Caribbean - Central America Weather

[cycloneye]

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
906 PM AST MON APR 13 2009

.UPDATE...CLOUDS AND MOST SHOWERS HAVE MOVED OFFSHORE OFF THE
WESTERN COAST OF PUERTO RICO THIS EVENING AND WILL CONTINUE TO
DRIFT WEST AS THEY DISSIPATE. TERMINAL DOPPLER RADAR SHOWED A LINE
OF CLOUDS ORIENTED NORTHWEST/SOUTHEAST THAT DRIFTED ACROSS MONA
ISLAND DURING THE LAST HOUR. OTHERWISE FEW SHOWERS ARE OBSERVED
ON THE RADAR...A FEW IN THE ATLANTIC AND SOME JUST OFF THE WESTERN
TIP OF VIEQUES. EXPECT CONDITIONS TO BE MOSTLY DRY AS LITTLE
ACTIVITY APPEARS ON THE SATELLITE. PRECIPITABLE WATER IS
RELATIVELY UNIFORM ACROSS OUR AREA.

TOOK ADVANTAGE OF THE LULL IN THE WEATHER TO ADD SOME FEATURES TO
THE FORECAST AND HAVE EXPLAINED THEM BELOW.

&&

.SYNOPSIS...AT UPPER LEVELS...A TROUGH PASSED THROUGH THE AREA
TODAY AND WILL BE FOLLOWED BY THE PASSAGE OF A JET CORE FROM THE
NORTHWEST AS A RIDGE MOVES ACROSS THE AREA ON WEDNESDAY. A SECOND
TROUGH WILL PASS THROUGH ON THURSDAY WITH ANOTHER INCREASE IN
WINDS...THEN ANOTHER TROUGH SAGS INTO THE AREA WITH A STRONGER JET
WHOSE MAXIMUM INFLUENCE WILL CROSS OVER ON SATURDAY NIGHT. RIDGING
INTO THE AREA DOES NOT REALLY BECOME SIGNIFICANT UNTIL THE
FOLLOWING WEDNESDAY LATE.

AT MID LEVELS...A RIDGE THAT EXTENDED FROM THE YUCATAN PENINSULA
TO THE NORTHERN BAHAMAS SPREADS OVER THE NORTHEASTERN CARIBBEAN
AND WEAKENS A LITTLE TONIGHT THROUGH TUESDAY NIGHT. A TROUGH THAT
EXTENDS INTO THE GULF OF MEXICO WILL MOVE EASTWARD...BUT A
SECONDARY TROUGH WILL FORM OVER THE LEEWARD ISLANDS ON THURSDAY
AND OBSCURE ITS PASSAGE OVER US. A SECOND AND BROADER TROUGH MOVES
TOWARD THE AREA ON SATURDAY WITH A PASSAGE SATURDAY NIGHT...BUT
SOME WEAK DIGGING OCCURS TO THE WEST DURING THE FOLLOWING THREE
DAYS AND FLOW DOES NOT RETURN TO NORTHWEST UNTIL THE FOLLOWING
WEDNESDAY. MID LEVELS REMAIN MOSTLY DRY EXCEPT FOR THE TROUGH
PASSAGE SATURDAY NIGHT.

AT LOWER LEVELS...HIGH PRESSURE OVER THE WESTERN ATLANTIC AND
HIGHER PRESSURE OVER THE NORTHEAST ATLANTIC JOIN OVER THE MID
ATLANTIC BY THURSDAY MORNING. A LOW PRESSURE OVER THE EASTERN
UNITED STATES MOVES OVER THE WESTERN ATLANTIC ON WEDNESDAY AND ITS
FRONT APPROACHES THE LOCAL AREA ON SATURDAY WITH POSSIBLE ENTRANCE
TO THE FORECAST AREA SATURDAY NIGHT. HIGH PRESSURE BUILDS WEAKLY
BEHIND IT SUSTAINING THE TRADE WIND FLOW.


&&

.DISCUSSION...SEVERAL FEATURES ARE BEGINNING TO BECOME MORE
CONSISTENT IN THE MODELS. THE PASSAGE OF A THETA-E RIDGE COINCIDES
WITH DIVERGENT FLOW ALOFT THAT WILL LIKELY INCREASE SHOWERS ON THE
EAST COAST OVERNIGHT TUESDAY AND EARLY WEDNESDAY MORNING. A LOW
LEVEL TROUGH WILL PASS THROUGH THEN AND WINDS ARE EXPECTED TO
SHIFT TO THE SOUTHEAST. THIS WILL CAUSE SHOWERS TO SHIFT INTO THE
NORTHWEST QUADRANT OF PUERTO RICO WEDNESDAY AFTERNOON...AND WILL
ALSO HOLD TEMPERATURES A LITTLE WARMER IN THE SAN JUAN PORTION OF
THE ISLAND BOTH WEDNESDAY AND THURSDAY...THE LATTER DAY WHICH
SHOULD ALSO BE A LITTLE DRIER. AS A MUCH STRONGER TROUGH ALOFT
MOVES OVER THE AREA ON SATURDAY...DIVERGENCE ALOFT INCREASES AGAIN
AND A FRONT APPROACHES THE AREA FROM THE NORTHWEST. MODEL
SOLUTIONS HAVE BROUGHT THE FRONT DEEPER INTO THE AREA IN PAST RUNS
AND THE TREND IS NOW FOR A WEAKER INTRUSION OF COOLER AIR AND MORE
TROPICAL AIR TO PUSH OVER THE EASTERN CARIBBEAN FROM THE EAST. NEVERTHELESS THIS
SHOULD GIVE US OUR BEST CHANCES FOR RAIN OF THE ENTIRE WEEK. THE
FRONT IS CURRENTLY BEING PREDICTED TO REACH" onClick="return popup(this, 'notes')">REACH ITS MAXIMUM
SOUTHEASTWARD POSITION SUNDAY AT 06Z AND THEN RETREAT...WITH MOIST
AIR OVER THE SOUTHERN WINDWARD ISLANDS MOVING TOWARD THE AREA ON
THE FOLLOWING WEDNESDAY IN A LONG FILAMENT. THIS
FILAMENT OF MOISTURE BRINGS IN THE BEST THETA-E RIDGE OF THE LAST
SEVERAL MONTHS.

UNFORTUNATELY MODELS ARE NOT PARTICULARLY CONSISTENT AFTER NEXT
WEEKEND AND IT IS DIFFICULT TO SAY JUST HOW RELIABLE THIS LAST
INCREASE OF MOISTURE WILL BE. HAVE ADJUSTED POPS TO REFLECT
CURRENT THINKING. ALSO HAVE RAISED MAXIMUM TEMPERATURES TUESDAY
THROUGH SATURDAY...THOUGH NEVER BY MORE THAN 2 DEGREES.

&&

.AVIATION...CURRENT DRY CONDITIONS ARE EXPECTED TO CONTINUE
THROUGH NEXT 24 HOURS AND MVFR CONDITIONS WILL BE BRIEF IF THEY
OCCUR. ISOLATED MOUNTAIN OBSCURATIONS WILL ALSO OCCUR IN WESTERN
PUERTO RICO BETWEEN 14/17Z AND 15/03Z.

&&

.MARINE...MARINE CONDITIONS REMAIN GENERALLY BELOW SMALL CRAFT
ADVISORY CONDITIONS UNTIL 6 FOOT SWELL MOVES IN FROM THE NORTH ON
SUNDAY AND MONDAY.

http://www.srh.noaa.gov/productview.php ... &version=0

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
623 AM AST TUE APR 14 2009

.DISCUSSION...HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE
WESTERN ATLANTIC AS IT MOVES EASTWARD FOR THE NEXT FEW
DAYS...WHILE MAINTAINING A MODERATE TO FRESH NORTHEASTERLY TRADE
WIND FLOW ACROSS THE LOCAL AREA.

FOR THE NEXT SEVERAL DAYS...EXPECT LIMITED SHOWER ACTIVITY ACROSS
THE LOCAL AREA WITH ONLY PATCHES OF MOISTURE MOVING IN FROM TIME
TO TIME. WESTERN HALF OF PUERTO RICO WILL EXPERIENCE MORE SHOWERS
DURING THE AFTERNOON HOURS DUE TO THE COMBINATION OF LOCAL ISLAND
EFFECTS AND SEA BREEZE CONVERGENCE.

NEXT SIGNIFICANT WEATHER MAKER TO AFFECT THE LOCAL AREA IS EXPECTED
FOR THE UPCOMING WEEKEND AS A FRONTAL BOUNDARY DIGS SOUTHEASTWARD
CURRENTLY LOCATED ACROSS THE SOUTHEAST PART OF THE UNITED STATES.


&&

.AVIATION...MAINLY VFR CONDITIONS ACROSS THE LOCAL ISLANDS AND AT ALL
LOCAL TAF SITES THROUGHOUT THE FORECAST PERIOD. WEAK TROF OVER THE
WINDWARD ISLANDS MAY PROVOKE SOME BRIEF PERIODS OF MVFR IN OR AROUND
TKPK AND POSSIBLY TNCM OVERNIGHT.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
509 AM AST WED APR 15 2009

.SYNOPSIS...
SURFACE HIGH PRESSURE CENTERED ACROSS THE WEST CENTRAL ATLANTIC WILL
SLOWLY SHIFT EAST OVER THE NEXT FEW DAYS...AND EVENTUALLY MERGE
WITH ANOTHER HIGH CENTERED ACROSS THE NORTHEAST ATLANTIC BY THE
END OF THE WEEK. THIS WILL MAINTAIN A MODERATE TRADE WIND FLOW
ACROSS THE REGION AT LEAST THROUGH THURSDAY. A COLD FRONT EXITING
THE EASTERN SEABOARD OF THE UNITED STATES THIS MORNING WILL CONTINUE
EASTWARD ACROSS THE WESTERN ATLANTIC THROUGH THE FRIDAY...THEN STALL
JUST NORTH OF THE REGION BY SATURDAY. TRAILING HIGH PRESSURE WILL
THEN QUICKLY BUILD ACROSS THE WEST AND SOUTHWEST ATLANTIC DURING
THE REMAINDER OF THE WEEKEND.

&&

.DISCUSSION...
ALTHOUGH A RELATIVELY DRY AND STABLE AIRMASS WILL PREVAIL ACROSS THE
REGION OVER THE NEXT SEVERAL DAYS...LATEST SATELLITE IMAGERY SHOWED
A FAIR AMOUNT OF LOW LEVEL MOISTURE ACCOMPANYING A WEAK EASTERLY
PERTURBATION NOW MOVING ACROSS THE NORTHEAST CARIBBEAN. THIS
FEATURE WILL CONTINUE TO CROSS THE AREA TODAY...AND WILL AID IN
ENHANCING THE DIURNALLY DRIVEN CONVECTION ACROSS PARTS OF THE
INTERIOR AND WEST SECTIONS OF PUERTO RICO DURING THE AFTERNOON.
THIS WILL BE FOLLOWED BY MAINLY FAIR WEATHER SKIES...AND A
GENERALLY DRY WEATHER PATTERN WITH ONLY LIMITED PASSING SHOWER
ACTIVITY ACROSS THE REST OF THE LOCAL ISLANDS AND SURROUNDING
WATERS THROUGH THE END OF THE WEEK.

FAIRLY STRONG HIGH PRESSURE TRAILING THE AFOREMENTIONED COLD FRONT
IS FORECAST TO INDUCE MORE OF A NORTHEASTERLY WIND FLOW ACROSS THE
LOCAL AREA BY SUNDAY. THIS WILL EVENTUALLY BRING FRAGMENTS OF FRONTAL
MOISTURE ACROSS THE LOCAL WATERS AND OVER THE COASTAL SECTION OF SOME
OF THE ISLANDS ESPECIALLY DURING THE EARLY MORNING HOURS. HOWEVER...THE
WEAK PRESSURE GRADIENT ACROSS THE REGION DURING THE WEEKEND AND LIGHT
WIND FLOW...SHOULD ALLOW FOR GOOD SEA BREEZE CONVERGENCE...AND DIURNALLY
INDUCED SHOWER ACTIVITY MAINLY ACROSS PARTS OF THE WEST INTERIOR OF
PUERTO RICO OVER THE WEEKEND.

&&

.AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS ALL THE LOCAL TAF
SITES THIS MORNING. TYPICAL SEA BREEZE CONVERGENCE WILL RESULT IN
THE DEVELOPMENT OF DIURNAL CONVECTION OVER THE INTERIOR OF PR THIS
AFTERNOON...RESULTING IN TEMPORARY MVFR CONDITIONS ACROSS TJBQ AND
TJMZ FROM 17-22Z...ALONG WITH MOUNTAIN OBSCURATIONS ACROSS THE
INTERIOR OF THE ISLAND. LATEST TJSJ 00Z SOUNDING INDICATED A
SOUTHEASTERLY WIND FLOW UP TO 25 KNOTS...FROM THE SURFACE TO
AROUND 20K FEET...BECOMING WEST NORTHWESTERLY AND STRONGER ALOFT.

&&

.MARINE...
SMALL CRAFTS ARE URGED TO EXERCISE CAUTION ACROSS THE LOCAL OFFSHORE
ATLANTIC WATERS...ALL PASSAGES AND THE OFFSHORE CARIBBEAN WATERS AT
LEAST THROUGH THURSDAY...WHERE WINDS UP TO 19 KNOTS AND SEAS UP TO
6 FEET CAN BE EXPECTED.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
231 PM AST THU APR 16 2009

.DISCUSSION...
CURRENT SATELLITE ANALYSIS DEPICTS A STRONG UPPER LEVEL SOUTHWEST
TO NORTHEAST ORIENTED SUBTROPICAL JET STREAK ACROSS THE AREA. THE
LATEST GFS RUN SHOWS THIS STREAK TO BE ROUGHLY 70 KNOTS JUST NORTH
OF THE ISLANDS. AT THE LOWER LEVELS...STRONG SOUTHEASTERLIES ARE
CROSSING THE FORECAST AREA HELPING TO INCREASE THE TEMPERATURE AT
THE SAN JUAN INTERNATIONAL AIRPORT. AS THESE WINDS TRAVERSE THE
ISLAND...COMPRESSIONAL HEATING ON THE LEE SIDE OF THE TERRAIN IS
INCREASING THE TEMPERATURES ALONG THE NORTH SIDE OF THE ISLAND.
WITHIN THE PAST HOUR...THE TEMPERATURE AT THE AIRPORT REACHED 91
DEGREES WITH THE RECORD STANDING AT 93 DEGREES BEFORE COOLING
SLIGHTLY. THE SEABREEZE FRONT IS SETTING UP ALONG THE NORTHWEST
SIDE OF THE ISLAND...WHICH SHOULD HELP INITIATE SHOWERS ALONG THE
PREFERRED REGIONS DOWN WIND OF THE HIGHER TERRAIN.

SYNOPTICALLY...THE NEXT MAJOR WEATHER FEATURE WILL BE THE TROUGH
AND ASSOCIATED COLD FRONT THAT IS CURRENTLY OFF THE EAST COAST OF
THE UNITED STATES. AS THE SURFACE ANTICYCLONE ACROSS THE CENTRAL
ATLANTIC SHIFTS EASTWARD...AND A STRONG SURFACE HIGH OVER THE
SOUTHEAST UNITED STATES PUSHES SOUTHEASTWARD...EXPECT THIS FRONT
TO INVADE THE NORTHERN FORECAST AREA BY SATURDAY EVENING. AS IT
DOES SO...THE SUBTROPICAL JET WILL BE REPLACED BY THE STRONGER
POLAR JET. THIS JET SHOULD AID IN THE MAINTENANCE THE FRONT AS IT
SINKS SOUTH INTO THE AREA. EXPECT AN INCREASE IN SHOWERS AND WAVE
HEIGHTS ACROSS THE AREA...ESPECIALLY THE NORTHERN FORECAST AREA.
WIDESPREAD FLOODING RAINS ARE NOT ANTICIPATED.

AFTERWARDS...THE NEW WORK WEEK LOOKS FAIRLY PLEASANT WITH TYPICAL
MESOSCALE DIURNAL SEABREEZE EFFECTS ENHANCING PRECIPITATION ALONG
THE PREFERRED REGIONS ACROSS PUERTO RICO.

&&

.AVIATION...
BRIEF PERIODS OF MVFR CONDITIONS DUE TO CEILINGS AND LIGHT TO
MODERATE SHOWERS ARE EXPECTED AT TJMZ AND TJBQ UNTIL AT LEAST
16/22Z. AFTER THAT...EXPECT PREVAILING VFR CONDITIONS ACROSS THE
LOCAL ISLANDS AND AT ALL LOCAL TAF SITES. LATEST TJSJ 12Z SOUNDING
INDICATED A LIGHT SOUTHEAST WIND FLOW UP TO 15 KNOTS FROM THE
SURFACE TO AROUND 10K FEET...BECOMING WESTERLY AND STRONGER ABOVE
THAT LEVEL.

&&

.MARINE...
TRANQUIL MARINE CONDITIONS WILL DOMINATE THE PERIOD THROUGH
SATURDAY MORNING. BY SATURDAY AFTERNOON AND EVENING...INCREASED
WAVE HEIGHTS AND SWELLS ARE EXPECTED TO INVADE THE LOCAL AREA FROM
NORTHWEST TO SOUTHEAST AS A RESULT OF A COLD FRONT NOW LOCATED OFF
THE EAST COAST OF THE UNITED STATES. AS THIS COLD FRONT SINKS
SOUTHEASTWARD...NORTHERLY SWELLS WILL USHER IN BEHIND
IT...INCREASING SEAS FOR THE WEEKEND. THIS HEIGHTENED SEA ACTIVITY
WILL BE SHORT-LIVED AS SEAS SHOULD BEGIN TO SUBSIDE BY THE NEW
WORK WEEK.

http://www.srh.noaa.gov/productview.php ... &version=0

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
536 AM AST FRI APR 17 2009

.SYNOPSIS...
GFS MODEL GUIDANCE CONTINUE TO SUGGEST A GRADUAL AMPLIFICATION OF
THE MID TO UPPER LEVEL LONG WAVE TROUGH ACROSS THE WESTERN ATLANTIC
OVER THE NEXT FEW DAYS AS IT SHIFTS EASTWARDS. THE TROUGH IS SUPPORTED
BY AN AREA OF LOW PRESSURE...AND ASSOCIATED COLD FRONT WHICH EXTENDS
SOUTHWEST ACROSS THE CENTRAL BAHAMAS. EXPECT THE FRONTAL SYSTEM TO
LIFT EAST NORTHEAST ACROSS THE WEST ATLANTIC WHILE SLOWLY DISSIPATING
OVER THE NEXT FEW DAYS. BY LATE SATURDAY INTO SUNDAY...EXPECT REMNANTS
OF THE FRONTAL BOUNDARY/SHEAR LINE AND ASSOCIATED BAND OF MOISTURE TO
SAG JUST NORTH OF THE AREA...THEN TO BE EVENTUALLY BE PUSHED SOUTHWARDS
ACROSS THE LOCAL OFFSHORE ATLANTIC...AS AN INDUCED TROUGH SETS UP NORTHWEST
OF THE AREA...AND ANOTHER STRONG AREA OF HIGH PRESSURE BUILDS AND SPREADS
ACROSS THE WEST AND SOUTHWEST ATLANTIC.

&&

.DISCUSSION...
LATEST SATELLITE IMAGERY SHOWED A SMALL AREA OF MOISTURE ASSOCIATED
WITH A WEAKLY INDUCED LOW LEVEL TROUGH MOVING ACROSS THE LOCAL AREA
DURING THE EARLY MORNING. WHILE MOST OF THE ACCOMPANYING SHOWER
ACTIVITY WILL MOVE WEST NORTHWEST ACROSS THE OFFSHORE COASTAL
CARIBBEAN WATERS...EXPECT SOME CLOUDINESS AND A FEW ISOLATED
SHOWERS TO REACH" onClick="return popup(this, 'notes')">REACH THE EAST AND SOUTHERN COASTAL AREAS DURING THE
REST OF THE MORNING HOURS. NO SIGNIFICANT RAINFALL IS HOWEVER
EXPECTED AS LOCAL LAND BREEZE EFFECT WILL MAINTAIN MUCH OF THE
ACTIVITY OFFSHORE. DURING THE REST OF THE DAY...LOCAL TERRAIN AND
DIURNAL EFFECTS WILL COMBINE WITH AVAILABLE POCKETS OF MOISTURE
MAINLY ACROSS PUERTO RICO...TO PRODUCE AND ENHANCE AFTERNOON
CONVECTION WHICH WILL BE FOCUSED ACROSS THE NORTHWEST INTERIOR
SECTION OF THE ISLANDS.

AS THE AFOREMENTIONED SYNOPTIC PATTERN UNFOLDS OVER THE WEEKEND...
EXPECT A SLIGHT INCREASE IN THE CHANCE OF LOCALIZED CONVECTION
ACROSS PARTS OF THE ISLANDS ESPECIALLY DURING THE TIME OF MAX
HEATING. THE INCREASED EAST NORTHEAST WIND FLOW BY SUNDAY SHOULD
ALLOW FOR OCCASIONAL PATCHES OF FRONTAL REMNANT MOISTURE TO BE
TRANSPORTED SOUTHWARD ACROSS THE LOCAL AREA FROM TIME TO TIME. IN
ADDITION...THE PROXIMITY OF THE BROAD MID TO UPPER LEVEL TROUGH
SHOULD ENHANCE AFTERNOON CONVECTION ESPECIALLY ACROSS THE WEST
SECTIONS OF PUERTO RICO. HOWEVER...OVERALL MOISTURE INFLUX AND
INSTABILITY WILL BE LIMITED...AND DO NOT FORESEE ANY WIDESPREAD
RAINFALL OVER THE NEXT SEVERAL DAYS...OTHER THAN ISOLATED AREAS OF
LOCALIZED MODERATE TO HEAVY RAINFALL.

&&

.AVIATION...
MOSTLY VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS ALL THE
LOCAL TAF SITES THIS MORNING. TYPICAL SEA BREEZE CONVERGENCE WILL
RESULT IN THE DEVELOPMENT OF DIURNAL CONVECTION OVER THE INTERIOR
AND NORTHWEST SECTIONS OF PR THIS AFTERNOON...RESULTING IN TEMPORARY
MVFR CONDITIONS ACROSS TJBQ AND TJMZ FROM 17-22Z...ALONG WITH
MOUNTAIN OBSCURATIONS ACROSS THE INTERIOR OF THE ISLAND. LATEST
TJSJ 00Z SOUNDING INDICATED A LIGHT AND VARIABLE WIND FLOW FROM
THE SURFACE TO AROUND 10K FEET...BECOMING WESTERLY AND STRONGER
ABOVE THAT LEVEL.

&&

.MARINE...
ACROSS THE LOCAL WATERS EXPECT SEAS OF 4 FEET OR LESS...AND WINDS
OF 14 KNOTS OR LESS AT LEAST THROUGH SATURDAY. SLIGHTLY INCREASING
WINDS AND SEAS...AND A NORTHERLY SWELL ARE EXPECTED TO IMPACT THE
LOCAL ATLANTIC WATERS AND CARIBBEAN PASSAGES BY SUNDAY.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
524 AM AST SAT APR 18 2009

.DISCUSSION...LATEST RADAR OBSERVATIONS AND SATELLITE IMAGES EARLY
THIS MORNING INDICATED A SMALL AREA OF CLOUDINESS WITH MINIMAL
SHOWERS ACTIVITY JUST ACROSS PUERTO RICO. THIS FEATURE IS
ASSOCIATED WITH A WEAK SURFACE TROUGH MOVING ACROSS THE REGION.
ACCORDINGLY WITH GFS MODEL GUIDANCE...THIS TROUGH WILL TRACK WESTWARD
DISSIPATING LATER IN THE DAY ACROSS EASTERN HISPANIOLA.

THE GFS MODEL GUIDANCE ALSO SUGGESTS THAT A MID TO UPPER LEVEL
LONG WAVE TROUGH ACROSS THE WESTERN ATLANTIC EARLY THIS MORNING...
WILL SHIFT EAST SOUTHEASTWARD ACROSS THE LOCAL REGION AND THE
CENTRAL ATLANTIC DURING THE NEXT FEW DAYS. AN ASSOCIATED WEAKENING
COLD FRONT EXTENDING FROM THE NORTHERN HISPANIOLA EAST NORTHEASTWARD
ACROSS THE CENTRAL ATLANTIC AND INTO A LOW PRESSURE CENTER NEAR 45
NORTH...34 WEST THIS MORNING...IS FORECAST TO MOVE SLOWLY EAST
SOUTHEASTWARD TODAY AND TONIGHT...DISSIPATING JUST OVER THE
ATLANTIC WATERS NORTH OF THE REGION DURING THE REST OF THE WEEKEND
AND EARLY NEXT WEEK. A SURFACE HIGH PRESSURE ACROSS THE SOUTHWESTERN
ATLANTIC THIS MORNING...WILL BUILD EASTWARD ACROSS THE CENTRAL
ATLANTIC NORTH OF THE REGION DURING THE NEXT FEW DAYS...INCREASING THE
WINDS ACROSS THE REGION AND PUSHING SOME MOISTURE...REMNANTS OF
THE DISSIPATING FRONTAL FRONTAL BOUNDARY...ACROSS THE LOCAL
ISLANDS. THUS...AN INCREASE IN LOW LEVEL MOISTURE IS EXPECTED FOR
THE NEXT FEW DAYS. THIS MOISTURE IN COMBINATION WITH DAYTIME
HEATING...LOCAL TERRAIN EFFECTS AND GOOD UPPER LEVEL DYNAMIC
PROVIDED BY THE UPPER TROUGH...WILL INDUCE THE DEVELOPMENT OF
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ESPECIALLY ACROSS
WESTERN AND INTERIOR SECTIONS OF PUERTO RICO DURING THE
AFTERNOONS. LIMITED SHOWERS ACTIVITY IS EXPECTED ELSEWHERE ACROSS
PUERTO RICO AND THE U.S. VIRGIN ISLANDS.

&&

.AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS THE LOCAL FLYING AREA
AND AT ALL LOCAL TAF SITES DURING THE MORNING HOURS. DURING THE
AFTERNOON...LOCAL TERRAIN AND DIURNALLY INDUCED CONVECTION CAN BE
EXPECTED ACROSS PARTS OF THE WEST AND NORTHWEST SECTIONS OF PUERTO
RICO. SOME OF THE SHOWERS AND ISOLATED THUNDERSTORMS WILL LEAD TO
INCREASED AFTERNOON CLOUDINESS ALONG THE CORDILLERA CENTRAL AND
BRIEF MVFR CONDITIONS BTWN 18-22Z MAINLY IN AND AROUND TJBQ...TJMZ
AND TJPS. NO OTHER OPERATIONAL IMPACT EXPECTED THEREAFTER.

&&

.MARINE...ACROSS THE REGIONAL WATERS...EXPECT WINDS OF 13 KNOTS
OR LESS AND SEAS OF 4 FEET OR LESS TODAY. SLIGHTLY INCREASING
SEAS IN NORTH SWELLS ARE EXPECTED TO IMPACT THE LOCAL ATLANTIC
WATERS AND CARIBBEAN PASSAGES LATE TONIGHT AND SUNDAY AND
PRECAUTIONARY STATEMENTS AND/OR SMALL CRAFT ADVISORIES WILL BE
NEEDED FOR THOSE WATERS.

[cycloneye]

Code: Select all

ASCA42 TJSJ 190110
RWRPR
PUERTO RICO/U.S. VIRGIN ISLANDS HOURLY WEATHER ROUNDUP
NATIONAL WEATHER SERVICE SAN JUAN PR
900 PM AST SAT APR 18 2009

PRZ001-004-190200-
PUERTO RICO

CITY           SKY/WX    TMP DP  RH WIND       PRES   REMARKS
SAN JUAN LMM   MOCLDY    79  72  78 E6        29.95R
PONCE          MOCLDY    75  66  73 CALM      29.91
AGUADILLA      PTCLDY    75  70  83 CALM      29.97R
$$


[cycloneye]

Gustywind,I saw your thread at Talking Tropics about what is going on in Guadeloupe,but here in PR,we are also getting plenty of showers and some thunder as a frontal trough moves thru.

[Gustywind]

Gustywind,I saw your thread at Talking Tropics about what is going on in Guadeloupe,but here in PR,we are also getting plenty of showers and some thunder as a frontal trough moves thru.

OK tkanks my friend for this info, humm thunder too... not too funny, no thunder here, but continious rain not copious hope no more... Have a good night Luis!

[cycloneye]

--------------------------------------------------------------------------------

FLASH FLOOD WARNING
PRC091-190645-
/O.NEW.TJSJ.FF.W.0008.090419T0248Z-090419T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN JUAN PR
1048 PM AST SAT APR 18 2009

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED A

* FLASH FLOOD WARNING FOR...
THE FOLLOWING MUNICIPALITY

IN PUERTO RICO
MANATI

* UNTIL 245 AM AST

* AT 1042 PM AST...A U.S.G.S. RIVER GAGE SENSOR ALONG THE RIO GRANDE
DE MANATI IN MANATI WAS INDICATING THE RIVER WAS RAPIDLY APPROACHING
FLOOD STAGE...AND CONTINUING TO RISE. WITH ADDITIONAL PERIODS OF
MODERATE TO HEAVY RAINFALL EXPECTED ACROSS THIS AREA THROUGH THE
EARLY MORNING HOURS...RESIDENTS AND MOTORISTS CAN EXPECT FLOODING
ALONG THE RIO GRANDE DE MANATI AND ITS TRIBUTARIES THROUGH AT LEAST
245 AM AST.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. DO NOT DRIVE YOUR VEHICLE
INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER DEPTH MAY
BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. MOVE TO HIGHER
GROUND.

LAT...LON 1847 6651 1845 6651 1838 6648 1838 6650
1844 6655 1848 6655

$$

SR

[cycloneye]

FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN JUAN PR
544 AM AST SUN APR 19 2009

.DISCUSSION...SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS
PERSISTED OVERNIGHT AND EARLY IN THE MORNING ACROSS THE NORTHERN
AND NORTHEASTERN SECTIONS OF PUERTO RICO AND ACROSS THE SURROUNDING
COASTAL WATERS. SEVERAL RIVERS ALONG THE NORTHERN SECTIONS OF PUERTO
RICO WERE OUT OF ITS BANKS OVERNIGHT. ALSO SEVERAL URBAN AND SMALL
STREAM FLOOD ADVISORIES AND FLASH FLOOD WARNING WERE ISSUED...
EXTENDED/CANCELLED OVERNIGHT AND EARLY IN THE MORNING...MAKING THIS
SHIFT UNUSUALLY BUSY FOR THIS TIME OF THE YEAR.

A MID TO UPPER LEVEL LONG WAVE TROUGH EXTENDING FROM THE CENTRAL
CARIBBEAN ACROSS THE LOCAL REGION AND THE CENTRAL ATLANTIC THIS
MORNING WILL SHIFT EASTWARD DURING THE NEXT FEW DAYS. AT THE SAME
TIME...A DISSIPATING COLD FRONT EXTENDING FROM SOUTHERN HISPANIOLA AND
PUERTO RICO EAST NORTHEASTWARD ACROSS THE CENTRAL ATLANTIC THIS
MORNING...IS FORECAST TO MOVE EAST SOUTHEASTWARD TODAY AND
TONIGHT. THE GFS MODEL GUIDANCE INDICATED THAT THE SHEAR LINE OR
CONVERGENCE ZONE ASSOCIATED WITH THE FRONTAL TROUGH WAS JUST
ACROSS PUERTO RICO BY 06Z SUNDAY MORNING. GFS MODEL GUIDANCE ALSO
INDICATED THAT THE ASSOCIATED AREA OF MOISTURE...EXTENDING FROM
EASTERN HISPANIOLA EASTWARD ACROSS PUERTO RICO AND THE U.S. VIRGIN
ISLANDS...WILL MOVE SLOWLY EASTWARD TODAY AND TONIGHT. THE SURFACE
HIGH PRESSURE ACROSS THE SOUTHWESTERN ATLANTIC THIS MORNING WILL
MOVE EASTWARD ACROSS THE CENTRAL ATLANTIC TODAY...PUSHING THE REMNANTS
OF THE FRONTAL BOUNDARY ACROSS THE FA. THIS MOISTURE IN
COMBINATION WITH DAYTIME HEATING...LOCAL TERRAIN EFFECTS AND GOOD
UPPER LEVEL DYNAMIC PROVIDED BY THE MID TO UPPER UPPER TROUGH...
WILL INDUCE THE DEVELOPMENT OF SCATTERED TO NUMEROUS SHOWERS AND
ISOLATED THUNDERSTORMS ESPECIALLY ACROSS WESTERN AND INTERIOR
PUERTO RICO THIS AFTERNOON. THE HEAVY CLOUD COVER ACROSS
THE FA EARLY THIS MORNING...WILL ACT TO INHIBIT SOME OF THE
EXPECTED CONVECTION ACROSS WESTERN AND INTERIOR PUERTO RICO THIS
AFTERNOON.

AN INCREASE IN WINDS ARE ALSO EXPECTED ACROSS THE FA TODAY. GFS
SUGGESTS THAT SOME LINGERING MOISTURE WILL PREVAIL ACROSS THE FA
AT LEAST UNTIL TUESDAY WITH A DRIER TRENDS EXPECTED FOR THE MIDDLE
OF THE WORK WEEK.

&&

.AVIATION...LOW TO MID LEVEL CLOUDINESS WILL CONTINUE ACROSS THE
LOCAL FLYING AREA...AS OCCASIONAL BANDS OF MOISTURE ASSOCIATED WITH
AN APPROACHING FRONTAL BOUNDARY SINKS SOUTHWARDS ACROSS THE REGION.
PREVAILING VFR CONDITIONS CAN BE EXPECTED ACROSS MOST OF THE THE
LOCAL TAF SITES. HOWEVER...EXPECT OCCASIONAL MVFR CONDITIONS AT
LEAST UNTIL 12Z...AS SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP
JUST OFF SHORE OF THE NORTH COAST OF PUERTO RICO...AND DRIFT
SOUTHWARDS TOWARDS THE COASTAL AREAS. AS A RESULT...TJSJ...TJBQ...
TJNR WILL BE AFFECTED DURING THE EARLY MORNING HOURS. TIST AND TISX
MAY SEE SOME EARLY MORNING SHOWERS BUT MVFR CONDITIONS WILL BE OF
SHORT DURATION...AS THE MAJORITY OF THE CONVECTION WILL BE IN AND
AROUND PUERTO RICO. DURING THE REST OF THE DAY...EXPECT SHOWERS AND
ISOLATED THUNDERSTORMS TO DEVELOP ACROSS PARTS OF THE INTERIOR
SECTION OF PUERTO RICO. THIS WILL AGAIN RESULT IN BRIEF PERIODS OF
MVFR CONDITIONS BTWN 18-22Z MAINLY IN AND AROUND TJBQ AND TJMZ.

&&

.MARINE...LONG PERIOD NORTHERLY SWELLS HAVE BEGUN TO INVADE THE
LOCAL ATLANTIC WATERS OVERNIGHT...AND ARE EXPECTED TO PEAK
BETWEEN 5 AND 7 FEET ACROSS THE OFFSHORE ATLANTIC WATERS AND
CARIBBEAN PASSAGES TONIGHT. A SMALL CRAFT ADVISORY IS IN EFFECT FOR
THE LOCAL OFFSHORE ATLANTIC WATERS UNTIL MONDAY NIGHT.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
546 AM AST MON APR 20 2009

.SYNOPSIS...AT UPPER LEVELS...A RIDGE IS BUILDING OVER THE LOCAL
AREA AND WILL HOLD THROUGH THE WEEK. A TROUGH WILL APPROACH PUERTO
RICO EARLY NEXT WEEK ACCOMPANIED BY AN 80 KNOT JET.

AT MID LEVELS...HIGH PRESSURE WILL BUILD EAST OF THE LESSER
ANTILLES AND SPREAD NORTH AND WEST OVER THE ATLANTIC AND EASTERN
CARIBBEAN THROUGH THURSDAY. THEN OVER THE WEEKEND THE FOCUS OF THE
HIGH WILL SHIFT TO THE WESTERN CARIBBEAN. BEGINNING ON THE
FOLLOWING MONDAY A TROUGH WILL MOVE OUT OF FLORIDA AND INTO HAITI
BY THURSDAY. AIR AT MID LEVELS REMAINS DRY THROUGH NEXT WEEKEND
EXCEPT FOR LOWER INTRUSIONS OF MOISTURE TUESDAY AND WEDNESDAY.

AT LOWER LEVELS...A COLD FRONT IS DISSIPATING OVER ATLANTIC WATERS
JUST NORTH OF PUERTO RICO AND THE U.S. VIRGIN ISLANDS. AS IT
RECEDES TO THE NORTH...MOIST TROPICAL AIR WILL CONTINUE TO FLOW OVER
THE AREA AND WINDS WILL INCREASE SOMEWHAT. MOISTURE REMAINS BETTER
THAN LAST WEEK FOR THE DURATION OF THE FORECAST PERIOD WITH ONLY
ONE BRIEF EXCEPTION...AND THAT MAY DISAPPEAR IN THE NEXT MODEL
RUN.

&&

.DISCUSSION...ALTHOUGH A FEW SHOWERS HAVE APPEARED IN BOTH THE
ATLANTIC AND CARIBBEAN WATERS OVERNIGHT...THE BEST ACTIVITY
OCCURRED EARLY YESTERDAY EVENING AND DURING THE DAY YESTERDAY. FOR
TODAY...MODELS HINT AT A LITTLE STRONGER SOUTHERLY COMPONENT IN
THE LOW LEVEL WINDS EVEN WHILE THE SURFACE WINDS EXHIBIT STRONG
SEA BREEZES. THIS SHOULD PUSH CONVECTION INLAND DURING THE DAY AND
BRING A GOOD CHANCE OF SHOWERS TO THE WESTERN INTERIOR WITH
ISOLATED THUNDERSTORMS. 1000-850 MB THICKNESSES...DECREASE TUESDAY
THROUGH THURSDAY AND IT IS NOT CLEAR WHY...BECAUSE MOS
TEMPERATURES IN THE AREA WILL REMAIN FAIRLY STEADY OR RISE
SLIGHTLY. WITH CLOUDS AND SOME SEA BREEZE SAN JUAN REACHED 85
YESTERDAY AND NOW THAT MOISTURE IS DIMINISHING...AND WINDS ARE
TURNING TOWARD THE SOUTHEAST...EXPECT TEMPERATURES TO WARM BOTH
TODAY AND TOMORROW BACK INTO THE UPPER 80S. SCATTERED SHOWERS IN
THE EAST DURING THE EARLY MORNINGS AND LATE AFTERNOONS...AND
NUMEROUS SHOWERS IN THE AFTERNOONS IN WESTERN PUERTO RICO SHOULD
BE THE GENERAL RULE FOR THE PATTERN EXPECTED THROUGH NEXT WEEKEND.
SOME THUNDERSTORMS ARE ALSO POSSIBLE IN THE AREAS WITH THE BEST
SHOWERS. CURRENT INDICATIONS ARE THAT TUESDAY WILL BE MORE ACTIVE
THAN TODAY...MONDAY.

&&

.AVIATION...GENERALLY VFR CONDITIONS CAN BE EXPECTED ACROSS THE LOCAL
TAF SITES THROUGHOUT THE NEXT 24 HOURS WITH THE EXCEPTION OF BRIEF
PERIODS OF MVFR CONDITIONS FOR TJMZ AND TJBQ FROM 18Z UNTIL 21Z AS
MODERATE TO LOCALLY HEAVY SHOWERS AND ISOLATED THUNDERSTORMS MOVE
FROM THE WESTERN INTERIOR SECTION OF THE ISLAND TOWARD THE
NORTHWEST. EXPECT MOUNTAIN OBSCURATIONS IN WESTERN PUERTO RICO
DURING THE SAME TIME PERIOD.

&&

.MARINE...WINDS WILL INCREASE OVER COASTAL WATERS TODAY THROUGH
WEDNESDAY AND CAUSE SEAS IN THE SOUTHERN PORTION OF THE CARIBBEAN
FORECAST ZONES TO REACH" onClick="return popup(this, 'notes')">REACH 7 FEET. WITH ONLY 6 SECOND PERIODS THIS
WILL CAUSE VERY CHOPPY CONDITIONS. IN THE ATLANTIC WAVE HEIGHT
HAS PEAKED NEAR 8 FEET AND WILL SLOWLY SUBSIDE THROUGH THURSDAY.

[cycloneye]

211850
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
250 PM AST TUE APR 21 2009

.SYNOPSIS...STRONG HIGH PRES S OF NEWFOUNDLAND WITH RIDGE
EXTENDING INTO THE NORTHEAST CARIBBEAN WILL MAINTAIN FRESH TRADES
ACROSS THE REGION. ALOFT...MID LVL RIDGE TO COLLAPSE BY THE END OF
THE WEEK AS A DEEP LYR TROUGH PASSES TO THE NORTH.

&&

.DISCUSSION...CONVECTION TO EXHIBIT A SHARP DOWNWARD TREND
THROUGH THU AS MID-LVL CAP STRENGTHENS/LOWERS IN RESPONSE TO
STRENGTHENING SFC TO MID-LVL RIDGE NORTHEAST OF THE REGION.
MOISTURE BEGINS TO INCREASE AGAIN ON FRI BUT REMAINS NEAR
CLIMATOLOGICAL VALUES. MOISTURE PEAKS ON SUN WITH PWATS VALUES
CLIMBING TO NEAR 2.0 INCHES OR ABOVE 140% OF NORMAL. IN
ADDITION...CUTOFF LOW ALSO FCST TO EVOLVE NORTH OF THE BAHAMAS OVR
THE WEEKEND WILL RESULT IN AN INCREASE IN MID LYR INSTABILITY AND
UPPER LVL DIVERGENCE TO HELP SUSTAIN DEEP CONVECTION.

&&

.AVIATION...TSRA WITH MVFR TO IFR CONDITIONS AT TJBQ AND POSSIBLY
TJMZ UNTIL AROUND 22Z. AFTERWARDS...AND AT ALL OTHER SITES VFR.

&&

.MARINE...EXERCISE CAUTION STATEMENTS REMAIN IN EFFECT FOR MOST
ZONES AND LIKELY TO REMAIN IN EFFECT FOR THE NEXT FEW DAYS FOR
BRISK EASTERLY WINDS.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
308 PM AST WED APR 22 2009

.SYNOPSIS...STRONG SFC HIGH PRES ACROSS THE N ATLC TO MAINTAIN
FRESH TRADES ACROSS THE REGION FOR THE NEXT FEW DAYS. ALOFT...MID
LEVEL RIDGING TO COLLAPSE BY SAT AS STRONG TROUGH LIFTS TO THE NORTH.
LARGE MID-UPPER LVL CUTOFF LOW TO FORM NORTH OF THE AREA OVR THE
WEEKEND AS ADDITIONAL S/W ENERGY DROPS SOUTH.

&&

.DISCUSSION...LATEST RADAR/SATELLITE COMPOSITE INDICATES A MARKED
DECREASE IN AFTN CONVECTION WHEN COMPARED TO 24 HRS AGO WITH ISOLD
SHRAS OVR WRN PR AND MUCH LOWER CLOUD TOPS. AMS TO DRY OUT EVEN MORE
NEXT 24 HRS WITH PWAT VALUES DROPPING BELOW AN INCH AND SUBSIDENCE
INVERSION STRENGHTENING/LOWERING TO BELOW H7 AS RIDGE TO THE NORTH
REMAINS STRONG AND ADVECTS DRIER AIR.

MOISTURE TO INCREASE AGAIN ON FRI BUT MORE SO ON SAT AND INTO NEXT
WEEK WITH PWAT VALUES CLIMBING TO BETWEEN ONE AND A HALF AND TWO
INCHES. LARGE CUTOFF LOW DEVELOPING NORTH OF THE AREA WILL ALSO
AID IN INCREASING MID LYR INSTABILITY AND DIVERGENCE ALOFT TO HELP
SUSTAIN DEEP CONVECTION WITH THE POTENTIAL FOR HEAVY RAINS AND FLASH
FLOODING. OVERALL...MUCH WETTER NEXT WEEK AS PATTERN WILL REMAIN
STAGNANT WITH MID-UPPER LVL TROUGH IN FULL CONTROL AND DEEP
MOISTURE IN PLACE.

&&

.AVIATION...MVFR CONDITIONS AT JMZ THRU 22Z WITH HEAVY RAIN. VFR
AT ALL OTHER SITES.


&&

.MARINE...EXERCISE CAUTION STATEMENTS REMAIN IN EFFECT FOR ALL
OFFSHORE WATERS AND THE WATERS SURROUNDING THE USVI. FRESH TRADES
TO PERSIST THROUGH THE WEEKEND OVER UNPROTECTED WATERS.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
535 AM AST THU APR 23 2009

.DISCUSSION...AN AREA OF LOW LEVEL MOISTURE HAS BEEN MOVING FROM
THE NORTHEASTERN CARIBBEAN TOWARDS THE LOCAL AREA SINCE WEDNESDAY
EVENING. AS OF 5 AM AST...BOTH SATELLITE IMAGERY AND RADAR
OBSERVATIONS ARE DEPICTING ISOLATED TO SCATTERED SHOWER ACTIVITY
JUST NORTHEAST OF THE SAINT THOMAS/SAINT JOHN AND ADJACENT SMALLER
ISLANDS. THESE SHOWERS ARE MOVING WEST SOUTHWESTWARD UNDER THE
INFLUENCE OF AN EAST NORTHEASTERLY FLOW. THEREFORE...SOME OF
THESE SHOWERS MAY ARRIVE TO THE NORTHEASTERN PART OF PUERTO RICO
JUST BEFORE DAWN OR A LITTLE AFTER.

CHANGES HAVE BEEN MADE ACCORDINGLY ON THIS MORNING FORECAST
PACKAGE TO SHOW AN INCREASE OF MOISTURE AND SHOWERS MAINLY OVER
THE EASTERN HALF OF PUERTO RICO. THE WESTERN HALF OF THE ISLAND
WILL BE RECEIVING SHOWERS THIS AFTERNOON AS AVAILABLE MOISTURE
COMBINE WITH LOCAL ISLAND EFFECTS. SOME OF THESE SHOWERS MAY BE
LOCALLY HEAVY AS A RESULT OF A THUNDERSTORM OR TWO.

LOOKING AHEAD...BEGINNING ON LATE FRIDAY AFTERNOON INTO
SUNDAY...LOW LEVEL MOISTURE WILL BE ON THE INCREASE ACROSS THE
LOCAL AREA WHICH MEANS THAT SHOWER ACTIVITY ACROSS THE LOCAL
ISLANDS AND COASTAL WATERS IS EXPECTED TO BE MORE FREQUENTLY. BY
LATE SUNDAY INTO THE FIRST PART OF THE UPCOMING WEEK...GFS MODEL
GUIDANCE SUGGESTS A RELATIVELY DRIER WEATHER TREND.


&&

.AVIATION...MVFR CONDITIONS WILL CONTINUE WITH A SHORT BREAK AFTER
23/10Z IN TNCM AS AN AREA OF MOISTURE DRIFTS BY ON A WEST SOUTHWEST
HEADING. SCATTERED SHOWERS ARE ALSO APPROACHING TIST AND MAY ALSO
LOWER CEILINGS BRIEFLY. OTHERWISE MVFR CONDITIONS WILL DEVELOP OVER
WESTERN PUERTO RICO AND BRIEFLY INCLUDE TJMZ. WINDS HAVE TURNED MORE
NORTHEASTERLY AS EVIDENCED BY CELL MOVEMENT OVER THE LOCAL AREA AND
SO EXPECT TJBQ TO REMAIN VFR EVEN IF SHOWERS WITH HEAVY RAIN DEVELOP
TO THE SOUTHEAST OVER THE INTERIOR. SHOWER COVERAGE WILL CONTINUE TO
INCREASE TONIGHT AND MUCH OF THE NORTHEAST COAST IS LIKELY TO
RECEIVE SOME SHOWERS. MOUNTAIN OBSCURATIONS WILL BEGIN AROUND 23/15Z
AND LAST BEYOND 23/04Z IN MANY PARTS OF PUERTO RICO AND A FEW AREAS
IN THE U.S. VIRGIN ISLANDS. RIDGING AT MID LEVELS IS STILL YIELDING
LIGHT WINDS...ESPECIALLY AROUND 19 THOUSAND FEET.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
443 AM AST SAT APR 25 2009

.SYNOPSIS...HIGH PRESSURE ACROSS THE SOUTHWEST ATLANTIC THIS MORNING...
WILL CONTINUE TO BUILD AND SPREAD NORTH AND EAST ACROSS THE WEST
ATLANTIC THROUGH THE WEEKEND. LOW LEVEL MOISTURE WILL MOVE ACROSS
THE LOCAL AREA THROUGH THIS AFTERNOON GENERATING ISOLATED TO
SCATTERED PASSING SHOWERS.

&&

.DISCUSSION...AT AROUND MIDNIGHT A LARGE AREA OF SHOWERS OVER THE
EXTREME NORTHEAST PORTIONS OF THE FORECAST AREA WAS MOVING SOUTHWEST
ACROSS THE LOCAL ATLANTIC WATERS. AT THIS MOMENT THE DOPPLER RADAR
IS SHOWING A SLIGHT INCREASE ON SHOWERS ACROSS THE EAST AND
NORTHEAST ATLANTIC WATERS. THESE SHOWERS ARE EXPECTED TO MOVE
SOUTHWEST AND AFFECT THE NORTHERN AND EASTERN PORTIONS OF PUERTO
RICO THROUGH LATE MORNING. DIURNAL HEATING WILL COMBINE WITH THIS
LOW LEVEL MOISTURE AND PRODUCE AFTERNOON SHOWERS ACROSS THE
INTERIOR AND SOUTHWEST PORTIONS OF PUERTO RICO. TONIGHT...PATCHES
OF LOW LEVEL MOISTURE WILL CONTINUE TO MOVE ON SHORE AND PRODUCING
SHOWERS MAINLY OVER THE EASTERN AND NORTHEAST PORTIONS OF PUERTO RICO.

THE GFS MODELS ARE SHOWING A SIGNIFICANT WIND INCREASE ACROSS THE
REGION. THEREFORE EXPECT MORE PASSING SHOWERS AFFECTING THE
EASTERN HALF OF PUERTO RICO OVERNIGHT AND AFTERNOON SHOWERS
DEVELOPING ACROSS THE WESTERN PORTIONS OF PUERTO RICO. THIS
WEATHER SCENARIO WILL PREVAIL THROUGH AT LEAST WEDNESDAY

&&

.AVIATION...EXPECT SHOWER ACTIVITY TO AFFECT ALL SITES IN PR/USVI
DURING THE NEXT 12 TO 18 HOURS. GONE WITH MENTION OF VCSH AT MOST
AIRPORTS... WITH VCTS OVER TJPS AND TJMZ BY AROUND 17Z TO 22Z.
THESE WILL BE THE AREAS OF CONCERN...MOST LIKELY TO EXPERIENCE
MVFR CIGS...BUT IT WILL BE POSSIBLE IN PASSING SHOWER ACTIVITY AT
ALL SITES.

&&

.MARINE...A MODERATE TO FRESH TRADE WINDS WILL GENERATE A LIGHT TO
MODERATE CHOP ACROSS THE LOCAL WATERS FOR THE NEXT SEVERAL DAYS.
ALTHOUGH A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE MARINE ZONE
AMZ710 UNTIL SUNDAY NIGHT...MODELS ARE SUGGESTING SIMILAR
CONDITIONS THROUGH THE INCOMING WEEK.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
527 AM AST SUN APR 26 2009

.SYNOPSIS...HIGH PRESSURE ACROSS THE SOUTHWESTERN ATLANTIC...WILL
CONTINUE TO BUILD AND SPREAD NORTH AND EAST ACROSS THE WEST ATLANTIC
THROUGH EARLY NEXT WEEK. PASSING SHOWERS EMBEDDED IN THE TRADE
WINDS WILL CONTINUE TO MOVE ACROSS THE LOCAL AREA THROUGH MID WEEK.

&&

.DISCUSSION...ISOLATED TO SCATTERED SHOWERS CONTINUED TO MOVE
ACROSS THE LOCAL WATERS OVERNIGHT. A FEW OF THESE SHOWERS BRUSHED
THE NORTHEAST...EAST AND SOUTHEAST COAST OF PUERTO RICO. THESE
SHOWERS GENERATED RAINFALL ACCUMULATIONS OF LESS THAN 1 INCH. A
SLIGHT DECREASE ON SHOWER COVERAGE IT IS EXPECTED AFTER MID
MORNING.

EXPECT LESS CLOUD COVERAGE ACROSS THE LOCAL ISLANDS TODAY
THEREFORE MORE HEATING REACHING THE GROUND. LOCAL EFFECTS WILL
COMBINE TO PRODUCE ISOLATED TO SCATTERED SHOWERS MAINLY ACROSS THE
INTERIOR AND WESTERN PORTIONS OF PUERTO RICO.

MODELS CONTINUE TO SHOW A MORE FAVORABLE CONDITIONS FOR SHOWER AND
THUNDERSTORM DEVELOPMENT STARTING ON WEDNESDAY. AS A UPPER LEVEL
TROUGH WILL HELP DESTABILIZE THE MID AND UPPER LEVELS OF THE
ATMOSPHERE.

&&

.AVIATION...PASSING LOW LEVEL CLOUDS AND ACCOMPANYING SHOWERS WILL
CONTINUE TO AFFECT THE LOCAL FLYING AREA THROUGH 13Z. ACTIVITY
SHOULD BE CONFINED TO VCSH...NOT PRODUCING SIGNIFICANT PERIODS OF
MVFR. THIS AFTERNOON...FOCUS WILL BE ON TJMZ AND VC OF TJBQ AS
SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED BEGINNING AROUND 18Z.
MVFR CIGS ARE LIKELY AT BOTH SITES 18-22Z.

&&

.MARINE...A MODERATE TO FRESH TRADE WINDS WILL GENERATE A LIGHT TO
MODERATE CHOP ACROSS THE LOCAL WATERS FOR THE NEXT SEVERAL DAYS.
ALTHOUGH A SMALL CRAFT ADVISORY ARE IN EFFECT FOR THE MARINE
ZONES AMZ710 AND AMZ741 UNTIL MONDAY NIGHT...MODELS ARE SUGGESTING
SIMILAR CONDITIONS THROUGH MID WEEK. THEREFORE SMALL CRAFT
ADVISORIES COULD BE EXTENDED TO OTHER MARINE ZONES

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
539 AM AST MON APR 27 2009

.SYNOPSIS...SURFACE HIGH PRESSURE ACROSS THE SOUTHWEST ATLANTIC...
WILL SPREAD EAST AND NORTHEAST ACROSS THE WEST ATLANTIC THROUGH
AT LEAST EARLY TUESDAY. THIS WILL HELP MAINTAIN MODERATE TO STRONG
WINDS ACROSS THE LOCAL FORECAST AREA FOR THE NEXT SEVERAL DAYS.

&&

.DISCUSSION...ISOLATED TO SCATTERED SHOWERS MOVED ACROSS THE LOCAL
WATERS OVERNIGHT WITH A FEW AFFECTING THE NORTHERN COAST OF PUERTO
RICO. EXPECT MORE SHOWERS TO AFFECT THE EAST AND NORTHERN COAST OF
PUERTO RICO THROUGH MID MORNING. THE MAIN WEATHER FEATURE FOR
TODAY WILL BE THE STRONG WINDS. WINDS ARE EXPECTED TO REMAIN AT
AROUND 20 KNOTS THROUGH AT LEAST LATE TUESDAY.

ISOLATED TO SCATTERED SHOWERS WILL DEVELOP ACROSS THE INTERIOR AND
WESTERN PORTIONS PUERTO RICO THIS AFTERNOON BUT STRONG WINDS WILL
QUICKLY MOVE THESE SHOWERS OVER THE MONA PASSAGE.

MODELS CONTINUE TO SHOW A MORE FAVORABLE CONDITIONS FOR SHOWER AND
THUNDERSTORM DEVELOPMENT STARTING ON WEDNESDAY. AS A UPPER LEVEL
TROUGH WILL HELP DESTABILIZE THE MID AND UPPER LEVELS OF THE
ATMOSPHERE.

&&

.AVIATION...VFR CONDITIONS THROUGH THE EARLY AFTERNOON. LATER THIS
AFTERNOON...FOCUS WILL BE ON TJMZ AND VC OF TJBQ AS SHOWER AND
THUNDERSTORM ACTIVITY IS EXPECTED BEGINNING AROUND 18Z. MVFR CIGS
ARE LIKELY AT TJMZ 18-22Z.

&&

.MARINE...WINDS WILL REMAIN MODERATE TO FRESH ACROSS MOST OF THE
LOCAL COASTAL WATERS. WINDS ARE FORECAST TO BE AT AROUND 20 KNOTS
WITH HIGHER GUSTS. THIS WILL PRODUCE A MODERATE CHOP ACROSS THE
LOCAL WATERS. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR AMZ722...
AMZ741 AND AMZ710 THROUGH AT LEAST TUESDAY NIGHT.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
424 PM AST MON APR 27 2009

.DISCUSSION...
THE MID TO UPPER LEVEL L/W TROUGH WILL CONTINUE TO AMPLIFY AND
DIP SOUTHWARDS ACROSS THE LOCAL REGION OVER THE NEXT FEW DAYS.
A SUBTROPICAL JET IS FORECAST TO THEN RIDE THE BASE OF THE UPPER
LEVEL TROUGH AND MOVE ACROSS THE NORTHEAST CARIBBEAN...WITH RIGHT
REAR QUAD OF JET MAX SETTING UP JUST ACROSS LOCAL AREA WEDNESDAY
THROUGH THURSDAY. AS THIS UPPER LEVEL DIVERGENT PATTERN UNFOLDS...
EXPECT ENHANCEMENT OF NOCTURNAL AND DIURNAL CONVECTION OVER THE AREA.
IN ADDITION...THE SUBTROPICAL RIDGE WILL CONTINUE TO WEAKEN/FLATTEN
UNDER THE EFFECTS OF THE MID TO UPPER TROUGH ACROSS WEST ATLANTIC...
AND EVENTUALLY WEAKENING THE SUBSIDENCE CAP WHICH HAS SO FAR LIMITED
THE PREVIOUS DAYS CONVECTIVE ACTIVITY.

THE CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORM ACTIVITY ACROSS
THE REGION WILL THEREFORE BE ON THE INCREASE...AS A FAIRLY MOIST AND
UNSTABLE AIRMASS WILL OCCUPY THE REGION DURING THE LATTER PART OF
THE WEEK. INDUCED LOW LEVEL EASTERLY PERTURBATIONS WILL CONTINUE
TO PROPAGATE ACROSS THE REGION UNDER THE INFLUENCE OF THE STRONG
ATLANTIC HIGH. THIS WILL BRING INTERVALS OF ADDITIONAL TROPICAL
MOISTURE TO THE LOCAL ISLANDS AND SURROUNDING WATERS OVER THE NEXT
FEW DAYS. EXPECT MODERATE TO LOCALLY HEAVY RAINFALL AT TIMES IN
SOME AREAS...AND THIS MAY LEAD TO MINOR URBAN AND SMALL STREAM
FLOODING...ESPECIALLY ON WEDNESDAY AND THURSDAY. THEREAFTER
RESIDUAL MOISTURE COMBINED WITH LOCAL TERRAIN AND DIURNAL EFFECTS
WILL LEAD TO MOSTLY ISOLATED AFTERNOON SHOWERS ACTIVITY AND ISOLATED
THUNDERSTORM ACTIVITY INTO THE WEEKEND.

&&

.AVIATION...
VFR CONDITIONS ARE EXPECTED ACROSS ALL LOCAL TAF SITES FOR THE NEXT
18 TO 24 HOURS. THE ONLY LOCAL AIRPORT THAT MAY BE EXPERIENCING
MVFR CONDITIONS FOR SHORT PERIOD OF TIMES WOULD BE TJMZ FROM NOW
TIL 21Z...AS LOW LEVEL CLOUDS AND MODERATE TO LOCALIZED HEAVY
SHOWERS MOVE ACROSS OR NEAR THE AIRPORT.

&&

.MARINE...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE LOCAL OFFSHORE ATLANTIC
WATERS AND CARIBBEAN PASSAGES...WITH PRECAUTIONARY STATEMENTS IN EFFECT
FOR THE REMAINDER OF THE LOCAL MARINE AREA.

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[cycloneye]

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000
FXCA62 TJSJ 280720
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
320 AM AST TUE APR 28 2009

.DISCUSSION...CUT-OFF U/L NEAR THE TURKS/CAICOS WILL BE THE MAIN
STORY OVER THE NEXT FEW DAYS. MODELS SHOW THIS FEATURE MOVING
SLOWLY EASTWARD...BRINGING UPPER LEVEL MOISTURE OVER REGION BY
LATE TONIGHT...FOCUSING WEDNESDAY AS MOST LIKELY DAY OF MORE LARGE
SCALE SHOWER ACTIVITY. BY 18Z WEDNESDAY...NAM12 SHOWING PW
REACHING NEAR 2 INCHES AS PROFILE BECOMES MOIST FROM THE SURFACE
TO THE UPPER LEVELS. AS ALWAYS...CONVECTIVE PLACEMENT WILL DEPEND
ON MORNING HEATING AND LOW LEVEL FLOW...BUT LOOKS LIKE EVERYWHERE
FROM THE CENTRAL INTERIOR TOWARDS MAYAGUEZ AND SOUTH TO CABO ROJO
SHOULD SEE SOME HEAVY RAIN WEDNESDAY. THURSDAY AND FRIDAY ALSO LOOK
MOIST...BUT TO A SLIGHTLY LESSER EXTENT.


&&

.AVIATION...MOSTLY VFR CONDITIONS WILL PREVAIL ACROSS ALL THE LOCAL
TAF SITES THROUGH MID MORNING. THIS AFTERNOON CONVECTION WILL
DEVELOP OVER THE INTERIOR OF PR AFTER 241700Z...WHICH WILL RESULT IN
TEMPORARY MOUNTAIN OBSCURATIONS AND BRIEF MVFR CONDITIONS ACROSS
TJMZ AND POSSIBLY TJPS FROM 17-22Z.


&&

.MARINE...WINDS HAVE PICKED UP TO NEAR 20 KNOTS OVER MOST WATERS.
SMALL CRAFT ADVISORIES IN EFFECT FOR MOST AREAS NEXT 24-36 HRS.