Caribbean - Central America Weather

[cycloneye]

Good morning. We will have to watch the SW Caribbean in the next few days.


AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN JUAN PR
458 AM AST THU OCT 18 2012

.SYNOPSIS...UPPER LEVEL RIDGE WILL REMAIN THE DOMINANT WX FEATURE
INTO EARLY NEXT WEEK. RIDGE WILL COLLAPSE ON TUE AS BROAD POLAR
TROUGH ESTABLISHES ACROSS THE WRN ATLC. BROAD SFC LOW PRES IS
FCST TO DEVELOP ACROSS THE SW CARIBBEAN AND REMAIN NEARLY STATIONARY
THROUGH MID NEXT WEEK.

&&

.DISCUSSION...TROPICAL WAVE THAT WE HAVE BEEN TRACKING PAST FEW
DAYS LOOKS TO BE ACROSS THE WINDWARD ISLANDS AND SHOULD REMAIN
MAINLY SOUTH OF OUR AREA. HOWEVER...MOISTURE REMAINS PRETTY DEEP
ACROSS MUCH OF THE CARIB BASIN AND ESPECIALLY AROUND PR AND THE
USVI WITH PWAT VALUES GREATER THAN 2.25 INCHES OR CLOSE TO TWO
STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF THE YEAR. SO A
EXPECT A REPEAT OF YESTERDAY BUT CONVECTION MOVING FASTER THAN
YDAY AND MOVING TO THE WSW. SLIGHT DRYING IS EXPECTED FOR FRI.

LOW LEVEL MOISTURE ERODES RAPIDLY ON SAT ACCORDING TO THE 00Z
ECMWF AND GFS AS TRADES STRENGTHEN AND SUBSIDENCE INCREASES. BOTH
THE ECMWF AND GFS INDICATE PWAT VALUES DROPPING BELOW 1.25 INCHES
OR TWO STANDARD DEVIATIONS BELOW NORMAL. THE NAM IS THE MOST AGGRESSIVE
WITH THE DRYING BUT ITS SOLUTION IS DISCOUNTED. SO OVERALL...FAIR
WEATHER CONDITIONS APPEAR IN STORE FOR SAT THAT SHOULD LAST
THROUGH TUE.

ATTENTION THEN TURNS TO THE SW CARIBBEAN WHERE MODELS CONTINUE TO
SUGGEST A BROAD SFC LOW PRES WILL FORM AND REMAIN NEARLY
STATIONARY FOR A FEW DAYS BEFORE GETTING PICKED UP EVENTUALLY BY
AN UPPER LEVEL TROUGH ACROSS THE WRN ATLC. GLOBAL MODELS AND THEIR
RESPECTIVE ENSEMBLE MEANS ARE STARTING TO SUGGEST THAT THIS UPPER
LEVEL TROF WILL BECOME CUTOFF ACROSS THE SW ATLC WITH SFC LOW
GETTING BLOCKED BY AMPLIFYING UPPER LEVEL RIDGE TO THE EAST OF
65W. IT APPEARS A MULTI-DAY HEAVY RAINFALL EVENT IS LIKELY FOR
THE ENTIRE REGION ESPECIALLY HISPANIOLA STARTING MID NEXT WEEK.
NOTE THAT MODELS CONTINUE TO SUGGEST THAT THIS SYSTEM WILL HAVE AN
EPAC MOISTURE CONNECTION. A BIT TOO FAR OUT FOR MORE DETAILS BUT
SYSTEM BEARS WATCHING AS IT HAS THE POTENTIAL TO BE A HIGH IMPACT
HEAVY RAINFALL EVENT ESPECIALLY CONSIDERING THAT THE MJO IS
AMPLIFYING ACROSS THE WRN HEMISPHERE AND IS FCST TO PROPAGATE
EASTWARD OVER THE NEXT TWO WEEKS.


&&

.AVIATION...SHRA/TSRA WILL CONTINUE TO AFFECT THE FLYING AREA AS A
TROPICAL WAVE MOVES ACROSS THE EASTERN CARIBBEAN. THEREFORE...BRIEF
PERIODS OF MVFR CIGS/VIS WILL BE POSSIBLE IN PASSING SHRA/TSRA AT
TIST/TISX AND TNCM/TKPK EARLY THIS MORNING...SPREADING OVER PR TAF
SITES DURING THE LATE MORNING AND AFTERNOON HOURS. LLVL WNDS MAINLY
LIGHT 5-10 KTS FROM THE EAST.


&&

.MARINE...SEAS 2-4 FT IN MIXED NORTH SWELLS AND EAST GENERATED
WIND WAVES. T-STORMS WILL REMAIN THE PRIMARY HAZARD.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 91 78 89 77 / 50 0 20 20
STT 89 79 88 78 / 50 20 20 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
358 PM AST THU OCT 18 2012

.SYNOPSIS...A TROPICAL WAVE WILL CONTINUE MOVING WEST ACROSS THE
REMAINDER OF THE LOCAL AREA TONIGHT THROUGH EARLY FRIDAY AND THEN
AWAY FROM THE REGION LATER FRIDAY. A MID TO UPPER LEVEL RIDGE
WILL GENERALLY REMAIN THE DOMINANT WEATHER FEATURE LOCALLY INTO
EARLY NEXT WEEK...WITH THE RIDGE THEN GRADUALLY WEAKENING AS A
BROAD TROUGH BECOMES ESTABLISHED ACROSS THE WESTERN ATLANTIC.
BROAD SURFACE LOW PRESSURE IS FORECAST TO DEVELOP ACROSS THE
SOUTHWEST CARIBBEAN AND REMAIN NEARLY STATIONARY THROUGH THE
MIDDLE OF NEXT WEEK.

&&

.DISCUSSION...EXPECT A FAIRLY MOIST AND UNSTABLE AIR MASS TO
CONTINUE ACROSS THE LOCAL AREA TONIGHT THROUGH FRIDAY...AS
TROPICAL WAVE CONTINUES MOVING WEST ACROSS THE REMAINDER OF THE
LOCAL AREA THROUGH EARLY FRIDAY AND THEN AWAY FROM THE REGION
LATER FRIDAY AND FRIDAY NIGHT THROUGH SATURDAY. EXPECT THIS
MOISTURE AND INSTABILITY TO CONTINUE TO COMBINE WITH LOCAL
EFFECTS AND GENERALLY FAVORABLE UPPER LEVEL VENTILATION TONIGHT
THROUGH FRIDAY...TO PRODUCE SOME ADDITIONAL CLOUDINESS...SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS. FOR SATURDAY THROUGH MONDAY
AND PROBABLY TUESDAY ALSO...IT STILL APPEARS THAT AN "OVERALL"
DRIER AND MORE STABLE AIR MASS AND CONTINUED MID TO UPPER LEVEL
RIDGING...SHOULD YIELD A LESS ACTIVE PATTERN...BUT STILL WITH SOME
LIMITED AND LOCALIZED CONVECTION EACH DAY. WE WILL CONTINUE TO
MONITOR THE POTENTIAL EVOLUTION OF THE AFOREMENTIONED BROAD
SURFACE LOW PRESSURE SYSTEM ACROSS THE SOUTHWEST CARIBBEAN FOR
NEXT WEEK.

&&

.AVIATION...SHRA/TSRA EXPECTED TO EXIT PUERTO RICO BY 18/22Z...
LEAVING VFR CONDITIONS ACROSS THE LOCAL TERMINALS WITH ONLY A FEW
PASSING SHOWERS. OVERNIGHT SURFACE WIND IS EXPECTED TO REMAIN
MAINLY EASTERLY AT AROUND 10 KNOTS OR LESS. SHRA/TSRA POSSIBLE
ACROSS NORTHWESTERN PUERTO RICO AFTER 18/16Z...POSSIBLY AFFECTING
AREAS IN AND AROUND TJMZ AND TJBQ.

&&

.MARINE...GENERALLY EXPECT WINDS OF 18 KNOTS OR LESS AND SEAS
OF 5 FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH AT LEAST
SATURDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 89 78 88 / 0 20 20 20
STT 79 88 78 88 / 20 20 20 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
954 PM AST THU OCT 18 2012

.UPDATE...THE TROPICAL WAVE OVER THE MONA PASSAGE THIS EVENING
WILL CONTINUE TO MOVE AWAY FROM THE LOCAL AREA DURING OVERNIGHT
HOURS. HOWEVER...DEEP MOISTURE WILL REMAIN ACROSS THE LOCAL AREA
THROUGH AT LEAST THE NEXT 24 HOURS. THIS HIGH MOISTURE CONTENT AND
A FAIRLY UNSTABLE ATMOSPHERE WILL MAINTAIN A SHOWERY WEATHER PATTERN
THROUGH FRIDAY EVENING. LATEST TJSJ SOUNDING INDICATED STEEP LAPSE
RATES WITH HIGH PRECIPITABLE WATER VALUES OF 2.35 INCHES. AS A RESULT...
EXPECT NEW SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPING ACROSS THE
REGIONAL WATERS OVERNIGHT...WITH SOME OF THESE SHOWERS AFFECTING THE
VIRGIN ISLANDS AND EASTERN PUERTO RICO. CHANGES WERE DONE TO THE
PREVIOUS FORECAST PACKAGE TO INCREASE THE POP`S IN FEW ZONES.

[Macrocane]

Hi guys! I'm on vacation in the United States so I have not been able to post too much this week but I've been reading your posts as always This is Thursday discussion from HPC:

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
227 PM EDT THU OCT 18 2012

DISCUSSION FROM OCT 18/00 UTC: ACROSS MEXICO...MID/UPPER RIDGE
WILL MEANDER OVER JALISCO/MICHOACAN THROUGH THE CYCLE HELPING TO
VENT CONVECTION IN ITS PERIPHERY. BEST MOISTURE WILL REMAIN ACROSS
SOUTHWESTERN COAST INTO JALISCO/NAYARIT/SOUTHERN
SINALOA/COLIMA/MICHOACAN. THIS WILL SUSTAIN DIURNAL CONVECTION
THROUGH THE CYCLE WITH ACCUMULATIONS IN THE ORDER OF
05-10MM/DAY...AND ISOLATED MAXIMA INCREASING FROM 15MM/DAY TO
15-25MM/DAY AFTER 36 HRS. AN ACTIVATION IS EXPECTED ACROSS THE
SOUTHERN GULF COAST/SOUTHERN YUCATAN THROUGH THE CYCLE AS TROUGH
ARRIVES IN FROM THE EAST...AND PERIPHERY OF UPPER RIDGE IS ERODED
BY UPPER TROUGH PATTERN ACROSS THE GULF OF MEXICO. ACROSS
CHIAPAS/TABASCO/CAMPECHE TO PRODUCE ACCUMULATIONS OF 00-05MM/DAY
AND LOCALIZED MAXIMA OF 10MM/DAY BY 36-84 HRS. ACROSS QUINTANA
ROO/BELIZE...ARRIVING TROUGH AND MOISTURE POOL WILL PRODUCE
15-20MM/DAY AND LOCALIZED MAXIMA OF 30-60MM/DAY BY 60-84 HRS.

ACROSS CENTRAL AMERICA...WIDE MID/UPPER TROUGH REMAINS IN PLACE AS
IT DIVIDES A RIDGE ACROSS SOUTHWESTERN MEXICO AND ONE OVER THE
CARIBBEAN. AT LOW LEVELS...DEEP MOISTURE POOL FROM SOUTHERN
NICARAGUA/COSTA RICA INTO THE CENTRAL CARIBBEAN/COLOMBIA IS
FAVORING SCATTERED CONVECTION. A BROAD SURFACE LOW CENTERING NORTH
OF PANAMA IS FORECAST TO MEANDER WESTWARD THROUGH THE CYCLE INTO
SOUTHEASTERN NICARAGUA BY 72-84 HRS. AS LOW AND MOISTURE POOL
PROGRESS WESTWARD...EXPECTING REGION OF MOST WIDESPREAD CONVECTION
TO DO SO AFFECTING NICARAGUA/HONDURAS/EL SALVADOR BY LATE CYCLE.
FURTHERMORE...A LOW-LEVEL TROUGH IN THE WESTERN CARIBBEAN WILL
ENHANCE CONVECTION ACROSS THE GULF OF HONDURAS BY LATE CYCLE.
ACROSS WESTERN PANAMA AND ESPECIALLY COSTA RICA...ACTIVE PATTERN
IS TO CONTINUE AND PEAK BY 36-60 HRS ASSOCIATED WITH ACTIVE ITCZ
IN PLACE/TROUGH ARRIVING FROM THE EAST. INITIALLY...EXPECTING
LARGEST ACCUMULATIONS ACROSS SOUTHERN NICARAGUA/COSTA RICA/PANAMA
WITH 15-20MM/DAY AND MAXIMA OF 30-60MM/DAY. ACROSS NICARAGUA/GULF
OF FONSECA EXPECTING MAXIMA OF 20-30MM/DAY. BY 36-60
HRS...EXPECTING STRONGEST CONVECTION TO DEVELOP ACROSS COSTA RICA
PRODUCING ACCUMULATIONS OF 15-30MM/DAY AND MAXIMA OF 40-80MM/DAY.
NOTE THAT LOCALLY HIGHER AMOUNTS ARE POSSIBLE. FURTHER
NORTH...EXPECTING ACCUMULATIONS OF 15-20MM/DAY AND MAXIMA OF
30-60MM/DAY ACROSS NICARAGUA/SOUTHERN HONDURAS/EASTERN EL
SALVADOR. BY 60-84 HRS...EXPECTING STRONGEST CONVECTION ACROSS
NORTHWESTERN NICARAGUA/HONDURAS/EL SALVADOR AND SOUTHEASTERN
GUATEMALA TO PRODUCE ACCUMULATIONS OF 15-20MM/DAY AND MAXIMA OF
30-60MM/DAY. EXPECTING A DECREASE ACROSS COSTA RICA TO MAXIMA OF
20-45MM/DAY.

COLOMBIA AND WESTERN VENEZUELA LAY BETWEEN THE SUBEQUATORIAL HIGH
ON THE CENTRAL CARIBBEAN AND THE SUBTROPICAL HIGH TO THE SOUTH
ACROSS PERU. THESE ARE PROVIDING DECENT VENTILATION IN UNISON WITH
THE DIVERGENT PHASE OF THE MJO. AT LOW LEVELS...LOW OVER THE
SOUTHERN CARIBBEAN HAS STARTED TO DRIFT WESTWARD BUT IS STILL
FAVORING WEST/SOUTHWESTERLY WINDS IN A DEEP MOISTURE POOL. THIS
PATTERN WILL CONTINUE ENHANCING DIURNAL CONVECTION ACROSS NORTHERN
CHOCO/EJE CAFETERO/LOWER MAGDALENA INTO THE GUAJIRA/LAGO
MARACAIBO. FORCING WILL DECREASE BY 36-60 HRS...BUT A NEW SURGE IN
CONVECTION IS EXPECTED ACROSS NORTHERN/CENTRAL COLOMBIA/NORTHWEST
VENEZUELA BY 60-84 HRS ASSOCIATED WITH TROPICAL WAVE. ACROSS THE
ABC...ENHANCED LOW-LEVEL CONVERGENCE ASSOCIATED WITH MODULATED
ITCZ AND THEN TROPICAL WAVE WILL SUSTAIN A SEASONABLY VERY ACTIVE
CONVECTION PATTERN. THROUGH 36 HRS...EXPECTING MOST ACTIVE ACROSS
NORTHWESTERN COLOMBIA/EJE CAFETERO/LOWER MAGDALENA WITH
ACCUMULATIONS OF 15-20MM/DAY AND LOCALIZED MAXIMA OF 30-60MM/DAY.
ACROSS THE NORTHERN CARIBBEAN COAST/GUAJIRA/NORTHERN
ZULIA...EXPECTING 10-15MM/DAY AND MAXIMA OF 20-30MM/DAY. ACROSS
THE ABC/NORTHERN VENEZUELA EXPECTING 05-10MM/DAY WITH MAXIMA OF
15MM/DAY. THE NEW SURGE IN CONVECTION WILL DEVELOP BY 36-60
HRS...LEADING TO ACCUMULATIONS OF 15-20MM/DAY AND LOCALIZED MAXIMA
OF 25-50MM/DAY ACROSS THE NORTHERN COLOMBIAN
LLANOS/SANTANDERES/GUAJIRA/ZULIA...AND WESTERN LLANOS OF
VENEZUELA.
BY 60-84 HRS EXPECTING LOCALIZED MAXIMA OF 35-70MM/DAY ACROSS
CENTRAL/NORTHERN CHOCO/LOWER MAGDALENA AND WESTERN LLANOS.

TO THE NORTH ACROSS THE CARIBBEAN...MID/UPPER RIDGE WILL LINGER IN
CENTRAL PORTIONS WHILE MEANDERING WESTWARD THROUGH THE CYCLE. AT
LOW LEVELS...DEEP MOISTURE POOL AND ITCZ WILL CONTINUE SUSTAINING
ACTIVE CONVECTION BETWEEN NORTHERN SOUTH AMERICA AND THE CARIBBEAN
COAST OF THE ANTILLES. A TROPICAL WAVE WILL CROSS THE DOMAIN
THROUGH THE CYCLE ENHANCING CONVECTION ACROSS PUERTO RICO AND
HISPANIOLA...YET BEST ENVIRONMENT FOR DEEP CONVECTION WILL FOCUS
SOUTH OF THE ISLANDS. BY MID/LATE CYCLE...A DRY AIR MASS AND
SUBSIDENCE INVERSION WILL ESTABLISH ACROSS THE LESSER ANTILLES AND
EVENTUALLY REACH PUERTO RICO/USVI...LEADING TO A RAPID DECREASE IN
PRECIPITATION TOWARDS LATE CYCLE. ACROSS PUERTO RICO...EXPECT
HEAVIEST THROUGH 36 HRS WITH ACCUMULATIONS OF 10-15MM/DAY AND
MAXIMA OF 20-45MM/DAY. ACROSS HISPANIOLA...EXPECTING HEAVIEST BY
36-60 HRS WITH ENHANCED DIURNAL CONVECTION PRODUCING 10-15MM/DAY
AND LOCALIZED MAXIMA OF 20-45MM/DAY. ACROSS THE LESSER
ANTILLES...EXPECTING HEAVIEST THROUGH 36 HRS ASSOCIATED WITH
PASSING TROPICAL WAVE. EXPECTING 10-15MM/DAY WITH MAXIMA OF
20-35MM/DAY.

TO THE NORTHWEST ACROSS CUBA/CAYMAN ISLANDS/BAHAMAS...WEATHER WILL
BE MODULATED BY BROAD MID/UPPER TROUGH THAT EXTENDS FROM THE EAST
COAST OF THE USA INTO THE REGION. ACROSS CUBA...EXPECTING HEAVIEST
ACCUMULATIONS THROUGH 36 HRS REACHING 10-15MM/DAY AND MAXIMA OF
20-30MM/DAY. ACROSS THE BAHAMAS...EXPECTING ACCUMULATIONS OF
05-10MM/DAY AND MAXIMA OF 15-25MM/DAY ACROSS THE
CENTRAL/NORTHWESTERN BAHAMAS THROUGH 36 HRS. DYNAMIC FORCING AND
PWAT WILL ENHANCE CONVECTION ACROSS SOUTHEASTERN BAHAMAS ALSO
LATER IN THE CYCLE PRODUCING MAXIMA OF 15-20MM/DAY.

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

INITIAL 24 36 48 60 72 84 TYPE
54W 56W 58W 60W 62W 65W 68W TW
61W 65W 68W 71W 73W 76W 78W TW

A TROPICAL WAVE IS INITIALIZED AT 54W AND TO THE SOUTH OF 15N.
THIS WAVE WILL HAVE A MARGINAL ENHANCEMENT OF ACCUMULATIONS ACROSS
THE CENTRAL LESSER ANTILLES BY 60-84 HRS...LEADING TO AMOUNTS OF
05-10MM/DAY AND ISOLATED MAXIMA OF 15MM/DAY.

A MORE POTENT TROPICAL WAVE IS INITIALIZED AT 61W AND TO THE SOUTH
OF 20N. THIS WAVE IS MORE SIGNIFICANT AND IS ASSOCIATED WITH HIGH
PWAT CONTENT. ALTHOUGH MOST WIDESPREAD CONVECTION WILL CONCENTRATE
IN OPEN WATERS OF THE CARIBBEAN...THE WAVE WILL ALSO ENHANCE
ACCUMULATIONS ACROSS THE ANTILLES. ACROSS THE LESSER ANTILLES
EXPECTING MAXIMA OF 20-35MM/DAY. ACROSS PUERTO RICO EXPECTING
MAXIMA OF 20-45MM/DAY. ACROSS THE DOMINICAN REPUBLIC/HAITI
EXPECTING MAXIMA OF 20-45MM/DAY. ACROSS THE ABC/NORTHERN COAST OF
VENEZUELA EXPECTING MAXIMA OF 15-20MM/DAY. ACROSS WESTERN
VENEZUELA/COLOMBIAN LLANOS EXPECTING MAXIMA OF 35-70MM/DAY.

SOLANO...IMN (COSTA RICA)
ALVAREZ...ONAMET (REPUBLICA DOMINICANA)
DAVISON...HPC (USA)
GALVEZ...HPC USA)

[cycloneye]

Good morning.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
444 AM AST FRI OCT 19 2012

.SYNOPSIS...UPPER LEVEL RIDGE WILL REMAIN THE DOMINANT WX FEATURE
INTO EARLY NEXT WEEK. RIDGE WILL THEN COLLAPSE ON TUE AS BROAD
TROF ESTABLISHES ACROSS THE WRN ATLC BEFORE BUILDING AGAIN LATE
NEXT WEEK AS AN UPPER TROF AMPLIFIES ACROSS THE ERN GMEX.


&&

.DISCUSSION...TROPICAL WAVE IS CURRENTLY MOVING ACROSS THE AREA
AND APPEARS TO BRING VERY ACTIVE WX TODAY SIGNIFICANTLY MORE THAN
I THOUGHT ATTM YESTERDAY. EXPECT NRMS SHOWERS/T-STORMS TO MOVE
INLAND ACROSS THE SOUTHEAST LATER THIS MORNING AND SPREAD WWD
INTO WRN PR. WHILE SHRA CVRG WILL BE HIGH TODAY A STORM MOTION OF
AROUND 15 KNOTS WILL KEEP T-STORMS MOVING AT A GOOD PACE AND KEEP
RAINFALL ACCUMULATIONS FROM BECOMING EXCESSIVE. NEVERTHELESS...EXPECT
SOME URBAN AND POOR DRAINANGE FLOODING ACROSS THE MAYAGUEZ.

MARKED IMPROVEMENT IS EXPECTED SAT AS TROPICAL WAVE FINALLY EXITS
AND TRADE WIND CAP STRENGTHENS. MAINLY FAIR WEATHER IS EXPECTED
THROUGH AT LEAST MON BUT STILL WITH THE TYPICAL AFTERNOON TSRA
ACROSS WRN PR.

ATTENTION THEN TURNS TO THE SW CARIBBEAN WHERE MODELS CONTINUE TO
SUGGEST A BROAD SFC LOW PRES WILL FORM AND REMAIN NEARLY
STATIONARY FOR A FEW DAYS BEFORE GETTING PICKED UP EVENTUALLY BY
AN UPPER LEVEL TROUGH ACROSS THE ERN GMEX. MODEL CONSENSUS
INDICATES THIS LOW WILL TRACK ACROSS THE WINDWARD PASSAGE NEXT
FRI AND MOVE INTO THE SW ATLC NEXT SAT. SRLY FLOW ON THE EAST SIDE
OF THE STORM WILL ADVECT DEEP MOISTURE QUICKLY INTO OUR AREA WITH
THE 00Z ECMWF BEING FASTER THAN THE 00Z GFS BY 24 HRS. A MULTI-DAY
PERIOD OF HEAVY RAINFALL APPEARS LIKELY MID TO LATE NEXT WEEK
ACROSS THE REGION WITH SIG RAINFALL TOTALS POSSIBLE OVER A 2-4 DAY
PERIOD ESPECIALLY IN AREAS OF UPSLOPE FLOW. WHILE IT APPEARS
HISPANIOLA WILL EXPERIENCE SIGNIFICANT IMPACTS FROM THIS STORM IT
IS STILL TOO EARLY TO SAY WITH CERTAINTY THE DEGREE OF IMPACT OVR
PR AS BEST INFLOW WILL BE FOCUSED JUST WEST OF OUR AREA AND HEAVY
RAIN WILL BE FALLING OVR A 2-4 DAY PERIOD. FOR NOW JUST RAISED THE
SKY CVR GRIDS AS IT APPEARS DENSE HIGH CLOUDS WILL STREAM NEWD AND
REMAIN WITH US FOR A GOOD PORTION OF NEXT WEEK.

&&

.AVIATION...BRIEF PERIODS OF MVFR CIGS/VIS WILL CONTINUE TO AFFECT
THE FLYING AREA...BUT ESPECIALLY THE REGIONAL WATERS THROUGH THE
FORECAST PERIOD. INTERMITTENT PERIODS OF MVFR CONDITIONS ARE
EXPECTED ACROSS TIST...TISX...TJPS AND TJSJ UNTIL 19/15Z. AFTER
19/16Z SHRA AND TSRA WILL DEVELOP MAINLY ACROSS WESTERN SECTIONS OF
PUERTO RICO WITH PERIODS OF MVFR OR EVEN IFR CONDITIONS ACROSS TJMZ.
19/00Z TJSJ RAOB INDICATED MAINLY EASTERLY WINDS AT 10 TO 15 KTS
BELOW 10 KFT.

&&

.MARINE...SEAS 3-5 FT IN EASTERLY WIND WAVES. T-STORMS WILL REMAIN
THE PRIMARY HAZARD.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 88 77 / 60 10 10 10
STT 88 79 89 78 / 50 10 10 10

[cycloneye]

.SYNOPSIS...A TROPICAL WAVE WILL CONTINUE MOVING WEST AND AWAY
FROM THE LOCAL AREA TONIGHT. A MID TO UPPER LEVEL RIDGE WILL
REMAIN THE DOMINANT WEATHER FEATURE LOCALLY INTO EARLY NEXT
WEEK...WITH THE RIDGE THEN GRADUALLY WEAKENING AS A BROAD TROUGH
BECOMES ESTABLISHED ACROSS THE WESTERN ATLANTIC AND CENTRAL AND
WESTERN CARIBBEAN. BROAD SURFACE LOW PRESSURE IS FORECAST TO
GRADUALLY DEVELOP ACROSS THE SOUTHWEST CARIBBEAN AND REMAIN
NEARLY STATIONARY THROUGH THE EARLY TO MIDDLE PART OF NEXT
WEEK...BEFORE LIFTING NORTHEAST.

&&

.DISCUSSION...A MOIST AND UNSTABLE AIR MASS WILL CONTINUE ACROSS
THE LOCAL THROUGH AT LEAST THE FIRST PART OF TONIGHT...AS THE
TROPICAL WAVE CONTINUES MOVING WEST AND AWAY FROM THE LOCAL AREA.
EXPECT THIS MOISTURE AND INSTABILITY TO CONTINUE TO COMBINE WITH
LOCAL EFFECTS AND GENERALLY FAVORABLE UPPER LEVEL VENTILATION...
TO PRODUCE SOME ADDITIONAL CLOUDINESS...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS. FOR LATE TONIGHT AND SATURDAY THROUGH
MONDAY AND PROBABLY TUESDAY ALSO...IT STILL APPEARS THAT AN
"OVERALL" DRIER AND MORE STABLE AIR MASS AND THE INFLUENCE OF A
SLOWLY WANING MID TO UPPER LEVEL RIDGE...SHOULD YIELD A LESS
ACTIVE PATTERN...BUT THERE WILL STILL BE ENOUGH MOISTURE AROUND
EACH DAY...TO PRODUCE SOME LIMITED AND LOCALIZED CONVECTION. WE
WILL CONTINUE TO MONITOR THE EVOLUTION OF THE AFOREMENTIONED
BROAD SURFACE LOW PRESSURE SYSTEM ACROSS THE SOUTHWEST CARIBBEAN
FOR NEXT WEEK. AT THIS TIME...IT APPEARS THAT THE MIDDLE TO END
OF NEXT WEEK WILL BECOME INCREASINGLY UNSETTLED LOCALLY...WITH
THE "POTENTIAL" FOR AN EXTENDED PERIOD OF ACTIVE WEATHER.

&&

.AVIATION...SHRA AND ISOLD TSRA ACROSS WESTERN PR MAY CAUSE BRIEF
MVFR CONDITIONS AT TJMZ AND TJBQ UNTIL 19/22Z. THEREAFTER...VFR
CONDITIONS ARE EXPECTED FOR THIS EVENING AND OVERNIGHT. WIND IS
EXPECTED TO DIMINISH AND REMAIN MAINLY EASTERLY. AFTER 20/16Z...
SHRA/TSRA ARE POSSIBLE ACROSS THE INTERIOR AND WESTERN SECTIONS
OF PUERTO RICO...POSSIBLY AFFECTING TJMZ AND TJBQ.

&&

.MARINE...STILL EXPECT WINDS OF 18 KNOTS OR LESS AND SEAS OF 5
FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH AT LEAST SUNDAY.
SMALL BOAT OPERATORS SHOULD EXERCISE CAUTION ACROSS PARTS OF THE
LOCAL COASTAL WATERS TONIGHT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 87 / 20 20 10 10
STT 79 89 78 89 / 20 20 10 10

[Macrocane]

Very wet for Central America this weekend:

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
251 PM EDT FRI OCT 19 2012

DISCUSSION FROM OCT 19/00 UTC: ACROSS MEXICO...MID/UPPER RIDGE
WILL MEANDER OVER JALISCO/MICHOACAN THROUGH THE CYCLE HELPING TO
VENT CONVECTION IN ITS PERIPHERY. YET...MOISTURE ACROSS MOST OF
MEXICO IS LIMITED. BEST MOISTURE AVAILABILITY WILL REMAIN ACROSS
SOUTHWESTERN COAST INTO JALISCO/NAYARIT/SOUTHERN
SINALOA/COLIMA/MICHOACAN. THIS WILL SUSTAIN DIURNAL CONVECTION
THROUGH THE CYCLE WITH ACCUMULATIONS IN THE ORDER OF 05-10MM/DAY
AND ISOLATED MAXIMA OF 15MM/DAY DECREASING THROUGH THE CYCLE.
ACROSS SOUTHEASTERN MEXICO/SOUTHERN YUCATAN...A CHANGE OF PATTERN
IS EXPECTED AS LOW/MID-LEVEL TROUGH ARRIVES FROM THE EAST. TROUGH
WILL BE ACCOMPANIED BY A DEEP MOIST LAYER RESULTING IN AN SURGE IN
CONVECTION. EXPECTING ACCUMULATIONS OF 05-10MM/DAY AND MAXIMA OF
15-20MM/DAY ACROSS CHIAPAS/TABASCO/CAMPECHE BY 36-60 HRS
INCREASING TO LOCALIZED MAXIMA OF 20-40MM/DAY BY 60-84 HRS. ACROSS
BELIZE/COASTAL QUINTANA ROO EXPECTING AMOUNTS OF 10-15MM/DAY AND
MAXIMA OF 20-40MM/DAY BY MID/LATE CYCLE.

ACROSS CENTRAL AMERICA...BROAD RIDGE EXTENDS FROM SOUTHWESTERN
MEXICO INTO NORTHERN HONDURAS AND THE CENTRAL CARIBBEAN. A WEAK
AND BROAD UPPER TROUGH EXTENDS FROM THE GULF OF PANAMA INTO COSTA
RICA/WESTERN NICARAGUA. AT LOW-LEVELS...BROAD LOW ACROSS THE
SOUTHERN CARIBBEAN IS NOW PROGRESSING INTO EASTERN COSTA
RICA/NICARAGUA WHILE WEAKENING. THE LOW EXTENDS A TROUGH TO THE
NORTHWEST THAT WILL MEANDER ACROSS NICARAGUA/EASTERN HONDURAS
EARLY IN THE CYCLE. THE ITCZ EXTENDS IN THE EASTERN PACIFIC ACROSS
10-12N INTO WESTERN NICARAGUA. THIS IS FAVORING SOUTHWESTERLY
WINDS THAT WILL ENHANCE MOISTURE CONVERGENCE ACROSS THE REGION
EARLY IN THE CYCLE. MODELS CONTINUE SHOWING BEST MOISTURE
CONVERGENCE ACROSS COSTA RICA/WESTERN NICARAGUA/SOUTHERN HONDURAS
AND EL SALVADOR THROUGH 60 HRS. AFTERWARDS...EASTERLY TRADES ARE
FORECAST TO INTENSIFY AS NEW LOW DEVELOP OFF CARTAGENA AND PUSH
ITCZ SOUTHWARD AGAIN...LEADING TO A DECREASE IN ACCUMULATIONS.
EXPECTING LARGEST ACCUMULATIONS ACROSS COSTA RICA/SOUTHWESTERN
NICARAGUA THROUGH 36 HRS WITH AMOUNTS OF 15-30MM/DAY AND ISOLATED
MAXIMA OF 40-80MM/DAY. NOTE THAT HIGHER AMOUNTS ARE POSSIBLE.
FURTHER NORTH ACROSS EASTERN AND SOUTHERN HONDURAS/NORTHERN
NICARAGUA AND EL SALVADOR...EXPECTING ACCUMULATIONS OF 15-20MM/DAY
WITH ISOLATED MAXIMA OF 30-60MM/DAY...ESPECIALLY ACROSS PACIFIC
BASIN. BY 36-60 HRS...EXPECTING MOST ACTIVE ACROSS NORTHWESTERN
COSTA RICA INTO WESTERN NICARAGUA/MOST OF HONDURAS/EL SALVADOR
WITH ACCUMULATIONS OF 15-20MM/DAY AND MAXIMA OF 30-60MM/DAY.
AMOUNTS WILL DECREASE GRADUALLY AFTERWARDS TO ISOLATED MAXIMA OF
20-40MM/DAY...WITH MOST ACTIVE ACROSS WESTERN EL SALVADOR AND MOST
OF GUATEMALA BY 60-84 HRS.

COLOMBIA AND WESTERN VENEZUELA LAY BETWEEN THE SUBEQUATORIAL HIGH
ON THE CENTRAL CARIBBEAN AND THE SUBTROPICAL HIGH TO THE SOUTH
ACROSS PERU/BOLIVIA. THESE ARE PROVIDING DECENT VENTILATION IN
UNISON WITH THE DIVERGENT PHASE OF THE MJO. MODELS SHOW TUTT
DEVELOPING BY 60-72 HRS...WHICH WILL PROVIDE SOME FORCING TO
ENHANCE CONVECTION ACROSS MOST OF THE ANDES BY LATE CYCLE. AT LOW
LEVELS...TROUGH PATTERN ACROSS NORTHERN COLOMBIA IS FADING AWAY AS
LOW IN SOUTHERN CARIBBEAN MOVES AWAY. BOUNDARY-LAYER MOISTURE IS
ALSO DECREASING...WHICH SHOULD LEAD TO A SHORT BREAK IN WIDESPREAD
HEAVY RAINFALL PATTERN OBSERVED DURING LAST SEVERAL DAYS. BEST
MOISTURE CONVERGENCE AND LOW-LEVEL FORCING WILL REMAIN ACROSS THE
LLANOS/AMAZONIA AND NORTHERN COAST...AIDED BY A TROPICAL WAVE
ARRIVING FROM THE EAST BY MID/LATE CYCLE. TROPICAL WAVE WILL ALSO
ENHANCE ACCUMULATIONS ACROSS NORTHERN VENEZUELA/THE ABC THROUGH
THE CYCLE...AND ACROSS NORTHERN COLOMBIA AND THE SANTANDERES LATER
AND EVENTUALLY MOST OF THE COLOMBIAN ANDES. ACROSS THE
ABC/NORTHERN VENEZUELA...EXPECTING ACCUMULATIONS IN THE ORDER OF
10-15MM/DAY AND ISOLATED MAXIMA OF 20-30MM/DAY. ACROSS NORTHERN
COAST OF COLOMBIA/NORTHEASTERN COLOMBIA/WESTERN VENEZUELA...
EXPECTING ACCUMULATIONS OF 15-20MM/DAY AND ISOLATED MAXIMA OF
30-60MM/DAY THROUGH 36 HRS. AMOUNTS WILL INCREASE BY 36-60 HRS IN
ASSOCIATION WITH TROPICAL WAVE TO MAXIMA OF 35-70MM. SIMILAR
AMOUNTS ARE EXPECTED FOR 60-84 HRS.

ACROSS THE CENTRAL/EASTERN CARIBBEAN...ACTIVE CONVECTION IS
HELPING MAINTAIN THE SUBEQUATORIAL RIDGE ACROSS THE BASIN. THIS
WILL IN TERM CONTINUE VENTILATING CONVECTION. MODELS ARE NOW
SHOWING A RIDGE SPLITTING AND TUTT DEVELOPING ACROSS CENTRAL
CARIBBEAN/NORTHWEST COLOMBIA/GULF OF PANAMA BY 60-72 HRS. THIS
WILL INTERACT WITH TROPICAL WAVE AT LOW LEVELS TO ENHANCE
CONVECTION ACROSS SOUTHERN CARIBBEAN AND RE-DEVELOP SURFACE LOW
OFF CARTAGENA/BARRANQUILLA. AT LOW-LEVELS...CONVECTIVE INSTABILITY
REMAINS ENHANCED IN DEEP MOISTURE POOL ACROSS MOST OF THE
CARIBBEAN. ADDITIONAL FORCING IS BEING PROVIDED BY A TROPICAL WAVE
THAT WILL CROSS THE BASIN. ONCE WAVE MOVES AWAY INTO THE CENTRAL
CARIBBEAN...A MUCH DRIER AIRMASS WILL BE ADVECTED FROM THE EAST
INTO THE LESSER ANTILLES/PUERTO RICO LEADING TO A SHARP DECREASE
IN ACCUMULATIONS BY MID-LATE CYCLE...WHILE VERY WET PATTERN
PERSISTS ACROSS SOUTHERN AND CENTRAL CARIBBEAN. ACROSS THE
WINDWARD ISLANDS/NORTHEAST VENEZUELA EXPECTING ACCUMULATIONS OF
10-15MM/DAY AND MAXIMA OF 20-30MM/DAY THROUGH 36 HRS WITH A RAPID
DECREASE AFTERWARDS. ACROSS PUERTO RICO/USVI...EXPECTING HEAVIEST
TODAY REACHING 10-15MM/DAY AND MAXIMA OF 20-30MM/DAY. ACROSS
HISPANIOLA EXPECTING HEAVIEST TODAY WITH ACCUMULATIONS OF
15-20MM/DAY AND ISOLATED MAXIMA OF 25-50MM/DAY. DIURNAL CONVECTION
WILL REMAIN ACTIVE AT LEAST THROUGH 72 HRS...BUT ACCUMULATIONS ARE
TO GRADUALLY DECREASE. ACROSS JAMAICA...EXPECTING AN INCREASE TO
05-10MM/DAY AND MAXIMA OF 15-20MM/DAY BY 60-84 HRS.

TO THE NORTHWEST ACROSS CUBA/CAYMAN ISLANDS/BAHAMAS...WEATHER WILL
BE MODULATED BY BROAD MID/UPPER TROUGH THAT EXTENDS FROM THE EAST
COAST OF THE USA INTO THE REGION. ACROSS CUBA/BAHAMAS...EXPECTING
AMOUNTS OF 05-10MM/DAY AND LOCALIZED MAXIMA OF 15-30MM/DAY THROUGH
60 HRS....DECREASING AFTERWARDS.

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

INITIAL 24 36 48 60 72 84 TYPE
32w 35W 38W 41W 43W 46W 50W TW
55W 57W 60W 63W 65W 68W DISS TW
68W 70W 72W 74W 76W DISS TW

A TROPICAL WAVE IS INITIALIZED IN THE OPEN ATLANTIC AT 32W. THIS
WAVE WILL APPROACH FRENCH GUIANA BY LATE CYCLE LEADING TO A LIGHT
INCREASE IN CONVECTION COVERAGE ALONG THE NORTHERN COAST.

A TROPICAL WAVE AT 55W AND TO THE SOUTH OF 15N WILL HAVE A
MARGINAL ENHANCEMENT OF ACCUMULATIONS ACROSS THE CENTRAL LESSER
ANTILLES BY 60-84 HRS.

A MORE POTENT TROPICAL WAVE IS INITIALIZED AT 68W AND TO THE SOUTH
OF 20N. THIS WAVE IS MORE SIGNIFICANT AND IS ASSOCIATED WITH HIGH
PWAT CONTENT. ALTHOUGH MOST WIDESPREAD CONVECTION WILL CONCENTRATE
IN OPEN WATERS OF THE CARIBBEAN...THE WAVE WILL ALSO ENHANCE
ACCUMULATIONS ACROSS THE ANTILLES IN INTERACTION WITH DIURNAL
CYCLE OF CONVECTION. THIS WAVE IS FORECAST TO EVOLVE INTO ANOTHER
SURFACE LOW ACROSS THE SOUTHERN CARIBBEAN JUST OFFSHORE
CARTAGENA/BARRANQUILLA BY LATE CYCLE. ACROSS PUERTO RICO EXPECTING
MAXIMA OF 20-35MM/DAY THROUGH 36 HRS. ACROSS THE DOMINICAN
REPUBLIC/HAITI EXPECTING MAXIMA OF 25-50MM/DAY THROUGH 36 HRS
DECREASING GRADUALLY LATER. ACROSS THE ABC/NORTHERN COAST OF
VENEZUELA EXPECTING MAXIMA OF 20-30MM/DAY. ACROSS WESTERN
VENEZUELA/COLOMBIAN LLANOS/ANDES/NORTHERN COAST EXPECTING MAXIMA
OF 35-70MM/DAY.

SOLANO...IMN (COSTA RICA)
ALVAREZ...ONAMET (REPUBLICA DOMINICANA)
DAVISON...HPC (USA)
GALVEZ...HPC (USA)

[cycloneye]

8 PM Tropical Weather Outlook


TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT FRI OCT 19 2012

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

A WESTWARD-MOVING TROPICAL WAVE LOCATED SOUTH OF HISPANIOLA IS
INTERACTING WITH AN ELONGATED TROUGH OF LOW PRESSURE THAT EXTENDS
FROM NICARAGUA EASTWARD TO THE SOUTHERN WINDWARD ISLANDS. THIS
BROAD DISTURBANCE IS PRODUCING WIDESPREAD CLOUDINESS AND SHOWERS
OVER MUCH OF THE SOUTHWESTERN...CENTRAL...AND EASTERN CARIBBEAN
SEA...AND ADJACENT LAND AREAS OF COLOMBIA AND VENEZUELA. OVER THE
NEXT FEW DAYS...ENVIRONMENTAL CONDITIONS ARE EXPECTED TO GRADUALLY
BECOME MORE CONDUCIVE FOR DEVELOPMENT TO OCCUR ACROSS THE CENTRAL
AND SOUTHWESTERN CARIBBEAN SEA. THIS SYSTEM HAS A LOW CHANCE...20
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS
AS IT MOVES SLOWLY WESTWARD.

A TROPICAL WAVE INTERACTING WITH AN UPPER-LEVEL LOW IS PRODUCING
WIDESPREAD CLOUDINESS AND SCATTERED THUNDERSTORMS OVER THE CENTRAL
TROPICAL ATLANTIC ABOUT 1000 MILES EAST OF THE LEEWARD ISLANDS.
DEVELOPMENT...IF ANY...OF THIS DISTURBANCE SHOULD BE SLOW TO OCCUR
DUE TO UNFAVORABLE UPPER-LEVEL WINDS. THIS SYSTEM HAS A LOW
CHANCE...10 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS AS IT MOVES SLOWLY WEST-NORTHWESTWARD.

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

$$
FORECASTER STEWART

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
855 PM AST FRI OCT 19 2012

.UPDATE...A TROPICAL WAVE SOUTHWEST OF THE MONA PASSAGE THIS EVENING
WILL MOVE AWAY FROM THE LOCAL AREA DURING OVERNIGHT HOURS. DEEP
SOUTHEASTERLY WINDS IN WAKE OF THE WAVE WILL CONTINUE TO BRING
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ACROSS THE LOCAL AREA
THE REST OF TONIGHT. SATELLITE BLENDED PWAT ANALYSIS SHOWS A DRIER
AIR MASS JUST UPSTREAM OF THE USVI AND PR. THIS WILL RESULT IN LESS
MOISTURE AVAILABLE FOR CONVECTION DURING THE WEEKEND. SO EXPECT A
GOOD DEAL OF SUNSHINE IN THE MORNING...FOLLOWED BY THE TYPICAL
SHOWERS/THUNDERSTORMS OVER WESTERN PR IN THE AFTERNOON. CHANGES
WERE DONE TO THE MID/LONG TERM GRIDS TO INCREASE THE POP`S AND
CLOUD COVER AS A BROAD SURFACE LOW PRESSURE WILL FORM WEST/SOUTHWEST
OF THE FORECAST AREA BY MIDWEEK NEXT WEEK.

[cycloneye]

Good morning. We continue to watch the SW Caribbean for possible Tropical Development and what effects that may have on the weather in the Caribbean.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
452 AM AST SAT OCT 20 2012

.SYNOPSIS...MID TO UPPER LEVEL HIGH PRESSURE RIDGE TO BUILD
NORTHWARDS ACROSS THE REGION OVER THE WEEKEND BEFORE GRADUALLY
ERODING BEGINNING ON MONDAY AS A LONG WAVE TROUGH EXITS THE EASTERN
SEABOARD OF THE UNITED STATES...THEN MOVES WESTWARD INTO THE
WESTERN ATLANTIC. THIS UPPER TROUGH IS TO EVENTUALLY DEEPEN AND
BECOME MORE AMPLIFIED ACROSS THE NORTHWESTERN CARIBBEAN BY THE
LATTER PART OF NEXT WEEK. AT THE SURFACE AND LOW LEVELS...A
TROPICAL WAVE NOW SOUTH OF HISPANIOLA...AND SURFACE HIGH PRESSURE
NORTH OF THE AREA WILL HELP MAINTAIN MODERATE EASTERLY TRADE WINDS
ACROSS THE REGION THROUGH THE WEEKEND. HOWEVER...BY THE EARLY PART
OF NEXT WEEK...A TUTT INDUCED SURFACE TROUGH IS FORECAST TO MOVE
WESTWARD ACROSS THE TROPICAL ATLANTIC TO JUST NORTHEAST OF THE
NORTHERN LEEWARDS. THIS WILL RESULT IN A SHIFT IN THE PREVAILING
TRADE WINDS TO MORE OF A LIGHT NORTHEASTERLY LOW LEVEL WIND FLOW.
DURING THE LATTER PART OF NEXT WEEK A LOW PRESSURE SYSTEM IS ALSO
FORECAST TO FORM ACROSS THE CENTRAL CARIBBEAN AND SLOWLY LIFT NORTH
NORTHEAST ACROSS HISPANIOLA THEN INTO THE SOUTHWEST ATLANTIC.


&&

.DISCUSSION...A SLOW AND OVERALL DRYING TREND WILL CONTINUE ACROSS
THE LOCAL AREA FOR MUCH OF THE WEEKEND...AS TROPICAL WAVE AND TRAILING
MOISTURE MOVES FURTHER AWAY FROM THE REGION AND SOMEWHAT DRIER AIR
FILTERS IN FROM THE EAST. LIGHT TO MODERATE EASTERLIES WILL PREVAIL
AND THIS WILL RESULT IN PERIODS OF PASSING SHOWERS ACCOMPANYING POCKETS
OF SHALLOW TRADE WIND MOISTURE. SOME SHOWERS WILL CONTINUE TO BRUSH
PARTS OF THE NORTH AND EAST COASTAL SECTIONS OF THE ISLANDS FOR
THE NEXT FEW DAYS. THIS WILL BRING PERIODS OF MOSTLY LIGHT TO MODERATE
RAINFALL DURING THE LATE EVENING AND EARLY MORNING HOURS. EXPECT SUFFICIENT
LINGERING MOISTURE ACROSS THE REGION TO AID IN THE DEVELOPMENT OF LOCAL
AND DIURNALLY INDUCED CONVECTION EACH DAY ACROSS PARTS OF THE ISLANDS.
MOST OF THE SHOWER ACTIVITY OVER THE VIRGIN ISLANDS WILL BE ISOLATED
DURING THE AFTERNOONS BUT EXPECT SOME SCATTERED AFTERNOON SHOWERS
AND ISOLATED THUNDERSTORMS ACROSS THE INTERIOR AND WEST SECTIONS
OF PUERTO RICO. EXPECT THIS PATTERN TO CONTINUE THROUGH AT LEAST
THE MIDDLE OF NEXT WEEK.

BY THE LATTER PART OF NEXT WEEK MODEL GUIDANCE CONTINUED TO SUGGEST A
SIGNIFICANT CHANGE IN THE OVERALL SYNOPTIC PATTERN. AS THE PREVIOUSLY
MENTIONED THE UPPER TROUGH IS FORECAST TO DEEPEN AND BECOME MORE AMPLIFIED
ACROSS THE NORTHWEST CARIBBEAN...WHILE THE ASSOCIATED SURFACE LOW PRESSURE
AND ACCOMPANYING DEEP LAYERED TROPICAL MOISTURE LIFTS NORTH NORTHEAST
CROSS THE GREATER ANTILLES. THIS IS TO THEN INDUCE A DEEP MOIST SOUTH
SOUTHWESTERLY FLOW ACROSS THE LOCAL REGION DURING THE LATTER PART
OF NEXT WEEK. STILL SOME WAYS OUT BUT WILL CONTINUE TO MONITOR AND
SEE HOW THIS UNFOLDS. REGARDLESS...THE TENDENCY OF ALL MODELS CONTINUE
TO SUGGEST A MUCH WETTER AND POSSIBLY VERY ACTIVE PATTERN DURING THE
LATTER PART OF NEXT WEEK. THEREFORE THE POTENTIAL FOR FLASH FLOODING
IN SOME AREAS MAY SIGNIFICANTLY INCREASE. STAY TUNED.

&&

.AVIATION...MOSTLY VFR CONDITIONS ARE EXPECTED TO CONTINUE THRU
20/16Z AT ALL LOCAL TAF SITES WITH ONLY BRIEF PASSING SHOWERS.
HOWEVER...AFTER 20/16Z SCT SHRA/ISOLD TSRA ARE EXPECTED TO DEVELOP
TO THE NORTHWEST AND INTERIOR SECTIONS OF PUERTO RICO LEADING TO
PERIODS OF MVFR AND MTN TOP OBSCURATIONS. EARLIER TJSJ 20/00Z
UPPER AIR SOUNDING INDICATED AN EASTERLY WIND FLOW OF 10-20 KTS
FROM THE SURFACE TO FL200 FEET...BECOMING NORTHWESTERLY AND INCR
W/HT ALOFT.



&&

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

[cycloneye]

8 AM Tropical Weather Outlook for Caribbean area

A LARGE BUT DISORGANIZED AREA OF CLOUDINESS AND THUNDERSTORMS
BETWEEN HISPANIOLA AND NORTHERN SOUTH AMERICA IS PRIMARILY
ASSOCIATED WITH A TROPICAL WAVE. ENVIRONMENTAL CONDITIONS ARE
FORECAST TO BECOME MORE FAVORABLE FOR DEVELOPMENT DURING THE NEXT
DAY OR TWO AS THE DISTURBANCE MOVES WESTWARD OVER THE CENTRAL AND
WESTERN CARIBBEAN SEA. THIS SYSTEM HAS A MEDIUM CHANCE...30
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

[cycloneye]

Since this thread is for all what occurs weatherwise in the whole Caribbean we now have to watch closely invest 99L in the Central Caribbean. Let's see how it all evolves as the conditions appear favorable for it to develop. Where will it go and how strong it may get are unknown at this point so you can follow what is going on with it in the 99L thread at Active Storms/invests forum. I will post important information about this system also in this thread.

viewtopic.php?f=59&t=114017&hilit=&p=2281254#p2281254

Gusty,have things returned to normal in the butterfly island after whar TS Rafael did there?

[Gustywind]

We now have invest 99L in the Central Caribbean. Let's see how it all evolve as the conditions appear favorable for it to develop. Where will it go and how strong it may get are unknown at this point so you can follow what is going on with ity in the 99L thread at Active Storms/invests forum.

viewtopic.php?f=59&t=114017&hilit=&p=2281254#p2281254

Gusty,have things returned to normal in the butterfly island after whar TS Rafael did there?

Hi Cycloneye, yeah i forgot to post that. Guadeloupe back off the yellow alert since Thursday night. We're under green code meaning no threat from any systems, etc. So good news

WEATHER FORECAST. Back to green

franceantilles.fr 18.10.2012
http://www.microsofttranslator.com/bv.a ... 189821.php

Cyclone Rafael remnants are far away very North of the Antillean Arc. From that night and until Monday, often dry, sunny weather settled. During this period, there will be no significant precipitation over the archipelago.


Cyclone Rafael remnants have moved away very North of the Caribbean Arc, off the coast of the North Atlantic. This phenomenon concerns us most. From that night and until Monday, often dry, sunny weather settled. During this period, there will be no significant precipitation over the archipelago.
The last 24 hours, rainfall amounts, once again, were locally significant. The area that has been the wettest is once more Southeast of Basse-Terre. On the Southeast slopes of the mountain, it counts 80 to 100 litres of water per m2. It fell between 40 and 50 litres of water per m2 on the coast between Trois-Rivières and guava. On the rest of the archipelago, it fell on average between 10 and 30 litres per m2 and locally on Sainte-Rose 30 to 40 liters of water per square metre.

[cycloneye]

2 PM Tropical Weather Outlook for 99L up to 60%

SATELLITE IMAGES INDICATE THAT SHOWERS AND THUNDERSTORMS HAVE BECOME
BETTER ORGANIZED IN ASSOCIATION WITH A TROPICAL WAVE LOCATED OVER
THE CENTRAL CARIBBEAN SEA. SURFACE PRESSURES ARE FALLING IN THE
AREA...AND ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BECOME
CONDUCIVE FOR A TROPICAL DEPRESSION TO FORM DURING THE NEXT COUPLE
OF DAYS. THIS SYSTEM HAS A HIGH CHANCE...60 PERCENT...OF BECOMING
A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS THE WAVE MOVES
SLOWLY WESTWARD.

[Caribwxgirl]

Hi all. Here in Jamaica we're having a bit of thunder and overcast conditions in some areas. I'm keeping a close eye on 99L though

[cycloneye]

Hi all. Here in Jamaica we're having a bit of thunder and overcast conditions in some areas. I'm keeping a close eye on 99L though

Welcome to our Caribbean - Central America Weather thread. This is our home to discuss all about weather in the islands and in Central America so when you can, stop by and let us know how is Jamaica doing weatherwise. About 99L,you have to watch it very closely as many models track close or over that island.

[Caribwxgirl]

Hi all. Here in Jamaica we're having a bit of thunder and overcast conditions in some areas. I'm keeping a close eye on 99L though

Welcome to our Caribbean - Central America Weather thread. This is our home to discuss all about weather in the islands and in Central America so when you can, stop by and let us know how is Jamaica doing weatherwise. About 99L,you have to watch it very closely as many models track close or over that island.

Thanks. I see it bears watching and I've been keeping a watch from this time last week when the models started sniffing at the possibility of something in the area for next week.

[cycloneye]

Afternoon San Juan NWS discussion.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
349 PM AST SAT OCT 20 2012

.SYNOPSIS...A MID TO UPPER LEVEL RIDGE WILL REMAIN THE DOMINANT
WEATHER FEATURE LOCALLY INTO EARLY NEXT WEEK...WITH THE RIDGE THEN
GRADUALLY WEAKENING AS A BROAD TROUGH BECOMES ESTABLISHED ACROSS
THE WESTERN ATLANTIC AND CENTRAL AND WESTERN CARIBBEAN. SURFACE
LOW PRESSURE IS FORECAST TO DEVELOP ACROSS THE SOUTHWEST
CARIBBEAN AND MOVE LITTLE THROUGH THE EARLY TO MIDDLE PART OF
NEXT WEEK...BEFORE LIFTING NORTH NORTHEAST AND THEN NORTHEAST BY
THE END OF NEXT WEEK INTO THE WEEKEND.

&&

.DISCUSSION...FOR SUNDAY AND TUESDAY...IT STILL APPEARS THAT AN
"OVERALL" DRIER AND MORE STABLE AIR MASS AND THE INFLUENCE OF A
SLOWLY WANING MID TO UPPER LEVEL RIDGE...SHOULD YIELD A LESS
ACTIVE PATTERN...BUT THERE WILL STILL BE ENOUGH MOISTURE AROUND
BOTH DAYS...TO PRODUCE SOME LIMITED AND LOCALIZED CONVECTION.
HOWEVER...FOR MONDAY...IT NOW APPEARS THAT A WEAK EASTERLY
DISTURBANCE AND ASSOCIATED MOISTURE WILL MOVE WEST NEAR OR ACROSS
THE LOCAL AREA AND WILL COMBINE WITH LOCAL EFFECTS AND UPPER LEVEL
ANTI-CYCLONIC SPEED DIVERGENCE...TO PRODUCE SOME CLOUDINESS...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. HAVE INCREASED THE
WEATHER A BIT IN THE GRIDS AND FORECASTS FOR MONDAY...BUT THESE
MAY NEED TO INCREASED FURTHER WITH TIME AND LATER GUIDANCE.

THEREAFTER...WE WILL CONTINUE TO MONITOR THE EVOLUTION OF THE
AFOREMENTIONED SURFACE LOW PRESSURE SYSTEM FOR NEXT WEEK.
ALTHOUGH THERE ARE STILL TIMING AND TRACK DIFFERENCES...MODELS
GENERALLY KEEP SURFACE LOW ON A TRACK WELL TO OUR WEST THROUGH
NORTH...BUT OPEN THE LOCAL AREA UP TO THE POSSIBILITY OF THE
INFLUX OF VERY DEEP TROPICAL MOISTURE...WITH VEERING WIND FLOW
WITH HEIGHT AND FAVORABLE UPPER LEVEL CONDITIONS...IN COMBINATION
WITH LOCAL EFFECTS...INCLUDING SOUTH TO NORTH OROGRAPHIC LIFTING
ACROSS THE CORDILLERA CENTRAL. THE CURRENTLY INDICATED
DEVELOPMENT AND TRACK OF THIS SYSTEM WOULD YIELD SEVERAL DAYS OF
UNSETTLED WEATHER...POSSIBLY BEGINNING AS EARLY AS LATE TUESDAY
NIGHT OR EARLY WEDNESDAY...AND THEN CONTINUING THROUGH THURSDAY
AND FRIDAY AND POSSIBLY BEYOND. ALTHOUGH IT IS STILL MUCH TOO
EARLY FOR ANY DETAILS...THE "POTENTIAL" REMAINS FOR HEAVY
RAINFALL...FLOODING...LOCALLY SEVERE WEATHER AND INCREASINGLY
HAZARDOUS WINDS AND SEAS AT SOME POINT DURING THE EVENT. STAY
TUNED.

&&

.AVIATION...BRIEF MVFR CONDITIONS WILL REMAIN POSSIBLE IN AND
AROUND TJMZ AND TJBQ THROUGH ABOUT 20/22Z AS AFTERNOON CONVECTION
PREVAILS. AFT 20/22Z...VFR CONDITIONS EXPECTED TO PREVAIL AT ALL
TAF SITES WITH PASSING SHOWERS POSSIBLE. LLVL WINDS EAST TO EAST
SOUTHEAST AT 10-15 KTS.

&&

.MARINE...STILL EXPECT WINDS OF 18 KNOTS OR LESS AND SEAS OF 5
FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH AT LEAST MONDAY.

&&

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

[Caribwxgirl]

From meteorological service of Jamaica earlier today:

SIGNIFICANT FEATURE… An Area of Low Pressure is over the southwestern and central Caribbean while a Tropical Wave is east of Jamaica.

Comment
The Area of Low Pressure is expected to increase rainfall over the
central Caribbean and Jamaica this weekend and into the coming week.

24-HOUR FORECAST
This Morning… Partly cloudy.
This Afternoon… Expect scattered showers and thunderstorms.
Tonight… Isolated showers and thunderstorms over sections of eastern
central parishes.

Maximum temperatures expected today for:
Kingston... 32 degrees Celsius
Montego Bay...32 degrees Celsius

3-DAY FORECAST (starting tomorrow)
Sun… Morning showers over northeastern and southern parishes. Scattered afternoon showers and thunderstorms.
Mon/Tue…Morning showers and isolated thunderstorms over northern and southeastern parishes. Scattered showers and isolated thunderstorms during the afternoons.

Regionally… A Tropical Wave is generating scattered showers and thunderstorms over the eastern and central Caribbean, while a Frontal Trough is producing thundershowers across the Cayman Islands and Cuba.

[cycloneye]

18z Surface Analysis.