Caribbean - Central America Weather

[cycloneye]

8 PM Discussion of Tropical Wave near Eastern Caribbean islands.

TROPICAL WAVE EXTENDS FROM 12N59W TO 19N56W MOVING W AT 15 KT.
THE WAVE REMAINS ON THE WESTERN PERIPHERY OF VERY BROAD LOW-
LEVEL TROUGHING ACROSS THE TROPICAL ATLC S OF 20N BETWEEN
45W-60W. TOTAL PRECIPITABLE WATER IMAGERY INDICATES ELEVATED
VALUES EAST OF THE LESSER ANTILLES FROM 10N-18N BETWEEN
53W-60W...WHICH STRETCH WESTWARD INTO THE SOUTHEASTERN CARIBBEAN
SEA S OF 15N E OF 69W. WHILE NO SIGNIFICANT DEEP CONVECTION IS
IN THE VICINITY OF THE AXIS OF THE WAVE...SCATTERED MODERATE
CONVECTION IS OCCURRING ACROSS THE EASTERN CARIBBEAN FROM
10N-17N BETWEEN 61W-68W.

[cycloneye]

Good morning.

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN JUAN PR
507 AM AST TUE SEP 25 2012

.SYNOPSIS...UPPER LEVEL RIDGE WILL BUILD OVER THE AREA AS UPPER
LEVEL LOW IN A NORTHEAST-SOUTHWEST TROUGH CONTINUES TO RETROGRESS
TOWARD THE HISPANIOLA.

&&

.DISCUSSION...UPPER LEVEL LOW IN A NORTHEAST-SOUTHWEST TROUGH WILL
CONTINUE TO RETROGRESS TOWARD THE HISPANIOLA. THIS WILL RESULT IN
MOISTURE ADVECTION AND FAVORABLE UPPER LEVEL DYNAMICS THROUGHOUT
THE DAY...WITH SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF THE
LOCAL AREA. THE HEAVIEST SHOWERS AND THUNDERSTORMS ARE ANTICIPATED
ACROSS CENTRAL AND SOUTHWEST PUERTO RICO LATER TODAY AND MAY INDUCE
URBAN FLOODING. UPPER LEVEL RIDGE IS THEN EXPECTED TO BUILD ACROSS
THE LOCAL AREA...BUT AVAILABLE MOISTURE AND DIURNAL HEATING WILL
COMBINE TO PRODUCE AFTERNOON SHOWERS AND THUNDERSTORMS ACROSS
CENTRAL AND SOUTHWEST PUERTO RICO WEDNESDAY AND THURSDAY SHIFTING
TOWARD CENTRAL AND WEST PUERTO RICO ON FRIDAY. THERE WILL BE A
DRYING TREND THURSDAY AND FRIDAY...HOWEVER SURFACE LOW PRESSURE
ACROSS THE CENTRAL CARIBBEAN IS EXPECTED TO DEEPEN. THIS WILL
CREATE A MORE SOUTHERLY FLOW...BRINGING UP SOME MOISTURE FROM
SOUTH AMERICA OVER THE WEEKEND.

&&

.AVIATION...SCT-NMRS SHRA AND ISOLD TSRA TODAY WITH PREDOMINANT CIGS
BKN040 DROPPING BELOW 3KFT IN TSRA ESPECIALLY AT JMZ. WINDS FROM THE
ENE AT 15G21KT XCPT FOR A NW WIND AROUND 10KT AT JMZ.

&&

.MARINE...SEAS HOLD NEAR 5 TO 6 FEET IN OPEN WATERS THROUGH WEDNESDAY
AND FALL AS WINDS DIMINISH. PULSES OF NORTHEAST SWELLS WILL AFFECT
THE ATLANTIC COASTAL WATERS AND THE CARIBBEAN PASSAGES FOR THE
NEXT FEW DAYS.

&&

.CLIMATE...AT THE SAN JUAN AREA...SEPTEMBER 2012 CURRENTLY RANKS AS
THE DRIEST SEPTEMBER ON RECORD WITH ONLY 0.81 INCHES SO FAR. IN
TERMS OF TEMPERATURES...SEPTEMBER 2012 REMAINS ON PACE TO BE ONE
OF THE WARMEST SEPTEMBER ON RECORD. THE AVERAGE TEMPERATURE SO FAR
HAS BEEN 85.1 DEGREES. THE WARMEST SEPTEMBER ON RECORD WAS
SEPTEMBER 1995 WITH AN AVERAGE TEMPERATURE OF 84.9 DEGREES. IN
ADDITION...SEPTEMBER 2012 CURRENTLY RANKS AS THE THIRD HOTTEST
MONTH OF ANY YEAR...TYING JUNE AND JULY 1980. THE HOTTEST MONTH
EVER WAS JUNE 2012 WITH AN AVERAGE TEMPERATURE OF 85.7 DEGREES.

AT CYRIL E. KING AIRPORT/SAINT THOMAS...SEPTEMBER 2012 CURRENTLY
RANKS AS THE DRIEST SEPTEMBER ON RECORD WITH 0.81 INCHES SO FAR.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 89 77 / 60 50 50 30
STT 88 80 88 79 / 50 50 50 30

[cycloneye]

2 PM Discussion of Eastern Caribbean Wave.

TROPICAL WAVE IN THE E CARIBBEAN EXTENDS FROM 17N64W TO 11N65W
MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP
MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY.
WAVE REMAINS TO THE E OF AN UPPER LOW/TROUGH COVERING THE
CENTRAL CARIBBEAN.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
301 PM AST TUE SEP 25 2012

.SYNOPSIS...LOW EMBEDDED IN THE NORTHEAST TO SOUTHWEST ORIENTED
TUTT WILL CONTINUE TO RETROGRESS TOWARD HISPANIOLA TONIGHT...WITH
MID TO UPPER LEVEL RIDGE THEN BUILDING ACROSS THE LOCAL AREA
DURING THE NEXT COUPLE OF DAYS.

&&

.DISCUSSION...UPPER LEVEL LOW WILL CONTINUE TO RETROGRESS TOWARD
HISPANIOLA TONIGHT...WITH CONTINUED MOISTURE ADVECTION AND
FAVORABLE UPPER LEVEL DYNAMICS ALLOWING AFTERNOON SHOWERS AND
THUNDERSTORMS ACROSS PARTS OF THE LOCAL AREA TO LINGER THROUGH AT
LEAST EARLY THIS EVENING. MID TO UPPER LEVEL RIDGE IS THEN
EXPECTED TO BUILD ACROSS THE LOCAL AREA...BUT AVAILABLE MOISTURE
AND DIURNAL HEATING WILL STILL COMBINE TO PRODUCE AFTERNOON
SHOWERS AND THUNDERSTORMS ACROSS CENTRAL AND SOUTHWEST PUERTO RICO
WEDNESDAY AND THURSDAY SHIFTING TOWARD CENTRAL AND WEST PUERTO
RICO ON FRIDAY. THEREAFTER...APPROACHING MID TO MOSTLY UPPER
TROUGH AND ASSOCIATED...SLOWLY DEEPENING SURFACE LOW PRESSURE
ACROSS THE CENTRAL CARIBBEAN...WILL EVENTUALLY CREATE A MORE
SOUTHERLY FLOW...BRINGING SOME MOISTURE FROM SOUTH AMERICA INTO
THE LOCAL AREA DURING THE WEEKEND.

&&

.AVIATION...AFTERNOON THUNDERSTORMS ACROSS THE INTERIOR AND
WESTERN SECTIONS OF PUERTO RICO WILL AFFECT THE AREAS AROUND TJMZ
AND POSSIBLY TJPS...THEREAFTER...VFR CONDITIONS WILL PREVAIL
ACROSS ALL TAF SITES THIS EVENING AND OVERNIGHT. WINDS WILL BECOME
LIGHT AND VARIABLE TONIGHT AT THE SURFACE AND FROM THE EAST
NORTHEAST AT AROUND 10 KTS AT 2K FT. SHRA/TSRA ARE ONCE AGAIN
EXPECTED TOMORROW AFTERNOON ACROSS THE INTERIOR...SOUTHERN...AND
WESTERN PR.

&&

.MARINE...GENERALLY EXPECT WINDS OF 17 KNOTS OR LESS AND SEAS OF
6 FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH AT LEAST
THURSDAY. PULSES OF NORTHEAST SWELLS WILL CONTINUE TO AFFECT
THE ATLANTIC COASTAL WATERS AND THE CARIBBEAN PASSAGES FOR THE
NEXT FEW DAYS. SMALL BOAT OPERATORS SHOULD CONTINUE TO EXERCISE
CAUTION ACROSS PARTS OF THE REGIONAL WATERS TONIGHT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 89 78 89 / 50 50 30 30
STT 80 88 79 87 / 50 50 30 30

[Macrocane]

Lateste HPC discussion:

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
228 PM EDT TUE SEP 25 2012

AT 15 UTC HURRICANE MIRIAM CENTERED NEAR 18.7N 114.5W...WITH
CENTRAL PRESSURE OF 969 HPA AND MAXIMUM SUSTAINED WINDS OF 85KT.
IT IS MOVING WEST-NORTHWEST AT 04KT. SEE NHC BULLETIN FOR DETAILS.

DISCUSSION FROM SEP 25/00 UTC: AN UPPER LEVEL HIGH NEAR NAYARIT/
COLIMA IN CENTRAL MEXICO EXTENDS A RIDGE EAST ACROSS THE SOUTHERN
STATES OF MEXICO TO NORTHERN CENTRAL AMERICA/WESTERN CARIBBEAN.
THROUGH 48-72 HRS THIS RIDGE IS FORECAST TO BUILD NORTH ACROSS
MEXICO TO TEXAS/SOUTHWEST USA. SIMILAR EVOLUTION IS EXPECTED AT
500 HPA...WITH RIDGE PATTERN STRENGTHENING ACROSS THE GULF INTO
THE SOUTHERN STATES OF MEXICO THROUGH 72-96 HRS. AS THE MID LEVEL
RIDGE BUILDS/INTENSIFIES...MODELS SHOWING SUBSIDENCE CAP
ESTABLISHING FIRST ACROSS THE YUCATAN PENINSULA...THEN BUILDING
SOUTHWARD INTO SOUTHERN AND CENTRAL STATES OF MEXICO LATER THIS
WEEK.

MEANWHILE...UNDER INFLUENCE OF THIS RIDGE...THE NHC IS FORECASTING
HURRICANE MIRIAM TO SLOWLY LIFT NORTH TOWARDS THE BAJA CALIFORNIA
PENINSULA. AS IT MOVES TO COLD WATERS THEY FORECAST TO CYCLONE TO
WEAKEN. THEY NOW EXPECT THIS SYSTEM TO ENTER CENTRAL BAJA LATER ON
DAY 05. AS THE CYCLONE LIFTS NORTH...OUTER BAND CONVECTION IS
EXPECTED TO AFFECT THE SOUTHERN PORTIONS OF THE BAJA PENINSULA AND
PORTIONS OF SINALOA/SIERRA MADRE OCCIDENTAL...WITH RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM/DAY. THROUGH DAY
03...THE MAXIMA IS TO INCREASE TO 25-50MM/DAY...WITH LOCALLY
HIGHER AMOUNTS POSSIBLE DUE TO TOPOGRAPHICAL FORCING.

EAST OF THE RIDGE...OVER THE GULF OF MEXICO...A TROUGH EXTENDS TO
THE SOUTHWEST ACROSS THE FLORIDA PENINSULA TO THE YUCATAN. THE
TROUGH IS TO MEANDER EAST INTO WESTERN CUBA EARLY IN THE
CYCLE...THEN QUICKLY PULLS AS ANOTHER DEEPENS TO THE WEST. THE
LATTER IS TO THEN DEEPEN ACROSS FLORIDA TO THE WESTERN/CENTRAL
CARIBBEAN BY 72-96 HRS. UNDER INFLUENCE OF THE RIDGE TO THE WEST
AND THE DIGGING TROUGH OVER FLORIDA/WESTERN CARIBBEAN...A COLD
ADVECTIVE PATTERN ALOFT IS TO ESTABLISH ACROSS THE
YUCATAN-NORTHERN CENTRAL AMERICA. THIS WILL ENHANCE CONVECTIVE
INSTABILITY IN THIS AREA. ACROSS YUCATAN-QUINTANA ROO-BELIZE TO
NORTHERN GUATEMALA EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND
MAXIMA OF 15-25MM/DAY. OVER THE NORTHWEST BAHAMAS EXPECTING
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM/DAY...WHILE
OVER WESTERN CUBA EXPECTING 10-15MM/DAY AND MAXIMA OF 20-45MM
THROUGH 36 HRS...AND 05-10MM/DAY AND MAXIMA 15-25MM AT 36-60 HRS.

AS UPPER LEVEL TROUGH DEEPENS ACROSS CUBA TO CENTRAL AMERICA...IT
WILL INTERACT WITH THE EASTERN PACIFIC ITCZ. THIS IS TO DRAW THE
CONVERGENCE ZONE NORTH INTO THE SOUTHERN CARIBBEAN. AS THE
CONVERGENCE ZONE LIFTS NORTH INTO THE BASIN...A LOW IS TO FORM
ALONG THIS AXIS OVER THE SOUTHERN CARIBBEAN BY 72-96 HRS. EARLY IN
THE CYCLE...AS THE ITCZ MEANDERS OVER PANAMA-COSTA RICA EXPECTING
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-45MM/DAY. AS THE
LOW LEVEL CIRCULATION ESTABLISHES...WE THEN EXPECT RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM/DAY. THE LOW IS TO
ALSO ENHANCE MOISTURE TRANSPORT ACROSS THE SOUTHERN CARIBBEAN...
WITH MOISTURE/CONVECTION TO BUILD NORTHWARD INTO JAMAICA THROUGH
54-60 HRS...AND INTO SOUTHERN HISPANIOLA BY 72-96 HRS. ACROSS
JAMAICA WE THEN EXPECT RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA
OF 20-35MM/DAY...SIMILARLY OVER SOUTHERN HISPANIOLA.

UPPER ANALYSIS SHOWS TUTT WITH AXIS SOUTHWEST ACROSS EASTERN
HISPANIOLA TO THE GULF OF URABA/PANAMA. THIS FAVORS A BROAD AREA
OF UPPER DIVERGENCE THAT IS VENTING DEEP CONVECTION ACROSS THE
EASTERN CARIBBEAN AND NORTHERN SOUTH AMERICA. THE UPPER TROUGH IS
TO MIGRATE WEST TO THE CENTRAL CARIBBEAN AS IT YIELDS TO A
BUILDING CELL OF THE SUBEQUATORIAL RIDGE. MEANWHILE...THE UPPER
LEVEL ENVIRONMENT ACROSS THE EASTERN CARIBBEAN IS TO REMAIN
FAVORABLE AND CONDUCIVE TO DEEP CONVECTION. THROUGH 54-66 HRS THE
TUTT IS TO WEAKEN/NEARLY DISSIPATE AS ENERGY SHEARS NORTH. ACROSS
PUERTO RICO TO HISPANIOLA...AS IT ENHANCES ACTIVITY WITH A
TROPICAL WAVE (SEE BELOW) THIS WILL FAVOR RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-25MM/DAY. FARTHER SOUTH...THE DEEP
TROUGH IS INTERACTING WITH THE ATLANTIC ITCZ/NEAR EQUATORIAL
TROUGH OVER NORTHERN SOUTH AMERICA. ACROSS THE ABC ISLANDS/
NORTHERN/NORTHWEST VENEZUELA TO NORTHERN COLOMBIA EXPECTING
ACCUMULATION OF 15-20MM/DAY AND MAXIMA OF 30-60MM/DAY THROUGH 36
HRS...AND 10-15MM/DAY AND MAXIMA OF 25-50MM AT 36-60 HRS. AS THE
ITCZ PULLS NORTH...THE MAXIMA DECREASES TO 20-35MM.

PERTURBATIONS IN THE EASTERLIES...INITIALIZED AT 12UTC...FORECAST
FROM 00UTC.

INITIAL 24 36 48 60 72 84 TYPE
49W 51W 53W 55W 57W 59W 61W TUTT INDCD
66W 69W 73W 76W 79W 82W 84W TW
81W 83W 86W 88W 90W 92W 94W EW
101W 103W 105W 107W 109W 110W 111W TW

A TUTT OVER THE EASTERN ATLANTIC SUSTAINS AN INDUCED TROUGH IN THE
LOW LEVEL EASTERLIES ALONG 49W. THIS ENTERS FRENCH GUIANA EARLY IN
THE CYCLE...WHERE IT IS TO FAVOR RAINFALL AMOUNTS OF 00-05MM/DAY
AND MAXIMA OF 10MM/DAY. ACROSS SURINAME TO GUYANA IT IS ALSO FAVOR
RAINFALL AMOUNTS OF 00-05MM/DAY AND MAXIMA OF 10MM/DAY THROUGH
54-60 HRS. HIGHER AMOUNTS OVER THE ISLAND CHAIN ARE FORECAST ON
DAY 03...WITH RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM.

A TROPICAL WAVE ALONG 66W/67W AND SOUTH OF 17N REMAINS ON THE
DIVERGENT SIDE OF THE CARIBBEAN TUTT. MOST ACTIVE CONVECTION IS
INITIALLY EXPECTED TO THE SOUTH OF 16N. ACROSS THE VIRGIN
ISLES/PUERTO RICO EXPECTING ACCUMULATION OF 05-10MM/DAY AND MAXIMA
OF 15-25MM/DAY THROUGH 24-30 HRS...WHILE ACROSS THE DOMINICAN
REPUBLIC TO HAITI IT IS TO THEN FAVOR ACCUMULATION OF 10-15MM/DAY
AND MAXIMA OF 25-50MM/DAY. OVER JAMAICA AND THE CAYMAN ISLANDS...
LATER IN THE CYCLE...IT WILL RESULT IN RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-35MM/DAY. OVER NORTHWEST
VENEZUELA-NORTHERN COLOMBIA IT WILL SUSTAIN RAINFALL AMOUNTS OF
15-20MM/DAY AND MAXIMA OF 30-60MM/DAY...WHILE OVER PANAMA
EXPECTING ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF 20-40MM/DAY.

AN EASTERLY WAVE ALONG 81W AND SOUTH OF 17N NOW LIES ON THE
CONVERGENT SIDE OF THE CARIBBEAN TUTT. AS A RESULT...MOST ACTIVE
CONVECTION IS TO THE SOUTH ALONG THE ITCZ. ACROSS PANAMA TO COSTA
RICA/SOUTHERN NICARAGUA THIS IS TO FAVOR RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-45MM. OVER WESTERN NICARAGUA TO
SOUTHERN HONDURAS/EL SALVADOR THEN EXPECT RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-25MM/DAY. SIMILARLY OVER SOUTHERN
MEXICO LATER IN THE CYCLE.

A TROPICAL WAVE ALONG 101W AND SOUTH OF 18N IS ENHANCING
CONVECTION ACROSS SOUTHWEST MEXICO...WHERE IT IS TO FAVOR RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM/DAY.

[cycloneye]

8 PM discussion of Tropical Wave in Caribbean.

TROPICAL WAVE EXTENDS FROM 12N71W TO 18N67W MOVING W AT 10 KT.
THE WAVE HAS COME INTO BETTER ALIGNMENT WITH A 700 MB TROUGH
OVER THE CENTRAL CARIBBEAN THE PAST 24 HOURS AND IS EXPECTED TO
MOVE WESTWARD ON THE SOUTHERN PERIPHERY OF A MID-LEVEL RIDGE
ANCHORED OVER THE SW NORTH ATLC NEAR 26N71W. PLENTY OF LOW TO
MIDDLE LEVEL MOISTURE ACCOMPANIES THE WAVE WITH TOTAL
PRECIPITABLE WATER IMAGERY INDICATING ELEVATED VALUES FROM
10N-17N BETWEEN 65W-75W. THE RESULT IS SCATTERED MODERATE
CONVECTION OCCURRING OVER A LARGE AREA OF THE EASTERN AND
CENTRAL CARIBBEAN FROM 12N-20N BETWEEN 63W-73W.

[cycloneye]

Good morning. Yes,rain is in the forecast for the next couple of days so be with umbrella.


AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN JUAN PR
420 AM AST WED SEP 26 2012

.SYNOPSIS...TUTT AXIS EXTENDING FROM HAITI SWD TO PANAMA WILL
CONTINUE TO MIGRATE WEST WITH MID-UPPER LEVEL RIDGE EXPECTED TO
BUILD OVER THE AREA OVER THE NEXT 24 HRS. RIDGE WILL HOLD THROUGH
EARLY NEXT WEEK WHEN IT WILL START TO MIGRATE WEST AS IT YIELDS TO
A DIGGING UPPER TROUGH ACROSS THE CNTRL ATLC NEXT WEEK.

&&

.DISCUSSION...DEEP MOISTURE IN COMBINATION WITH AN UNSTABLE
ATMOSPHERE AND UPPER LEVEL VENTILATION ASSOCIATED WITH BUILDING
UPPER RIDGE WILL YIELD SVRL DAYS OF ACTIVE WX THE MOST ACTIVE
WEATHER WE HAVE SEEN SO FAR THIS MONTH. BEST RAINFALL ACCUMULATIONS
LOOK TO BE THU AND FRI WHEN THE STEERING FLOW WILL BE WEAKEST.
TODAY AND THU CONVECTION WILL CONCENTRATE IN THE SOUTH BUT ON FRI
STEERING FLOW TURNS SOUTHEASTERLY WITH CONVECTION SHIFTING TO THE
NORTH COAST.

ON SAT...UPPER TROUGH ACROSS THE WRN CARIBBEAN INTERACTING WITH
BROAD SFC LOW AND TROPICAL WAVE OVER THE SOUTH CNTRL CARIBBEAN SEA WILL
RESULT IN A SIG HEAVY RAINFALL EVENT FOR HISPANIOLA AND JAMAICA.
H85 FCST FIELDS FROM GFES SHOW TWO SEPARATE AREAS OF LIFT ONE
AIMED AT JAMAICA AND ANOTHER ONE INTO THE FAR ERN DOMINICAN
REPUBLIC. CONVECTION WILL START TO BUILD ACROSS THE MONA CHANNEL
SAT MORNING AND AFFECT PORTIONS OF WESTERN PR. WHILE THERE SHOULD
BE ACTIVE WX RAINFALL ACCUMULATIONS ARE NOT EXPECTED TO BE
EXCESSIVE.

DEEP MOISTURE GETS SHUNTED AWAY FROM THE AREA SUN WITH HOT
TEMPERATURES RETURNING TO THE AREA AND IMPROVING WEATHER
CONDITIONS.

&&

.AVIATION...MOSTLY VFR CONDS ARE EXPECTED TO PREVAIL ACROSS ALL TAF
SITES THIS MORNING. HOWEVER...SHRA EMBEDDED IN THE LLVL NELY FLOW
MAY AFFECT TIST...TISX AND TJSJ FROM TIME TO TIME UNTIL 26/15Z. AFTER
26/16Z THUNDERSTORMS WILL DEVELOP ACROSS THE INTERIOR AND
WESTERN SECTIONS OF PUERTO RICO...AFFECTING THE AREAS AROUND TJMZ
AND POSSIBLY TJPS. TJSJ 26/00 SOUNDING SHOWED MAINLY NE WINDS AT 15
KTS OR LESS BLW 25 KFT.


&&

.MARINE...PULSES OF NORTHEAST SWELLS WILL AFFECT THE COASTAL
WATERS OVER THE NEXT FIVE DAYS. ACTIVE WX IS EXPECTED ACROSS THE
MONA PASSAGE SAT WHICH MAY REQUIRE SMWS.


&&

.CLIMATE...RELATIVELY COOL NEXT 3-4 DAYS DUE TO BETTER CHANCES OF
RAIN AND CONSIDERABLE CLOUDS COULD RESULT IN SEP NOT ENDING IN THE
WARMEST AND DRIEST SEP ON RECORD. ANOTHER HALF TO ONE INCH OF RAIN
SEEMS POSSIBLE AT SJU THROUGH THE REMAINDER OF SEP WHICH WOULD PUT
THE RAINFALL TOTALS OVER 1.5 INCHES AND THE RECORD IS 1.49 INCHES. SO
WE`LL HAVE TO WAIT AND SEE WHAT HAPPENS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 89 78 / 50 60 60 30
STT 87 79 86 79 / 50 50 50 30

[cycloneye]

A new area to watch ENE of the Leewards.Let's watch this to see if it moves to our area. Here is the 8 AM Tropical Weather Outlook.

AN AREA OF DISTURBED WEATHER HAS FORMED ABOUT 700 MILES
EAST-NORTHEAST OF THE LEEWARD ISLANDS. UPPER-LEVEL WINDS ARE
CURRENTLY NOT FAVORABLE FOR ADDITIONAL DEVELOPMENT...AND THIS
SYSTEM HAS A LOW CHANCE...10 PERCENT...OF BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS.

[msbee]

Good morning everyone

Luis, did you see this posted on stormcarib.com?
Do you knwo anything about this?

Monday, September 24, 2012 10:32AM PDT - GOES-13 outage
Just a quick note, the geostationary satellite that I have been using to show images for the Caribbean and Atlantic is out of commission. The coverage by GOES-15, a more westerly stationed satellite, is just out of reach for us. There is a 'spare' satellite parked in orbit (GOES-14) that might be pulled out of storage. There are also some other satellite that can provide some imagery, but for the time being we won't have the 15 minute satellite imagery of the Caribbean and Atlantic. Luckily we don't have any storms coming... -Gert

[cycloneye]

Good morning everyone

Luis, did you see this posted on stormcarib.com?
Do you knwo anything about this?

Monday, September 24, 2012 10:32AM PDT - GOES-13 outage
Just a quick note, the geostationary satellite that I have been using to show images for the Caribbean and Atlantic is out of commission. The coverage by GOES-15, a more westerly stationed satellite, is just out of reach for us. There is a 'spare' satellite parked in orbit (GOES-14) that might be pulled out of storage. There are also some other satellite that can provide some imagery, but for the time being we won't have the 15 minute satellite imagery of the Caribbean and Atlantic. Luckily we don't have any storms coming... -Gert

Hi Barbara. I didn't go to stormcarib but the news about the outage of Goes -13 was released on Monday and I made a topic about it at Talking Tropics forum.

viewtopic.php?f=31&t=113771&start=0

But Goes-14 has replaced the other one so we can continue to see what is going on in the Caribbean and most of the Atlantic.

[cycloneye]

2 PM Tropical Weather Outlook

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT WED SEP 26 2012

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL
STORM NADINE...LOCATED ABOUT 545 MILES SOUTH-SOUTHWEST OF THE
AZORES.

1. AN AREA OF DISTURBED WEATHER ABOUT 650 MILES EAST-NORTHEAST OF THE
LEEWARD ISLANDS IS MOVING WESTWARD AT 10 TO 15 MPH. UPPER-LEVEL
WINDS ARE NOT FAVORABLE FOR DEVELOPMENT...AND THIS SYSTEM HAS A LOW
CHANCE...10 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BEVEN

[msbee]

Good morning everyone

Luis, did you see this posted on stormcarib.com?
Do you knwo anything about this?

Monday, September 24, 2012 10:32AM PDT - GOES-13 outage
Just a quick note, the geostationary satellite that I have been using to show images for the Caribbean and Atlantic is out of commission. The coverage by GOES-15, a more westerly stationed satellite, is just out of reach for us. There is a 'spare' satellite parked in orbit (GOES-14) that might be pulled out of storage. There are also some other satellite that can provide some imagery, but for the time being we won't have the 15 minute satellite imagery of the Caribbean and Atlantic. Luckily we don't have any storms coming... -Gert

Hi Barbara. I didn't go to stormcarib but the news about the outage of Goes -13 was released on Monday and I made a topic about it at Talking Tropics forum.

viewtopic.php?f=31&t=113771&start=0

But Goes-14 has replaced the other one so we can continue to see what is going on in the Caribbean and most of the Atlantic.

thanks Luis
Do you have a link for GOES 14?

[cycloneye]

Barbara,what you see now in the images is from Goes-14.Here is the Puerto Rico section that covers the EastCentral Caribbean.

http://www.ssd.noaa.gov/goes/east/pr.html

[wxman57]

I think that estimate of potential development within 48 hrs (10%) is about 10% too high. Even for the life of the system, a 10% chance of TC development is probably a good bit high. Closer to 5% at least, and possibly closer to 0% than 5%, though the NHC only makes estimates in 10 point ranges. It's battling high shear and plenty of dry air, and that's not likely to change anytime soon.

[Macrocane]

Interesting HPC discussion today:


TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
231 PM EDT WED SEP 26 2012

AT 15 UTC TROPICAL STORM MIRIAM CENTERED NEAR 20.0N 115.7W...WITH
CENTRAL PRESSURE OF 992 HPA AND MAXIMUM SUSTAINED WINDS OF 55KT.
IT IS MOVING NORTH-NORTHWEST AT 05KT. SEE NHC BULLETIN FOR DETAILS.

DISCUSSION FROM SEP 26/00 UTC: AT 250 HPA...A HIGH NEAR NAYARIT/
COLIMA IN MEXICO ANCHORS A RIDGE AS IT EXTENDS NORTH TO THE
SOUTHERN USA. THE RIDGE IS BUILDING NORTH...AND REACHES MAXIMUM
AMPLITUDE EARLY IN THE CYCLE. MODELS SHOW A SIMILAR EVOLUTION AT
500 HPA...WITH MID LEVEL RIDGE PATTERN STRENGTHENING ACROSS THE
GULF INTO THE SOUTHERN/CENTRAL STATES OF MEXICO THROUGH 72 HRS.
THE 500 HPA RIDGE IS TO CENTER ON A CLOSED HIGH OFF THE COAST OF
TAMAULIPAS/NORTHERN VERACRUZ. AS THE MID LEVEL RIDGE BUILDS/
INTENSIFIES...MODELS SHOWING SUBSIDENCE CAP ESTABLISHING FIRST
ACROSS THE YUCATAN PENINSULA...THEN BUILDING SOUTHWARD INTO
SOUTHERN AND CENTRAL STATES OF MEXICO LATER THIS WEEK. THIS WILL
LEAD TO GRADUAL EROSION OF AVAILABLE MOISTURE LATER IN THE PERIOD.

THE BROAD RIDGE PATTERN IS STEERING TROPICAL STORM MIRIAM
NORTH...BUT AS IT ENTERS COOLER WATERS THE NHC CONTINUES TO
FORECAST THIS SYSTEM WEAKENING TO A DEPRESSION. IN A
SOUTH-SOUTHWESTERLY DEEP LAYER FLOW...MOISTURE FROM THE WANING
STORM WILL LIFT ACROSS THE CENTRAL/SOUTHERN BAJA PENINSULA TO
SINALOA/SIERRA MADRE OCCIDENTAL OF MEXICO. IN THIS AREA EXPECTING
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM/DAY.

DOWNSTREAM FROM THE CONTINENTAL RIDGE...A DIGGING UPPER LEVEL
TROUGH QUICKLY MOVES TO THE EASTERN GULF/YUCATAN PENINSULA EARLY
IN THE CYCLE. THROUGH 48 HRS THE TROUGH WILL AMPLIFY AS IT MOVES
ACROSS FLORIDA-WESTERN CUBA TO THE WESTERN CARIBBEAN/NORTHERN
CENTRAL AMERICA. DEEP TROUGH IS TO REACH MAXIMUM AMPLITUDE BY
60-72 HRS. AS IT AMPLIFIES...A WANING SHORT WAVE TROUGH OVER THE
EASTERN GULF IS TO QUICKLY LIFT ACROSS WESTERN CUBA/SOUTHERN
FLORIDA TO THE BAHAMAS. MEANWHILE...THE SHORT WAVE TROUGH IS TO
TRIGGER SCATTERED CONVECTION AS IT LIFTS ACROSS CUBA...WITH
RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 25-50MM/DAY...WHILE
OVER THE CENTRAL/NORTHWEST BAHAMAS IT WILL FAVOR RAINFALL AMOUNTS
OF 10-15MM/DAY AND MAXIMA OF 20-35MM/DAY.

FURTHERMORE...UNDER INFLUENCE OF THE RIDGE TO THE WEST AND THE
DIGGING TROUGH OVER FLORIDA/WESTERN CARIBBEAN...A COLD ADVECTIVE
PATTERN ALOFT IS TO ESTABLISH ACROSS THE YUCATAN-NORTHERN CENTRAL
AMERICA. THIS WILL ENHANCE CONVECTIVE INSTABILITY IN THIS AREA.
ACROSS YUCATAN-QUINTANA ROO-BELIZE TO NORTHERN GUATEMALA EXPECTING
RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 25-50MM THROUGH
36-48 HRS...AND 05-10MM/DAY AND MAXIMA OF 15-25MM/DAY AFTERWARDS.
ACROSS WESTERN/CENTRAL CUBA...AS CYCLONIC VORTICITY ADVECTS ACROSS
THE AREA...EXPECTING A SURGE IN DIURNAL CONVECTION WITH RAINFALL
AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 25-50MM/DAY BY 48 HRS. THIS
BUILDS EAST THROUGH 72 HRS...WITH RAINFALL AMOUNTS OF 15-20MM/DAY
AND MAXIMA OF 40-80MM/DAY. OVER THE NORTHWEST BAHAMAS EXPECTING
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-30MM/DAY. NOTE
THAT THIS IS HIGHER THAN WHAT MODEL GUIDANCE SUGGESTS.

AS UPPER LEVEL TROUGH DEEPENS ACROSS CUBA TO CENTRAL AMERICA...
MODELS CONTINUE TO SHOW POSITIVE INTERACTION WITH THE EASTERN
PACIFIC ITCZ. THE DIGGING TROUGH ALOFT WILL DRAW THE CONVERGENCE
ZONE NORTH INTO THE SOUTHERN CARIBBEAN. AS THE CONVERGENCE ZONE
ENTERS THE BASIN...A LOW IS TO FORM ALONG THIS AXIS OVER THE
SOUTHERN CARIBBEAN BY 48-72 HRS. EARLY IN THE CYCLE...AS THE ITCZ
MEANDERS OVER PANAMA-COSTA RICA EXPECTING RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-35MM/DAY. AS THE LOW LEVEL
CIRCULATION ESTABLISHES...WE THEN EXPECT MOST ACTIVE RAINFALL
BETWEEN SOUTHERN NICARAGUA AND WESTERN PANAMA...WITH RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM/DAY. THE LOW IS TO
ALSO ENHANCE MOISTURE TRANSPORT ACROSS THE SOUTHERN
CARIBBEAN...WITH MOISTURE/CONVECTION TO BUILD NORTHWARD INTO
JAMAICA THROUGH 30-36 HRS...AND INTO SOUTHERN HISPANIOLA BY 48-72
HRS. ACROSS JAMAICA EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND
MAXIMA OF 20-35MM/DAY...TO INCREASE TO MAXIMA OF 40-80MM THROUGH
72-84 HRS. ACROSS SOUTHERN HISPANIOLA EXPECT RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-35MM...TO INCREASE THROUGH 96-108 HRS.

A WANING TUTT NOW EXTENDS SOUTH ACROSS HAITI/WINDWARD PASSAGE OF
CUBA TO THE GULF OF URABA/EASTERN PANAMA. DIGGING/AMPLIFYING
TROUGH TO THE WEST WILL FORCE MOST OF THE SHORT WAVE ENERGY TO
QUICKLY SHEAR NORTH...LEADING TO RAPID DISSIPATION OF THIS TROUGH
THROUGH 48-54 HRS. MEANWHILE...WANING TUTT IS TO ENHANCE
CONVECTION ACROSS HISPANIOLA EARLY THIS CYCLE...WITH RAINFALL
AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 25-50MM. OTHER ACTIVITY TO
THE SOUTH IS EXPECTED ACROSS NORTHERN COLOMBIA...WHERE IT IS TO
FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 25-50MM/DAY.

FARTHER EAST...OVER THE EASTERN CARIBBEAN...BUILDING UPPER LEVEL
RIDGE IS SLOWLY BECOMING THE DOMINANT FEATURE. THROUGH 42/48 HRS
THE RIDGE IS TO BECOME WELL ENTRENCHED...WITH AXIS BUILDING NORTH
INTO THE WESTERN ATLANTIC WHILE CENTERING ON A CLOSED HIGH OVER
EASTERN HISPANIOLA/PUERTO RICO. THE RIDGE ALOFT IS TO CONTINUE
FAVORING AN UPPER DIVERGENT PATTERN...WITH ENVIRONMENTAL
CONDITIONS REMAINING CONDUCIVE TO DEEP CONVECTION. K INDEX
RESPONDS IN KIND...AS IT IS TO REMAIN IN THE LOW 30S DURING THE
NEXT FEW DAYS. MODELS GENERALLY AGREE ON SCATTERED CONVECTION TO
AFFECT PUERTO RICO-VIRGIN ISLANDS...WITH SEA BREEZE DRIVEN
ACTIVITY TO DOMINATE. IN THIS PATTERN EXPECTING RAINFALL AMOUNTS
OF 10-15MM/DAY AND MAXIMA OF 20-35MM/DAY.

EAST OF THIS RIDGE...A TUTT LOW NEAR 28N 47W EXTENDS A TROUGH TO
THE SOUTHWEST TO THE LESSER ANTILLES. AS THE RIDGE TO THE WEST
BUILDS NORTH...BASE OF THE TROUGH WILL GRADUALLY AMPLIFY SOUTH
INTO THE NORTHERN GUIANAS BY 54-66 HRS...WHERE IT IS TO MEANDER
THROUGH 84 HRS. THIS TROUGH WILL INTERACT WITH THE ATLANTIC ITCZ/
SEA BREEZE CONVERGENCE...TO ENHANCE CONVECTION ACROSS THE NORTHERN
GUIANAS-ORINOCO DELTA REGION AND THE SOUTHERN WINDWARD ISLANDS. IN
THIS AREA EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-25MM/DAY...WITH MOST ACTIVE ON DAYS 02-03.

PERTURBATIONS IN THE EASTERLIES...INITIALIZED AT 12UTC...FORECAST
FROM 00UTC.

INITIAL 24 36 48 60 72 84 TYPE
53W 55W 57W 58W 59W 60W 61W TUTT INDCD
73W 76W 78W 80W 82W 83W 84W TW
86W 88W 90W 92W 94W 96W 98W EW
105W 107W 109W 110W DISSIPATES TW

THE TUTT EAST OF THE ISLANDS SUSTAINS AN INDUCED TROUGH IN THE LOW
LEVEL EASTERLIES ALONG 53W AND SOUTH OF 23N. MODELS CONTINUE TO
SHOW A SLOW WESTWARD PROGRESSION OVER THE NEXT COUPLE OF
DAYS...WITH PERTURBATION THEN QUICKLY DAMPENING AS IT ENTERS THE
LEEWARD ISLES ON DAY 03. INITIALLY IT IS TO ENHANCE SOME OF THE
ACTIVITY AS IT MOVES ACROSS THE GUIANAS...WITH RAINFALL AMOUNTS OF
00-05MM/DAY AND MAXIMA OF 10MM/DAY. ON THE LEEWARD ISLANDS IT IS
TO THEN FAVOR RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM.

A TROPICAL WAVE ALONG 73W AND SOUTH OF 17N CONTINUES TO INTERACT
WITH WANING TUTT OVER THE CENTRAL CARIBBEAN. THIS WILL ENHANCE
ACTIVITY EARLY THIS PERIOD AS THE WAVE MOVES ACROSS HISPANIOLA...
WHERE IT IS TO FAVOR ACCUMULATION OF 15-20MM/DAY AND MAXIMA OF
25-50MM/DAY. OVER JAMAICA-EASTERN CUBA AND THE CAYMAN ISLANDS IT
WILL RESULT IN RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-35MM/DAY BY 48 HRS. OVER NORTHERN COLOMBIA TO PANAMA EXPECTING
ACCUMULATION OF 15-20MM/DAY AND MAXIMA OF 25-50MM/DAY... WHILE
OVER COSTA RICA TO EASTERN NICARAGUA IT WILL SUSTAIN ACCUMULATION
OF 10-15MM/DAY AND MAXIMA OF 20-40MM/DAY.

AN EASTERLY WAVE ALONG 86W AND SOUTH OF 18N REMAINS ON CONVERGENT
SIDE OF THE CARIBBEAN TUTT...WITH ACTIVITY LIMITING TO COSTA
RICA/SOUTHERN NICARAGUA. BUT AS IT MOVES ACROSS NICARAGUA TO EL
SALVADOR/HONDURAS ENVIRONMENTAL CONDITIONS WILL IMPROVE...TO
RESULT IN RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-25MM/DAY. ACROSS SOUTHERN-CENTRAL MEXICO IT IS TO THEN FAVOR
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-45MM/DAY.

A TROPICAL WAVE ALONG 105W AND SOUTH OF 18N IS ENHANCING ACTIVITY
ALONG THE EASTERN PACIFIC ITCZ...WITH CONVECTION ON ITS NORTHERN
FRINGES TO AFFECT COLIMA/NAYARIT MEXICO EARLY IN THE CYCLE WITH
ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF 20-40MM/DAY.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
318 PM AST WED SEP 26 2012

.SYNOPSIS...UPPER LEVEL RIDGE WILL EXTEND ACROSS THE LOCAL AREA
DURING THE NEXT SEVERAL DAYS.

&&

.DISCUSSION...DEEP MOISTURE IN COMBINATION WITH AN UNSTABLE
ATMOSPHERE...LOCAL EFFECTS AND UPPER LEVEL VENTILATION ASSOCIATED
WITH THE AFOREMENTIONED UPPER RIDGE WILL YIELD A FEW MORE DAYS OF
FAIRLY ACTIVE WEATHER ACROSS THE LOCAL AREA...WITH SHOWERS AND
THUNDERSTORMS CONCENTRATING OVER THE SOUTH PART OF PUERTO RICO
THURSDAY...THEN ACROSS THE NORTH COAST ON FRIDAY AND SATURDAY IN
SOUTHEAST LOW TO MID LEVEL FLOW. AN OVERALL DRIER...MORE STABLE
AND "WARMER" AIR MASS IS GENERALLY EXPECTED FOR SUNDAY AND
MONDAY.

&&

.AVIATION...AFTERNOON THUNDERSTORMS ACROSS THE SOUTH AND WESTERN
SECTIONS OF PUERTO RICO WILL AFFECT THE AREAS AROUND TJMZ AND
TJPS. THEREAFTER...MOSTLY VFR CONDITIONS ARE EXPECTED ACROSS ALL
TAF SITES THIS EVENING AND OVERNIGHT WITH PASSING SHRA. WINDS WILL
BECOME LIGHT AND VARIABLE TONIGHT AT THE SURFACE AND FROM THE EAST
NORTHEAST AT AROUND 5 TO 10 KTS AT 2K FT. SHRA/TSRA ARE ONCE AGAIN
EXPECTED TOMORROW AFTERNOON ACROSS THE LOCAL ISLANDS...THE MOST
PERSISTENT SHRA/TSRA EXPECTED TO BE ACROSS PUERTO RICO.

&&

.MARINE...GENERALLY EXPECT WINDS OF 14 KNOTS OR LESS AND SEAS OF
5 FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH AT LEAST
FRIDAY. PULSES OF NORTHEAST SWELLS WILL CONTINUE TO AFFECT THE
ATLANTIC COASTAL WATERS AND THE CARIBBEAN PASSAGES FOR THE NEXT
FEW DAYS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 88 78 89 / 60 60 30 40
STT 79 86 79 86 / 50 50 30 30

[msbee]

I think that estimate of potential development within 48 hrs (10%) is about 10% too high. Even for the life of the system, a 10% chance of TC development is probably a good bit high. Closer to 5% at least, and possibly closer to 0% than 5%, though the NHC only makes estimates in 10 point ranges. It's battling high shear and plenty of dry air, and that's not likely to change anytime soon.

Right on the mark, Wxman !

AN AREA OF DISTURBED WEATHER...LOCATED SEVERAL HUNDRED MILES
EAST-NORTHEAST OF THE LEEWARD ISLANDS...CONTINUES TO MOVE WESTWARD
AT 10 TO 15 MPH. THIS SYSTEM HAS NOT BECOME ANY BETTER
ORGANIZED...AND UPPER-LEVEL WINDS REMAIN UNFAVORABLE FOR
DEVELOPMENT. THIS SYSTEM HAS A LOW CHANCE...NEAR 0 PERCENT...OF
BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

[cycloneye]

I think that the Eastern Caribbean is pretty safe from any Tropical Cyclones comming from Africa as the Cape Verde Season ends.However, is not over yet as things can still form on October/November in the Caribbean or west of 53W like Hurricane Thomas did. Remember a few that affected the Eastern Caribbean in the October/November period like Hurricane Klaus,Hurricane Lenny,Hurricane Omar and Hurricane Thomas.

Hurricane Klaus




Hurricane Lenny



Hurricane Omar



Hurricane Thomas

[cycloneye]

Good morning.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
608 AM AST THU SEP 27 2012

.SYNOPSIS...COMPUTER MODEL GUIDANCE DEPICTED TWO WEAK TUTT LOWS...
ONE ACROSS THE CENTRAL CARIBBEAN JUST OVER CUBA AND ANOTHER ONE
NORTHEAST OF THE REGION. BOTH SYSTEMS ARE EXPECTED TO FILLED RAPIDLY
TODAY AS AN UPPER LEVEL RIDGE BUILDS AND EXTENDS ACROSS THE LOCAL
AREA FOR THE NEXT SEVERAL DAYS. A RELATIVELY UNSTABLE WEATHER
PATTERN WILL PREVAIL ACROSS THE REGION UNTIL AT LEAST
FRIDAY.

&&

.DISCUSSION...VARIABLY CLOUDY SKIES PREVAILED ACROSS PUERTO RICO
OVERNIGHT AND EARLY THIS MORNING. SCATTERED TO NUMEROUS SHOWERS AND
A FEW THUNDERSTORMS DOTED THE ATLANTIC AND CARIBBEAN COASTAL WATERS
OVERNIGHT AND EARLY THIS MORNING...WITH FEW OF THEM AFFECTING THE
NORTHERN AND EASTERN SECTIONS OF PUERTO RICO FROM TIME TO TIME. SOME
PERIODS OF MODERATE RAINFALL WAS OBSERVED ACROSS THE NORTHEASTERN
AND EASTERN SECTIONS OF THE ISLAND.

A VERY WEAK TUTT LOWS...ONE ACROSS CENTRAL CARIBBEAN AND ANOTHER ONE
NORTHEAST OF PUERTO RICO WILL CONTINUE TO FILL AS AN UPPER LEVEL
RIDGE BUILDS ACROSS THE REGION TODAY AND FOR THE NEXT SEVERAL DAYS.
HOWEVER...DEEP MOISTURE IN COMBINATION WITH AN UNSTABLE
ATMOSPHERE...LOCAL EFFECTS AND UPPER LEVEL VENTILATION ASSOCIATED
WITH THE AFOREMENTIONED DEVELOPING UPPER LEVEL RIDGE...WILL YIELD A
FEW MORE DAYS OF FAIRLY ACTIVE WEATHER ACROSS THE LOCAL AREA...WITH
SHOWERS AND THUNDERSTORMS MAINLY OVER THE SOUTH PART OF PUERTO RICO
TODAY...THEN ACROSS THE NORTH COAST ON FRIDAY AND SATURDAY UNDER THE
INFLUENCE OF A SOUTHEAST LOW TO MID LEVEL FLOW. AN OVERALL
DRIER...MORE STABLE AND "WARMER" AIR MASS IS GENERALLY EXPECTED FOR
SATURDAY...SUNDAY AND MONDAY.

&&

.AVIATION...VFR CONDS ARE EXPECTED TO PREVAIL ACROSS ALL TAF SITES
OVERNIGHT. HOWEVER...SCT -SHRA EMBEDDED IN THE LLVL NELY FLOW MAY
AFFECT TIST...TISX AND TJSJ FM TIME TO TIME. AFTERNOON CONVECTION
WILL DEVELOP ONCE AGAIN TOMORROW ACROSS CENTRAL...SOUTH AND WESTERN
PR. AS A RESULT...EXPECT MOUNTAIN OBSCURATION AND PERIODS OF
MVFR/IFR CONDS NEAR TJMZ AND TJPS BTWN 27/17 AND 27/21Z. EVENING
TJSJ RAOB SHOWED MAINLY NE WINDS AT 10 KTS OR LESS BLW 20 KFT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 78 89 78 / 60 30 30 0
STT 86 79 86 79 / 50 30 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
ISSUED BY NATIONAL WEATHER SERVICE MIAMI FL
438 PM AST THU SEP 27 2012


.DISCUSSION...

A TROPICAL WAVE JUST WEST OF HISPANIOLA WILL CONTINUE MOVING WEST
TONIGHT. IN ITS WAKE A PLUME OF MOISTURE EXTENDS EASTWARD ACROSS
PUERTO RICO AND THE U.S. VIRGIN ISLANDS...WITH THE 12Z JSJ
SOUNDING INDICATING A PWAT IN EXCESS OF TWO INCHES. THE
COMBINATION OF THE MOISTURE SOURCE AND A LOW LEVEL INVERTED TROUGH
EXTENDING ACROSS THE ISLANDS WILL CONTINUE TO FAVOR SHOWERS AND
THUNDERSTORMS ACROSS THE REGION THIS AFTERNOON AND EVENING...WITH
MOST OF THE ACTIVITY EXPECTED ACROSS PUERTO RICO WITH
CULEBRA...VIEQUES AND THE U.S. VIRGIN ISLANDS EXPECTING PASSING
SHOWERS. REPORTED ACCUMULATIONS SO FAR INDICATE NEAR 4 INCHES OF
RAIN HAVE BEEN REPORTED NEAR GURABO AND VILLALBA WITH URBAN FLOOD
STATEMENTS ISSUED FOR THESE AREAS EARLIER.

THE RECENT GUIDANCE INDICATES A LIGHT TO MODERATE SOUTHEASTERLY
FLOW WILL PREVAIL ACROSS THE REGION FRIDAY AND SATURDAY. THE
SOUTHEASTERLY FLOW AND SUFFICIENT MOISTURE ACROSS THE REGION WILL FAVOR
CHANCES OF SHOWERS AND THUNDERSTORMS MAINLY ACROSS PUERTO
RICO...WITH THE MOST FAVORED AREAS OF CONVECTION UNDER THIS FLOW
REGIME BEING THE NORTHERN AND NORTHWESTERN PORTIONS OF THE
ISLAND...WITH NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS
INDICATED IN THE FORECAST WITH MORE SCATTERED ACTIVITY EXPECTED
ELSEWHERE. BY SUNDAY SOME DRIER AIR IS FORECAST TO ENTER THE
REGION WITH A RIDGE BUILDING AT THE UPPER LEVELS..WITH CHANCES OF
SHOWERS AND THUNDERSTORMS DIMINISHING.

&&

.MARINE...

THE FORECAST FOR THE ATLANTIC WATERS IS FOR SEAS RANGING FROM NEAR
3 TO 5 FEET TONIGHT INTO THE WEEKEND WITH A LIGHT TO MODERATE EAST
TO SOUTHEAST FLOW FORECAST ACROSS THE REGION. FOR THE CARIBBEAN
WATERS GOING INTO THE WEEKEND SEAS FROM 1 TO 3 FEET ARE FORECAST
THEN INCREASING TO 3 TO 4 FEET INTO SUNDAY.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 89 78 89 / 30 30 0 50
STT 79 86 79 85 / 30 30 30 30