Caribbean - Central America Weather

[cycloneye]

Afternoon discussion by NWS San Juan

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
313 PM AST THU APR 29 2010

.SYNOPSIS...MID UPPER LEVEL HIGH PRES WILL DOMINATE THROUGH FRI
THEN COLLAPSE AS TROUGH AMPLIFIES ACROSS THE CNTRL ATLC INTO THE
NORTHEAST CARIBBEAN LATE SAT INTO EARLY NEXT WEEK.

&&

.DISCUSSION...AIR MASS WILL REMAIN RELATIVELY DRY AND STABLE
THROUGH SAT AS IT REMAINS UNDER THE INFLUENCE OF A STRONG MID-
UPPER LEVEL HIGH PRESSURE LOCATED EAST OF THE ISLAND CHAIN. EVEN
SO...ISOLD AFTERNOON CONVECTION WILL STILL REMAIN POSSIBLE ACROSS
WRN PR BUT BELIEVE CHANCES WILL BE LESS THAN TODAY DUE TO TIGHTER
PRES GRADIENT AND LESS THAN LIKELY SEA BREEZE DEVELOPMENT.

CNTRL ATLC TROUGH FCST TO AMPLIFY DURING THE NEXT 48-60 HRS AND
EVOLVE INTO A TUTT LOW JUST NORTH OF PR SUN NIGHT. MODELS INDICATE
A SUBSTANTIAL INCREASE IN MOISTURE SUN WITH PWAT VALUES CLIMBING
TO NEAR 2.0 INCHES BY SUN NIGHT. AS TUTT LOW MOVES OVER PR...MID
LEVEL COOLING AND POOLING OF MOISTURE SHOULD RESULT IN MUCH BETTER
CHANCES FOR DEEP CONVECTION ACROSS THE REGION.

TUTT WEAKENS MIDDLE OF NEXT WEEK ACCORDING TO LATEST GFS WITH
DRYING INDICATED FOR THE END OF NEXT WEEK.

&&

.AVIATION...MVFR CIGS AT JMZ THRU 23Z...OTHERWISE HAZY SKIES WITH
5-6SM VSBY. NAAPS GUIDANCE SUGGESTS THAT SKIES SHOULD BECOME LESS
HAZY TOMORROW WITH FURTHER IMPROVEMENT FOR THE WEEKEND.

&&

.MARINE...SEAS WILL BUILD TO 4-6 FT OVR THE WEEKEND IN COMBINATION
OF EASTERLY WIND WAVES AND SMALL NORTH SWELLS.

&&

.FIRE WEATHER...DESPITE THE HEAVY RAINS OF LAST WEEK AND THE
GREENER VEGETATION...FIRES HAVE DEVELOPED OVR PR OVER THE LAST
TWO DAYS. 88D AND TDWR RADARS BOTH DETECTED TWO SMOKE PLUMES ONE
OVER ISABELA AND ANOTHER OVER COAMO TODAY WHICH HAVE ALREADY
DISSIPATED. THESE WERE ALSO DETECTED BY WFABBA GIVING ME
CONFIDENCE THAT THESE WERE FIRES. AIR MASS WILL REMAIN RELATIVELY
DRY THROUGH SAT WITH A CONTINUED RISK OF BRUSH FIRES. WINDS WILL
ALSO INCREASE TOMORROW AND SAT THAT COULD IGNITE AND SPREAD FIRES.

[cycloneye]

FLOOD ADVISORY
NATIONAL WEATHER SERVICE SAN JUAN PR
448 PM AST THU APR 29 2010

PRC003-011-117-292345-
/O.NEW.TJSJ.FA.Y.0078.100429T2048Z-100429T2345Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
AGUADA PR-RINCON PR-ANASCO PR-
448 PM AST THU APR 29 2010

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED AN

* URBAN AND SMALL STREAM FLOOD ADVISORY
FOR THE FOLLOWING MUNICIPALITIES...

IN PUERTO RICO
AGUADA...RINCON AND ANASCO

* UNTIL 745 PM AST

* AT 447 PM AST...NATIONAL WEATHER SERVICE DOPPLER RADAR DETECTED
HEAVY RAINFALL ACROSS THESE AREAS. THIS SHOWER ACTIVITY WILL HAVE
THE CAPABILITY OF PRODUCING RAPID RISES IN SMALL STREAMS AND
CREEKS...AS WELL AS MINOR FLOODING ALONG ROADWAYS...THROUGH AT LEAST
7:45 PM AST.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

[cycloneye]

FLOOD ADVISORY
NATIONAL WEATHER SERVICE SAN JUAN PR
529 PM AST THU APR 29 2010

PRC107-292330-
/O.NEW.TJSJ.FA.Y.0079.100429T2129Z-100429T2330Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
OROCOVIS PR-
529 PM AST THU APR 29 2010

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED AN

* URBAN AND SMALL STREAM FLOOD ADVISORY
FOR THE FOLLOWING MUNICIPALITY...

IN PUERTO RICO
OROCOVIS

* UNTIL 730 PM AST

* AT 523 PM AST...STATE EMERGENCY MANAGEMENT OFFICIALS REPORTED A
RIO IN OROCOVIS OUT OF ITS BANKS IN SECTOR BAJURAS. THIS FLOODING IS
IN RESPONSE TO VERY HEAVY RAINFALL EARLIER THIS AFTERNOON.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

[Macrocane]

Well below normal maximum temperatures were registered today in most parts of Central America today thanks to the clouds associated to the disturbance in the Pacific. Thsese are today's maximum and the average maximum temperatures for this time of year:

Santa Ana, El Salvador: 28.7°C/83.7°F average: 33°C/91.4°F
San Salvador, El Salvador: 26.4°C/79.5°F average: 32.5°C/90.5°F
San Miguel, El Salvador: 31.9°C/89.4°F average: 37.5°C/99.5°F
Guatemala city, Guatemala: 25°C/77°F average:27°C/81°F
Belize city, Belize: 30°C/86°F average 32°C/90°F
Tegucigalpa, Honduras: 29°C/84°F average 30°C/86°F
Managua, Nicaragua: 32°C/90°F average 36°C/97°F
San Jose, Costa Rica 27°C/81°F average 30°C/86°F
Panama city, Panama 32°C/90°F average 37°C/98°F

[cycloneye]

Good morning to all. A variable weekend ahead.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
525 AM AST FRI APR 30 2010

.SYNOPSIS...AT UPPER LEVELS...HIGH PRESSURE OVER THE CARIBBEAN
WILL RIDGE NORTHWARD AND FORM A HIGH OVER WESTERN CUBA DURING THE
WEEKEND. THIS WILL CAUSE A TROUGH TO DIG OVER THE DOMINICAN
REPUBLIC AND PUERTO RICO. A CUT-OFF LOW WILL FORM SOMEWHERE
BETWEEN PUERTO RICO AND JUST SOUTH OF THE WINDWARD PASSAGE EARLY
NEXT WEEK. THE LOW WILL MERGE WITH A TROUGH AND PULL NORTHEAST...
PASSING NORTH OF THE AREA LATE NEXT WEEK.

AT MID LEVELS...HIGH PRESSURE WILL MOVE WEST ACROSS THE GREATER
ANTILLES TODAY AND TOMORROW AND BUILD OVER FLORIDA SUNDAY AND
MONDAY. LOW PRESSURE WILL FORM SOUTH OF HISPANIOLA AND MOVE WEST
AS THE HIGH MOVES EAST NORTH OF IT. THE HIGH WILL CONTINUE EAST
UNTIL IT IS FOUND EAST NORTHEAST OF THE LEEWARD ISLAND BY THE END
OF NEXT WEEK.

AT LOWER LEVELS...HIGH PRESSURE OVER THE WESTERN ATLANTIC EAST OF
FLORIDA WILL BUILD NORTH OF PUERTO RICO UNTIL MONDAY MORNING AND
THEN PULL NORTHEAST INTO THE CENTRAL ATLANTIC TUESDAY THROUGH
SATURDAY OF NEXT WEEK. A COLD FRONT NORTH OF THE AREA WILL SAG
SOUTH OVER THE WEEKEND AND SETTLE OVER PUERTO RICO MONDAY THROUGH
WEDNESDAY...BUT CONTINUE INTO THE CARIBBEAN THROUGH THE END OF
THE WEEK.

&&

.DISCUSSION...MODELS HAVE BEEN SUGGESTING THAT LOWER LEVEL WINDS
WILL SHIFT FROM NORTHEAST TO EAST SOUTHEAST BETWEEN EARLY MORNING
AND MID AFTERNOON THIS AFTERNOON...AND THE VAD RADAR PRODUCT
APPEARS TO CONFIRM THE BEGINNING OF THIS TREND. CONVECTION WAS
STRONGER THAN EXPECTED YESTERDAY AND THERE IS NO REASON TO EXPECT
THAT IT CANNOT OCCUR AGAIN TODAY. WITH WINDS VEERING FOR THE TIME
BEING DO NOT EXPECT THAT INITIAL CONVECTION WILL BE IN THE SAME
PLACE AS YESTERDAY HOWEVER. THEREFORE HAVE PLACED GOOD POPS OVER
MUCH OF WESTERN PUERTO RICO WITH THE CENTER FALLING OVER THE
ANASCO RIVER BASIN. JUST THE FACT THAT THE WINDS WILL SHIFT
RAPIDLY BACK DURING THE LATE AFTERNOON COULD PRODUCE SOME STRONGER
CONVERGENCE PATTERNS THAT WILL YIELD COPIOUS AMOUNTS OF RAIN IN
SOME AREAS. THEREFORE CANNOT RULE OUT SOME URBAN AND SMALL STREAM
FLOODING AFTER 30/18Z WITH THE RISK EXTENDING TO A FEW HOURS AFTER
SUNSET. PRECIPITABLE WATER HAS FLUCTUATED SOME BUT HAS BEEN
BASICALLY STEADY FOR THE LAST 48 HOURS BETWEEN 1.3 AND 1.6 INCHES AND
THERE IS NO REASON TO EXPECT A RAPID INCREASE OF MOISTURE BEFORE
SUNDAY. HOWEVER...HEATING CONTINUES TO BE STRONG WITH ABNORMALLY
HIGH TEMPERATURES FOR THE MONTH AND THEREFORE CONVECTION THAT
FIRES OFF WILL BE STRONG AND WILL LIKELY CONTAIN LOCALLY FREQUENT
LIGHTNING AS WELL.

ALTHOUGH SATURDAY MAY BE DRIER...MODELS INDICATE THAT THE FRONTAL
BOUNDARY HOVERING NEAR 23 NORTH THIS MORNING WILL MOVE SOUTH OVER
THE AREA BRINGING WIDESPREAD CLOUDINESS AND SCATTERED TO NUMEROUS
SHOWERS OVER THE ISLANDS LATE SUNDAY THROUGH TUESDAY. WITH MOSTLY
EAST NORTHEAST FLOW...EXPECT EARLY MORNING SHOWERS OVER THE
NORTHEAST QUADRANT OF THE ISLAND AND STRONGER THUNDERSTORMS EACH
DAY SUNDAY THROUGH TUESDAY IN THE SOUTHWEST. DRYING FOR THE U.S.
VIRGIN ISLANDS WILL BEGIN TUESDAY NIGHT AS DRIER AIR BEHIND THE
BOUNDARY CLAIMS ITS PLACE BEHIND THE FRONT AND REMAINS UNTIL LATE
SATURDAY. THEREFORE...THOSE LOOKING FOR SUNNIER WEATHER WILL NEED
TO WAIT TILL WEDNESDAY OR THURSDAY OF NEXT WEEK. SHOWERS SLOWLY
INCREASE AS MOISTURE FROM THE EAST FILTERS INTO THE AREA AFTER
FRIDAY OF NEXT WEEK.

&&

.AVIATION...
EXPECT PREVAILING VFR CONDITIONS ACROSS ALL TAF SITES.
HOWEVER...VCSH AND A POSSIBILITY OF A THUNDERSTORM OR TWO ARE
POSSIBLE MAINLY OVER THE WEST AND INTERIOR SECTION OF PUERTO RICO
THIS AFTERNOON. MOUNTAIN OBSCURATIONS AND BRIEF MVFR CONDITIONS ARE
LIKELY AT TJMZ AND TJBQ FROM 18-22Z. EASTERLY SFC WIND WILL
REMAIN AROUND 10 KNOTS WITH SOME HIGHER GUSTS...EXPECT SEA BREEZE
VARIATIONS AT COASTAL AREAS.

&&

.MARINE...SEAS REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH
THE NEXT 10 DAYS AT THIS TIME. INCREASING WINDS HAVE PUSHED SOME
AREAS INTO EXERCISE CAUTION CONDITIONS. THESE ARE LIKELY TO
CONTINUE WELL INTO NEXT WEEK. APPROACH OF THE FRONT EARLY NEXT
WEEK WILL CAUSE SOME DETERIORATION IN OVERALL WEATHER PICTURE WITH
RESPECT TO NAVIGATION.

[cycloneye]

Updated discussion by NWS San Juan

The important part of this mini update is the winds are from the east meaning that it will not be as hot as in the past few days.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1015 AM AST FRI APR 30 2010

.UPDATE...NO CHANGES NEEDED TO FORECAST PACKAGE AT THIS TIME.

&&

.AVIATION...EXPECT PREVAILING VFR CONDITIONS ACROSS ALL TAF SITES.
HOWEVER...VCSH AND A POSSIBILITY OF A THUNDERSTORM OR TWO ARE
POSSIBLE MAINLY OVER THE WEST AND INTERIOR SECTION OF PUERTO RICO
THIS AFTERNOON. MOUNTAIN OBSCURATIONS AND BRIEF MVFR CONDITIONS ARE
LIKELY AT TJMZ AND TJBQ FROM 18-22Z. EASTERLY SFC WIND WILL
REMAIN AROUND 10 KNOTS WITH SOME HIGHER GUSTS...EXPECT SEA BREEZE
VARIATIONS AT COASTAL AREAS.

[tropicana]

PIARCO INTERNATIONAL AIRPORT, TRINIDAD APRIL 2010 STATS

Apr 1 35.0C 95F 95F
2nd 34.8C 95F
3rd 35.3C 95F trace
4th 35.6C 96F 0.2mm
5th 35.0C 95F

6th 34.9C 95F
7th 35.7C 96F
8th 33.7C 93F trace
9th 35.7C 96F 0.2mm
10th 35.4C 95F

11th 35.5C 96F
12th 35.3C 95F
13th 34.9C 95F
14th 36.0C 97F **51st cons. day at or over 33.7C 93F**
15th 31.1C 88F 0.1mm

16th 31.5C 89F 2.7mm
17th 35.0C 95F 19.6mm
18th 34.7C 95F trace
19th 35.9C 96F
20th 36.0C 96F

21st 34.7C 95F 1.5mm
22nd 35.1C 95F
23rd 35.6C 96F
24th 34.4C 94F 12.6mm
25th 34.9C 95F

26th 34.5C 94F
27th 34.3C 94F 15.0mm
28th 33.7C 93F trace
29th 33.1C 92F 8.0mm
30th 34.6C 94F

TOTAL 59.9mm (slightly above April average)

Point-a-Pierre, SW T'dad 169.2mm

Maraval, W. Trinidad 65.8mm
(average April 37mm)

Grantley Adam's B'dos 86.0mm
Rockley, S. B'dos 215.1mm


Overall, April showers did materialise this month. easing the drought conditions most especially in the second half of the month.
But despite the more numreous rain-showers, the month continued hot, despite the consecutive heatwave that was ongoing since February having broken on April 15. With all the cloud cover around, the 15th and 16th were the only compartively cooler days.

The coolest temperature at Piarco Airport was 22.8C 73F early on April 12.

[cycloneye]

Afternoon discussion by NWS San Juan

A rainy period for part of the weekend until mid-week.

http://forecast.weather.gov/product.php ... glossary=1

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
303 PM AST FRI APR 30 2010

.SYNOPSIS...MID-UPPER LEVEL HIGH PRES WILL BE REPLACED BY AN UPPER
LEVEL TROUGH THIS WEEKEND. THIS TROUGH WILL REMAIN THE MAIN
DOMINANT WX FEATURE TIL THE MIDDLE OF NEXT WEEK.

&&

.DISCUSSION...TROUGH TO AMPLIFY ACROSS THE WRN ATLC INTO THE
NORTHEAST CARIBBEAN OVER THE NEXT 36-48 HRS WITH MODELS INDICATING
EVENTUAL EVOLUTION INTO A CUTOFF LOW OVR THE MONA PASSAGE. AS MID-UPPER
LEVELS COOL AND MOISTURE GETS PULLED NORTH FROM SAMERICA EXPECT A
SIGNIFICANT INCREASE IN SHRA/TSTM COVERAGE ACROSS THE REGION SUN-
TUE. MJO CONDITIONS ALSO VERY FVRBL ACROSS THE CARIBBEAN OVER THE
NEXT FEW DAYS SUGGESTING THE POTENTIAL FOR A SIGNIFICANT HEAVY
RAINFALL EVENT SOMEWHERE ACROSS THE REGION. HOWEVER...LOCATION IS
STILL VERY UNCERTAIN. CONDITIONS REMAIN RATHER WET AND UNSETTLED
THROUGH TUE.

MODELS SHOW TUTT LOW WEAKENING RAPIDLY MIDDLE OF NEXT WEEK WITH
SIG DRYING FOR NEXT WED AND BEYOND. THIS IS ALSO SUPPORTED BY
POSITIVE 250 MB VELOCITY POTENTIAL ANOMALIES AND RAPID WEAKENING
OF THE MJO. SO HAVE GOOD DEAL OF CONFIDENCE ON THIS DRYING AFTER
THE MIDDLE OF NEXT WEEK.


&&

.AVIATION...MVFR CIGS AT JMZ THRU 23Z WITH VCSH. OTHERWISE...VSBYS
WILL CONTINUE TO IMPROVE AS EAST WINDS RESULT IN BETTER MIXING
AND PUSH HAZE TO THE CNTRL/WRN CARIBBEAN.

&&

.MARINE...SEAS BUILDING TO 6 FT ATLC WATERS BY SUN NIGHT IN ENE
WIND WAVES AND SMALL NORTH SWELLS. SCEC IN EFFECT FOR SVRL MARINE
ZONES DUE TO FRESH TRADE WINDS.

[cycloneye]

Precipitation on April in San Juan LMM Airport

http://www.weather.gov/climate/getclimate.php?wfo=sju

Code: Select all

WEATHER ITEM   OBSERVED TIME   RECORD YEAR NORMAL DEPARTURE LAST
                VALUE   (LST)  VALUE       VALUE  FROM      YEAR
                                                  NORMAL
..................................................................
PRECIPITATION (IN)
  TODAY            0.00          2.95 1986   0.16  -0.16     0.13
  MONTH TO DATE    3.46                      3.71  -0.25     2.79


[Gustywind]

[cycloneye]

Good morning to all.

A rather wet period for the next few days.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
550 AM AST SAT MAY 1 2010

.SYNOPSIS...AT UPPER LEVELS...A TROUGH WILL BEGIN TO EXTEND FROM
THE NORTHEAST OVER THE DOMINICAN REPUBLIC TODAY AND IS EXPECTED TO
CUT-OFF A WEAK LOW IN THE CARIBBEAN NEAR THE WINDWARD PASSAGE OR
JUST SOUTH OF HISPANIOLA BY MONDAY MORNING. THE LOW WILL MOVE WEST
ON TUESDAY AND BE RE-ABSORBED BY THE NEXT TROUGH DIGGING INTO CUBA
LATE IN THE WEEK. THIS TROUGH WILL MOVE LITTLE BUT WILL GIVE A
SOUTHERLY COMPONENT TO THE FLOW OVER PUERTO RICO AND THE U.S.
VIRGIN ISLANDS OVER THE NEXT WEEKEND.

AT MID LEVELS...HIGH PRESSURE WILL MOVE WEST OVER THE CHAIN OF THE
GREATER ANTILLES TO FLORIDA BY SUNDAY. LOW PRESSURE WILL FORM IN
THE CARIBBEAN SOUTH OF THE WINDWARD PASSAGE ON MONDAY AND MOVE
WEST THROUGH MID-WEEK NEXT WEEK. A TROUGH WILL DIG INTO THE
WESTERN CARIBBEAN AFTER MID WEEK NEXT WEEK...WHILE HIGH PRESSURE
SHIFTS INTO THE TROPICAL ATLANTIC.

AT LOWER LEVELS...HIGH PRESSURE NORTH OF PUERTO RICO AT ABOUT 28
NORTH WILL BUILD THROUGH MONDAY AND REMAIN IN PLACE UNTIL
WEDNESDAY NIGHT. A SECOND HIGH EXITING THE EASTERN SEABOARD OF
THE UNITED STATES ON WEDNESDAY WILL CAUSE IT TO SHIFT NORTH AND
MOVE TO THE WESTERN CENTRAL ATLANTIC BY THE FOLLOWING MONDAY. A
FRONTAL BAND WILL STRENGTHEN JUST NORTH OF PUERTO RICO AND THE
U.S. VIRGIN ISLANDS TODAY AND TONIGHT AND DRIVE SOUTH SOUTHWEST
OVER THE LEEWARD ISLANDS SATURDAY NIGHT AND OVER THE LOCAL AREA ON
SUNDAY. IT WILL SHIFT SLIGHTLY NORTH ON MONDAY BUT ANOTHER PUSH
FROM HIGH PRESSURE TO OUR NORTH WILL DRIVE IT THROUGH PUERTO RICO
AND THE U.S. VIRGIN ISLANDS TUESDAY NIGHT. THIS BOUNDARY WILL
RETURN LATE NEXT WEEK WITH MORE MOISTURE AND REMAIN THROUGH THE
FOLLOWING MONDAY.


&&

.DISCUSSION...SHOWERS FROM A BOUNDARY THAT HAS YET TO STRENGTHEN
TO OUR NORTH ARE VISIBLE ON RADAR THIS MORNING AND ARE MOVING WEST
SOUTHWEST AT ABOUT 17 KNOTS. WINDS HAVE STRENGTHENED OVERNIGHT AND
AT 4 THOUSAND FEET ARE JUST SOUTH OF EAST AT ABOUT 15-20 KTS.
MODELS SHOW THE WINDS SHIFTING BACK TO EAST NORTHEAST BETWEEN
1000-850 MB INCLUSIVE BY 02/00Z AND SEA BREEZES ARE EXPECTED TO
FORM BY MID MORNING THIS MORNING. THIS WILL SET UP A CIRCULATION PATTERN
THAT WILL GENERATE SHOWERS AND ISOLATED THUNDERSTORMS OVER WESTERN
PUERTO RICO BEGINNING IN THE NORTHWEST...BUT EVENTUALLY SPREADING
SOUTH TO THE CORDILLERA CENTRAL MUCH AS OCCURRED FRIDAY. SOME OF THESE
SHOWERS WILL BE LOCALLY HEAVY AND COULD SPAWN SOME LOCAL URBAN AND
SMALL STREAM FLOODING. ON SATURDAY NIGHT THE FRONTAL BOUNDARY IS
EXPECTED TO INTRUDE INTO THE FORECAST AREA MORE AND BEGIN TO
SPREAD SHOWERS OVER THE LOCAL WATERS THAT WILL MOVE ONSHORE FROM
THE ATLANTIC AROUND DAWN. THE NAM IS ESPECIALLY EMPHATIC THAT
SHOWERS WILL FORM OVER NORTHEASTERN PUERTO RICO AS IT ENHANCES THE
DIVERGENCE ALOFT AT 02/26Z SUNDAY MORNING. ALL THE MODELS BEGIN TO
LOWER THE PRESSURE AT UPPER LEVELS ALONG AN AXIS THAT EXTENDS FROM
THE ATLANTIC SOUTHWEST ACROSS THE EASTERN DOMINICAN REPUBLIC ON
SUNDAY. PUERTO RICO REMAINS ON THE SOUTHEAST SIDE OF THIS TROUGH
WITH INCREASING UPPER LEVEL DYNAMICS THROUGH WEDNESDAY NIGHT WHEN
A WEAK JETLET AT THAT LEVEL PASSES OVER THE AREA FROM THE
RETURNING LOW. THUS HAVE KEPT AND EVEN AUGMENTED SLIGHTLY THE
ENHANCED POPS FOR SUNDAY THROUGH TUESDAY NIGHT. DRYING ON
WEDNESDAY APPEARS TO BE BRIEF AS WEAKER MOISTURE RETURNS THURSDAY
NIGHT IN THE EASTERLY FLOW THAT MAY BE ASSOCIATED WITH THE OLD
BOUNDARY RETURNING FROM THE SOUTH. THIS MOISTURE STAYS THROUGH THE
FOLLOWING WEEKEND. AS MENTIONED IN A PREVIOUS AFD...THE MJO ALSO
APPEARS TO BE SUPPORTIVE OF THIS TURN TO WETTER WEATHER NEXT WEEK.

ALSO TODAY...HAVE CAPPED HIGH TEMPERATURES SEVERAL DEGREES BELOW
MOS TODAY ON THE NORTHEAST COAST. SIMILAR TO YESTERDAY...SEA
BREEZES SHOULD KEEP TEMPERATURES IN CHECK.

&&

.AVIATION...
EXPECT PREVAILING VFR CONDITIONS ACROSS ALL TAF SITES
DURING THIS MORNING. HOWEVER...MVFR CONDITIONS ARE POSSIBLE OVER THE
WEST AND WEST INTERIOR SECTIONS OF PUERTO RICO AS VCSH AND A
POSSIBILITY OF A THUNDERSTORM OR TWO EXISTS THIS AFTERNOON. SFC WIND
WILL INCREASE TO AROUND 10 TO 15 KNOTS TODAY WITH SOME HIGHER
GUSTS...EXPECT SEA BREEZE VARIATIONS AT COASTAL AREAS.

&&

.MARINE...SEAS BEGIN TO INCREASE IN RESPONSE TO WINDS GENERATED BY
THE STRONGER PRESSURE GRADIENTS FROM THE HIGH THAT WILL BUILD
NORTH OF PUERTO RICO TODAY THROUGH MONDAY. SMALL CRAFT ADVISORIES
ARE EXPECTED MONDAY MORNING THROUGH TUESDAY MORNING BUT MAY BE
MARGINAL AT FIRST DUE TO UNCERTAINTY AS TO HOW STRONG THE
APPROACHING FRONT WILL BE. THEREFORE HEADLINES FOR THIS ADVISORY
WILL BE DELAYED UNTIL THIS AFTERNOON IN CASE THEY FAIL TO
MATERIALIZE. WETTER CLOUDIER WEATHER IS EXPECTED NEXT WEEK.

[Macrocane]

Good morning. Last night was a rainy night for El Salvador and this morning it's still raining in some areas, in San Salvador it has been drizzling at times. This is the rainfall registered between 0:00 a.m and 6:00 am

Acajutla 16 mm/0.63 inches
San Salvador 30mm/1.18 inches
San Vicente 35 mm/1.38 inches
San Miguel 6 mm/0.24 inches
La Union 35 mm/1.38 inches

This is an IR picture of today at 6:15 am


As you can see in this surface analysis the rain is caused by a trough and the ITCZ:

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1123 AM AST SAT MAY 1 2010

.UPDATE...CONTINUE TO EXPECT SOME DIURNAL SHOWER DEVELOPMENT
ACROSS THE WESTERN INTERIOR AND WESTERN SECTIONS OF PUERTO RICO
THIS AFTERNOON...SO LEFT FORECAST FOR TODAY UNTOUCHED.
HOWEVER...DECIDED TO TONE DOWN EXPECTED WEATHER FOR THE NEXT FEW
EVENINGS AS ALTHOUGH WE WILL HAVE FAVORABLE UPPER LEVEL
CONDITIONS...LOW LEVEL MOISTURE WILL BE LIMITING AND CHANCES FOR
ANY THUNDERSTORM TYPE CONVECTION UNLIKELY DURING THE OVERNIGHT
HOURS. HOWEVER EXPLOSIVE CONVECTION DURING THE AFTERNOON HOURS
WILL REMAIN POSSIBLE UNDER THE DEVELOPING WEATHER PATTERN.

&&

.AVIATION...PREVAILING VFR CONDS EXPECTED THROUGH 01/18Z...WITH A
VCSH OR PASSING SHRA OR TSRA EXPECTED TO RESULT IN TEMPORARY MVFR
CIGS AND VSBY ACROSS TJMZ AND POSSIBLY TJBQ FROM 01/18-01/23Z.
LLVL WINDS EXPECTED TO BE GENERALLY ENE AT 12 TO 17 KNOTS FOR THE
NEXT 24 HOURS.

[cycloneye]

Afternoon discussion by NWS San Juan

It looks like the NE Caribbean will be under a rainy period during the next few days.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
307 PM AST SAT MAY 1 2010

.SYNOPSIS...STRONG SURFACE HIGH PRESSURE NORTH OF PUERTO RICO...WILL
REMAIN IN PLACE BUT CONTINUE TO BUILD AND SPREAD EASTWARD ACROSS THE
WEST ATLANTIC THROUGH MOST OF NEXT WEEK. THIS IN TURN WILL FURTHER
TIGHTEN THE PRESSURE GRADIENT ACROSS THE REGION TO MAINTAIN A MODERATE
TO STRONG AND DOMINANT EASTERLY TRADE WIND FLOW ACROSS THE NORTHEAST
CARIBBEAN. SHEARED OFF MOISTURE REMNANTS FROM A WEAKENING FRONTAL
BOUNDARY JUST NORTH OF THE AREA...WILL SAG SOUTH SOUTHWEST OVERNIGHT
THROUGH SUNDAY AND LINGER ACROSS THE REGION THROUGH A LEAST THE MIDDLE
OF NEXT WHILE SLOWLY DISSIPATING. MID TO UPPER LEVEL HIGH PRESSURE
RIDGE ACROSS THE CARIBBEAN BASIN WILL CONTINUE TO BUILD NORTHWARD
ACROSS THE SOUTHWEST AND WEST ATLANTIC THROUGH THE WEEKEND...WHILE
A BROAD UPPER TROUGH/TUTT NORTH OF THE AREA WILL DEEPEN AND SPREAD
SOUTHWEST ACROSS THE NORTHEAST CARIBBEAN...THEN INTO THE CENTRAL
CARIBBEAN BY EARLY NEXT WEEK. LATEST MODEL GUIDANCE CONTINUED TO
SUGGEST A CUT OFF TUTT LOW TO FORM ACROSS THE WINDWARD PASSAGE BY
TUESDAY BEFORE FILLING AND SLOWLY LIFTING NORTHWARDS DURING THE
LATTER PART OF THE UPCOMING WEEK.


&&

.DISCUSSION...LOCAL AND DIURNAL EFFECTS WERE THE MAIN DRIVING FORCE OF
AFTERNOON CONVECTION TODAY..AND THEREFORE EXPECT MOST OF THE ACTIVITY
TO DISSIPATE OVER LAND DURING THE EVENING HOURS. HOWEVER EXPECT THE
INCREASING EAST NORTHEAST WIND FLOW OVERNIGHT THROUGH SUNDAY TO AID
IN BRINGING SUFFICIENT MOISTURE ACROSS THE ISLANDS AND LOCAL WATERS
TO INDUCE EARLY MORNING CLOUDINESS AND SHOWERS MAINLY ACROSS THE
NORTHEAST AND EAST SECTIONS OF PUERTO RICO...AS WELL AS OVER PARTS
OF THE VIRGIN ISLANDS. THEREAFTER AND FOR THE REST OF THE DAY...DUE
TO THE PROXIMITY OF THE UPPER TROUGH...ALONG WITH AVAILABLE MOISTURE
AND DIURNAL EFFECT...EXPECT INCREASED AFTERNOON CONVECTION MAINLY
ACROSS THE INTERIOR AND SOUTHWEST SECTIONS OF PUERTO RICO. EXPECT
LESSER ACTIVITY ACROSS THE VIRGIN ISLANDS DURING THE REST OF THE
DAY ALTHOUGH INCREASED CLOUDINESS CAN BE EXPECTED ACROSS THE REGION
AT LEAST THROUGH TUESDAY...AS MOISTURE ALONG THE FRONTAL REMNANTS
WILL LINGER ACROSS THE NORTHEAST CARIBBEAN.

FOR THE LONG TERM...ALTHOUGH FAVORABLE UPPER LEVEL DYNAMICS CAN BE
EXPECTED OVER THE NEXT SEVERAL DAYS. SO FAR DO NOT SEE A SIGNIFICANT
INFLUX OF TROPICAL MOISTURE...AS THE FAIRLY STRONG EASTERLIES WILL
PREVAIL ACROSS THE REGION THROUGH MUCH OF THE WORK WEEK. THEREFORE
HAVE MADE FURTHER ADJUSTMENTS TO THE INHERITED FORECAST FOR NOW
ALTHOUGH I STILL EXPECT A SLIGHTLY WETTER PATTERN FOR THE NEXT
FEW DAYS. THE PREVAILING EASTERLIES WILL BRING SUFFICIENT LOW
LEVEL MOISTURE SURGES ACROSS THE ISLANDS AND SURROUNDING WATERS
TO HELP WITH DIURNAL AND NOCTURNAL CONVECTION ACROSS THE REGION.
ALSO... EXPECT THE UPPER LEVEL FEATURE MENTIONED ABOVE TO FURTHER
ENHANCE SOME OF THE CONVECTIVE ACTIVITY ESPECIALLY DURING THE
DAYTIME. IN ADDITION TO THE PROXIMITY OF THE UPPER LEVEL TROUGH...A
JET SEGMENT IS FORECAST TO CUT ACROSS THE REGION ALONG THE BASE OF
THE TROUGH OVER THE NEXT FEW DAYS...AND THIS WILL INCREASE POTENTIAL
FOR POSSIBLY STRONG AND EXPLOSIVE DIURNAL CONVECTION EVEN MORE AT
LEAST THROUGH TUESDAY. THIS WILL RESULT IN INCREASED CHANCES FOR
DAILY URBAN AND FLASH FLOODING ESPECIALLY ACROSS PUERTO RICO. STAY
TUNED...AS FURTHER ADJUSTMENTS MAY BE NEEDED WITH TIME IF AND WHEN
THIS WEATHER UNFOLDS.

&&

.AVIATION...A VCSH OR SHRA MAY BRING BRIEF MVFR CONDITIONS TO TJMZ
THROUGH 01/23Z...WITH PREVAILING VFR CONDS EXPECTED REMAINDER OF TAF
SITES. VFR CONDITIONS EXPECTED ALL TAF SITES OVERNIGHT...WITH A VCSH
POSSIBLE ACROSS NORTHERN PR AND ALL OF THE SMALLER ISLANDS. LLVL WIND
FLOW EXPECTED TO INCREASE TO ENE AT 15 TO 20 KTS TOMORROW.

&&

.CLIMATE...THE AVERAGE TEMPERATURE FOR APRIL IN SAN JUAN ENDED AT
80.8 DEGREES...WHICH WAS 1.7 DEGREES ABOVE NORMAL. THIS MARKS THE 11
STRAIGHT MONTH OF ABOVE NORMAL TEMPERATURES IN SAN JUAN. AS OF MAY
1ST...2010 RANKS AS THE THIRD WARMEST START TO A YEAR ON RECORD.
TEMPERATURES ON AT THE CHRISTIANSTED AIRPORT ON SAINT CROIX AND THE
CYRIL E. KING AIRPORT ON SAINT THOMAS WERE BOTH 0.8 DEGREES ABOVE
NORMAL FOR THE MONTH OF APRIL.

[cycloneye]

Stats for week 17 of 2010 in Puerto Rico

http://www.srh.noaa.gov/sju/?n=2010coopwk17

Code: Select all

Week Ending Friday         Week 17
4/30/2010             
STATION/SECTOR   7-day 7-day 7-day 24-hour 7-day
    Max T (F) Min T (F) Avg T (F) Rain (in.) Rain (in.)
NORTH COASTAL             
LEVITTOWN   - - - - -
BORINQUEN AIR   - - - - -
RIO PIEDRAS AES   - - - - -
SAN JUAN, WSFO   94 74 83.40 0.01 0.01
             
SOUTH COASTAL             
BOCA   - - - - -
CENTRAL AGUIRRE   - - - - -
ENSENADA   - - - 0.07 0.09
LAJAS AES   92 69 82.20 0.80 1.35
MAGUEYES ISLAND   - - - - -
PONCE 4 E   93 67 81.10 0.02 0.05
SANTA ISABEL   - - - - -
SANTA RITA   - - - - -
             
NORTHERN SLOPES             
BARCELONETA   - - - - -
CALERO CAMP   - - - - -
CANOVANAS   - - - 1.80 2.48
ISABELA AES   - - - - -
MANATI 2 E   - - - - -
MORA CAMP   - - - - -
RINCON POWER PLANT    - - - - -
TRUJILLO ALTO   - - - - -
             
SOUTHERN SLOPES             
CORRAL VIEJO   - - - - -
GUAYAMA   90 76 83.20 0.06 0.09
JUANA DIAZ CAMP   - - - - -
MAYAGUEZ CITY   - - - - -
PENUELAS   - - - - -
ROOSEVELT ROADS   - - - - -
SABANA GRANDE   - - - - -
YAUCO   - - - - -
             
EASTERN INTERIOR             
AIBONITO   85 64 72.50 0.29 0.53
GURABO AES   94 69 78.50 0.00 0.00
JAJOME ALTO   - - - - -
JUNCOS 1 NNE   93 71 80.70 0.53 0.60
PARAISO   - - - - -
RIO BLANCO LOWER   - - - 0.58 0.99
SAN LORENZO 3 S   - - - - -
             
WESTERN INTERIOR             
ACEITUNA   - - - - -
ADJUNTAS 1 NW   - - - - -
ADJUNTAS AES   88 57 71.80 2.68 3.68
ARECIBO OBS   91 66 76.70 2.04 2.52
CACAOS OROCOVIS   - - - 6.05 11.03
CERRO MARAVILLA   - - - - -
COLOSO   92 58 76.70 0.19 0.24
COROZAL AES   - - - - -
DOS BOCAS   - - - - -
GUAJATACA DAM   - - - - -
HAC. CONSTANZA   - - - - -
MARICAO 2 SSW   80 65 70.80 4.24 4.27
MARICAO HATCH   - - - 4.80 6.14
MOROVIS   - - - 1.10 1.31
NEGRO-COROZAL   - - - - -
TORO NEGRO   80 60 70.90 5.04 7.32
VILLALBA 1E   - - - - -
             
U.S. VIRGIN ISLANDS             
BETH UPPER NEW WORKS   - - - - -
CHARLOTTE AMALIE   90 77 82.70 0.16 0.16
CHRISTIANSTED AIRPORT   89 76 82.60 0.36 0.44
CORAL BAY   - - - - -
CRUZ BAY   - - - - -
EAST END   - - - - -
EAST HILL   - - - 0.36 0.39
FORT CHRISTIANSTED   88 78 82.60 0.25 0.58
MONTEPILLAR   - - - 0.39 0.46
REDHOOK   85 78 81.30 - 0.49
WINTBERG   - - - - -


Code: Select all

Sector Weekly Normal Weekly Rain Normal  PON
  Rain Rain PON YTD YTD YTD
X North Coast 0.01 1.15 1% 19.23 13.80 139%
X South Coast 0.50 0.58 86% 5.86 4.12 142%
X North Slopes 2.48 1.31 189% 21.87 12.89 170%
X South Slopes 0.09 1.12 8% 11.72 9.32 126%
X East Interior 0.53 1.47 36% 18.35 16.10 114%
X West Interior 4.56 1.93 236% 22.33 15.58 143%
             
Puerto Rico Average 1.36 1.26 108% 16.56 11.97 138%
X U.S. Virgin Islands 0.42 0.70 60% 8.32 7.85 106%
             
  PON = Percent of Normal YTD = Year to Date


[cycloneye]

I am worried if the worse case scenario about the oil spill getting into the loop current. What are the chances that the oil reaches the Western Caribbean Sea if it gets ingested to the loop current?

[Macrocane]

The rains have continued in El Salvador this is the accumulated rainfall between 0:00 am and 17:00 in some stations:

Acajutla 30 mm/1.18 inches
San Salvador 45 mm/1.77 inches
San Vicente 75 mm/2.95 inches
San Miguel 12 mm/0.47 inches
La Union 39 mm/1.54 inches
Vado Marin 78 mm/3.07 inches

[Gustywind]

I am worried if the worse case scenario about the oil spill getting into the loop current. What are the chances that the oil reaches the Western Caribbean Sea if it gets ingested to the loop current?

[cycloneye]

Here come the rains.

WEATHER SUMMARY FOR PUERTO RICO
NATIONAL WEATHER SERVICE SAN JUAN PR
1000 PM AST SAT MAY 1 2010

PARTLY CLOUDY SKIES WERE OBSERVED ACROSS PUERTO RICO...VIEQUES...
CULEBRA AND THE SURROUNDING WATERS THIS EVENING. THE DOPPLER WEATHER
RADAR DETECTED ISOLATED TO SCATTERED SHOWERS ACROSS WESTERN AND
EASTERN PUERTO RICO EARLY IN THE EVENING. AN AREA OF CLOUDINESS AND
SHOWERS WERE ALSO DETECTED ACROSS THE ATLANTIC COASTAL WATERS...
MOVING TO THE SOUTHWEST AT 10 TO 15 MPH. THE WINDS WERE MAINLY
EASTERLY AT AROUND 10 MPH AND THE COASTAL TEMPERATURES LATE IN THE
EVENING WERE MOSTLY IN THE LOWER 80S.

EXPECT SCATTERED SHOWERS TO EVENTUALLY DEVELOP ACROSS THE NORTHERN
AND EASTERN COASTAL AREAS OF PUERTO RICO OVERNIGHT. WITH FAVORABLE
ATMOSPHERIC CONDITIONS EXPECTED TO DEVELOP OVER THE NEXT SEVERAL
DAYS...EXPECT A GENERAL INCREASE IN SHOWER ACTIVITY ACROSS PUERTO
RICO EACH AFTERNOON...WITH THE HEAVIEST AND MOST WIDESPREAD
PRECIPITATION EXPECTED OVER THE INTERIOR AND WESTERN SECTIONS OF THE
ISLAND.

ACROSS THE LOCAL WATERS...MARINERS CAN EXPECT SEAS UP TO 6 FEET
AND WINDS UP TO 20 KNOTS OVERNIGHT AND ON SUNDAY. DUE TO CHOPPY SEA
CONDITIONS...SMALL CRAFTS ARE URGED TO EXERCISE CAUTION ACROSS
MOST OF THE LOCAL WATERS THROUGH TOMORROW.

[Gustywind]