENHANCE AFTERNOON CONVECTION. THEREFORE THE POTENTIAL
FOR LOCALLY HEAVY SHOWERS AND ISOLATED STRONG THUNDERSTORMS WILL
REMAIN HIGH AT LEAST THROUGH MID WEEK... ESPECIALLY OVER THE
CENTRAL INTERIOR AND WEST SECTIONS OF PUERTO RICO EACH AFTERNOON.

&&

.AVIATION...MOSTLY VFR CONDITIONS ARE EXPECTED ACROSS THE LOCAL
TERMINALS WITH TIST/TISX OBSERVING PERIODS OF MVFR CONDITIONS DUE TO
PERSISTENT SHRA ACTIVITY THROUGH THE AFTERNOON. SHRA/TSRA
DEVELOPMENT WILL AFFECT AREAS IN AND AROUND TJMZ AND TJPS...CAUSING
BRIEF MVFR OR EVEN IFR CONDITIONS. WEATHER EXPECTED TO IMPROVE AFTER
06/00Z...LEAVING VFR CONDITIONS ACROSS THE LOCAL TERMINALS
OVERNIGHT. SFC WINDS WILL REMAIN FROM THE EAST NORTHEAST TONIGHT AT
AROUND 10 KTS.

&&

.MARINE...TRADE WINDS TO REMAIN GENERALLY MODERATE NEXT COUPLE
OF DAYS AND SEAS AT 6 FT OR LESS. HIGH PRESSURE IN THE CENTRAL
ATLANTIC TO STAY THERE AND WILL KEEP THE RIDGE IN THE WEST WEAK.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 89 78 89 / 30 30 30 30
STT 79 89 80 90 / 30 30 30 30

[Macrocane]

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
244 PM EDT MON AUG 05 2013

DISCUSSION FROM AUGUST 05/00UTC: POTENT MID/UPPER RIDGE HAS
MIGRATED FROM NORTHERN MEXICO INTO EASTERN TEXAS. RIDGE IS STILL
VENTING DEEP CONVECTION ALONG ITS PERIPHERY THUS ENHANCING DIURNAL
ACTIVITY ALONG THE SIERRA MADRE OCCIDENTAL AND CENTRAL MEXICO.
MID/UPPER SOUTHEASTERLIES IN PERIPHERY OF THE RIDGE ARE STEERING
DIURNAL STORMS TO THE NORTHWEST. RIDGE IS TO MEANDER LITTLE
THROUGH THE CYCLE...REMAINING CENTERED OVER EASTERN TEXAS WHILE
PERTURBATIONS PROPAGATE ALONG THE PERIPHERY TO ENHANCE CONVECTION.
ONE PERTURBATION IS A TUTT FORECAST TO CENTER OVER VERACRUZ BY 24
HRS...ZACATECAS/DURANGO BY 48 HRS...SINALOA-DURANGO-CHIHUAHUA BY
72 HRS. AT LOW-LEVELS EASTERLY WAVE IS EXITING INTO THE OPEN
PACIFIC STILL AIDING MOISTURE TRANSPORT FROM THE SOUTHEAST INTO
SINALOA/SONORA. THIS WILL STILL AID CONVECTION THROUGH 24-36
HRS...TO START DECREASING AFTERWARDS. ANOTHER WAVE IS MOVING
WESTWARD ALONG SOUTHERN MEXICO TO HELP MODULATE THE LOCATION OF
STRONGEST CONVECTION FROM EAST TO WEST ALONG THE PACIFIC COAST.
THROUGH 36 HRS...EXPECTING HEAVIEST AMOUNTS OVER JALISCO/NAYARIT
REACHING 10-15MM/DAY AND ISOLATED MAXIMA OF 20-35MM. TO THE EAST
EXPECTING 05-10MM/DAY AND MAXIMA OF 15-30MM. ON DAY 02...EXPECTING
10-15MM/DAY AND MAXIMA OF 20-35MMM OVER GUERRERO/MICHOACAN INTO
JALISCO. ON DAY 03...EXPECTING MAXIMA TO DECREASE TO 15-30MM.

POTENT TUTT IS RETROGRESSING TO THE NORTH OF HISPANIOLA INTO THE
BAHAMAS/CUBA. THE TUTT WILL CENTER OVER THE TURKS AND CAICOS
EXTENDING INTO HISPANIOLA BY 24 HRS...MOVE LITTLE BY 48 HRS...TO
EXTEND OVER THE CENTRAL BAHAMAS-SOUTHEASTERN CUBA-JAMAICA BY 72
HRS. AT LOW LEVELS...PRE-FRONTAL TROUGH AND NORTHWESTERLIES ARE
ESTABLISHING OVER THE BAHAMAS WHILE STRONG RIDGE BUILDS OVER
CUBA-GULF OF MEXICO. THIS WILL ENHANCE CONVECTIVE INSTABILITY AS
SLIGHTLY COOLER AIR MASS IS ADVECTED OVER WARM WATERS. BEST
INSTABILITY WILL REMAIN NEAR THE TAIL OF A FRONT ACROSS CENTRAL
FLORIDA...AND PRE-FRONTAL TROUGH ACROSS THE NORTHERN BAHAMAS. AS
THIS INTERACTS WITH UPPER TROUGH TO THE NORTH...EXPECTING SHOWERS
AND THUNDERSTORMS THROUGH 36 HRS WITH ACCUMULATIONS OF 05-10MM/DAY
AND MAXIMA OF 15-25MM. INSTABILITY WILL CONTINUE ENHANCED BY 36-60
HRS IN INTERACTION WITH APPROACHING TUTT TO SUSTAIN SIMILAR
AMOUNTS WITH MAXIMA DECREASING TO 15MM. BY 60-84
HRS...SOUTHEASTERLY FLOW IS TO REESTABLISH WHILE CONVECTIVE
INSTABILITY DECREASES. STILL...TUTT WILL ENHANCE SHALLOW AND A FEW
ISOLATED THUNDERSTORMS SUSTAINING ACCUMULATIONS OF 05-10MM/DAY AND
MAXIMA OF 15-20MM OVER CUBA...AND 00-05MM/DAY AND MAXIMA OF 10MM
OVER THE CAYMAN ISLANDS AND JAMAICA. OVER HISPANIOLA... EXPECTING
AMOUNTS TO INCREASE TO 05-10MM/DAY AND MAXIMA OF 15-25MM AS EARLY
AS DAY 02 UNDER INFLUENCE OF TUTT.

ACROSS NORTHERN CENTRAL AMERICA DRY CONDITIONS ARE REESTABLISHING
AS STRONG INVERSION AND SAL OVER THE NORTHWESTERN CARIBBEAN IS
ADVECTED INTO THE REGION. THROUGH 36 HRS...STRONGEST CONVECTION
WILL CLUSTER ACROSS WESTERN PANAMA/COSTA RICA INTO WESTERN
NICARAGUA WITH ACCUMULATIONS OF 10-15MM/DAY AND MAXIMA OF 20-45MM.
COVERAGE WILL DECREASE FURTHER BY 36-60 HRS WITH STRONGEST
CONVECTION CLUSTERING OVER PANAMA WITH ISOLATED MAXIMA OF 25-50MM.
SOME ENHANCEMENT IS EXPECTED ACROSS EASTERN PANAMA/AZUERO
PENINSULA ON DAY 03 AS PANAMANIAN LOW INTENSIFIES AND STRONG
CONVECTION IS GENERATED ACROSS THE CHOCO IN COLOMBIA. EXPECTING
AMOUNTS TO INCREASE TO 15-20MM/DAY AND MAXIMA OF 40-80MM.

ACROSS NORTHERN SOUTH AMERICA...CONVECTION IS CLUSTERING ALONG THE
ITCZ/NET AND WAVES IN THE EASTERLIES. TROPICAL WAVE WILL ENTER
COLOMBIA LATE ON DAY 01 INTO DAY 02. PANAMANIAN LOW WILL GRADUALLY
INTENSIFY AND LOW-LEVEL CONVERGENCE WILL PEAK LATE ON DAY 02 INTO
DAY 03. AT UPPER LEVELS...DIFFLUENT PATTERN BETWEEN ANTICYCLONE
OVER THE CARIBBEAN AND ONE OVER CENTRAL BRASIL WILL ENHANCE
VENTILATION AND SUSTAIN DEEP CONVECTION. THUS EXPECTING A
REACTIVATION LATE ON DAY 02 INTO DAY 03. EXPECTING STRONGEST
CONVECTION WITH HEAVIEST ACCUMULATIONS OVER NORTHWESTERN COLOMBIA
TO PRODUCE AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 40-80MM ON DAY 03.
ACTIVE DIURNAL CONVECTION IS ALSO EXPECTED OVER THE COLOMBIAN
ANDES WITH AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM.

CHANGE IN PATTERN IS ALSO BEING FELT ACROSS THE EASTERN CARIBBEAN
AS DRY AIRMASS EXITS TO THE WEST AND DEEPER MOISTURE GRADUALLY
RETURNS/BUILDS BACK. STILL EXPECTING SHALLOW CONVECTION TO
DOMINATE THE REGION WHILE STRONG SUBSIDENCE INVERSION PERSISTS.
LOW-LEVEL CONVECTIVE INSTABILITY WILL BE SLIGHTLY ENHANCED BY
NORTHWESTERLY WINDS AS THEY TRANSPORT A COOLER AIRMASS INTO WARMER
WATERS. A MUCH MARKED INCREASE IS EXPECTED BY 60-72 HRS AS
TROPICAL WAVE ENTERS THE BASIN. THIS WAVE WILL ARRIVE WITH A
DEEPER MOISTURE POOL AND LARGER CONVECTIVE INSTABILITY LEADING TO
AN INCREASE IN ACCUMULATIONS. FURTHER CONVECTION ENHANCEMENT IS
EXPECTED ON DAY 04 AS TUTT ENTERS THE BASIN FROM THE
ATLANTIC...AND BETTER VENTILATION ESTABLISHES OVER NORTHEASTERN
VENEZUELA/NORTHERN GUIANAS TO SUSTAIN MODERATE AMOUNTS. BY 36-60
HRS...EXPECTING AMOUNTS INCREASING TO 05-10MM/DAY AND MAXIMA OF
15-25MM ACROSS THE CENTRAL LESSER ANTILLES. BY 60-84
HRS...EXPECTING SIMILAR AMOUNTS SPREADING INTO THE LEEWARDS/VIRGIN
ISLANDS AND PUERTO RICO. FURTHER SOUTH...ITCZ CONVECTION WILL LEAD
TO AMOUNTS GENERALLY IN THE ORDER OF 10-15MM/DAY AND MAXIMA OF
20-35MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL 24 36 48 60 72 84 96 TYPE
43W 46W 48W 51W 54W 56W 59W 62W TW
53W 55W 58W 60W 63W 65W 68W 71W EW
66W 68W 70W 72W 75W 78W 80W 82W TW
82W 86W 90W 94W 98W 102W 105W 108W TW
87W 91W 95W 99W 103W 107W 110W 113W EW
95W 97W 99W 101W 103W 105W 107W 108W TUTT INDCD

NEW TROPICAL WAVE IS INITIALIZED AT 43W AND TO THE SOUTH OF 17N.
THIS WAVE WILL ENTER FRENCH GUIANA BY 54-60 HRS PRODUCING ONLY A
SLIGHT INCREASE IN ACCUMULATIONS. THIS WAVE WILL BE MOSTLY
CONSTRAINED TO NORTHERN SOUTH AMERICA.

EASTERLY WAVE IS ORGANIZING AT 53W AND WILL SLOWLY EVOLVE AND
MEANDER INTO THE CARIBBEAN BASIN. THIS WAVE WILL HAVE LIMITED
EFFECTS ON CONVECTION WITH STRONGEST ENHANCEMENT ON DAY 03 ACROSS
THE FRENCH ANTILLES INTO THE LEEWARDS/VIRGIN ISLANDS.

TROPICAL WAVE AT 66W WILL CROSS SOUTHERN/EASTERN VENEZUELA INTO
EASTERN COLOMBIA THROUGH 24-36 HRS...WESTERN VENEZUELA/COLOMBIAN
LLANOS/ANDES BY 48 HRS...TO EXIT INTO THE EASTERN
PACIFIC/PANAMA/SOUTHERN CARIBBEAN BY 72 HRS. STRONGEST EFFECTS ON
CONVECTION WILL BE FELT ACROSS COLOMBIA LATE ON DAY 02 INTO DAY
03. THIS WAVE WILL INTERACT WITH FAVORABLE VENTILATION AT UPPER
LEVELS...LEADING TO ACCUMULATIONS OF 15-20MM/DAY AND MAXIMA OF
40-80MM ACROSS THE CHOCO/NORTHWESTERN COLOMBIA...AND 10-15MM/DAY
AND MAXIMA OF 20-35MM ACROSS THE ANDES.

TROPICAL WAVE AT 82W HAS A SIGNATURE NORTH INTO HONDURAS.
YET...DRY AIRMASS TO THE NORTH IS CONSTRAINING STRONGEST
PRECIPITATION TO EL SALVADOR/SOUTHERN HONDURAS/WESTERN NICARAGUA
AND REGIONS TO THE SOUTH.

EASTERLY WAVE AT 87W IS EXITING INTO THE EASTERN PACIFIC WITH
LIMITED EFFECTS ON CONTINENTAL CONVECTION.

TUTT-INDUCED WAVE AT 95W WILL MODULATE PRECIPITATION ACROSS MEXICO
AS IT EVOLVES IN UNISON WITH RETROGRESSING TUTT. YET...SEASONALLY
DRY AIRMASS WILL LIMIT ACCUMULATIONS.

ROBINSON...MSJ (JAMAICA)
MILLER...CINWS (CAYMAN ISLANDS)
DAVISON...WPC (USA)
GALVEZ...WPC (USA)

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
936 PM AST MON AUG 5 2013

.UPDATE...DOPPLER WEATHER RADAR DETECTED ISOLATED TO SCATTERED
SHOWERS MOVING SOUTHWESTWARD ACROSS THE COASTAL WATERS AND THE
NORTHERN SECTIONS OF PUERTO RICO THIS EVENING. THE EAST NORTHEAST
LOW LEVEL WIND FLOW WILL CONTINUE TO TRANSPORT PATCHES OF MOISTURE
FROM THE ATLANTIC WATERS OVER NORTHERN PUERTO RICO AS WELL OVER
VIEQUES...CULEBRA AND THE U.S. VIRGIN ISLANDS DURING THE
REST OF THE EVENING AND OVERNIGHT. HOWEVER THESE SHOWERS ARE MOVING
RAPIDLY LEAVING MINIMAL RAINFALL ACCUMULATIONS. FOR TOMORROW
AFTERNOON THIS MOISTURE WILL COMBINE WITH THE PROXIMITY OF THE UPPER
LEVEL TROUGH...DAYTIME AND LOCAL OROGRAPHIC EFFECTS TO INDUCE THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS MAINLY ACROSS WESTERN AND
INTERIOR SECTIONS OF PUERTO RICO. A TROPICAL WAVE ALONG 57 WEST THIS
EVENING...WILL REACH THE LOCAL ISLANDS TUESDAY NIGHT AND WEDNESDAY.
THIS WAVE WITH THE PRESENCE OF AN UPPER LEVEL RIDGE WILL PROVIDE
GOOD UPPER LEVEL VENTILATION AND LOW LEVEL MOISTURE TO ENHANCE
AFTERNOON CONVECTION. THEREFORE THE POTENTIAL FOR LOCALLY HEAVY
SHOWERS AND ISOLATED STRONG THUNDERSTORMS WILL REMAIN POSSIBLE AT
LEAST ON WEDNESDAY...ESPECIALLY OVER THE CENTRAL INTERIOR AND WEST
SECTIONS OF PUERTO RICO DURING THE AFTERNOON.

[cycloneye]

Good morning. A series of Tropical Waves and troughs will keep the weather variable with periods of sun but also with scattered showers for the next few days.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
503 AM AST TUE AUG 6 2013

.SYNOPSIS...ELONGATED TUTT AXIS EXTENDS ACROSS HISPANIOLA AND
THE MONA PASSAGE INTO THE SOUTHWEST ATLANTIC...WILL CONTINUE TO
SLOWLY RETROGRESS WESTWARD AS UPPER RIDGE BUILDS ACROSS THE
NORTHEAST CARIBBEAN. STRONG SURFACE HIGH PRESSURE ACROSS THE
CENTRAL AND NORTHEAST ATLANTIC WILL HELP MAINTAIN PREVAILING
EASTERLIES THROUGH THE MIDDLE OF THE WORK WEEK. A WEAK TROPICAL
WAVE APPROACHING THE LESSER ANTILLES IS FORECAST TO ENTER THE
EASTERN CARIBBEAN THIS MORNING AND ACROSS THE LOCAL REGION
WEDNESDAY.

&&

.DISCUSSION...SCATTERED SHOWERS WERE NOTED ACROSS THE COASTAL
WATERS...WITH SOME AFFECTING THE NORTHEAST COAST OF PUERTO RICO
AND THE U.S. VIRGIN ISLANDS FROM TIME TO TIME. ELONGATED TUTT AXIS
EXTENDS ACROSS HISPANIOLA AND THE MONA PASSAGE INTO THE SOUTHWEST
ATLANTIC...WILL CONTINUE TO SLOWLY RETROGRESS WESTWARD AS UPPER
RIDGE BUILDS ACROSS THE NORTHEAST CARIBBEAN. THIS TROUGH WILL
COMBINED WITH DAYTIME HEATING AND LOCAL EFFECTS TO PRODUCE
SCATTERED TO NUMEROUS SHOWERS WITH THUNDERSTORMS MAINLY OVER THE
WESTERN INTERIOR AND SOUTHWEST SECTIONS OF PUERTO RICO.

IN ADDITION...A TROPICAL WAVE LOCATED NEAR 58 WEST LONGITUDE THIS
MORNING...WILL CONTINUE TO MOVE WEST AND WILL APPROACH THE LOCAL
AREA WEDNESDAY. SJU-GFS COMPUTER MODEL INDICATED PRECIPITABLE
WATER VALUES WILL BE AROUND 2.0 INCHES TOMORROW WITH A MINIMUM IN
THETAE VALUES AT 700MB AROUND 18Z. THESE FACTORS...IN COMBINATION
WIT THE AFOREMENTIONED UPPER TROUGH...PROMISE TO BRING AN ACTIVE
DAY TOMORROW. FOR THE REST OF THE WEEK...MOISTURE WILL LINGER
ACROSS THE REGION MAINTAINING GOOD CHANCES FOR SHOWERS ACROSS THE
REGION.

IN THE LONG TERM...ANOTHER UPPER LEVEL TROUGH IS FORECAST TO DEVELOP
ACROSS THE WESTERN ATLANTIC EARLY NEXT WEEK. THIS SYSTEM IS
FORECAST TO LINGER OVER THE NORTHEAST CARIBBEAN...KEEPING GOOD
CHANCES FOR SHOWERS ACROSS THE LOCAL AREA. THEREFORE...LOOKS LIKE
WE WILL BE ENTERING IN A MORE WETTER PATTERN AS A SERIES OF UPPER
LEVEL PERTURBATION MOVES ACROSS THE REGION. THE TROPICS LOOKS
QUIET...FOR NOW.

&&

.AVIATION...MOSTLY VFR CONDITIONS EXPECTED ACROSS THE LOCAL FLYING
AREA OVER THE NEXT 24 HOURS. PASSING SHOWERS WILL BE LIKELY IN AND
AROUND USVI AND EASTERN PR THROUGH MID-MORNING. THEN...AFTERNOON
SHRA/TSRA WILL DEVELOP OVER THE INTERIOR AND WEST SECTIONS OF PR. AS
A RESULT...BRIEF MVFR CONDS ARE POSSIBLE NEAR TJMZ AND POSSIBLY TJBQ
BTWN 17Z-22Z. MOUNTAIN OBSCURATIONS WILL OCCUR OVER THE WESTERN
INTERIOR PR. LLVL WINDS WILL REMAIN MAINLY FM THE E AT 10-15 BLW 10K
FT.

&&

.MARINE...SEAS UP TO 5 FEET AND WINDS UP TO 16 KNOTS ARE EXPECTED
OVER THE LOCAL COASTAL WATERS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 77 89 78 / 30 30 30 20
STT 89 79 90 80 / 30 30 30 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
331 PM AST TUE AUG 6 2013

.SYNOPSIS...ELONGATED TUTT CONTINUED TO SLOWLY RETROGRESS WEST
NORTHWEST ACROSS HISPANIOLA...WITH UPPER RIDGE BUILDING ACROSS THE
EASTERN CARIBBEAN FROM THE TROPICAL ATLANTIC. THIS PATTERN IS CREATING
SOME SOUTHWESTERLY SHEAR ACROSS THE REGION. STRONG SURFACE HIGH NORTH
OF THE AREA AND BROAD TROUGH ACROSS THE CARIBBEAN BASIN HELPING TO
MAINTAIN A MODERATE EASTERLY TRADE WIND FLOW ACROSS THE REGION. A
TROPICAL WAVE AND ASSOCIATED MOISTURE NOW CROSSING THE LESSER
ANTILLES WILL ENTER THE EASTERN CARIBBEAN LATER THIS EVENING THEN
CONTINUE TO MOVE ACROSS THE REGION WEDNESDAY THROUGH THURSDAY.

&&

.DISCUSSION...
THE PROXIMITY OF THE UPPER TROUGH...ALONG WITH DIURNAL AND LOCAL
EFFECTS LEAD TO AREAS OF ENHANCED SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS PARTS OF PUERTO RICO. SOME OF THESE SHOWERS AND STORMS PRODUCED
BRIEF PERIODS OF LOCALLY HEAVY DOWNPOURS. A FEW PASSING SHOWERS WERE
NOTED IN AND AROUND SOME OF THE VIRGIN ISLANDS BUT NO SIGNIFICANT
RAINFALL WAS DETECTED OR REPORTED.

THE TROPICAL WAVE NOW MOVING ACROSS THE LESSER ANTILLES WILL CONTINUE
WESTWARD INTO THE EASTERN CARIBBEAN AND BRING AN INCREASE IN TROPICAL
MOISTURE TO THE LOCAL REGION. LATEST MODEL GUIDANCE CONTINUED TO
SUGGEST INCREASING PWAT VALUES TO NEAR TWO INCHES WITH THE PASSING
WAVE ON WEDNESDAY. THIS INCREASING MOISTURE ALONG WITH LOCAL AND
DIURNAL EFFECTS DURING THE DAYTIME WILL FURTHER INCREASE THE
CHANCES FOR CONVECTIVE INSTABILITY AND PERIODS OF LOCALLY HEAVY
RAINFALL ACROSS THE ISLANDS ESPECIALLY DURING EARLY MORNING AND
THE AFTERNOON HOURS. FOR THE REST OF THE WORK WEEK...MOISTURE WILL
LINGER ACROSS THE REGION AS WEAK EASTERLY PERTURBATIONS AND ACCOMPANYING
SURGES OF MOISTURE WILL MOVE WESTWARD ACROSS THE REGION MAINTAINING
GOOD CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS EACH DAY ACROSS
PARTS OF THE ISLANDS.

&&

.AVIATION...PASSING SHOWERS WILL BE LIKELY IN AND AROUND TIST...
TISX... TKPK AND TNCM. AFTERNOON SHRA/TSRA HAVE DEVELOPED OVER THE
INTERIOR AND WEST SECTIONS OF PR. AS A RESULT...BRIEF MVFR CONDS
ARE POSSIBLE NEAR TJMZ AND TJBQ BTWN 17Z-22Z. MOUNTAIN
OBSCURATIONS WILL OCCUR OVER THE NORTHWESTERN AND WESTERN INTERIOR
PR AT LEAST UNTIL 06/22Z. LLVL WINDS WILL REMAIN MAINLY FM THE ESE
BETWEEN 15-20 KTS.

&&

.MARINE...MODERATE TRADE WINDS CONTINUE ACROSS THE REGIONAL WATERS
WITH SEAS OF 5 FEET OR LESS AT LEAST THROUGH WEDNESDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 89 78 90 / 20 20 20 20
STT 78 89 80 91 / 40 40 20 20

[Macrocane]

Finally the anticipated haze reached El Salvador today, here's a view of San Salvador volcano that I took this afternoon: