Caribbean - Central America Weather

[cycloneye]

Good morning to all.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
430 AM AST WED OCT 21 2009

.SYNOPSIS...
UPPER LEVEL HIGH PRESSURE RIDGE EXTENDING NORTHEAST ACROSS THE
REGION FROM THE CENTRAL CARIBBEAN...WILL REMAIN IN PLACE TODAY
THROUGH THURSDAY...BUT THEN BECOMES FLATTENED BY FRIDAY...AS A
LONG WAVE TROUGH DEEPENS AND SINKS SOUTHWARDS OVER THE SOUTHWEST
ATLANTIC AND ACROSS EASTERN CUBA. THE MID LEVEL SUBTROPICAL RIDGE
EXTENDING ACROSS THE REGION WILL SHIFT FURTHER EAST ACROSS THE
LESSER ANTILLES BY FRIDAY...AS A SHORT WAVE TROUGH AMPLIFIES
ACROSS THE WEST AND SOUTHWEST ATLANTIC. A STRONG SURFACE HIGH
PRESSURE RIDGE BUILDING ACROSS THE WESTERN ATLANTIC AND ANOTHER
ACROSS THE EASTERN CARIBBEAN...IS SEPARATED BY A SURFACE TROUGH/OLD
FRONTAL BOUNDARY WHICH EXTENDS SOUTHWARDS ACROSS THE WEST CENTRAL
ATLANTIC TO JUST EAST OF THE LESSER ANTILLES. THIS WILL MAINTAIN
AN FAIRLY LIGHT EAST NORTHEAST WIND FLOW ACROSS THE AREA TODAY.
THIS WIND FLOW IS HOWEVER EXPECTED TO BECOME MORE EAST SOUTHEASTERLY
BY FRIDAY AS THE CENTRAL ATLANTIC HIGH SINKS FURTHER SOUTH INTO
THE TROPICAL ATLANTIC AND THE SURFACE TROUGH EAST OF THE AREA
WEAKENS AND LIFTS NORTHWARDS.

&&

.DISCUSSION...
PREVAILING LIGHT EAST NORTHEAST LOW LEVEL WIND FLOW WILL CONTINUE TO
TRANSPORT FRAGMENTS OF LOW TO MID LEVEL MOISTURE FROM OLD FRONTAL
BOUNDARY/SHEAR LINE SOUTHWARDS ACROSS THE REGION TODAY THROUGH
THURSDAY. THIS WILL LEAD TO OCCASIONAL BANDS OF EARLY MORNING CLOUDS
AND SHOWERS ACROSS PARTS OF THE NORTHEAST AND EAST COASTAL SECTIONS
OF PUERTO RICO...AND SOME OF THE VIRGIN ISLANDS. MOSTLY FAIR WEATHER
SKIES EXPECTED TODAY...HOWEVER THE LIGHT WIND FLOW AND DAYTIME
HEATING...WILL LEAD TO LOCAL SEA BREEZE VARIATIONS AND DIURNAL
INDUCED SHOWER ACTIVITY MAINLY ACROSS PARTS OF THE WEST AND
SOUTHWEST SECTIONS OF PUERTO RICO DURING THE AFTERNOON. RECENT
UPPER AIR DATA AND MIMIC-TPW ANALYSIS PRODUCT INDICATED LOW PWAT
VALUES AND LIMITED MOISTURE ACROSS THE REGION...THEREFORE ONLY
VERY SHALLOW MOISTURE...AND ISOLATED AREAS OF CONVECTION IS
EXPECTED WITH NO WIDESPREAD RAINFALL ACROSS THE REGION. IN ADDITION...
ALTHOUGH MID TO UPPER LEVEL RIDGE IS EXPECTED TO MAINTAIN SUBSIDENCE
CAP ACROSS REGION...EXPECT SUFFICIENT DIURNAL FORCING TO INDUCE
ISOLATED AFTERNOON THUNDERSTORMS MAINLY ACROSS THE WEST SECTIONS
OF PUERTO RICO. MOST SUNNY AND FAIR WEATHER CONDITIONS WITH
ISOLATED PASSING EARLY MORNING SHOWERS AND LIMITED AFTERNOON
CONVECTION IS EXPECTED ACROSS THE ADJACENT ISLANDS...SURROUNDING
WATERS AND THE U.S. VIRGIN ISLANDS TODAY.

AS WIND BECOME MORE EAST SOUTH EAST BY THE END OF THE WEEK...PATCHES
OF TROPICAL MOISTURE ACCOMPANYING WEAK EASTERLY PERTURBATIONS WILL
MOVE ACROSS THE LOCAL REGION WHICH WOULD HELP ENHANCE DIURNAL CONVECTION
AND INCREASE THE CHANCES FOR MORE AFTERNOON SHOWERS AND THUNDERSTORM
ACTIVITY ACROSS THE ISLANDS AND LOCAL WATERS DURING THE LATTER PART
OF THE WEEK. HOWEVER...NO SIGNIFICANT WEATHER FEATURE IS EXPECTED
ACROSS THE FORECAST AREA FOR THE NEXT SEVERAL DAYS.

&&

.AVIATION...PREVAILING VFR CONDITIONS EXPECTED ACROSS ALL OF THE
LOCAL TAF SITES THROUGH 21/1400Z...WITH A VCSH POSSIBLE IN AND
AROUND TJSJ...TJBQ...THE VI...TNCM AND TKPK. AFTER 21/1600Z...EXPECT
SHRA AND TSRA DEVELOPMENT ACROSS THE CORDILLERA CENTRAL AND SOUTH
WESTERN SECTIONS OF PR...POSSIBLY BRINGING TEMPORARY MVFR CONDITIONS
AROUND TJPS AND TJMZ BETWEEN 21/1700Z-2200Z.

[cycloneye]

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT WED OCT 21 2009

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

A NEARLY STATIONARY AREA OF LOW PRESSURE OVER THE SOUTHWESTERN
CARIBBEAN SEA AND CENTRAL AMERICA IS PRODUCING A LARGE AREA OF
CLOUDINESS AND SHOWERS. THIS SYSTEM REMAINS POORLY ORGANIZED AND
DEVELOPMENT...IF ANY...WILL BE SLOW TO OCCUR. HEAVY RAINS WILL
LIKELY CONTINUE OVER COSTA RICA...NICARAGUA...AND HONDURAS
DURING THE NEXT FEW DAYS. THERE IS A LOW CHANCE... LESS THAN 30
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS.

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

$$
FORECASTER AVILA

[Gustywind]

[Gustywind]

000
AXNT20 KNHC 211701
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT THU OCT 21 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1645 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 30W/31W FROM 4N-17N AND MOVING WESTWARD
AT 8 KNOTS OVER THE PAST 24 HOURS. CYCLONIC CURVATURE OF THE
CLOUD FIELD IS NOTED ON SATELLITE IMAGERY. SCATTERED SHOWERS ARE
NOTED FROM 14N-18N BETWEEN 25W-34W.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 10N15W 8N20W 9N30W 6N35W 11N44W
11N61W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 3N-8N
BETWEEN 18W-23W. ISOLATED MODERATE CONVECTION IS FROM 1N-6N
BETWEEN 30W-37W.

...DISCUSSION...

GULF OF MEXICO...
A 1028 MB HIGH CENTERED OVER WESTERN NORTH CAROLINA NEAR 36N83W
IS PRODUCING SURFACE RIDGING OVER THE ENTIRE GULF OF MEXICO. THE
SURFACE PRESSURE GRADIENT HAS INCREASED OVER THE GULF...THUS
WINDS ARE NOW 15-20KT FROM THE NE OVER THE E GULF E OF 90W...AND
15-20KT FROM THE SE OVER THE W GULF. PATCHES OF BROKEN TO
OVERCAST LOW CLOUDS ARE OVER THE GULF. IN THE UPPER LEVELS... AN
UPPER LEVEL TROUGH IS OVER THE FAR E GULF AND FLORIDA. AN UPPER
LEVEL HIGH IS CENTERED OVER S MEXICO NEAR 18N98W. UPPER LEVEL
RIDGING IS OVER THE W GULF W OF 85W PRODUCING NW FLOW. STRONG
SUBSIDENCE IS OVER THE E GULF E OF 87W WHILE CONSIDERABLE
MOISTURE IS OVER THE W GULF. WITHIN 24 HOURS...A COLD FRONT WILL
BE APPROACHING THE TEXAS COAST. EXPECT PREFRONTAL CONVECTION
OVER THE NW GULF OVER THE NEXT 24 HOURS.

CARIBBEAN SEA...
RESIDUAL CONVECTION ASSOCIATED WITH A DISSIPATED STATIONARY
FRONT IS SOUTH OF CUBA FROM 17N-20N BETWEEN 75W-85W. A
QUASI-STATIONARY 1008 MB LOW IS CENTERED OVER THE SW CARIBBEAN
NEAR 11N82W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 8N-14N
BETWEEN 76W-84W. A 1010 MB LOW IS LOCATED IN THE GULF OF
HONDURAS NEAR 17N88W. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE
CENTER. THE E CARIBBEAN E OF 70W HAS MOSTLY FAIR WEATHER...
HOWEVER ISOLATED SHOWERS ARE NOTED. MODERATE TO FRESH TRADEWINDS
ARE OVER THE CARIBBEAN. IN THE UPPER LEVELS...UPPER LEVEL
TROUGHING IS OVER THE WESTERN AND EASTERN CARIBBEAN...WITH
RIDGING PREVAILING IN THE CENTRAL CARIBBEAN. SIGNIFICANT UPPER
LEVEL MOISTURE IS OVER THE W CARIBBEAN W OF 70W. STRONG
SUBSIDENCE IS OVER THE E CARIBBEAN. EXPECT THE LOW IN THE GULF
OF HONDURAS TO DISSIPATE WHILE THE LOW IN THE SW CARIBBEAN TO
REMAIN STATIONARY OVER THE NEXT 24 HOURS.

ATLANTIC OCEAN...
THE TAIL END OF A COLD FRONT IS OVER THE W ATLANTIC FROM 32N53W
TO 28N59W. A DISSIPATING STATIONARY FRONT CONTINUES TO E CUBA
ALONG 24N67W 20N74W. WIDELY SCATTERED MODERATE CONVECTION IS
OVER THE S BAHAMAS FROM 21N-25N BETWEEN 70W-75W. SCATTERED
SHOWERS ARE OVER THE REMAINDER OF THE FRONT. A SURFACE TROUGH IS
FROM 28N51W TO 19N55W. AN EMBEDDED 1010 MB LOW IS ON THE TROUGH
AXIS NEAR 25N52W. A 1019 MB HIGH IS OVER THE CENTRAL ATLANTIC
NEAR 28N29W. IN THE TROPICS...A 1009 MB LOW IS JUST NORTH OF THE
ITCZ NEAR 13N40W. SCATTERED SHOWERS ARE WITHIN 90 NM OF THE
CENTER. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE
W ATLANTIC N OF 20N AND W OF 70W. AN UPPER LEVEL RIDGE IS
BETWEEN 55W-70W. AN UPPER LEVEL LOW IS OVER THE CENTRAL ATLANTIC
NEAR 24N47W. UPPER LEVEL DIFFLUENCE E OF THE CENTER IS PRODUCING
WIDELY SCATTERED MODERATE CONVECTION FROM 23N-31N BETWEEN
38W-48W. AN UPPER LEVEL HIGH IS OVER THE TROPICAL ATLANTIC NEAR
10N40W. AN UPPER LEVEL RIDGE AXIS EXTENDS NE FROM THIS CENTER TO
25N25W. EXPECT...MORE CONVECTION ALONG THE ITCZ ESPECIALLY E OF
35W OVER THE NEXT 24 HOURS.

$$
AL/MRF

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
332 PM AST WED OCT 21 2009

.SYNOPSIS...AN ELONGATED MID TO UPPER LEVEL RIDGE WILL GENERALLY
REMAIN IN CONTROL OF THE LOCAL WEATHER FOR THE NEXT SEVERAL
DAYS...MAINTAINING A GENERALLY FAIR AND MAINLY DRY WEATHER PATTERN
ACROSS THE LOCAL ISLANDS. BY SATURDAY AND SUNDAY...RIDGE RE-ALIGNS
AND MAY ALLOW UPPER LEVEL TROUGHINESS TO AFFECT THE LOCAL AREA...
BUT TROUGH COULD BE TOO FAR EAST TO HAVE MUCH AFFECT ON THE LOCAL
WEATHER.

&&

.DISCUSSION...SENSIBLE WEATHER THE NEXT FEW DAYS WILL STILL BE
DICTATED BY SMALL BANDS AND PATCHES OF MOISTURE MOVING ACROSS THE
LOCAL ISLANDS FROM TIME TO TIME AND INTERACTING WITH LOCAL
EFFECTS...INCLUDING VERY GOOD SEA BREEZE CONVERGENCE...TO PRODUCE
SOME CLOUDS...SHOWERS AND POSSIBLY A COUPLE OF THUNDERSTORMS IN
DIURNALLY AND NOCTURNALLY FAVORED AREAS EACH DAY.

&&

.AVIATION...WENT WITH VA IN FORECAST FOR TKPK CONSIDERING VERY WEAK
FLOW ATTM...AND EXPECTED TURN TO THE SOUTHEAST NEXT 12 HOURS OVER
LEEWARD ISLES. FOR PR/USVI SITES...MOSTLY VFR CONDITIONS EXCEPT TJPS
AND TJMZ WHERE MVFR SHOULD LAST THRU 22Z. TJPS SHOULD SEE IFR
CONDITIONS AND TSRA BETWEEN 19 AND 21Z.

VOLCANIC ASH SCENARIO MAY BE A PROBLEM FOR THE TISX/TIST SITES
TOMORROW AFTERNOON WHEN WIND FLOW TURNS TO THE SOUTHEAST.
CONSIDERING VERY WEAK FLOW...WILL TAKE A WHILE FOR THE ASH CLOUD TO
ARRIVE...IF SITUATION PANS OUT.

&&

.MARINE...WINDS OF 13 KNOTS OR LESS AND SEAS OF 5 FEET OR LESS
WILL CONTINUE ACROSS THE REGIONAL WATERS THROUGH AT LEAST FRIDAY.
LONG PERIOD...NORTH NORTHWEST AND THEN NORTH SWELLS WILL AFFECT
THE ATLANTIC WATERS AND THE CARIBBEAN PASSAGES TONIGHT THROUGH
THURSDAY NIGHT. THESE SWELLS WILL LIKELY PRODUCE SOME LOCALLY
ROUGH SURF AND RIP CURRENTS TONIGHT AND THURSDAY.

[cycloneye]

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT WED OCT 21 2009

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

A NEARLY STATIONARY AREA OF LOW PRESSURE OVER THE SOUTHWESTERN
CARIBBEAN SEA AND CENTRAL AMERICA IS PRODUCING A LARGE AREA OF
CLOUDINESS AND SHOWERS. THIS SYSTEM REMAINS POORLY ORGANIZED AND
DEVELOPMENT...IF ANY...WILL BE SLOW TO OCCUR. REGARDLESS OF
DEVELOPMENT...HEAVY RAINS WILL LIKELY CONTINUE OVER COSTA
RICA...NICARAGUA...AND HONDURAS DURING THE NEXT FEW DAYS. THERE IS
A LOW CHANCE... LESS THAN 30 PERCENT...OF THIS SYSTEM BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

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

$$
FORECASTER PASCH

[Gustywind]

000
AXNT20 KNHC 212345
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED OCT 21 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND
RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 31W/32W S OF 18N MOVING W NEAR 10 KT.
WAVE EXHIBITS A VERY SHARP AND NARROW AXIS WITH CYCLONIC
CURVATURE OF THE LOW LEVEL CLOUD FIELD NOTED ON SATELLITE
IMAGERY. SCATTERED SHOWERS ARE FROM 12N-17N BETWEEN 25W-30W
ENHANCED BY AN UPPER RIDGE.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 11N15W 8N24W 8N37W 10N47W 9N62W.
CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 2N-8N BETWEEN
22W-42W.

...DISCUSSION...

GULF OF MEXICO...
THE GULF IS DOMINATED BY A SURFACE RIDGE ANCHORED IN THE W ATLC
OFF THE NORTH CAROLINA COAST. THE RETURN FLOW AROUND THIS
SURFACE RIDGE AND THE INCREASE PRESSURE GRADIENT HAS INCREASED
WINDS ACROSS THE GULF. PATCHES OF BROKEN LOW CLOUDS ARE ACROSS
MOST OF THE GULF BECOMING MOSTLY OVERCAST WITH SCATTERED SHOWERS
ALONG THE N GULF COAST N OF 27N W OF 87W. SIMILAR ACTIVITY IS
OVER THE STRAITS OF FLORIDA FROM THE FLORIDA KEYS TO THE N COAST
OF CUBA E OF 84W. A HIGHLY AMPLIFIED UPPER RIDGE EXTENDS FROM S
MEXICO ACROSS THE BAY OF CAMPECHE TO OVER THE LOWER MISSISSIPPI
VALLEY WITH AN EQUALLY AMPLIFIED UPPER TROUGH COVERING THE E
GULF EXTENDING S INTO THE CARIBBEAN AND E TO OVER THE W ATLC AND
STRONG SUBSIDENCE OVER THE E GULF E OF 86W. THE SURFACE RIDGE IS
EXPECTED TO RETREAT E AS A COLD FRONT MOVES OFF THE TEXAS COAST
LATE THU.

CARIBBEAN SEA...
A 1008 MB LOW IS IN THE SW CARIBBEAN OFF THE COAST OF NICARAGUA
NEAR 11N83W THAT HAS A LOW POTENTIAL OF TROPICAL DEVELOPMENT.
THE UPPER TROUGH THAT COVERS THE E GULF OF MEXICO DIPS S OVER
THE NW CARIBBEAN N OF 17N W OF 74W TO OVER THE YUCATAN. AN UPPER
RIDGE ANCHORED OVER NW VENEZUELA COVERS THE S CARIBBEAN S OF 16N
FROM 67W-83W. THIS SCENARIO IS PROVIDING DIFFLUENCE ALOFT TO
GENERATE A BROAD AREA OF MULTILAYERED OVERCAST CLOUDS WITH
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS E OF A LINE FROM CUBA
NEAR 22N81W TO HONDURAS NEAR 16N87W AND W OF LINE FROM
HISPANIOLA NEAR 18N71W TO PANAMA NEAR 9N78W. AND UPPER TROUGH
FROM THE CENTRAL ATLC EXTENDS SW OVER THE E CARIBBEAN PROVIDING
DRY STABLE AIRMASS E OF 70W THUS GIVING THE E CARIBBEAN CLEAR
SKIES THIS EVENING. THE LOW IN THE SW CARIBBEAN IS EXPECTED TO
REMAIN STATIONARY OVER THE NEXT 24 HOURS.

ATLANTIC OCEAN...
A BROAD UPPER TROUGH COVERS THE W INTO THE CENTRAL ATLC N OF 30N
WITH A NARROW AMPLIFIED AXIS EXTENDING S OVER THE W ATLC THROUGH
30N74W ACROSS CUBA INTO THE CARIBBEAN NEAR 23N80W AND W OVER THE
E GULF OF MEXICO PROVIDING STRONG SUBSIDENCE AND MOSTLY DRY
STABLE AIR W OF 76W. THE BROAD UPPER TROUGH IS SUPPORTING THE
REMNANTS OF A STATIONARY FRONT ENTERING THE W/CENTRAL ATLC NEAR
32N52W EXTENDING SW TO 25N64W WHILE THE REMAINDER OF THE W ATLC
TO INLAND OVER THE E US AND THE GULF OF MEXICO IS DOMINATED BY A
SURFACE RIDGE ANCHORED BY A 1024 MB HIGH OFF THE COAST OF NORTH
CAROLINA. AN UPPER RIDGE EXTENDS FROM NEAR 21N66W TO 29N54W
PROVIDING DIFFLUENCE ALOFT TO GENERATE AN AREA OF SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS S OF 27N TO OVER HISPANIOLA AND
CUBA BETWEEN 67W-76W. A SURFACE TROUGH EXTENDS FROM 27N50W TO
23N55W. A SECOND UPPER TROUGH IS OVER THE E/CENTRAL ATLC
EXTENDING FROM 29N45W THROUGH AN UPPER LOW NEAR 22N48W THEN SW
TO OVER THE E CARIBBEAN GENERATING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS WITHIN 60/75 NM OF LINE FROM 22N48W 24N43W TO
32N38W WHILE A WEAK SURFACE RIDGE DOMINATES THE REMAINDER OF THE
E ATLC ANCHORED BY A 1017 MB HIGH NEAR 30N29W. IN THE TROPICS...
A 1009 MB LOW IS N OF THE ITCZ NEAR 14N42W WITH SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS E OF THE LOW FROM 12N-16N BETWEEN
38W-42W.

$$
WALLACE

[cycloneye]

Good morning to all.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
447 AM AST THU OCT 22 2009

.SYNOPSIS...
MID TO UPPER LEVEL RIDGE WILL CONTINUE ACROSS THE REGION THOUGH THE
END OF THE WEEK...AND THUS MAINTAIN CONTROL OF THE LOCAL WEATHER
PATTERN. UPPER TROUGH JUST WEST OF THE AREA SINKING SOUTH ACROSS
THE WINDWARD PASSAGE IS CREATING A WEAK AREA OF DIFFLUENCE ACROSS
THE MONA PASSAGE AND JUST WEST OF PUERTO RICO. THIS IS HELPING TO
ENHANCE SHOWERS AND THUNDERSTORMS ACROSS THE OFFSHORE ATLANTIC AND
CARIBBEAN WATERS JUST WEST AND SOUTHWEST OF PUERTO RICO THIS MORNING.
STRONG SURFACE HIGH PRESSURE CONTINUES TO BUILD ACROSS THE WESTERN
ATLANTIC WHILE A WEAKENING SURFACE TROUGH EXTENDS FROM THE CENTRAL
ATLANTIC SOUTHWEST ACROSS THE NORTHEAST CARIBBEAN. THIS WILL MAINTAIN
A LIGHT EASTERLY TRADE WIND FLOW ACROSS THE REGION TODAY. THE WIND
FLOW WILL HOWEVER BECOME MORE SOUTHEASTERLY BY THIS AFTERNOON AND
INTO THE WEEKEND...AS THE ATLANTIC HIGH PRESSURE REESTABLISHES ITSELF
AND SINKS SOUTHWARD ACROSS THE FORECAST AREA.

&&

.DISCUSSION...
THE DRY AND STABLE MID TO UPPER LEVEL AIRMASS WILL HELP MAINTAIN
A GENERALLY FAIR WEATHER PATTERN ACROSS THE LOCAL ISLANDS...AS NO
SIGNIFICANT MOISTURE ADVECTION IS EXPECTED FOR THE REST OF THE
WORK WEEK. OCCASIONAL PATCHES OF SHALLOW MOISTURE WILL HOWEVER
CONTINUE TO MOVE ACROSS THE ISLANDS AND SURROUNDING WATERS FROM
TIME TO TIME. THIS WILL BRING A FEW EARLY MORNING SHOWERS TO THE
COASTAL AREAS OF SOME OF THE ISLANDS. LATER IN THE DAY RESIDUAL
MOISTURE WILL COMBINE WITH DAYTIME HEATING AND LOCAL EFFECTS...TO
INCREASE AFTERNOON CLOUDINESS...AND PRODUCE SHOWERS AND ISOLATED
THUNDERSTORMS ESPECIALLY OVER THE CENTRAL AND WEST SECTIONS OF
PUERTO RICO. DUE TO VERY LIGHT WINDS ACROSS THE ISLANDS...THE
SHOWER AND THUNDERSTORM ACTIVITY WILL PRODUCE PERIODS OF LOCALLY
HEAVY RAINFALL WHICH COULD LEAD TO URBAN AND SMALL STREAM FLOODING
IN ISOLATED SPOTS. NO SIGNIFICANT RAINFALL OR WEATHER FEATURE IS
EXPECTED ACROSS THE U.S. VIRGIN ISLANDS FOR THE NEXT FEW DAYS.

OVERALL MOSTLY FAIR WEATHER CONDITIONS WILL PREVAIL ACROSS THE ISLANDS
WELL INTO THE WEEKEND. THE UPPER RIDGE IS FORECAST TO WEAKEN OVER THE
AREABY SUNDAY...AND AN UPPER LEVEL TROUGH IS TO SLOWLY LIFT WEST NORTHWEST
ACROSS THE NORTHEAST CARIBBEAN. THEREFORE EXPECT THE LOCAL AREA TO SLOWLY
BECOME MORE FAVORABLE AND CONDUCIVE FOR CONVECTIVE DEVELOPMENT ESPECIALLY
DURING THE AFTERNOONS...AS MORE OF A MOIST AND HUMID ENVIRONMENT WILL
BE IN PLACE LATE SUNDAY INTO THE EARLY PART OF NEXT WEEK.

&&

.AVIATION...PREVAILING VFR CONDITIONS EXPECTED ACROSS ALL TAF SITES
THROUGH 22/1400Z...WITH A VCSH POSSIBLE IN AND AROUND TJSJ...THE
VI...TNCM AND TKPK. AFTER 22/1600Z...EXPECT SHRA AND TSRA
DEVELOPMENT ACROSS THE CORDILLERA CENTRAL...WESTERN AND NW SECTIONS
OF PUERTO RICO...LIKELY BRINGING TEMPORARY MVFR CONDS AROUND TJMZ
AND TJBQ BETWEEN 22/1700Z-2200Z. IN ADDITION...IF EMISSIONS CONTINUE
FROM MONTSERRAT...VA MAY BE A PROBLEM FOR TKPK...TISX AND TJPS AS
WINDS BECOME MORE SOUTHEASTERLY BY THE MORNING HOURS.

[cycloneye]

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT THU OCT 22 2009

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

DISORGANIZED CLOUDINESS AND SHOWERS OVER THE SOUTHWESTERN CARIBBEAN
SEA ARE ASSOCIATED WITH A NEARLY-STATIONARY AREA OF LOW PRESSURE.
THERE IS A LOW CHANCE...LESS THAN 30 PERCENT...OF THIS SYSTEM
BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

CLOUDINESS AND SHOWERS OVER PORTIONS OF THE BAHAMAS AND THE ADJACENT
ATLANTIC ARE ASSOCIATED WITH AN UPPER-LEVEL TROUGH AND THE REMNANTS
OF A COLD FRONT. UPPER-LEVEL WINDS ARE EXPECTED TO REMAIN
UNFAVORABLE FOR SIGNIFICANT DEVELOPMENT DURING THE NEXT COUPLE OF
DAYS WHILE THE SYSTEM DRIFTS WESTWARD. THERE IS A LOW CHANCE...
LESS THAN 30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL OR
SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS.

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

$$
FORECASTER AVILA

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
232 PM AST THU OCT 22 2009

.SYNOPSIS...MID-UPPER LEVEL RIDGE IS EXPECTED TO BREAK DOWN OVER
THE WEEKEND WITH TUTT LOW FCST TO DEVELOP EAST OF THE ISLAND CHAIN
AND THEN RETROGRESS INTO THE ERN CARIBBEAN NEXT WEEK.

&&

.DISCUSSION...A VERY DRY AIR MASS IN SUBSIDENCE HAS SETTLED
ACROSS THE REGION AS SEEN ON MORNING REGIONAL SOUNDINGS AND TPW
IMAGERY WITH THE LATTER SHOWING PWAT VALUES RANGING FROM 1.26
INCHES OVER THE USVI TO 1.5 INCHES OVER PR. THESE VALUES ARE ONLY
ABOUT 70% OF NORMAL FOR THIS TIME OF THE YEAR. THIS HAS GREATLY
LIMITED CONVECTION ACROSS THE PR THIS AFTERNOON WITH ONLY A LONE
SHOWER OF SIGNIFICANCE IN THE VICINITY OF MAYAGUEZ.

THESE "DRY" CONDITIONS WILL PERSIST THROUGH TOMORROW AND BY SAT
MODELS SHOW DEEP LYR MOISTURE INCREASING AND CAP WEAKENING ENOUGH
TO ALLOW FOR MORE SCT/NRMS DEEP CONVECTION ACROSS THE ISLAND.
ANTICIPATE DAILY AFTERNOON CONVECTION INTO NEXT WEEK AS MOISTURE
VALUES CHANGE LITTLE. TUTT LOW FCST TO EVOLVE ACROSS THE TROP ATLC
ON SUNDAY WILL POSITION SOUTHWEST OF PR BY THE MIDDLE OF NEXT WEEK
AND ALLOW ITCZ MOISTURE TO SURGE NORTHWARD INTO THE AREA.

&&

.AVIATION...VOLCANIC ASH AFFECTING TNCM AND TKPK SITES WITH HIGHEST
CONCENTRATION OF ASH. LATEST PIREPS AND VIS SATELLITE INDICATE ASH
CLOUD MOVING WNW WITH LIGHTER ASH OVER TISX AND HEADED FOR TIST
AND TJPS. EXPECT ASH TO BE IN LAYER BETWEEN 080 AND 180...AND
PROBABLY VERY DIFFUSE BY THE TIME IT REACHES PR SOMETIME
OVERNIGHT. WILL LEAVE MENTION OUT OF TAF FOR TJSJ ATTM...BUT
AVIATION INTERESTS SHOULD BE AWARE OF POSSIBILITY OF THIN ASH IN
THIS LAYER.

&&

.MARINE...NRLY SWELLS OF 11-12 SECS ARE EXPECTED TO DIMINISH OVER
THE NEXT 12 HRS.

[cycloneye]

TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT THU OCT 22 2009

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

CLOUDINESS AND DISORGANIZED SHOWERS OVER THE SOUTHWESTERN CARIBBEAN
SEA ARE ASSOCIATED WITH A NEARLY-STATIONARY AREA OF LOW PRESSURE
JUST OFF THE EAST COAST OF NICARAGUA. FURTHER DEVELOPMENT OF THIS
SYSTEM... IF ANY...SHOULD BE SLOW TO OCCUR. THERE IS A LOW
CHANCE...LESS THAN 30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS.

SHOWER AND THUNDERSTORM ACTIVITY OVER PORTIONS OF THE EASTERN
BAHAMAS AND THE ADJACENT SOUTHWESTERN ATLANTIC OCEAN IS PRIMARILY
ASSOCIATED WITH THE REMNANTS OF A COLD FRONT. THIS ACTIVITY IS
FORECAST TO MOVE SLOWLY WEST-NORTHWESTWARD WITH NO SIGNIFICANT
DEVELOPMENT. THERE IS A LOW CHANCE...LESS THAN 30 PERCENT...OF THIS
SYSTEM BECOMING A TROPICAL OR SUBTROPICAL CYCLONE DURING THE NEXT
48 HOURS.

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

$$
FORECASTER PASCH/ROBERTS

[cycloneye]

Good morning to all.I am late to post because of the emergency in Puerto Rico caused by explosions at a refinary.More details at off topic forum.

000
FXCA62 TJSJ 230917
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
517 AM AST FRI OCT 23 2009

.SYNOPSIS...AT UPPER LEVELS...A RIDGE OF HIGH PRESSURE EXTENDS
NORTH NORTHEAST FROM SOUTH AMERICA ACROSS THE LEEWARD ISLANDS. IT
WILL BE DISPLACED BY A LOW PRESSURE DROPPING SOUTH OVER THE
TROPICAL ATLANTIC THROUGH SUNDAY MORNING AND THEN MOVING WEST TO
CROSS PUERTO RICO ON TUESDAY. THE UPPER LEVEL HIGH WILL MOVE WEST
OVER THE DOMINICAN REPUBLIC ON WEDNESDAY...AND THEN DRIFT SOUTH
OVER THE REMAINDER OF THE WEEK WHILE DISSIPATING.

AT MID LEVELS...HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL DRIFT
SLOWLY EAST UNTIL WEDNESDAY...BUT WILL REMAIN OVER THE WESTERN
ATLANTIC THROUGH THE PERIOD. A TROUGH WILL MOVE THROUGH THE LOCAL
AREA ON MONDAY AND PREVAIL OVER THE CARIBBEAN THROUGH THE END OF
THE WEEK.

AT LOWER LEVELS...HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL BE
SUBSUMED INTO A HIGH JUST EAST OF NEWFOUNDLAND. THIS HIGH WILL
DRIFT SOUTH DURING THE FIRST HALF OF NEXT WEEK AND THEN REMAIN
NEARLY STATIONARY DURING THE LATTER HALF...MAINTAINING EAST TO
SOUTHEAST FLOW DURING THE ENTIRE PERIOD.

&&

.DISCUSSION...THE CAPECO/GULF TANK FARM EXPLOSION AND FIRE IN
SOUTHERN CATANO HAS DOMINATED THE WEATHER FOCUS THIS SHIFT. WINDS
ARE SOUTHEAST AT LOWER LEVELS DUE TO THE HIGH PRESSURE AND NEARLY
CALM AT THE SURFACE. THIS SITUATION WILL CONTINUE UNTIL SEA BREEZE
INFLUENCES CAN OVERCOME THE GENERAL FLOW AND FORCE SOME OF THE
SMOKE PLUME BACK INTO NORTH CENTRAL PUERTO RICO. TIMING...
DURATION AND WIND SPEEDS OF THE SHIFT FROM THE GENERAL FLOW TO
THE SEA BREEZE CONDITIONS ARE UNCERTAIN AND WINDS MAY VACILLATE
BETWEEN THE TWO CONDITIONS DURING THE DAY AS THE GENERAL FLOW
FIGHTS THE INFLUENCE OF THE SEA BREEZE. WINDS WILL CARRY THE PLUME
OUT TO SEA AT LEVELS ABOVE ABOUT 3 TO 5 THOUSAND FEET...BUT DUE TO
UNSTABLE CONDITIONS SMOKE MAY RISE TO ABOVE 15 THOUSAND FEET FROM
TIME TO TIME DURING THE DAY. SMOKE SHOULD DISPERSE WIDELY AFTER
ABOUT 10 AM AST. SCATTERED SHOWERS ARE EXPECTED BUT SHOULD BE
CONFINED TO NORTHWEST PUERTO RICO TODAY. ISOLATED SHOWERS ARE
EXPECTED ELSEWHERE. THE NORMAL DIURNAL SHOWER PATTERN WILL
CONTINUE THROUGH TUESDAY. AFTER THE UPPER LEVEL LOW MOVES PAST
PUERTO RICO MODELS INDICATE BETTER MOISTURE OVER THE AREA AND
BETTER DYNAMICS SHOULD CONTRIBUTE TO INCREASED PRECIPITATION
WEDNESDAY AND THURSDAY.

&&

.AVIATION...VFR CONDITIONS ARE EXPECTED TO CONTINUE AT ALL TAF
STATIONS...EXCEPT AT TJMZ WHERE CONDITIONS WILL BE MVFR DURING
PART OF THE AFTERNOON BETWEEN 23/16-23Z.

&&

.MARINE...MODELS SHOW SEAS DIMINISHING THROUGH TODAY AND THEN
RISING TO 5 TO 6 FEET IN THE ATLANTIC...4 TO 5 FEET IN THE CARIBBEAN...AND
CONTINUING FOR THE REST OF THE PERIOD. SMALL CRAFT ADVISORIES ARE
NOT EXPECTED THROUGH THE NEXT 7 DAYS.

[Gustywind]

Ok tkanks Luis .

[cycloneye]

000
FXCA62 TJSJ 232018
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
418 PM AST FRI OCT 23 2009

.SYNOPSIS...UPPER RIDGE WILL BREAK DOWN WITH TUTT LOW DEVELOPING
EAST OF THE LESSER ANTILLES AND RETROGESSING INTO ERN CARIBBEAN NEXT
WEEK.

&&

.DISCUSSION...SUBSIDENCE CAP WILL CONTINUE TO WEAKEN AS UPPER RIDGE
BREAKS DOWN. BROAD LOW-MID LVL RIDGE TO THE NORTH WILL CAUSE PRES
GRADIENT TO TIGHTEN AND WINDS TO TURN MORE EASTERLY TOMORROW. THIS
WILL RESULT IN AN INCREASE IN NOCTURNAL SHOWERS ACROSS THE EASTERN
SECTIONS OF PUERTO RICO WITH AFTERNOON CONVECTION TO FOCUS ACROSS
WESTERNS SECTIONS OF PR. THIS PATTERN WILL CONTINUE INTO NEXT WEEK.
BY THE MIDDLE OF NEXT WEEK TUTT LOW WILL POSITION SW OF PR AND ALLOW
FOR A SURGE INTO DEEP MOISTURE INCREASING INTO THE AREA.

&&

.AVIATION...VOLCANIC ASH WILL CONTINUE TO AFFECT TKPK/TNCM THROUGH
TONIGHT AND POSSIBLY USVI AIRPORTS. TSRA LIKELY AT JBQ THIS
AFTERNOON WITH MVFR CONDITIONS. SMOKE FROM CATANO NOT EXPECTED TO
AFFECT ANY OF THE AIRPORTS.


&&

.MARINE...SEAS 2 TO 4 FEET. AREAS OF SMOKE NORTH OF CATANO. HIGH
RESOLUTION MODIS IMAGERY SHOWS THAT PLUME EXTENDS 75 NM FROM THE COAST.


&&

.FIRE WEATHER...RADAR IMAGERY SHOWS THAT SMOKE PLUME EXTENDS UP TO
17.5 KFT UP INTO THE ATMOSPHERE. AS SUN SETS TONIGHT AND ATMOSPHERE
STABILIZES AND SFC WINDS BECOME LIGHTER EXPECT SMOKE PLUME TO
FLATTEN WITH TOXIC GASES/POLLUTANTS EMIITED FROM THE SOURCE TO
GET TRAPPED UNDER NOCTURNAL INVERSION. THIS WILL CREATE VERY
UNHEALTHFUL CONDITIONS ESPECIALLY ACROSS CATANO AND TOA BAJA AND
EXTREME NORTHEASTERN DORADO.

STEERING WINDS WILL SHIFT TOMORROW AFTERNOON MORE TO THE EAST AS
OPPOSED TO SOUTH SOUTHEAST TODAY MAKING NORTHERN COUNTIES MORE
VULNERABLE TO SMOKE. LATEST NOAA HYSPLIT MODEL SUGGESTS THAT SMOKE
PLUME WILL AFFECT COUNTIES AS FAR WEST AS MANATI. PLEASE MONITOR
SPECIAL WEATHER STATEMENTS FOR MORE DETAILS.

[Gustywind]

000
FXCA62 TJSJ 240905
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
505 AM AST SAT OCT 24 2009

.SYNOPSIS...UPPER LEVEL RIDGE OVER LOCAL AREA WILL GIVE WAY TO A
LOW PUSHING IN FROM THE EAST THAT WILL CROSS PUERTO RICO ON
WEDNESDAY. THE LOW WILL MOVE TO THE SOUTH OF THE DOMINICAN
REPUBLIC BEFORE BECOMING INSIGNIFICANT ON THE FIRST MONDAY OF
NOVEMBER.

AT MID LEVELS...HIGH PRESSURE WILL REMAIN NORTH OF THE LOCAL AREA
THROUGH FRIDAY OF NEXT WEEK. HIGH PRESSURE RE-FORMS IN THE ATLANTIC
OFF GEORGIA LATE IN THE FORECAST PERIOD. MID LEVELS ARE GENERALLY
DRY EXCEPT ON THURSDAY AND FRIDAY.

AT LOWER LEVELS...A SUCCESSION OF HIGH PRESSURE SYSTEMS IN THE
WESTERN ATLANTIC AND LOW PRESSURE IN THE SOUTHWEST CARIBBEAN WILL
SUPPORT MODERATE TRADE WIND FLOW FOR MUCH OF THE PERIOD.

&&

.DISCUSSION...FAIRLY LIGHT WINDS HAVE BEEN PRESENT AS HIGH
PRESSURE IS NOT YET FULLY DEVELOPED IN THE WESTERN ATLANTIC. THIS
WILL ALLOW ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IN A
MODERATELY MOIST ENVIRONMENT TO FORM IN THE NORTHWEST QUADRANT OF
PUERTO RICO DURING THE AFTERNOON. SHOWERS HAVE CONTINUED OVER BOTH
ATLANTIC AND CARIBBEAN WATERS OVERNIGHT AND LITTLE CHANGE IN THE
AIR MASS IS EXPECTED IN THE IMMEDIATE FUTURE. THEREFORE ISOLATED
SHOWERS ARE ALSO POSSIBLE OVER MOST OTHER AREAS OF PUERTO
RICO...ALTHOUGH DOWNSLOPE WINDS WILL WITHER ALL BUT THE HARDIEST
SHOWERS OVER NORTHEAST PUERTO RICO. AS A STRONG LOW IN THE NORTH
CENTRAL ATLANTIC PULLS TO THE NORTHEAST HIGH PRESSURE WILL BE ABLE
TO BECOME MORE EAST- WEST ORIENTED. THIS WILL ALLOW WINDS TO
BECOME MORE EASTERLY OVER THE LOCAL AREA BEGINNING ON SUNDAY. AN
UPPER LEVEL LOW WILL MOVE OVER PUERTO RICO AND THE U.S. VIRGIN
ISLANDS ON WEDNESDAY FROM THE EAST AND CONTINUE WEST SOUTHWEST.
AFTER ITS PASSAGE BETTER DYNAMICS WILL BE IN PLACE AND SHOWERS ARE
EXPECTED TO INCREASE. GENERAL IMPROVEMENT SHOULD BE SEEN OVER THE
FOLLOWING WEEKEND.


&&

.AVIATION...PREVAILING VFR CONDITIONS EXPECTED ACROSS ALL TAF SITES
THROUGH 24/1700Z...WITH A VCSH POSSIBLE IN AND AROUND
TKPK...TNCM...TIST...TISX...TJSJ AND TJPS. AFTER 24/1800Z...EXPECT
SHRA AND TSRA DEVELOPMENT ACROSS THE CORDILLERA CENTRAL...WESTERN
AND NW SECTIONS OF PUERTO RICO...LIKELY BRINGING TEMPORARY MVFR
CONDS AROUND TJMZ AND TJBQ BETWEEN 24/1800Z-2200Z.

ASH PLUME FROM LAST EMISSION FROM THE SOUFRIERE HILLS TO AFFECT
ST KITTS...ST MARTEN AND ST THOMAS THIS MORNING. THE ASH PLUME
WILL CROSS OVER PUERTO RICO BRIEFLY THIS AFTERNOON AND IS EXPECTED
TO BE OVER THE CARIBBEAN WATERS SOUTH OF PUERTO RICO BY SUNDAY
MORNING.


&&

.MARINE...MODEST WINDS AND ONLY DISTANT STORMS WILL KEEP WAVE
ACTION MINIMAL IN THE SURROUNDING WATERS THROUGH THE NEXT 5 DAYS.

&&

.FIRE WEATHER...VERY LIGHT WINDS OVERNIGHT WILL CONTINUE TO
PREVAIL THROUGH THE EARLY MORNING. FLOW AT LOWER LEVELS IS
GENERALLY FROM THE EAST SOUTHEAST AT 15 KNOTS OR LESS...BUT MAY BE WEAK
ENOUGH TO ALLOW SOME SEA BREEZE ACTION NEAR THE NORTH COAST OF
PUERTO RICO. SEA BREEZES ARE THEREFORE POSSIBLE BETWEEN 11 AM AND
4 PM AST...BUT WINDS ABOVE 2 TO 3 THOUSAND FEET WILL CONTINUE TO
BE EAST SOUTHEAST UNTIL SUNDAY. THIS MAY SEND SOME SMOKE FROM THE
CAPECO/GULF TANK FARM FIRE WESTWARD AS FAR AS MANATI AND TOA ALTA.
IT IS MORE LIKELY THAT AREAS WEST OF THE FIRE WILL SEE SOME SMOKE
BY SUNDAY AFTERNOON. EXPECT THAT THE PLUME WILL RISE AT LEAST 2
THOUSAND FEET BEFORE SPREADING TOO MUCH.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 77 87 76 / 20 30 30 30
STT 88 78 87 78 / 30 20 30 40

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&

$$

17/12

[Gustywind]

000
AWCA82 TJSJ 240918
RWSVI

WEATHER SUMMARY FOR THE U.S. VIRGIN ISLANDS
NATIONAL WEATHER SERVICE SAN JUAN PR
518 AM AST SAT OCT 24 2009

PARTLY CLOUDY SKIES PREVAILED ACROSS THE U.S. VIRGIN ISLANDS AND
THE SURROUNDING COASTAL WATERS OVERNIGHT. LIGHT TO MODERATE SHOWER
ACTIVITY WAS DETECTED BY DOPPLER WEATHER RADAR OVER THE LOCAL
ISLANDS AND COASTAL WATERS. THE WINDS WERE MOSTLY FROM THE SOUTHEAST
AT AROUND 10 MPH OR LESS.

FOR THE NEXT SEVERAL DAYS...EXPECT MAINLY FAIR WEATHER CONDITIONS
ACROSS THE LOCAL ISLANDS WITH ISOLATED TO SCATTERED PASSING
SHOWERS OVER PARTS OF THE ISLANDS FROM TIME TO TIME.

SURFACE HIGH PRESSURE TO BUILD ACROSS THE WESTERN CENTRAL ATLANTIC
AND PRODUCE MODERATE TRADE WIND FLOW ACROSS THE LOCAL ISLANDS FOR
THE NEXT SEVERAL DAYS.

ACROSS THE REGIONAL WATERS...NO PRECAUTIONARY STATEMENTS ARE IN
EFFECT AT THIS TIME AS SEAS OF 5 FEET OR LESS AND WINDS OF 13 KNOTS
OR LESS ARE EXPECTED THROUGH AT LEAST SUNDAY.

$$

[Gustywind]

000
ABNT20 KNHC 240554
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT SAT OCT 24 2009

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

A BROAD AREA OF LOW PRESSURE LOCATED BETWEEN THE NORTHERN COAST OF
CUBA AND THE BAHAMAS IS PRODUCING DISORGANIZED SHOWER AND
THUNDERSTORM ACTIVITY AS IT MOVES SLOWLY WEST-NORTHWESTWARD. SOME
SLOW DEVELOPMENT OF THIS SYSTEM IS POSSIBLE BEFORE IT IS ABSORBED
BY A COLD FRONT IN THE NEXT DAY OR TWO. THERE IS A LOW CHANCE...
LESS THAN 30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL OR
SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS.

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

$$
FORECASTER BRENNAN

[Gustywind]

000
AXNT20 KNHC 240533
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT OCT 24 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND
RADAR.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS TILTED FROM 21N36W TO 12N38W MOVING NW NEAR 10
KT. WAVE IS AT THE LEADING EDGE OF A MAXIMUM IN TOTAL
PRECIPITABLE WATER WITH SATELLITE DERIVED WINDS SHOWING A
CYCLONIC CURVATURE ALONG THE WAVE AXIS. WIDELY SCATTERED
MODERATE CONVECTION IS FROM 12N-17N BETWEEN 33W-38W.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 9N13W 7N20W 10N32W 16N45W
11N63W. WIDELY SCATTERED MODERATE CONVECTION IS ALONG THE COAST
OF W AFRICA FROM 4N-10N BETWEEN 8W-15W...AND FROM 9N-12N BETWEEN
16W-18W. WIDELY SCATTERED MODERATE CONVECTION IS ALSO FROM
7N-10N BETWEEN 25W-30W. SCATTERED MODERATE TO ISOLATED STRONG
CONVECTION IS FROM 13N-17N BETWEEN 43W-47W.

...DISCUSSION...

GULF OF MEXICO...
A COLD FRONT IS OVER THE GULF OF MEXICO FROM THE FLORIDA
PANHANDLE NEAR 31N86W TO THE BAY OF CAMPECHE ALONG 27N86W 21N95W
19N96W. SCATTERED MODERATE CONVECTION IS ALONG THE COAST OF
MEXICO FROM 20N-22N BETWEEN 95W-97W. SCATTERED SHOWERS ARE
WITHIN 60 NM OF THE REMAINDER OF THE FRONT. 10-15 KT NW WINDS
ARE N OF THE FRONT WHILE 5 -10 KT SE WINDS ARE S OF THE FRONT.
IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE W GULF W
OF 93W. AN UPPER LEVEL HIGH IS CENTERED OVER THE CENTRAL GULF
NEAR 25N90W. UPPER LEVEL MOISTURE IS OVER THE W GULF W OF 95W...
AND OVER THE NE GULF N OF 23N BETWEEN 83W-89W. EXPECT THE COLD
FRONT TO EXTEND FROM SOUTH FLORIDA TO THE YUCATAN PENINSULA IN
24 HOURS WITH CONVECTION. ALSO EXPECT MORE CONVECTION OVER THE
BAY OF CAMPECHE DURING THE NEXT 24 HOURS.

CARIBBEAN SEA...
MODERATE TRADEWINDS ARE OVER THE CARIBBEAN SEA AND CENTRAL
AMERICA. A SURFACE TROUGH EXTENDS FROM JAMAICA TO N OF EASTERN
CUBA. SCATTERED SHOWERS ARE OVER HAITI AND EASTERN CUBA N OF 18N
BETWEEN 72W-80W. MORE SHOWERS ARE OVER THE CENTRAL CARIBBEAN
BETWEEN 70W-75W. FURTHER S... SCATTERED MODERATE TO STRONG
CONVECTION IS OVER THE SW CARIBBEAN FROM 8N-12N BETWEEN 80W-84W.
IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS CENTERED OVER
EASTERN CUBA NEAR 20N78W. AN UPPER LEVEL RIDGE IS OVER THE E
CARIBBEAN E OF 70W. CONSIDERABLE UPPER LEVEL MOISTURE IS OVER
THE SW AND CENTRAL CARIBBEAN. EXPECT...LITTLE CHANGE OVER THE
NEXT 24 HOURS.

ATLANTIC OCEAN...
A SURFACE TROUGH IS OVER THE BAHAMAS AND EASTERN CUBA ALONG 77W
S OF 27N. SCATTERED SHOWERS ARE S OF 27N BETWEEN 70W-80W. A 1023
MB HIGH IS OVER THE W ATLANTIC NEAR 33N66W. ANOTHER 1020 MB HIGH
IS OVER THE CENTRAL ATLANTIC NEAR 32N43W. A FRONTAL TROUGH IS
OVER THE CENTRAL ATLANTIC ALONG 32N30W 26N40W 23N50W 23N60W.
SCATTERED SHOWERS ARE WITHIN 90 NM OF THE TROUGH AXIS. IN THE
UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE W ATLANTIC
BETWEEN 70W-80W. AN UPPER LEVEL RIDGE IS OVER THE W ATLANTIC
BETWEEN 60W-70W. AN UPPER LEVEL TROUGH IS OVER THE CENTRAL
ATLANTIC N OF 20N BETWEEN 40W-60W. UPPER LEVEL ZONAL FLOW IS
OVER THE REMAINDER OF THE ATLANTIC.

$$
FORMOSA

[Gustywind]

Seems that an area of moderate strong convection near the 47 WEST has popped, let's wait and see what could happen with this blob...

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
147 PM AST SAT OCT 24 2009

.SYNOPSIS...UPPER RIDGE OVR THE REGION WILL YIELD TO A RETROGRESSING
TUTT LOW THAT WILL ENTER THE ERN CARIBBEAN NEXT WEEK. AT LOW AND
MID LEVELS...BROAD RIDGE EXPECTED TO REMAIN NORTH OF THE AREA AND
MAINTAIN AN EAST SOUTHEAST WIND FLOW ACROSS THE REGION.

&&

.DISCUSSION...FOR INFORMATION ON THE GULF FIRE SEE FIRE WEATHER SECTION.

AREA STILL UNDER THE EFFECTS OF DEEP LAYERED RIDGING TO THE NORTH
AND INCREASING WIND GRADIENT IN THE LOWER LEVELS HELPING TO
INCREASE LOW LEVEL FLOW FROM THE RECENT SEVERAL DAYS OF LIGHT
WINDS. OVER THE NEXT FEW DAYS TUTT LOW FROM THE EAST CAUSES UPPER
RIDGE TO BUCKLE WITH MID TO UPPER MOISTURE ADVECTION INCREASING
LAYER MOISTURE. BY WEDNESDAY MID TO UPPER DYNAMICS BECOME MOST
FAVORABLE AS TUTT MOVES OVER HISPANIOLA PUTTING FA UNDER FAVORABLE
AREA FOR ENHANCED DEEP CONVECTION THROUGH THE END OF THE FORECAST PERIOD.


&&

.AVIATION...VFR CONDS FOR ALL SITES WITH VCSH TJBQ AND TJSJ UNTIL
20Z. VA STAYING SOUTH OF ALL SITES.


&&

.FIRE WEATHER...SEA BREEZE DEVELOPED AS EXPECTED TODAY WITH NORMAL
NORTH COAST ACCELERATION DURING EAST TO EAST SOUTHEAST FLOW
BRINGING 15 TO 20 KT FLOW TO THE SAN JUAN COAST. STREAMER (LINE OF
SHOWERS) DID DEVELOP FROM EL YUNQUE TO OLD SAN JUAN...JUST EAST OF
THE GULF FIRE. HOWEVER...THE STABILITY EFFECTS WERE OBVIOUS TO THE
LOCAL OBSERVER AS CONVECTIVE COOLING STABILIZED THE REGION AND
CAUSE SOME CAPPING OF SMOKE LOWER THAN PREVIOUSLY EXPERIENCED.
STILL EXPECTING A MEAN EASTERLY FLOW UNDER THE BOUNDARY
LAYER...WITH ESE TO SE FLOW ABOVE...ALLOWING FOR DECENT VENTING OF
SMOKE PLUME. WINDS AND SEA BREEZE TO TURN MORE SOUTHEASTERLY AND
WEAKEN AROUND SUNSET LEAVING 5 KT FLOW FROM THE ESE FOR THE
OVERNIGHT. FOR TOMORROW...SYNOPTIC FLOW INCREASES AND SURFACE TO
5000 FT FLOW TURNS MORE ENE PRESENTING A PROBLEM FOR AREAS TO THE
WEST AND SLIGHTLY WSW OF THE FIRE...WHICH HAVE BEEN SAVED FROM THE
SMOKE SO FAR. INCIDENT OFFICIALS WILL NEED TO CONSIDER POTENTIAL
IMPACTS TO RESIDENTS IN A SLIGHTLY LARGER RADIUS TO THE IMMEDIATE
WEST...WEST SOUTH WEST...AND WEST NORTHWEST OF THE FIRE TOMORROW.
NEVERTHELESS...INSTABILITY WILL BE SAME FOR NEXT FEW DAYS...LIKELY
ALLOWING GOOD VENTING OF SMOKE PLUME AS HAS BEEN THE CASE FOR THE
LAST FEW DAYS.

THE CHANCE OF RAIN TONIGHT OVER THE FIRE IS ABOUT 30 PERCENT
AGAIN...OF TYPICAL NOCTURNAL PASSING SHOWERS. FOR TOMORROW...MORE
CONVECTION IS EXPECTED OVER INTERIOR TO WESTERN PR...BUT THE
CHANCE OF A STREAMER OVER THE FIRE WILL BE MINIMAL DUE TO ENE FLOW.