Caribbean - Central America Weather

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
310 PM AST MON AUG 25 2014

.SYNOPSIS...UPPER LEVEL TROUGH ACROSS THE TROPICAL ATLANTIC INTO THE
EASTERN CARIBBEAN WILL MOVE WESTWARD WHILE DISSIPATES. ANOTHER UPPER
LEVEL TROUGH WILL DEVELOP ACROSS THE CENTRAL ATLANTIC WEDNESDAY AND
THURSDAY AMPLIFYING INTO THE NORTHEAST CARIBBEAN EARLY FRIDAY.
MID LEVEL RIDGE WILL HOLD THRU AT LEAST THURSDAY. A PAIR OF TROPICAL
WAVES WILL MOVE ACROSS THE AREA ON TUESDAY AND A SECOND ONE DURING
THE WEEKEND.

&&

.DISCUSSION...MOSTLY SUNNY TO PARTLY CLOUDY SKIES PREVAILED ACROSS
THE LOCAL ISLANDS THROUGH THE DAY...WITH ISOLATED TO LOCALLY SCATTERED
SHOWERS OBSERVED ACROSS LOCAL WATERS...USVI AND SOUTHWEST PUERTO RICO.
TEMPERATURES WERE IN THE LOW TO MID 90S AT LOWER ELEVATIONS...WITH
SOUTHEASTERLY WINDS.

TROPICAL WAVE ACROSS THE LESSER ANTILLES WILL CONTINUE TO MOVE WESTWARD
TONIGHT AND TOMORROW. THIS WAVE WILL BRING AN INCREASE IN LOW LEVEL
MOISTURE...RESULTING IN A BETTER CHANCE OF PASSING SHOWERS ACROSS
SOUTHEAST PUERTO RICO LATE TONIGHT AND EARLY TOMORROW MORNING WITH
PM SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS NORTHWEST PUERTO
RICO ON TUESDAY.

A GENERALLY FAIR WEATHER PATTERN IS EXPECTED TO PREVAIL WEDNESDAY
THRU FRIDAY AS SUBSIDENT SIDE OF NEXT UPPER LEVEL TROUGH MOVES IN.
HOWEVER...STILL EXPECT A FEW PASSING SHOWERS ACROSS WINDWARD AREAS
IN THE MORNING FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE MAINLY
FOCUSED ACROSS WESTERN PUERTO RICO. TRADES ARE EXPECTED TO RETURN
WEDNESDAY AND THURSDAY...BRINGING A RELIEF TO HOT TEMPERATURES.

A WETTER WEATHER PATTERN IS POSSIBLE THE UPCOMING WEEKEND AND INTO
EARLY NEXT WORKWEEK AS A TROPICAL WAVE AND ASSOCIATED MOISTURE MOVES
TO THE NORTHEAST OF THE LOCAL ISLANDS. NHC GIVES IT 30% CHANCE OF TC
DEVELOPMENT IN THE NEXT FIVE DAYS. REGARDLESS OF TC DEVELOPMENT...
THIS FEATURE COULD BE A RAINFALL PRODUCER.

&&

.AVIATION...DRY SE FLOW OVR LOCAL ISLANDS MOST OF THIS WEEK...TIL TS
CRISTOBAL MOVE FARTHER N. MAINLY ISOLD SHRA EACH DAY CAUSING ISOLD
MVFR AND FEW OBSCD MTNS IN AFT ACROSS LOCAL TAF SITES. WIND BLO FL100
SE 14-26 KT THRU TUE.

&&

.MARINE...A SOUTHEAST WIND FLOW WILL PERSIST THROUGH TUESDAY...WITH
TRADE WINDS RETURNING TO THE LOCAL AREA TUESDAY NIGHT AND WEDNESDAY.
A WEAK TROPICAL WAVE WILL MOVE ACROSS THE LOCAL AREA TUESDAY AND A
SECOND ONE DURING THE UPCOMING WEEKEND.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 90 81 89 / 20 20 20 20
STT 79 90 79 90 / 20 20 20 20

[cycloneye]

A tropical wave located about 1100 miles east of the Lesser Antilles
continues to produce disorganized showers and a few thunderstorms.
Environmental conditions are not expected to be favorable for
significant development during the next couple of days, but could
become more conducive by the end of the week while the system moves
westward to west-northwestward at about 15 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...30 percent.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
428 AM AST TUE AUG 26 2014

.SYNOPSIS...UPPER LEVEL RIDGE WILL BUILD IN TODAY. ANOTHER TUTT
WILL PASS NORTH OF THE AREA THU WITH UPPER RIDGE BUILDING IN
DURING THE WEEKEND. WEAK LOW PRES EXPECTED TO PASS NORTHEAST OF
THE AREA DURING THE WEEKEND.

&&

.DISCUSSION...WEAK TROPICAL WAVE WILL PASS MAINLY SOUTH OF THE
AREA TODAY. MOISTURE WILL INCREASE THROUGH THE MORNING BUT STRONG
SOUTHEAST WINDS WILL LIMIT SEA BREEZE FORMATION AND CONVECTIVE
DEVELOPMENT. HOTTER AND MORE HUMID THAN YESTERDAY WILL MAKE FOR
VERY UNCOMFORTABLE CONDITIONS. TRADE WINDS WILL FINALLY ESTABLISH
LATE TONIGHT BUT REMAIN STRONG THRU THURSDAY WITH SOLID 20 KNOTS.
SUBSTANTIAL MID-LEVEL DRYING WED-THU WILL LIMIT AREAL COVERAGE OF
T-STORMS BUT NOT INTENSITY. STRONG DEEP LAYER FLOW EXCEEDING 25 KT
AND MID LEVEL DRYING ON WED WILL AUGMENT DOWNDRAFT POTENTIAL WITH
SEVERE WIND GUSTS LIKELY WITH ANY STRONG CELLS THAT DEVELOP.
FURTHER DRYING AND WEAKENING LOW-MID LEVEL FLOW ON THU SHOULD
REDUCE THE SVR WX POTENTIAL.

TROPICAL WAVE OVR THE CNTRL ATLC WILL BEGIN TO APPROACH THE
LEEWARD ISLANDS FRI WITH MOISTURE SLOWLY INCREASING THROUGH THE
DAY. WINDS WILL SHIFT TO THE NORTHEAST FOCUSING SHOWERS AND
T-STORMS OVR SW PR BUT THESE WILL BE ISOLATED. WINDS SHIFT TO THE
SOUTHEAST SAT AND SUN WITH SHOWERS INCREASING IN AREAL COVERAGE
AREA WIDE. MODELS A BIT MORE AGGRESSIVE WITH DEVELOPMENT THAN 24
HRS AGO WITH ALMOST HALF OF GEFS ENSEMBLE MEMBERS NOW INDICATING
DEVELOPMENT BUT MOST KEEP THE LOW PRES CENTER NORTHEAST OF THE
AREA. THIS SYSTEM IS EXPECTED TO SLOW DOWN SIGNIFICANTLY ONCE IT
GETS NORTH OF THE AREA AND WILL MAINTAIN A MOIST ESE OR SE FLOW
INTO EARLY NEXT WEEK. SO EXPECT CHANCES OF RAINFALL TO INCREASE
DURING THE LABOR DAY WEEKEND AND THROUGH EARLY NEXT WEEK.

&&

.AVIATION...CONT SE FLOW TDY BCMG E WED. SCT SHRA/ISOLD TSRA NOW OVR
NE CARIBBEAN QUICKLY MOVG TWD PR/USVI. TJPS/TISX TO HV CHC MVFR IN
SHRA/TSRA THIS MRNG WI SOME OBSCD MTNS OVR PR. BUT THESE TO BCM
ISOLD THROUT PR/USVI/LEEWARDS BY AFT. WIND BLO FL200 SE 14-30 KT
GRDLLY BCMG E LATE TONITE/WED.

&&

.MARINE...STRONG SOUTHEAST WINDS TODAY BECOMING EASTERLY WED-THU
WITH SOLID 20-KT. ISOLD TSTMS TUE-FRI. WINDS DIMINISH FRI THROUGH
EARLY NEXT WEEK AS LOW PRES PASSES TO THE NORTHEAST OF ANEGADA BUT
AREAL COVERAGE OF SHOWERS AND T-STORMS INCREASES.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 91 80 91 82 / 10 20 20 20
STT 83 82 83 82 / 20 20 20 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
258 PM AST TUE AUG 26 2014

.SYNOPSIS...UPPER LEVEL TROUGH ACROSS THE EASTERN CARIBBEAN WILL
CONTINUE TO MOVE WESTWARD WHILE DISSIPATES. ANOTHER UPPER LEVEL
TROUGH WILL DEVELOP ACROSS THE CENTRAL ATLANTIC WEDNESDAY...MOVING
NORTH OF THE AREA THURSDAY AND FRIDAY. WEAK TROPICAL WAVE PASSAGE
EXPECTED TOMORROW. AREA OF LOW PRESSURE WILL PASS NORTHEAST OF
THE AREA DURING THE WEEKEND.

&&

.DISCUSSION...MOSTLY SUNNY TO PARTLY CLOUDY SKIES PREVAILED ACROSS
THE LOCAL ISLANDS THROUGH THE DAY...WITH ISOLATED TO LOCALLY
SCATTERED SHOWERS OBSERVED ACROSS LOCAL WATERS...USVI AND PORTIONS
OF THE SOUTHERN SLOPES OF PR. TEMPERATURES WERE IN THE LOW TO MID
90S AT LOWER ELEVATIONS...WITH SOUTHEASTERLY WINDS.

TYPICAL TRADE WIND PATTERN IS EXPECTED TO PREVAIL ACROSS THE
LOCAL ISLANDS THRU AT LEAST FRIDAY...WITH PASSING SHOWERS ACROSS
WINDWARD AREAS IN THE MORNING FOLLOWED BY SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS ACROSS WESTERN PUERTO RICO IN THE AFTERNOON.
ALTHOUGH PRECIPITABLE WATER WILL REMAIN NEAR OR JUST BELOW AVERAGE...
AFTERNOON CONVECTION MAY BE ENHANCE AS AFOREMENTIONED UPPER LEVEL
TROUGH MOVES NORTH OF THE AREA AND DRIER AIR FILTERS AT MID LEVELS.
TRADES ARE EXPECTED TO RETURN LATE TONIGHT AND TOMORROW...BRINGING
A RELIEF TO HOT TEMPERATURES AS WELL AS FOCUSING AFTERNOON
CONVECTION ACROSS MAYAGUEZ AND VICINITY WEDNESDAY AND THURSDAY. ON
FRIDAY...WINDS WILL SHIFT TO THE NORTHEAST FOCUSING SHOWERS AND
T-STORMS OVER CABO ROJO AND VICINITY.

A WETTER WEATHER PATTERN IS POSSIBLE THE UPCOMING WEEKEND AND INTO
EARLY NEXT WORKWEEK AS A LOW PRESSURE AND ASSOCIATED MOISTURE MOVES
NORTHEAST OF THE LOCAL ISLANDS. NHC GIVES IT 20% CHANCE OF TC
DEVELOPMENT IN THE NEXT FIVE DAYS. REGARDLESS OF TC DEVELOPMENT...
THIS FEATURE COULD BE A RAINFALL PRODUCER. STAY TUNED.

&&

.AVIATION...SE FLOW CONTINUES TODAY BCMG E ON WED. SOME OBSCD MTNS
OVR CENTRAL AND W PR THIS AFTERNOON. CHANCE OF VCSH FOR TJPS AND
TJMZ AND VCTS FOR TJBQ UNTIL AROUND 26/22Z. WIND BLO FL200 SE 14-30
KT GRADUALLY BCMG E LATE TONIGHT/WED.

&&

.MARINE...LOW LEVEL WINDS BECOMING EASTERLY WED-THU. ISOLD TSTMS
TUE-FRI. WINDS DIMINISH FRI THROUGH EARLY NEXT WEEK AS LOW PRES
PASSES TO THE NORTHEAST OF ANEGADA BUT AREAL COVERAGE OF SHOWERS
AND T-STORMS INCREASES.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 80 91 79 91 / 20 20 20 20
STT 81 83 80 83 / 20 20 20 20

[cycloneye]

A tropical wave located about 750 miles east of the Lesser Antilles
continues to produce a large area of disorganized showers and
thunderstorms. Environmental conditions are not expected to be
favorable for significant development during the next couple of
days, but could become slightly more conducive by the end of the
week or this weekend while the system moves west-northwestward at
about 15 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

[Gustywind]

A tropical wave located about 750 miles east of the Lesser Antilles
continues to produce a large area of disorganized showers and
thunderstorms. Environmental conditions are not expected to be
favorable for significant development during the next couple of
days, but could become slightly more conducive by the end of the
week or this weekend while the system moves west-northwestward at
about 15 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE AUG 26 2014

TROPICAL WAVE EXTENDS FROM 12N52W TO 19N51W MOVING W AT 15-20
KT. THE WAVE REMAINS LOW AMPLITUDE AND EMBEDDED IN THE ITCZ
REGION. SCATTERED MODERATE CONVECTION IS FROM 10N-14N BETWEEN
45W-59W.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
517 AM AST WED AUG 27 2014

.DISCUSSION...UPPER LEVEL TROUGH EXTENDING SOUTHWEST TO JUST
NORTHEAST OF THE NORTHERN LEEWARDS FROM THE EASTERN ATLANTIC....
WILL CONTINUE TO DEVELOP AND SHIFT TO JUST NORTH OF THE REGION BY
THE END OF THE WORK WEEK. WEAK TROPICAL WAVE WILL CONTINUE TO MOVE
MAINLY SOUTH OF THE REGION TODAY HAVING LITTLE OR NO EFFECT ON THE
LOCAL ISLANDS. ANOTHER WEAK AREA OF LOW PRESSURE AND ASSOCIATED
TROPICAL WAVE NOW ACROSS THE OPEN TROPICAL ATLANTIC IS SO FAR
FORECAST TO ENTER THE EASTERN CARIBBEAN LATE FRIDAY...THEN MOVE
ACROSS THE NORTHEASTERN CARIBBEAN SATURDAY THROUGH SUNDAY.

&&

.DISCUSSION...LATEST SATELLITE IMAGERY AND DOPPLER WEATHER RADAR
SHOWED ONLY FEW LIGHT SHOWERS MOVING ACROSS THE REGION DURING THE
EARLY MORNING HOURS AS MOST OF LOW TO MID LEVEL MOISTURE ASSOCIATED
WITH WEAK TROPICAL WAVE WAS WELL SOUTH OF THE REGION. THIS FEATURE
WILL CONTINUE WESTWARDS TODAY AND HAVE NO DIRECT AFFECT ON THE
LOCAL ISLANDS AS IT WILL CONTINUE TO MOVE WELL SOUTH OF THE REGION.
WINDS ARE FORECAST TO BECOME MORE EASTERLY LATER TODAY THROUGH
THE END OF THE WEEK AS SURFACE HIGH PRESSURE REESTABLISHES ITSELF
NORTH OF THE REGION TO INDUCE MODERATE TRADE WINDS.

FOR THE REST OF THE DAY...AFTERNOON CONVECTION WILL BE MAINLY
DRIVEN BY SEAS BREEZE VARIATIONS AND LOCAL TERRAIN EFFECTS ACROSS
THE ISLANDS WITH THE MAIN FOCUS OVER THE WEST INTERIOR SECTIONS
OF PUERTO RICO. NO WIDESPREAD OR SIGNIFICANT RAINFALL IS EXPECTED
FOR THE NEXT COUPLE OF DAYS ACROSS THE FORECAST AREA. HOWEVER...
PERIODS OF LATE EVENING AND EARLY MORNING PASSING SHOWERS CAN BE
EXPECTED EACH DAY FOLLOWED BY LIMITED DIURNALLY DRIVEN AFTERNOON
CONVECTION. BY FRIDAY LOCAL WINDS ARE TO BECOME MORE NORTHEASTERLY
IN ADVANCE OF ANOTHER TROPICAL WAVE FORECAST TO ENTER THE EASTERN
CARIBBEAN. THEREAFTER...AFTERNOON CONVECTION SHOULD THEN BE STEERED
TOWARDS PARTS OF THE SOUTHWEST SECTIONS OF PUERTO RICO WITH SOME
ENHANCEMENT EXPECTED DUE TO THE PROXIMITY OF THE UPPER TROUGH.

INCREASING TROPICAL MOISTURE AND BETTER CHANCE OF SHOWERS AND
THUNDERSTORM ACTIVITY IS FORECAST FOR THE UPCOMING WEEKEND WITH
THE APPROACH OF THE NEXT TROPICAL WAVE...AS SUGGEST BY LATEST GFS
MODEL... WHICH HAS SO FAR BEEN INITIALIZING FAIRLY WELL.

MORE TO COME ON THIS FEATURE DURING THE NEXT COUPLE OF DAYS BUT
WILL CONTINUE TO MONITOR AND MAKE THE NECESSARY ADJUSTMENT TO THE
LONG TERM FORECAST GRIDS FOR THE WEEKEND AND BEYOND. FOR NOW...THE
BEST CHANCE FOR GOOD WETTING RAINS ACROSS THE FORECAST AREA LOOKS
LIKE LATE FRIDAY THROUGH SATURDAY.

&&

.AVIATION...THE PREVAILING EAST SOUTHEAST L/LEVEL WIND FLOW WILL
BECOME EASTERLY BY THIS AFN. BRIEF MTN OBSCURATIONS ERN PR AFT
27/10Z AS A BAND OF SHALLOW L/LVL CLOUDS WILL MOVES WEST ACROSS
THE LOCAL FLYING AREA. DAYTIME HEATING AND LOCAL EFFECTS WILL AID
IN DVLP OF ISOLD TSRA OVR W PR WITH VCTS FOR TJMZ AND TJBQ
MAINLY BTW 27/17Z-27/22Z ALONG W/MTN OBCR OVR CORDILLERA CENTRAL
AND WESTERN PR. WIND BLO FL200 FM ESE 14-25 KT...STRONGEST BTW
FL100-FL150...GRADUALLY BCMG FM DURG THE AFN.

&&

.MARINE...SMALL CRAFT SHOULD EXERCISE CAUTION DUE TO WINDS UP TO
20 KNOTS AND SEAS INCREASING UP TO 6 FEET DURING THE DAY. PLEASE
REFER TO THE LATEST COASTAL WATERS FORECAST ISSUED BY WFO SAN JUAN
PR.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 80 89 78 / 10 20 20 30
STT 89 81 90 80 / 20 20 20 30

[abajan]

Looks like a very rainy and thundery day on the way for Barbados. A tropical wave is affecting us and there are lots of cumulonimbus clouds around. I can see from satellite imagery that convection is building just east of us.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
303 PM AST WED AUG 27 2014

.SYNOPSIS...TUTT LOW WILL PASS NORTH OF THE AREA THURSDAY AND
FRIDAY WITH UPPER LEVEL RIDGE BUILDING IN DURING THE WEEKEND.
TROPICAL WAVE IS FORECAST TO ENTER THE EASTERN CARIBBEAN FRIDAY
AFTERNOON AND MOVE ACROSS THE NORTHEASTERN CARIBBEAN SATURDAY
THROUGH SUNDAY.

&&

.DISCUSSION...MOSTLY SUNNY TO PARTLY CLOUDY SKIES PREVAILED ACROSS
THE LOCAL ISLANDS THROUGH THE DAY...WITH ISOLATED TO LOCALLY
SCATTERED SHOWERS OBSERVED ACROSS LOCAL WATERS AND WESTERN PUERTO
RICO. TEMPERATURES WERE IN THE LOW 90S AT LOWER ELEVATIONS...WITH
EASTERLY WINDS.

A TYPICAL WEATHER PATTERN IS EXPECTED TO PREVAIL ACROSS THE LOCAL
ISLANDS THRU AT LEAST FRIDAY...WITH PASSING SHOWERS ACROSS WINDWARD
AREAS IN THE MORNING FOLLOWED BY SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS THE CORDILLERA CENTRAL AND WESTERN PUERTO
RICO IN THE AFTERNOON. ALTHOUGH PRECIPITABLE WATER WILL REMAIN
NEAR OR JUST BELOW AVERAGE...AFTERNOON CONVECTION MIGHT BE ENHANCE
AS AFOREMENTIONED UPPER LEVEL TROUGH MOVES NORTH OF THE AREA. AS
WINDS SHIFT TO THE NORTHEAST ON FRIDAY SHOWERS AND T-STORMS WILL
BE FOCUSED OVER CABO ROJO AND VICINITY.

INCREASING TROPICAL MOISTURE AND BETTER CHANCE OF SHOWERS AND
THUNDERSTORM ACTIVITY IS FORECAST FOR THE UPCOMING WEEKEND WITH
THE APPROACH OF THE NEXT TROPICAL WAVE. UNCERTAINTY IS HIGH...
INTERACTION BETWEEN THIS FEATURE AND THE TUTT TO THE NORTH IS
POSSIBLE...INTENSITY/ORGANIZATION OF THE CONVECTION WILL BE
HIGHLY DEPENDENT ON AMPLITUDE AND TIMING. A FAIR WEATHER PATTERN
IS EXPECTED TO PREVAIL EARLY NEXT WORKWEEK AS LOCAL ISLANDS
REMAINS UNDER UPPER LEVEL RIDGE PATTERN.

&&

.AVIATION...VFR CONDS EXPECTED FOR ALMOST ALL TAF SITES. DAYTIME
HEATING AND LOCAL EFFECTS WILL AID IN DVLP OF ISOLD TSRA OVR W PR
WITH TSRA FOR TJMZ AND VCTS FOR TJBQ TIL 27/22Z ALONG W/MTN OBCR OVR
CORDILLERA CENTRAL AND WESTERN PR. WIND BLO FL200 FM ESE 14-30
KT...STRONGEST BTW FL100-FL150...GRADUALLY BCMG FM EAST DURG THE AFN.

&&

.MARINE...A MODERATE TO LOCALLY FRESH EASTERLY WIND FLOW WILL PREVAIL
THROUGH AT LEAST THURSDAY...BECOMING NORTHEAST FRIDAY AND SATURDAY.
A TROPICAL WAVE IS FORECAST TO ENTER THE EASTERN CARIBBEAN FRIDAY
AFTERNOON AND MOVE ACROSS THE NORTHEASTERN CARIBBEAN SATURDAY
THROUGH SUNDAY. THIS WILL BRING AN INCREASE IN SHOWER AND THUNDERSTORM
ACTIVITY ACROSS THE REGIONAL WATERS. SMALL CRAFT SHOULD EXERCISE
CAUTION DUE TO WINDS UP TO 20 KNOTS AND SEAS UP TO 6 FEET.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 80 89 78 90 / 20 20 30 30
STT 81 90 80 89 / 30 30 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
537 AM AST THU AUG 28 2014

.SYNOPSIS...RETROGRESSING TUTT LOW NOW CENTERED JUST NORTHEAST OF
THE NORTHERN LEEWARDS NEAR 21N 57W WILL CONTINUE TO SHIFT FURTHER
WEST NORTHWEST DURING THE NEXT FEW DAYS. AT LOW LEVELS...A BROAD
SURFACE HIGH PRESSURE CENTERED OVER THE CENTRAL ATLANTIC AND A
AND EASTERLY PERTURBATION/TROPICAL WAVE MOVING ACROSS THE EASTERN
CARIBBEAN...WILL HELP TIGHTEN THE LOCAL PRESSURE GRADIENT AND
INCREASE THE LOCAL TRADE WINDS GENERATING A WINDS SURGE WHICH WILL
MOVE ACROSS AND AFFECT THE FORECAST AREA TODAY.

&&

.DISCUSSION...TUTT LOW AND ASSOCIATED TROUGH WILL CONTINUE TO MOVE
WESTWARDS TO JUST NORTHWEST OF THE ISLANDS OVER THE NEXT FEW DAYS...
WHERE IT WILL LINGER AND BECOME AMPLIFIED ACROSS THE SOUTHWEST
ATLANTIC THROUGH SATURDAY. TUTT INDUCED LOW TO MID LEVEL TROUGH
AND WEAK TROPICAL WAVE WILL BRING A SLIGHT INCREASE IN MOISTURE
ACROSS THE REGION TODAY. ALTHOUGH THE MAJORITY OF THE ACCOMPANYING
MOISTURE WILL REMAIN MAINLY SOUTH OF THE ISLANDS...STILL EXPECT
SUFFICIENT MOISTURE CONVERGENCE AND INSTABILITY FOR SOME EARLY
MORNING AND AFTERNOON CONVECTION ACROSS PARTS OF THE ISLANDS AND
COASTAL WATERS. MOST OF THE AFTERNOON SHOWERS AND ISOLATED THUNDERSTORM
ACTIVITY SHOULD HOWEVER BE FOCUSED MAINLY ACROSS THE INTERIOR AND
WEST SECTIONS OF PUERTO RICO DUE LOCAL TERRAIN EFFECTS.

THE NEXT TROPICAL WAVE IS STILL FORECAST TO ENTER THE EASTERN
CARIBBEAN LATE FRIDAY AND MOVE ACROSS THE REGION OVER THE UPCOMING
WEEKEND. AT THIS TIME GFS MODEL GUIDANCE SUGGEST A SIGNIFICANT
INCREASE IN TROPICAL MOISTURE TO BE LIFTED NORTHWARDS ACROSS THE
REGION WITH THIS WAVE WITH PWAT VALUES TO ONCE AGAIN EXCEED TWO
INCHES BY SATURDAY AND SUNDAY. SO FAR THE GFS CONTINUED TO INITIALIZE
WELL AND IF IN FACT THIS SCENARIO UNFOLDS...EXPECT THE INTERACTION
BETWEEN THE TUTT LOW AND THE THE TROPICAL WAVE...WILL LEAD TO INCREASED
POTENTIAL FOR SHOWER DEVELOPMENT AND ENHANCED THUNDERSTORM ACTIVITY
ACROSS THE ISLANDS FOR MOST OF THE WEEKEND.

&&

.AVIATION...A WIND SURGE CREATED BY THE TIGHTENING OF THE LOCAL
PRESSURE GRADIENT IN RESPONSE TO AN EASTERLY PERTURBATION MOVING
ACROSS THE EASTERN CARIBBEAN...WILL BRING AND IN INCREASE IN THE
LOW LEVEL EASTERLY TRADE WINDS TODAY. BRIEF PERIODS OF MVFR
EXPECTED THIS MORNING ACROSS TNCM...TKPK AND TIST DUE TO QUICK
PASSING SHRA AND FEW-SCT LOW CLDS. PREVIOUS TJSJ 28/00Z SOUNDING
INDICATED STRONG EASTERLY WINDS OF 20 KTS TO UP TO AS MUCH AS 45
KNOTS BLO FL150. EXPCT BRIEF SFC WND GUST MAINLY W/PASSING SHRA AT
ALL TAF SITES TIL 28/15Z. MVFR LIKELY IN AT TJMZ AFT 28/16Z WITH
MTN OBSC DUE TO SHRA/ISOLD TSRA TIL 28/22Z.VCSH NR TJBQ FM
28/17Z-28/22Z.

&&

.MARINE...PREVIOUSLY MENTIONED WIND SURGE MOVING ACROSS THE REGIONAL
WATERS TODAY WILL HELP TO GENERATE ROUGH AND HAZARDOUS SEA CONDITIONS
ACROSS THE LOCAL WATERS AT LEAST UNTIL THE AFTERNOON HOURS. FOR THIS
REASON SMALL CRAFT ADVISORIES WILL REMAIN IN EFFECT UNTIL LATER TODAY
FOR PARTS OF THE LOCAL WATERS. ELSEWHERE SMALL CRAFT OPERATORS
SHOULD EXERCISE CAUTION.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 78 88 77 / 20 30 30 50
STT 89 79 88 77 / 30 30 30 50

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
237 PM AST THU AUG 28 2014

.SYNOPSIS...RETROGRESSING TUTT LOW NOW CENTERED JUST NORTHEAST OF
THE US VIRGIN ISLANDS WILL CONTINUE TO SHIFT FURTHER WEST NORTHWEST
DURING THE NEXT FEW DAYS. AT LOW LEVELS...A BROAD SURFACE HIGH
PRESSURE CENTERED OVER THE CENTRAL ATLANTIC AND AN EASTERLY
PERTURBATION/TROPICAL WAVE MOVING ACROSS THE EASTERN
CARIBBEAN...WILL HELP TIGHTEN THE LOCAL PRESSURE GRADIENT AND
INCREASE THE LOCAL TRADE WINDS GENERATING A WINDS SURGE WHICH WILL
MOVE ACROSS AND AFFECT THE FORECAST AREA THE REST OF THIS
AFTERNOON THROUGH TONIGHT. MOISTURE WILL INCREASE FRIDAY THROUGH
SUNDAY.

&&

.DISCUSSION...VERY ACTIVE WEATHER WAS OCCURRING OVER THE COASTAL
WATERS SOUTH OF PUERTO RICO THIS MORNING AND EARLY AFTERNOON...AS
EASTERLY PERTURBATION MOVES SOUTH OF THE AREA. MEANWHILE...OVER
THE U.S. VIRGIN ISLANDS...PARTLY SUNNY SKIES PREVAILED. A STREAMER
FROM VIEQUES DEVELOPED...PRODUCING SHOWERS OVER THE EASTERN
SECTION OF PUERTO RICO THIS AFTERNOON. THROUGH 2 PM AST THIS
AFTERNOON...REST OF PUERTO RICO WAS UNDER PARTLY CLOUDY SKIES.
A RETROGRESSING TUTT LOW NORTH OF THE U.S. VIRGIN ISLANDS WILL
CONTINUE TO MOVE WEST AND WILL BE LOCATED NORTHWEST OF THE LOCAL
REGION TOMORROW AFTERNOON. THIS UPPER LOW...IN COMBINATION WITH
THE AFOREMENTIONED EASTERLY PERTURBATION AND DAYTIME HEATING...ARE
EXPECTED TO ENHANCE THE SHOWER AND THUNDERSTORMS DEVELOPMENT
TOMORROW AFTERNOON.

MOISTURE IS FORECAST TO INCREASE BY SATURDAY AND SUNDAY WHICH
WILL INCREASE THE CHANCES FOR SHOWERS AND THUNDERSTORMS ACTIVITY
BOTH DAYS. GFS COMPUTER MODEL INDICATED THETAE VALUES AT 700MB
WILL INCREASE UP TO 335K WITH PW VALUES REACHING 2.0 INCHES SUNDAY
AFTERNOON. IN THE LONG RANGE...AT THIS TIME..NO SIGNIFICANT WEATHER
EVENTS ARE FORECAST TO AFFECT THE LOCAL REGION.

&&

.AVIATION...VFR CONDS WILL CONTINUE FOR ALMOST ALL TAF SITES. TJSJ
28/12Z SOUNDING INDICATED STRONG EASTERLY WINDS OF 20 KTS TO UP TO
AS MUCH AS 40 KNOTS BLO FL150. EXPCT BRIEF SFC WND GUST AT ALL TAF
SITES TIL AROUND 28/22Z. MVFR LIKELY IN AT TJMZ DUE TO SHRA/ISOLD
TSRA AND VCSH NR TJBQ TIL 28/22Z.

&&

.MARINE...WINDS WILL CONTINUE TO MAINTAIN HAZARDOUS MARINE
CONDITIONS THROUGH TONIGHT MAINLY ACROSS THE OFFSHORE ATLANTIC AND
CARIBBEAN WATERS. CONDITIONS WILL IMPROVE FRIDAY. HOWEVER..SMALL
CRAFT SHOULD CONTINUE TO EXERCISE CAUTION AS SEAS UP TO 6 FEET AD
WINDS UP TO 18 KNOTS ARE EXPECTED.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 88 77 89 / 30 30 50 50
STT 79 88 77 88 / 30 30 50 50

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
946 PM AST THU AUG 28 2014

.UPDATE...A BAND OF MOISTURE CONTINUES TO INTERSECT PUERTO RICO
AND THE U.S. VIRGIN ISLANDS AS ANOTHER MOISTURE MASS APPROACHES THE
SOUTHERN BORDER OF THE FORECAST AREA. MIMIC PRODUCT IS THE MOST
INSTRUCTIONAL AS IT SHOWS A VERY RICH AIR MASS JUST TO THE SOUTH
WITH THE AXIS OF THE MOISTURE MOVING SLOWLY TOWARD THE AREA FROM
THE SOUTH. SAHARAN DUST HAS CLEANED UP SIGNIFICANTLY WITH
VISIBILITIES OUTSIDE OF RAIN AREAS APPROACHING 40 PLUS MILES.
LITTLE DUST IS EXPECTED THROUGH THE WEEKEND.

&&

.DISCUSSION...HAVE UPDATED THE FORECAST TO INCLUDE HIGHER POPS
ALTHOUGH MOST MODELS EXPECT LOW LEVEL MOISTURE TO TAPER OFF
OVERNIGHT. PRECIPITABLE WATER HOWEVER INCREASES TO ALMOST 2.1
INCHES IN THE WRF AND OVER 2.0 IN THE GFS. ALSO OF NOTE IS THAT
STRONG DIVERGENCE PASSES OVER THE ISLAND BETWEEN 29/06-12Z. THIS
MAY NOT BE AS INFLUENTIAL AS IT COULD BE OWING TO THE LACK OF
HEATING AT THE SURFACE. FOR NOW WILL MAINTAIN SCATTERED TO
NUMEROUS SHOWERS IN THE EAST AND CENTRAL PUERTO RICO INCLUDING THE
SOUTH COAST...AND ISOLATED ELSEWHERE. SCATTERED SHOWERS IN THE
USVI BUT LOOKS LIKE THEY WILL GET AT LEAST A FEW HUNDREDTHS
EVERYWHERE THERE.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
501 AM AST FRI AUG 29 2014



.SYNOPSIS...RETROGRESSING TUTT LOW JUST NORTH OF PUERTO RICO AND
WILL CONTINUE TO MOVE WEST NORTHWEST WHILE GRADUALLY FILLING. AT
LOW LEVELS TUTT INDUCED LOW TO MID LEVEL TROUGH AND A TROPICAL
WAVE WILL CONTINUE TO ENTER AND MOVE ACROSS THE EASTERN CARIBBEAN
TODAY THROUGH SATURDAY. SURFACE HIGH PRESSURE RIDGE EXTENDING
ACROSS THE NORTHEASTERN CARIBBEAN FROM THE CENTRAL ATLANTIC WILL
WEAKEN THROUGH SATURDAY...AS IT PULLS FARTHER NORTH AND EAST
ACROSS THE ATLANTIC. THIS WILL HELP TO LOOSEN THE LOCAL PRESSURE
GRADIENT...WHICH IN TURN WILL RESULT IN A GRADUAL DECREASING OF
THE LOCAL TRADE WINDS OVER THE NEXT FEW DAYS AND THROUGH THE
UPCOMING WEEKEND.

&&

.DISCUSSION...BROAD SWATH OF ITCZ MOISTURE WILL BE LIFTED NORTHWARDS
ACROSS THE REGION AS LOW LEVEL TROUGH AND TROPICAL WAVE WILL CONTINUE
TO QUICKLY MOVE WESTWARD ACROSS EASTERN CARIBBEAN OVER THE NEXT
COUPLE OF DAYS. THE PROXIMITY OF THE TUTT LOW WILL HELP TO ENHANCE
EARLY MORNING AND AFTERNOON CONVECTION ACROSS THE COASTAL WATERS
AND LOCAL ISLANDS TODAY. WITH FAIRLY LIGHT WINDS...LOCAL SEA BREEZE
CONVERGENCE SHOULD ALSO AID IN AFTERNOON SHOWERS AND THUNDERSTORM
DEVELOPMENT ESPECIALLY ACROSS PARTS OF THE INTERIOR AND WEST SECTIONS
OF PUERTO RICO.

FAIR AMOUNTS OF TROPICAL MOISTURE ADVECTION IS FORECAST TO CONTINUE
OVER THE FORECAST AREA THROUGH AT LEAST THE EARLY PART OF THE
OF THE WEEKEND WITH THE PASSAGE OF A TROPICAL WAVE. THIS FAIRLY
MOIST ENVIRONMENT WILL THEREFORE INCREASE THE CHANCES FOR SHOWERS
AND THUNDERSTORM ACTIVITY THROUGH AT LEAST SATURDAY AND POSSIBLE
ON SUNDAY. LATEST GFS COMPUTER MODEL GUIDANCE CONTINUED TO SUGGEST
INCREASING THETA-E VALUES UP TO NEAR 338K WITH PWAT VALUES TO RANGE
BETWEEN 1.8 TO NEAR 2.0 INCHES. THEREFORE FOR THE LABOR DAY WEEKEND
EXPECT A MIXTURE OF SUNSHINE AND CLOUDS WITH PERIODS OF EARLY MORNING
AND AFTERNOON SHOWERS AND THUNDERSTORMS...SOME OF WHICH MAY BE HEAVY
AT TIMES ESPECIALLY LATER TODAY AND ON SATURDAY. SO FAR LOOKING FOR
GRADUALLY IMPROVING CONDITIONS ON SUNDAY AND MONDAY.

&&

.AVIATION...MOSTLY VFR CONDITIONS ARE EXPECTED ACROSS THE LOCAL
FLYING AREA THIS MORNING WITH PASSING SHOWERS WITH BRIEF PERIODS OF
MVFR CONDITIONS ACROSS TIST AND TISX. SFC WINDS WILL BE MAINLY LIGHT
AND VARIABLE. AFTER 29/13Z WINDS WILL REMAIN EASTERLY AT AROUND
10 KNOTS WITH AFTERNOON SHRA/TSRA EXPECTED ACROSS THE WESTERN
INTERIOR OF PR...LIKELY AFFECTING AREAS IN AND AROUND TJPS...TJMZ...
AND TJBQ.

&&

.MARINE...WINDS AND SEAS ACROSS THE LOCAL WATERS WILL CONTINUE TO
SUBSIDE TODAY AND THROUGH THE UPCOMING WEEKEND. HOWEVER...SMALL
CRAFT OPERATORS SHOULD CONTINUE EXERCISE CAUTION ACROSS THE OFFSHORE
ATLANTIC DUE TO SEAS OF 6 FEET OR SO. ELSEWHERE SEAS WILL BE 5
FEET OR LESS AND WINDS 17 KNOTS OR LESS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 89 78 / 50 50 50 50
STT 87 78 89 79 / 40 50 50 50

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
303 PM AST FRI AUG 29 2014

.SYNOPSIS...RIDGE PATTERN WILL BUILD ACROSS THE LOCAL AREA DURING
THE UPCOMING WEEKEND AS TUTT LOW...NOW LOCATED NORTH OF THE ISLANDS...
MOVES WESTWARD. AN INDUCED SURFACE TROUGH WILL CONTINUE TO MOVE
ACROSS THE EASTERN CARIBBEAN TONIGHT AND SATURDAY. A PAIR OF
TROPICAL WAVES WILL MOVE ACROSS THE LOCAL ISLANDS NEXT WORKWEEK.

&&

.DISCUSSION...AS INDUCED SURFACE TROUGH CONTINUES TO MOVE ACROSS
THE EASTERN CARIBBEAN TONIGHT AND SATURDAY...DEEP TROPICAL
MOISTURE FROM THE ITZC WILL CONTINUE TO BE LIFTED NORTHWARDS
ACROSS LOCAL ISLANDS. THEREFORE STILL EXPECT TRADE WIND SHOWERS
ACROSS WINDWARD AREAS TONIGHT AND SATURDAY MORNING. RIDGE ALOFT
WILL BUILD OVER THE AREA AS THE AFOREMENTIONED TUTT LOW MOVES
FURTHER WEST DURING THE WEEKEND. HOWEVER DUE TO THE PROXIMITY OF
THIS FEATURE...SHOWERS AND THUNDERSTORMS WERE INCLUDED IN THE
FORECAST FOR SATURDAY AFTERNOON. UNDER THE PREVAILING EASTERLY
WIND FLOW...MOST AFTERNOON ACTIVITY WILL BE FOCUSED ACROSS THE
CORDILLERA AND WEST PUERTO RICO.

LATEST MODEL GUIDANCE INDICATED A DECREASING TREND IN PRECIPITABLE
WATER OVER THE NEXT FEW DAYS. THIS TREND COMBINED WITH BUILDING
UPPER LEVEL RIDGE SHOULD RESULT IN A MORE TYPICAL WEATHER PATTERN
WITH A FEW TRADE WIND SHOWERS ACROSS WINDWARD AREAS IN THE MORNING
FOLLOWED BY SOME AFTERNOON CONVECTION ACROSS WESTERN PUERTO RICO.
THEREFORE...SO FAR LOOKING FOR GRADUALLY IMPROVING CONDITIONS ON
SUNDAY AND MONDAY. THERE IS A PAIR OF TROPICAL WAVE ACROSS THE
CENTRAL TROPICAL ATLANTIC THAT AREA EXPECTED TO MOVE ACROSS THE
EASTERN CARIBBEAN BY THE MID AND LATER PART OF NEXT WORKWEEK.

&&

.AVIATION...WINDS WILL REMAIN GENERALLY EASTERLY AT AROUND 10 KNOTS
WITH SHRA/TSRA DEVELOPING ACROSS NORTHERN SECTIONS OF PR WITH MTN
OBSCURATIONS TIL AROUND 29/22Z. THESE STORMS ARE MOVING TO THE NORTH
DUE TO THE STEERING FLOW FROM THE SOUTH ABOVE 20KFT. VFR AFT 29/22Z
FOR ALL TAF SITES WITH VCSH POSSIBLE FOR THE LOCAL ISLANDS AND TJSJ.

&&

.MARINE...A MODERATE TO LOCALLY FRESH TRADE WIND FLOW WILL CONTINUE
TO PREVAIL ACROSS THE LOCAL WATERS THROUGH EARLY NEXT WEEK. AN
INDUCED SURFACE TROUGH WILL CONTINUE MOVE ACROSS THE EASTERN CARIBBEAN
TONIGHT AND SATURDAY. THIS WILL CONTINUE TO ENHANCE SHOWER AND
ISOLATED THUNDERSTORM ACTIVITY ACROSS PARTS OF THE COASTAL WATERS.

IN TERMS OF SEAS...SEAS ACROSS THE LOCAL WATERS WILL CONTINUE TO
SUBSIDE TONIGHT AND THROUGH THE UPCOMING WEEKEND. HOWEVER...SMALL
CRAFT OPERATORS SHOULD CONTINUE EXERCISE CAUTION ACROSS THE OFFSHORE
ATLANTIC DUE TO SEAS OF UP TO 6 FEET. ELSEWHERE SEAS WILL BE 5
FEET OR LESS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 89 78 89 / 50 50 40 30
STT 78 89 79 88 / 50 50 50 30

[cycloneye]

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN JUAN PR
426 AM AST SAT AUG 30 2014

.SYNOPSIS...UPPER LEVEL RIDGE WILL CONTINUE TO BUILD OVER THE LOCAL
REGION AND REMAINS AS THE WEATHER FEATURE ACROSS THE LOCAL ISLANDS
FOR THE NEXT FEW DAYS AS TUTT LOW...NORTH OF HISPANIOLA...MOVES
WESTWARD. A SURFACE TROUGH WILL CONTINUE TO MOVE ACROSS THE REGION
TODAY. A WEAK TROPICAL ALONG 55 WEST THIS MORNING...IS EXPECTED TO
REACH THE REGION BY WEDNESDAY.

&&

.DISCUSSION...DOPPLER WEATHER RADAR DETECTED ISOLATED TO SCATTERED
SHOWERS ACROSS THE REGION THIS MORNING. SOME OF THESE SHOWERS
AFFECTED VIEQUES...CULEBRA...THE USVI AND EASTERN SECTIONS OF PUERTO
RICO FROM TIME TO TIME OVERNIGHT AND EARLY THIS MORNING. THIS
ACTIVITY WAS ASSOCIATED WITH A SURFACE TROUGH MOVING ACROSS THE
REGION TODAY...ENHANCED BY AN UPPER LOW JUST TO THE NORTH OF
HISPANIOLA. FOR THIS AFTERNOON...THE AVAILABLE MOISTURE ACROSS THE
REGION WILL COMBINE WITH DIURNAL HEATING AND LOCAL OROGRAPHIC
EFFECTS TO INDUCE THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS.
UNDER THE PREVAILING EASTERLY WIND FLOW...MOST AFTERNOON ACTIVITY
WILL BE FOCUSED ACROSS THE CORDILLERA AND WEST PUERTO RICO.

RIDGE ALOFT WILL CONTINUE TO BUILD OVER THE LOCAL ISLANDS FOR THE
FEW DAYS...AS THE UPPER LOW JUST NORTH OF HISPANIOLA...MOVES FURTHER
WEST AND AWAY FROM THE FORECAST AREA. AS THE UPPER RIDGE BUILDS OVER
THE REGION...PWAT VALUES ARE EXPECTED TO DECREASE FOR THE NEXT
SEVERAL DAYS. HOWEVER...SHOWERS AND A FEW THUNDERSTORMS WILL DEVELOP
EACH DAY OVER WESTERN AND INTERIOR SECTIONS OF PUERTO RICO. A WEAK
TROPICAL WAVE...ALONG 55 WEST THIS MORNING WILL CONTINUE TO MOVE
WESTWARD APPROACHING THE LOCAL ISLANDS ON WEDNESDAY...INDUCING A
MODEST INCREASE IN CLOUDINESS...SHOWERS AND THUNDERSTORMS OVER THE
LOCAL ISLANDS.

&&

.AVIATION...PASSING TRADE WIND -SHRA/SHRA WILL AFFECT THE COASTAL
WATERS OF THE LOCAL ISLANDS AND EN ROUTE BTW PR AND NRN LEEWARD TIL
30/14Z. SFC WINDS LGT AND VRB AT LCL TAF SITES TIL AT LEAST
30/14Z...BCMG E-NE 10-15 KTS THEREAFTER WITH SEA BREEZE VARIATIONS.
SCT-NMRS SHRA/ISOLD TSRA FCST ACROSS CENTRAL AND W PR AFTER
30/17Z...W/ISOLD TSRA VCTY TJMZ AND TJBQ PSBL. L/LVL WNDS FM E-NE
5-15 KTS UP FL150 BCMG FM SW AT 10-20 KTS UP TO FL350.

&&

.MARINE...SMALL CRAFT SHOULD EXERCISE CAUTION ACROSS THE ATLANTIC
WATERS. ELSEWHERE ACROSS THE REGION A GENERALLY QUIET MARINE
CONDITIONS ARE EXPECTED.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 76 88 78 / 50 40 30 40
STT 88 78 89 79 / 50 50 30 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
256 PM AST SAT AUG 30 2014

.DISCUSSION...QUITE A FEW SHOWERS AND SOME THUNDERSTORMS OVER PR
CURRENTLY AND EXPECT A LITTLE URBAN/SMALL STREAM FLOODING NEXT
COUPLE HOURS. BUT OTHERWISE EXPECT THEY WILL BEHAVE THEMSELVES
AND EVEN DECREASE BEFORE 5PM AS THE CLOUD COVER IS BECOMING QUITE
EXPANSIVE...CUTTING OFF THE SOURCE OF HEAT.

UPPER TROPOSPHERIC TROUGH NORTH OF HISPANIOLA WILL CREEP WEST
NEXT SEVERAL DAYS WHILE RIDGE AT THAT LEVEL SETTLES OVER EASTERN
CARIBBEAN INTO MID-WEEK. SO THE SOUTHWEST FLOW ABOVE 500 MB IS
ALREADY DECREASING THIS AFTERNOON AND WILL NO LONGER HELP IN
CONVECTIVE DEVELOPMENT AFTER TODAY.

DRY ADVECTION TO KICK IN SUNDAY THOUGH PRECIPITABLE WATER WILL
BEGIN THE DAY WITH NEAR SEASONAL LEVELS. EASTERLY TRADES WILL
RETURN ISLAND TO TYPICAL FAR WEST PR SHOWERS/THUNDER AND ISOLATED
SHOWERS ELSEWHERE. EXTREMELY WEAK TROPICAL WAVE ARRIVES TUE BUT
WITHOUT MUCH WAVE DYNAMICS TO ENHANCE CONVECTIVE DEVELOPMENT. SO
EXPECT THE NEXT WAVE OF NOTE TO ONE CURRENTLY HANGING BACK AT 30W
WHICH GFS EXPECTS TO ARRIVE THU NIGHT/FRI. IT LOOKS UNIMPRESSIVE
ON SATELLITE AND LIMITED FURTHER DEVELOPMENT EXPECTED IN THE WAVE.

&&

.AVIATION...SHRA/ISOLD TSRA WILL CONTINUE TO DEVELOP ACROSS CENTRAL
AND W PR AFTER THRU 21Z...W/ISOLD TSRA IN AND AROUND TJMZ. VCTS
POSSIBLE NEAR TJPS/TJBQ AND VFR EXPECTED ELSEWHERE. THEN...PASSING
-SHRA WILL AFFECT THE COASTAL WATERS OF THE LOCAL ISLANDS TONIGHT
AND OVERNIGHT. L/LVL WNDS FM E-NE 10-20 KTS UP FL100.

&&

.MARINE...SEAS HAVE DROPPED TO 4 FT OR LESS AT BUOYS THOUGH WOULD
EXPECT A SLIGHT INCREASE THIS AFTERNOON SINCE THE DIURNAL NATURE
OF THE WINDS HAS KICKED UP TODAY. BUT 5 FT APPEARS THE LIMIT IN
SHORT TERM.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 88 79 89 / 40 30 30 30
STT 78 89 79 89 / 50 30 40 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
418 AM AST SUN AUG 31 2014

.SYNOPSIS...UPPER LEVEL RIDGE WILL CONTINUE TO BUILD OVER THE LOCAL
REGION AND REMAINS AS THE MAIN WEATHER FEATURE ACROSS THE LOCAL
ISLANDS FOR THE NEXT FEW DAYS AS TUTT LOW...NORTH OF HISPANIOLA...
MOVES WESTWARD. A WEAK TROPICAL ALONG 60 WEST THIS MORNING...IS
EXPECTED TO REACH THE REGION BY TUESDAY.

&&

.DISCUSSION...DOPPLER WEATHER RADAR DETECTED ISOLATED TO SCATTERED
SHOWERS ACROSS THE REGION OVERNIGHT AND EARLY THIS MORNING. SOME OF
THESE SHOWERS AFFECTED THE EASTERN SECTIONS OF PUERTO RICO FROM TIME
TO TIME. THIS ACTIVITY WAS ASSOCIATED WITH A MOIST WIND FLOW OVER
THE REGION...ENHANCED BY AN UPPER LOW JUST TO THE NORTH OF
HISPANIOLA. FOR THIS AFTERNOON...THE AVAILABLE MOISTURE ACROSS THE
REGION WILL COMBINE WITH DIURNAL HEATING AND LOCAL OROGRAPHIC
EFFECTS TO INDUCE THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS.
UNDER THE PREVAILING EASTERLY WIND FLOW...MOST AFTERNOON ACTIVITY
WILL BE FOCUSED ACROSS THE CORDILLERA AND WEST PUERTO RICO.

RIDGE ALOFT WILL CONTINUE TO BUILD OVER THE LOCAL ISLANDS FOR THE
FEW DAYS...AS THE UPPER LOW JUST NORTH OF HISPANIOLA...MOVES FURTHER
WEST AND AWAY FROM THE FORECAST AREA. AS THE UPPER RIDGE BUILDS OVER
THE REGION...PWAT VALUES ARE EXPECTED TO DECREASE FOR THE NEXT
SEVERAL DAYS. HOWEVER...SHOWERS AND A FEW THUNDERSTORMS WILL DEVELOP
EACH DAY OVER WESTERN AND INTERIOR SECTIONS OF PUERTO RICO. A WEAK
TROPICAL WAVE...ALONG 60 WEST THIS MORNING WILL CONTINUE TO MOVE
WESTWARD APPROACHING THE LOCAL ISLANDS ON TUESDAY...INDUCING A
MODEST INCREASE IN CLOUDINESS...SHOWERS AND THUNDERSTORMS OVER THE
LOCAL ISLANDS.

&&

.AVIATION...VFR AT LCL TAF SITES...MOSTLY PASSING -SHRA/SHRA OVR
COASTAL WATERS BTW PR AND NRN LEEWARDS. SCT-BKN LOW CLDS BTW
FL020-FL100...SCT-BKN HI CLDS FL200 MAINLY W-NW OF PR. L/LVL WNDS
MAINLY FM E-NE 5-15 KTS UP FL100...BCMG S-SW 10-20 KTS UP TO FL350.
AFT 31/17Z TYPICAL SCT SHRA/ISOLD TSRA FCST ACROSS CTRL AND W PR NR
TJMZ AND TJBQ...FEW -SHRA/SHRA VCTY REST OF TAF SITES TIL 31/22Z. NO
OTHER SIG OPERATIONAL WX IMPACTS ATTM.

&&

.MARINE...SEAS WILL REMAINS UP TO 5 FEET AND WINDS UP TO 18 KNOTS
ACROSS THE REGIONAL WATERS TODAY. SMALL CRAFT ARE URGED TO
EXERCISE CAUTION ACROSS THE ATLANTIC WATERS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 78 89 79 / 30 30 30 30
STT 88 78 90 80 / 30 40 40 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
246 PM AST SUN AUG 31 2014

.DISCUSSION...SHOWERS CONTINUE ACROSS CWA IN SPITE OF DECREASING
MOISTURE CURRENTLY ARRIVING FROM THE EAST. PRECIPITABLE WATER
PRODUCTS SHOW THAT VALUES HAVE DROPPED OFF TO ABOUT 45 MM (1.77
IN.) AT USVI WITH STILL 48 MM (1.9 IN.) OVER WEST PR. SO NOT A LOT
OF GRADIENT HERE SO NO DRAMATIC DECREASE IN SHOWERS. HOWEVER RADAR
CLEARLY SHOWS THAT THE NUMBER OF SHOWERS HAS DECREASED ON THE
SURROUNDING WATERS SINCE THIS MORNING. WHILE SHOWERS AND THUNDER
ARE INCREASING ACROSS WESTERN PR THEY ARE FEWER THAN OCCURRED ON
SAT. BY 06Z TONIGHT GFS INDICATES THAT PRECIPITABLE WATER WILL
DROP TO 1.5 INCHES THROUGHOUT THE AREA WITH MOST SIGNIFICANT
DRYING ABOVE 850 MB.

SCATTERED SHOWERS STILL EXPECTED BOTH NORTH AND SOUTH OF THE
ISLANDS TONIGHT SINCE BETTER MOISTURE WILL STILL STRADLE THE
BOUNDARIES BUT TRADE WIND SHOWERS TO BE ISOLATED CLOSER TO LAND
WHERE MOISTURE IS MORE CONFINED TO THE BOUNDARY LAYER.

RELATIVELY DRIER WEATHER TO CONTINUE THRU TUE MORNING THEN A REMNANT
TROPICAL WAVE ARRIVES IN AFTERNOON. THE WAVE ITSELF LOOKS NEARLY
FLAT BUT THE MOISTURE WILL STILL PASS OVER. GFS EXPECTS 700 MB
THETA-E TO BE AROUND 331K...CLOSE TO TODAYS VALUE FOR WEST PR.

&&

.AVIATION...SHRA/ISOLD TSRA WILL CONTINUE TO DEVELOP ACROSS WEST
PR AFTER THRU 31/21Z. TEMPO MVFR/IFR POSSIBLE AT TJMZ. MOUNTAIN
OBSCURATION LIKELY ACROSS WEST/INTERIOR PR. VCTS POSSIBLE NEAR
TJPS/TJBQ AND VFR EXPECTED ELSEWHERE. EASTERLY WINDS OF 10-20 KT
EXPECTED THROUGH THE FORECAST PERIOD FM SFC TO FL150.

&&

.MARINE...CONDITIONS REMAIN RATHER QUIET AND MODELS DO NOT INCREASE
WIND OR SEAS VERY MUCH ALL WEEK. GFS SHOWS THE SURFACE PRESSURE
GRADIENT INCREASES SLIGHTLY ON WED LEADING TO A MINOR RISE IN
WINDS AND SEAS (NO MORE THAN 6 FT) BUT THEN BOTH DROP OFF AGAIN
TOWARDS THE END OF THE WEEK AS THE WEST ATLANTIC RIDGE GREATLY
WEAKENS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 89 79 90 / 20 30 30 30
STT 78 90 80 89 / 40 40 30 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
502 AM AST MON SEP 1 2014

.SYNOPSIS...AT UPPER LEVELS...LOW PRESSURE OVER THE BAHAMA ISLANDS
WILL MOVE WESTWARD TODAY THROUGH THURSDAY AND ALLOW A RIDGE OF
HIGH PRESSURE TO SHIFT TO THE U.S. VIRGIN ISLANDS AND PUERTO
RICO. ON THURSDAY...LOW PRESSURE OVER THE WEST CENTRAL ATLANTIC
WILL MOVE SOUTH AND EXPAND OVER THE LOCAL AREA CAUSING WINDS TO
BECOME WEST NORTHWEST AND GENERALLY MORE UNSTABLE CONDITIONS.
OVER THE WEEKEND AND INTO THE FOLLOWING WEEK...THIS LOW PRESSURE
MOVES SOUTHWEST BUT CONTINUES TO DOMINATE THE AREA.

AT MID LEVELS...LOW PRESSURE OVER THE BAHAMAS RETREATS TO THE WEST
DURING THE WEEK...WHILE HIGH PRESSURE TO THE NORTHEAST MOVES WEST
NORTHWEST TOWARD THE ATLANTIC SEA BOARD OF THE UNITED STATES. THIS
HOLDS THE AREA UNDER WEAK HIGH PRESSURE AND WEAK GRADIENTS. OVER
THE WEEKEND AND INTO THE FOLLOWING WEEK A TROUGH FORMS OVER THE
WINDWARD PASSAGE WITH WEAK SOUTHERLY FLOW OVER THE LOCAL AREA.

AT LOWER LEVELS...HIGH PRESSURE OVER THE WEST CENTRAL ATLANTIC
SAGS SOUTH AND WEAKENS CONSIDERABLY DURING THE WEEK WHILE LOW
PRESSURE REMAINS IN THE SOUTHWEST CARIBBEAN. HENCE MODERATE TO
FRESH EASTERLY TRADE WINDS WILL SHIFT TO EAST SOUTHEAST AND WEAKEN
AFTER THURSDAY. SEVERAL BANDS OF MOISTURE IN WEAK TROUGHS OR
WAVES WILL PASS THROUGH MONDAY...TUESDAY...LATE THURSDAY AND
FRIDAY AND AGAIN ON SUNDAY BRINGING SCATTERED TO NUMEROUS SHOWERS
AND SOME AREAS OF HEAVY RAIN.

&&

.DISCUSSION...SHOWERS INCREASED OVER THE LOCAL WATERS OVERNIGHT EXCEPT
IN THE SHADOWS OF PUERTO RICO...BUT DUE TO THEIR SIZE AND MOVEMENT
OF 17 KNOTS...ONLY MINOR ACCUMULATIONS WERE SEEN AND ONLY A FEW
PASSED OVER LAND. AS MENTIONED IN THE SYNOPSIS...SEVERAL BANDS OF
MOISTURE WILL MOVE THROUGH IN THE NEXT 48 HOURS. THE FIRST IS
RELATIVELY SMALL BUT WILL PASS OVER THE AREA INCREASING
PRECIPITABLE WATER VALUES TODAY. ARRIVING AFTER MOST OF THE
HEATING IS ACCOMPLISHED...THIS AREA OF MOISTURE COULD PRODUCE SOME
ACTIVE CONVECTION AND SIGNIFICANT AMOUNTS OF RAIN IN WESTERN
PUERTO RICO INCLUDING SOME LOCALIZED URBAN AND SMALL STREAM
FLOODING. AFTER AN INTERMISSION BETTER MOISTURE FOLLOWS ABOUT 24
HOURS BEHIND AND SHOWERS AND THUNDERSTORMS SHOULD INCREASE ON
TUESDAY. IN FACT THE GFS SHOWS PRECIPITABLE WATER VALUES EXCEEDING
2 INCHES ON TUESDAY AT 02/18Z. MOISTURE THEN ABATES UNTIL THURSDAY
NIGHT. SHOWERS SHOULD INCREASE OVERNIGHT THEN...AT LEAST ON THE
WINDWARD SIDE OF PUERTO RICO AND IN THE U.S. VIRGIN ISLANDS AND
BECOME HEAVY ON FRIDAY. AT THIS TIME MODEL SOLUTIONS SUGGEST THAT
RAINFALL ACCUMULATIONS SHOULD NOT EXCEED URBAN AND SMALL STREAM
FLOODING...ALTHOUGH GREATER AMOUNTS THAN TODAY AND TUESDAY ARE
EXPECTED FRIDAY AS THE TROPICAL WAVE TAKES ON MORE OF AN INVERTED
V SHAPE. ANOTHER BAND OF MOISTURE MOVES THROUGH ON SUNDAY MORNING.

ALTHOUGH THE GFS DOES SHOW TROPICAL CYCLONE FORMATION OUT OF LOW
PRESSURE OFF THE AFRICAN COAST FRIDAY SIMILAR TO THE FALSE ALARMS
OF LAST WEEK. IT MOVES IT NORTH OF 20 NORTH BEFORE 50 WEST BY THE
MIDDLE OF NEXT WEEK WHERE IT WILL NOT BE ABLE TO AFFECT PUERTO
RICO OR THE VIRGIN ISLANDS.

&&

.AVIATION...VFR CONDS AT LOCAL TAF SITES. VCSH AT TJSJ AND LOCAL
ISLANDS THRU MORNING HOURS. THEN IN THE AFTERNOON...SHRA POSSIBLE
WITH CHANCE OF TSRA FOR TJMZ AND VCTS FOR TJBQ TIL AROUND 01/22Z.
WNDS E-SE AT 10-15 KTS FM SFC TO FL200 ON LABOR DAY...WITH SEA
BREEZE VARIATIONS. MTN OBSCURATIONS EXPECTED AFT 01/16Z AREA WIDE...AND
AS EARLY AS 01/10Z OVER THE HIGHEST MTN TOPS OF EL YUNQUE.

&&

.MARINE...SEAS WILL INCREASE TO AS MUCH AS 5 FEET THROUGH
WEDNESDAY AND THEN RETURN TO 3 TO 4 FEET THEREAFTER. SMALL CRAFT
ADVISORIES ARE NOT EXPECTED UNTIL BEYOND AT LEAST NEXT MONDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 79 90 79 / 40 30 40 30
STT 88 79 89 80 / 30 30 40 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
517 AM AST TUE SEP 2 2014

.SYNOPSIS...AT UPPER LEVELS...THE AXIS OF HIGH PRESSURE WILL CROSS
THROUGH THE LOCAL AREA FROM THE EAST AS LOW PRESSURE OVER THE
BAHAMAS MOVES WEST. ANOTHER LOW PRESSURE NORTH OF THE AREA WILL
SINK SOUTH TO ABOUT 25 NORTH BY SUNDAY. THIS LOW WILL MOVE
NORTHWEST AND THEN BACK TO CUBA DURING THE FOLLOWING WEEK.

AT MID LEVELS...HIGH PRESSURE JUST NORTH OF THE LOCAL AREA WILL
RETREAT TO FLORIDA LEAVING A WEAK RIDGE OVER THE AREA. WEAK LOW
PRESSURE WILL APPEAR OVER THE WEEKEND. HIGH PRESSURE WILL THEN
RIDGE IN WEAKLY FROM THE NORTH AND NORTHEAST NEXT WEEK.

AT LOWER LEVELS...HIGH PRESSURE CONTINUES IN THE WESTERN ATLANTIC
THIS WEEK AND INTO THE NEXT. MOISTURE FROM A TROPICAL WAVE THAT
HAS CROSSED THROUGH THE AREA OVERNIGHT WILL MOVE THROUGH TODAY AND
LINGER INTO WEDNESDAY. A SECOND TROPICAL WAVE WILL MOVE THROUGH ON
FRIDAY WITH MOISTURE ON BOTH SIDES OF ITS AXIS WHILE A THIRD WILL
PULL THROUGH THE AREA ON SATURDAY NIGHT KEEPING THE PERIOD
THURSDAY THROUGH SUNDAY RELATIVELY WET. MOISTURE LINGERS THROUGH
MID WEEK NEXT WEEK.

&&

.DISCUSSION...THE MIMIC PRODUCT SHOWED A STRONG GRADIENT OF
MOISTURE MOVING THROUGH SAINT CROIX...SAINT THOMAS AND SAINT JOHN
EARLIER MONDAY NIGHT AS A BAND OF MOISTURE APPROACHES. THERE WERE SHOWERS
ON THE LEADING EDGE. AT 5 AM AST THESE SHOWERS HAD CROSSED THROUGH
THE WATERS SURROUNDING VIEQUES AND CULEBRA AND WERE ABOUT TO ENTER
PUERTO RICO. THE BAND OF MOISTURE RESPONSIBLE FOR THE SHOWER
ACTIVITY IS ABOUT 180 MILES WIDE AND WILL NOT HAVE COMPLETED ITS
TRANSIT OF PUERTO RICO BY LATE THIS AFTERNOON. HENCE...THE WAVE
WILL ENHANCE SHOWERS AND THUNDERSTORMS DURING THE DAY IN EASTERN
PUERTO RICO AND THIS AFTERNOON IN WESTERN PUERTO RICO. ALTHOUGH
RAINFALL AMOUNTS WILL LIKELY NOT BE EXTREME DUE TO THE GOOD
MOVEMENT OF THE SHOWERS THROUGH THE AREA...SOME AREAS MAY RECEIVE
AMOUNTS HEAVY ENOUGH TO CAUSE LOCAL URBAN AND SMALL STREAM
FLOODING. ALSO THE CULEBRINAS RIVER REACHED FLOOD STAGE OVERNIGHT
MONDAY AND MAY DO SO AGAIN TONIGHT AS WIND FLOW HAS NOT CHANGED
SUBSTANTIALLY SINCE YESTERDAY...BUT MOISTURE HAS INCREASED. IN
GENERAL FLOODING WAS VERY MINOR AND THE PUERTO RICO EMERGENCY
MANAGEMENT AGENCY DID NOT REPORT ANY CLOSED ROADS DURING THE
NIGHT. MOISTURE WILL NOT DIMINISH RAPIDLY TONIGHT ALLOWING SHOWERS
TO CONTINUE FORMING EVEN INTO THE EVENING...MAINLY OVER THE LOCAL
WATERS. SHOWERS AND MOISTURE LINGER INTO WEDNESDAY WITH A SHORT BREAK
LATE WEDNESDAY AND WEDNESDAY NIGHT...BUT MOISTURE AND INSTABILITY
BEGIN TO INCREASE ON THURSDAY WITH THE APPROACH OF THE NEXT WAVE.
THIS APPEARS TO HAVE THE MOST MOISTURE AND ALSO ITS PASSAGE WILL
COINCIDE WITH TEMPERATURES AT THE 500 MB LEVEL REACHING MINUS 8
DEGREES FRIDAY FOR ADDED INSTABILITY... ACCORDING TO THE GFS.
MOISTURE CONTINUES TO STREAM ACROSS PUERTO RICO AND THE U.S.
VIRGIN ISLANDS THURSDAY THROUGH WEDNESDAY...BUT FRIDAY AND SUNDAY
WILL HAVE THE MOST ACTIVE CONVECTION DUE TO THE TROPICAL WAVES
MOVING THROUGH THEN.

&&

.AVIATION...VFR CONDS AT LOCAL TAF SITES WITH VCSH AT TJSJ AND LOCAL
ISLANDS THRU MORNING HOURS. THEN TYPICAL AFTERNOON SHRA POSSIBLE WITH
CHANCE OF TSRA FOR TJMZ AND TJBQ TIL AROUND 02/21Z. WINDS E-SE AT
10-15 KTS FM SFC TO FL200 AFT 02/14Z...WITH SEA BREEZE VARIATIONS.
MTN OBSCURATIONS ARE EXPECTED THROUGHOUT THE PERIOD.

&&

.MARINE...SEAS WILL REACH 5 FEET IN PARTS OF OUR ATLANTIC WATERS
BETWEEN NOW AND THURSDAY NIGHT...BUT CONDITIONS IMPROVE
CONSIDERABLY AFTER THAT.`SEAS IN THE CARIBBEAN WILL REMAIN
GENERALLY 3 TO 5 FEET THROUGH EARLY NEXT WEEK. SMALL CRAFT
ADVISORIES ARE NOT EXPECTED DURING THE NEXT 7 DAYS...BUT
THUNDERSTORMS ARE EXPECTED WITH EACH OF THE WAVE
PASSAGES...ESPECIALLY FRIDAY THROUGH SUNDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 89 79 / 60 40 40 50
STT 89 79 89 80 / 50 40 30 50