Caribbean - Central America Weather

[cycloneye]

FLOOD ADVISORY
NATIONAL WEATHER SERVICE SAN JUAN PR
907 AM AST THU JAN 7 2010

PRC051-135-137-143-145-071600-
/O.NEW.TJSJ.FA.Y.0004.100107T1307Z-100107T1600Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
TOA ALTA PR-VEGA ALTA PR-DORADO PR-VEGA BAJA PR-TOA BAJA PR-
907 AM AST THU JAN 7 2010

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED AN

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

IN PUERTO RICO
TOA ALTA...VEGA ALTA...DORADO...VEGA BAJA AND TOA BAJA

* UNTIL NOON AST

* AT 905 AM...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED AN
AREA OF MODERATE TO HEAVY RAINFALL MOVING ACROSS WESTERN PORTIONS OF
THE SAN JUAN METRO AREA. TEMPORARILY REDUCED VISIBILITIES...PONDING
OF WATER ON ROADWAYS AND LOCALIZED URBAN FLOODING IN AREAS OF POOR
DRAINAGE...CAN BE EXPECTED WITH THIS SHOWER ACTIVITY THROUGH THE
LATE MORNING HOURS. DUE TO THE SLOW MOVEMENT OF THESE
SHOWERS...ISOLATED RAINFALL TOTALS OF TWO TO THREE INCHES CAN BE
EXPECTED THROUGH NOON AM AST.

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

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1058 AM AST THU JAN 7 2010

.UPDATE...SENT A QUICK UPDATE TO FORECAST TO INCREASE POPS AND
CLOUD COVER ACROSS MUCH OF PUERTO RICO...AS FRONTAL TROUGH IS
MAINTAINING CLOUDY SKIES AND FREQUENT LIGHT TO MODERATE RAIN
SHOWERS...MAINLY ACROSS THE NORTHERN HALF OF THE ISLAND. THIS
TROUGH IS FORECAST TO MEANDER ACROSS THE LOCAL AREA FOR THE NEXT
12-24 HOURS...BEFORE EVENTUALLY LIFTING NORTHWEST AND AWAY FROM
THE LOCAL ISLANDS BY THE UPCOMING WEEKEND. WILL KEEP AN EYE ON
RIVERS TODAY AS PERSISTENT STEADY RAIN MAY LEAD TO SOME RISES IN
RIVER LEVELS...ESPECIALLY ACROSS THE NORTHEASTERN QUADRANT OF THE
ISLAND.

&&

.AVIATION...PREVAILING MVFR CONDS EXPECTED TO CONTINUE ACROSS PR
AND TIST THROUGH AT LEAST 07/23Z...OR LONGER...WITH TEMPORARY IFR
CONDITIONS POSSIBLE IN +RA OR BR ACROSS TJSJ AND TIST. PREVAILING
VFR CONDITIONS EXPECTED TO PERSIST ACROSS TISX...TNCM AND TKPK
THROUGH THE AFTERNOON HOURS. PRESENTLY...VA FROM MONTSERRAT
SHIFTING DIRECTIONS TOWARDS THE SOUTHWEST...WITH DIFFUSE VA
PERSISTING ACROSS TKPK THIS MORNING AND WILL KEEP VA IN THEIR TAF
THROUGH 07/23Z.

[cycloneye]

Flood Advisory Extended

FLOOD ADVISORY
NATIONAL WEATHER SERVICE SAN JUAN PR
1126 AM AST THU JAN 7 2010

PRC021-029-031-061-087-119-127-139-071730-
/O.EXT.TJSJ.FA.Y.0003.000000T0000Z-100107T1730Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BAYAMON PR-TRUJILLO ALTO PR-GUAYNABO PR-CANOVANAS PR-CAROLINA PR-
SAN JUAN PR-LOIZA PR-RIO GRANDE PR-
1126 AM AST THU JAN 7 2010

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS EXTENDED THE

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR MINOR FLOODING OF POOR
DRAINAGE AREAS IN
FOR THE FOLLOWING MUNICIPALITIES...

IN PUERTO RICO
BAYAMON...TRUJILLO ALTO...GUAYNABO...CANOVANAS...CAROLINA...SAN
JUAN...LOIZA AND RIO GRANDE

* UNTIL 130 PM AST

AT 1120 AM AST...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED
TO DETECT LARGE AREAS OF LIGHT TO MODERATE RAINFALL AFFECTING
SECTIONS OF THE SAN JUAN METRO AREA. EXPECT THIS RAINFALL TO
CONTINUE THROUGH THE EARLY AFTERNOON HOURS...WITH TOTAL RAINFALL
ACCUMULATIONS OF ONE TO THREE INCHES EXPECTED BY 130 PM AST. THIS
WILL RESULT IN THE LIKELIHOOD OF URBAN AND SMALL STREAM FLOODING TO
CONTINUE THROUGH THE EARLY AFTERNOON HOURS.

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

[msbee]

I guess we are on the edge of that trough. gray cloudy skies here but no rain.

[cycloneye]

Afternoon Discussion=New Record rainfall in Saint Thomas

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
348 PM AST THU JAN 7 2010

.SYNOPSIS...OLD FRONTAL BOUNDARY/SHEAR LINE WILL CONTINUE DRAPED
ACROSS THE FA TONIGHT...BEFORE MOVING BACK TO THE WEST NORTHWEST
FRIDAY. MID TO UPPER LEVEL HIGH PRESSURE WILL THEN TAKE CONTROL OF
THE LOCAL WEATHER REGIME FOR THE WEEKEND...BEFORE HEIGHTS FALL
AGAIN EARLY NEXT WEEK...AS NEXT FRONTAL BOUNDARY APPROACHES.

&&

.DISCUSSION...OLD FRONTAL BOUNDARY/SHEAR LINE WILL CONTINUE
DRAPED ACROSS THE FA TONIGHT...BEFORE MOVING BACK TO THE WEST
NORTHWEST FRIDAY. THIS SHOULD CONTINUE TO PRODUCE A GOOD DEAL OF
CLOUDINESS ACROSS THE LOCAL ISLANDS...WITH SCATTERED TO NUMEROUS
SHOWERS EXPECTED...ESPECIALLY OVER THE INTERIOR AND NORTH
SECTIONS OF PUERTO RICO. AT THIS TIME...DO NOT EXPECT ANY
SIGNIFICANT FLOODING PROBLEMS FOR TONIGHT...BUT STEADY LIGHT TO
MODERATE RAIN...WITH EMBEDDED HEAVIER SHOWERS WILL CONTINUE TO
RESULT IN LOCALIZED URBAN AND SMALL STREAM FLOODING. FOR
FRIDAY...MODELS ARE FAIRLY CERTAIN THAT BOUNDARY WILL MOVE BACK TO
THE WEST NORTHWEST...BUT HISTORY HAS SHOWN THIS TO SOMETIMES BE A
SLOW PROCESS. SO...EXPECT GRADUAL IMPROVEMENT TOMORROW...BUT STILL
WITH SOME CLOUDINESS AND SHOWERS AROUND FOR AT LEAST THE FIRST
PART OF THE DAY. THEREAFTER...OVERALL "DRIER" CONDITIONS ARE
GENERALLY EXPECTED FOR SATURDAY AND SUNDAY.

&&

.AVIATION...PREVAILING MVFR CONDITIONS ARE EXPECTED TO CONTINUE
ACROSS THE PR TAF SITES IN ADDITION TO TIST AND TISX THROUGH THE
OVERNIGHT HOURS AS AN OLD FRONTAL BOUNDARY REMAINS DRAPED ACROSS
THE LOCAL ISLANDS. IN ADDITION...BRIEF IFR CONDITIONS WILL BE
POSSIBLE THROUGH 08/00Z. PREVAILING VFR CONDITIONS EXPECTED ACROSS
TNCM AND TKPK AS THIS BOUNDARY WILL REMAIN TO THEIR NW...BUT VA
WILL REMAIN IN THE VICINITY OF TKPK THROUGH AT LEAST 07/23Z.

&&

.MARINE...NORTH NORTHWEST SWELLS WILL CONTINUE TO AFFECT THE
LOCAL ATLANTIC WATERS AND THE CARIBBEAN PASSAGES THROUGH AT LEAST
FRIDAY NIGHT...RESULTING IN HAZARDOUS MARINE CONDITIONS ACROSS THE
WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR MOST OF THE
LOCAL ATLANTIC WATERS AND THE CARIBBEAN PASSAGES.

&&

.CLIMATE...A NEW RAINFALL RECORD HAS BEEN ESTABLISHED FOR SAINT
THOMAS TODAY...WITH A TOTAL OF 1.13 INCHES OF RAIN ACCUMULATING AT
THE CYRIL E KING AIRPORT ON SAINT THOMAS THROUGH 2 PM AST. IN SAN
JUAN...WE HAVE SEEN THE SECOND WETTEST JANUARY 7 ON RECORD...WITH
1.02 INCHES ACCUMULATING AS OF 2 PM AST. THE WETTEST JANUARY 7TH
OCCURRED IN 1998...WHEN 3.70 INCHES OF RAINFALL ACCUMULATED AT THE
LUIS MUNOZ MARIN AIRPORT IN SAN JUAN. INTERESTINGLY...AFTER THE
WARMEST START TO A YEAR ON RECORD IN SAN JUAN...WITH AN AVERAGE HIGH
TEMPERATURE OF 87.5 DEGREES THROUGH THE 1ST 6 DAYS OF THE YEAR...THE
HIGH TEMPERATURE WILL LIKELY NOT EVEN REACH 80 DEGREES TODAY.

[cycloneye]

Early night updated discussion

Winter-type weather here as fresh brezzes and scattered showers are the dominant features tonight.

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
919 PM AST THU JAN 7 2010

.UPDATE...A 115 MILE WIDE BAND OF RAIN IS LINGERING A LITTLE
LONGER THAN THE GFS WOULD HAVE US BELIEVE...BUT THE NAM AND THE
WRF HAVE THE PULL-OUT TOWARD THE NORTHWEST SET CLOSER TO 06Z FOR
SAN JUAN WITH LIGHT RAIN STILL LINGERING ALONG THE NORTH COAST BY
12Z. THERE APPEAR TO BE TWO BANDS AT PLAY IN THIS SCENARIO...A
FIRST WHICH...WHICH AT 08/00Z WAS STRETCHED ACROSS THE EASTERN
EDGE OF PUERTO RICO AND JUST NORTH OF CULEBRA. A SECOND IS ABOUT
120 MILES SOUTHEAST OF THE RADAR IN CAYEY. THE SECOND ONE IS
EXPECTED TO CROSS. SAINT CROIX BY ABOUT 6 AM AST AT ITS CURRENT
SPEED...MOVING TO THE NORTHWEST. BOTH BANDS SEEM TO HAVE
STRENGTHENED IN THE PAST HOUR AS EVIDENCED BY THE ADDITION OF
CLOUD TOPS COLDER THAN 0 DEGREES CELSIUS. SHOWERS WERE FORECAST
TO LESSEN AFTER 04Z AND HAVE TRIED TO TAILOR POP GRIDS TO REFLECT
THIS.

&&

.DISCUSSION...ALTHOUGH GFS BRINGS IN A WIDE AREA OF DRY AIR AT 850
MB AFTER 18Z...THE NAM SHOWS THE SECONDARY BAND THAT HAS BEEN
PROGRESSING SLOWLY TO THE NORTHWEST AT 7 KNOTS AND IS NOW ABOUT
60 MILES SOUTHEAST OF SAINT CROIX. THE SHOWERS IN THE BAND ARE NOT
CONTINUOUS AND SAINT CROIX MAY STILL BE MISSED BY SHOWERS. THIS
BAND WILL ROLL THROUGH THE U.S. VIRGIN ISLANDS BETWEEN 08/09-12Z
AND EASTERN PUERTO RICO BETWEEN 08/18-21Z. SHOWERS ALSO APPEAR
COMING OUT OF THE EAST SOUTHEAST ON SATURDAY AND SUNDAY MORNINGS
IN THE NAM...THOUGH THE GFS EMPHASIZES SUNDAY MORNING MORE. EARLY
INDICATIONS SHOW THE NORTH COAST WET MID WEEK AS WELL.

&&

.AVIATION...
MVFR VSBYS AND CIGS AT TJSJ/TJBQ THROUGH MID MORNING
TOMORROW WITH INTERMITTENT -SHRAS. CONDITIONS IMPROVING TO VFR BY
MIDDAY TOMORROW IF NOT SOONER. NE WINDS 15 KT DECREASING TO 10 KT
OR LESS TOWARD DAYBREAK AND BECOMING MORE EASTERLY TOMORROW.
VOLCANIC ASH WILL CONTINUE TO AFFECT TKPK THROUGH 09/00Z.

[cycloneye]

Good morning to all.A good weekend ahead expected weatherwise.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
332 AM AST FRI JAN 8 2010

.SYNOPSIS...REMNANTS OF OLD SHEAR LINE FRONTAL BOUNDARY NOW
DISSIPATING OVER THE LOCAL AREA AS TRADE WIND FLOW RETURNS. DRY
AIR MASS TO REPLACE RESIDENT AIR MASS PROVIDING STABLE CONDITIONS
AND MINIMAL POPS FOR THE WEEKEND. BY EARLY NEXT WEEK...A NEW
FRONTAL SYSTEM SWEEPS THE WESTERN ATLANTIC APPROACHING THE
AREA...LIKELY STALLING OVER LOCAL AREA BY MID TO LATE WEEK.


&&

.DISCUSSION...REMNANTS OF OLD SHEAR LINE BOUNDARY NOW DISSIPATING
OVER THE LOCAL AREA AS TRADE WIND FLOW RETURNS. WEAK LOW LEVEL
EASTERLY MOISTURE ADVECTION IN DEFORMATION BAND WILL APPROACH FROM
THE EAST DURING THE DAY AS LOW CLOUDS BREAK UP NORTH OF THE
CORDILLERA CENTRAL. MID TO LOW LEVEL HIGH PRESSURE BEGINS TO BUILD
THIS WEEKEND OVER E CARIB AS LOW LEVEL SELY FLOW USHERS IN MUCH
DRIER AND MORE STABLE LOW LEVEL AIR MASS LIMITING POPS THROUGH THE
WEEKEND. MEANWHILE...YET ANOTHER DEEP LOW PRESSURE OVER NW ATLC
SENDS DEEP LAYERED TROUGH LINE ACROSS W ATLC TOWARDS THE LOCAL
AREA...NEARLY THE SAME SCENARIO AS PLAYED OUT ONE WEEK PRIOR. 00Z
GFS STILL KEEPING STRONG SUBTROPICAL RIDGE IN PLACE JUST EAST OF
THE LEEWARDS BY MONDAY...AS PRE FRONTAL TROUGHS DEVELOP AHEAD OF
THE MAIN SHEAR LINE OVER THE USVI. TIMING OF MOISTURE ADVECTION
MONDAY THROUGH WED WILL BE PROBLEMATIC AS SCENARIO WILL BE HIGHLY
DEPENDENT ON STRENGTH OF RIDGE AND HOW FAR SOUTH SHEAR LINE IS
ALLOWED. MOST LIKELY SCENARIO IS THAT SHEAR LINE WILL STALL OVER
REGION SOME TIME TUESDAY THROUGH FRIDAY...RESULTING IN ANOTHER
SEVERAL DAYS OF LOW CLOUDS AND HIGHER POPS ON WINDWARD SIDE OF
MOUNTAINS (NORTH AND EASTERN PR) AND USVI.


&&

.AVIATION...ALTHOUGH WEATHER CONDITIONS ARE EXPECTED TO IMPROVE
THROUGH LATE MORNING...MVFR CONDITIONS ARE POSIBLE FOR THE
TIST...TISX AND TJSJ AS FEW PATCHES OF LEVEL MOISTURE WILL CONTINUE
TO AFFECT THE EASTERN HALF OF PUERTO RICO INCLUDING THE USVI AND
SURROUNDING WATERS. VFR CONDITIONS WILL PREVAIL OVER MOST TERMINAL
AFTER 16Z WITH EXCEPTION OF TJMZ AND TJPS WHERE MVFR CONDITIONS ARE
POSIBLE DURING THE AFTERNOON HOURS...BETWEEN 18Z-22Z.

[cycloneye]

Afternoon Discussion by NWS San Juan

As I said this morning,good weather is expected this weekend.Showers appear again for midweek.

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

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
313 PM AST FRI JAN 8 2010

.SYNOPSIS...SKIES ARE EXPECTED TO CLEAR OVERNIGHT...WITH FAIR
WEATHER AND PARTLY SUNNY SKIES EXPECTED ACROSS THE LOCAL ISLANDS
OVER THE UPCOMING WEEKEND.

&&

.DISCUSSION...SE WINDS VISIBLE IN SATELLITE BEHIND THE REMNANTS
OF AN OLD FRONTAL BOUNDARY...CURRENTLY DRAPED ACROSS OF MUCH OF
PUERTO RICO AND THE VI...WILL HELP TO PUSH THESE REMNANTS ACROSS
PUERTO RICO AND AWAY FROM THE LOCAL ISLANDS OVERNIGHT. DRIER AIR
AND LESS SHOWER ACTIVITY IS THEN EXPECTED THROUGH THE WEEKEND...AS
HIGH PRESSURE STRENGTHENS ACROSS THE LOCAL ISLANDS IN THE MID TO
UPPER LEVELS OF THE ATMOSPHERE.

CONTINUE TO EXPECT THE NEXT FRONTAL BOUNDARY...CURRENTLY EXITING
THE EAST COAST OF THE UNITED STATES...TO NEAR THE LOCAL ISLANDS
TOWARDS THE MIDDLE OF NEXT WEEK. LATEST GFS STALLS THIS BOUNDARY
TO THE NORTH...AS A SURGE OF MOISTURE FROM THE SOUTHEAST STREAMS
ACROSS THE LOCAL AREA AND INTO THIS BOUNDARY ON TUESDAY AND
WEDNESDAY...WITH THE ACTUAL BOUNDARY DETERIORATING JUST TO OUR
NORTH THROUGH THE END OF NEXT WEEK. PREVIOUS FORECAST ALREADY
INTRODUCED SCATTERED SHOWER ACTIVITY ACROSS MUCH OF THE LOCAL AREA
FOR THE MIDDLE OF NEXT WEEK...WHICH SEEMS REASONABLE CONSIDERING
TIMING AND UNCERTAINTY.

&&

.AVIATION...EXPECT PREVAILING VFR CONDITIONS ACROSS ALL THE LOCAL
TAF SITES OVERNIGHT. HOWEVER...MVFR CEILINGS WILL CONTINUE ACROSS
TJBQ THROUGH AT LEAST 08/22Z...WITH BRIEF MVFR CONDITIONS AND
LOCAL MOUNTAIN OBSCURATIONS POSSIBLE ACROSS THE REMAINDER OF THE
TAF SITES THROUGH 08/22Z. IN ADDITION...VA FROM MONTSERRAT IS
EXPECTED TO CONTINUE MOVING GENERALLY WEST NORTHWEST THROUGH
TONIGHT AND ALTHOUGH IT IS STILL EXPECTED TO REMAIN SOUTH OF MOST
OF THE LOCAL ISLANDS...IT WILL LIKELY GET CLOSE TO TISX THIS EVENING.

&&

.CLIMATE...FOR THE SECOND DAY IN A ROW...THE MAXIMUM TEMPERATURE
IN SAN JUAN FAILED TO RISE ABOVE 80 DEGREES. THIS IS FAR SHY FROM
THE RECORD OF 18 DAYS CONSECUTIVE DAYS IN 2005 WHEN THE TEMPERATURE
DID NOT EXCEED 80 DEGREES IN SAN JUAN.

[Macrocane]

Today has been the warmest day of the week with the maximum temperature in san Salvador reaching 32 °C though the minimum was still cool 17 °C (63 °F). The warming is expected to end soon because of a strong cold front approaching Central America, actually it seems that it could be so far the strongest event of the season. A new special report has been issued: http://www.snet.gob.sv/ver/meteorologia/informes+especiales/?evento=167

Translation

Strong to occasionally very strong northerly winds this weekend

Description: A cold front will enter Central america and the Caribbean and a 1040 mb high pressure system will produce strong and occasionally very strong northerly winds this weekend.

Forecast:

Friday January 8 2009: El Salvador will be under the influence of a high pressure ridge producing northerly winds in the 15-25 km/h (9-16 mph) range and gusts in the 25-35 km/h (16-22 mph) range. It will feel cool at night

Saturday January 9 2009: The northerly winds will reach moderate to strong intensity, the winds will be in the 20-30 km/h (13-19 mph) range and the gusts in the 40-50 km/h (25-31 mph) range, being stronger in high areas, in the plains and the eatern part of the country.

Sunday January 10 2010: Strong to very strong northerly winds are expected, they will be in the 30-50 km/h (19-31 mph) range and the gusts up to 75 km/h (47 mph), occasionally higher gusts can't be discarded.

The temperatures will drop down to 6-10 °C (43-50 °F) in high areas and mountains, 14-16°C (57-61 °F) in the valleys and 17-19 °C (63-66) in the coast.

[cycloneye]

This is an off topic message to let know the Eastern Caribbean friends that NHC has positioned a satellite floater.No,there is not a strong wave off Africa,or a TD 300 miles east of Barbados.They are focused on the Soufriere Volcano in the island of Montserrat.For those who may not know,there is a thread that you can visit and get all the details of what the Soufriere volcano is doing at the Geology subforum as part of Global Weather forum.Link to Soufriere thread below.

viewtopic.php?f=67&t=107244&hilit=&p=1957727#p1957727

[Macrocane]

I have just posted the observations of the last centralamerica cold surge on this thread: http://www.storm2k.org/phpbb2/viewtopic.php?f=22&t=106879&p=1957733#p1957733

The cold front already approaching the area is so strong that a very special report has been issued by SNET (El Salvador met agency): http://www.snet.gob.sv/ver/meteorologia/informes+especiales/impacto+e+incidencia/

It's in Spanish but the meteorological info is the same as what I posted a few hours ago but it has plus information about oceanographic conditions and possible impacts:

Oceanographic conditions: On sunday and monday rough seas with moderate wave heights are expected due to strong northeasterly wind up to 40 km/h (25 mph) and gusts up to 60 km/h (38 mph).

150 km (94 miles) away from the coast surface waves from the northeast are expected, with height up to 2.2 meters (7 ft) and occasionally maximums upto 3.3 meters (10.6 ft).

30 km (19 miles) away from the coast the winds will have 30 km/h (19 mph) speed or more and the wave height upto 2.3 meters (7.5 ft).

Possible Impacts
Based on similar historical events when winds have reached 70 km/h (44 mph) or more the following impacts may occur:

Agriculture: Winds may damage coffee beans production affecting present and future harvest, the low temperatures may damage other crops especially ornamental plants and vegetables on the northern and central mountain regions.

Homes and public infrastructure may suffer damage, especially fragile and weak roofs and walls. Fallen trees can also damage homes, poles, roads and other structures.

The increase in windspeed have already produced a increase in wildfires and the low temperatures an increase in respiratory diseases.

At the end is a list of the most affected cities, towns and villages on other similar events.

[cycloneye]

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
940 PM AST FRI JAN 8 2010

.SYNOPSIS...STATIONARY FRONT DRAPED ACROSS THE REGION WILL
DISSIPATE BY TOMORROW. MEANWHILE...MID LEVEL HIGH PRES WILL BUILD
ACROSS THE ERN CARIBBEAN AND BRING INCREASING SUNSHINE AND WARMER
TEMPERATURES.

&&

.DISCUSSION...SHOWERS HAVE PRETTY MUCH DISSIPATED WITH ONLY
SPRINKLES ALONG THE NORTH COAST AND ATLC WATERS BUT LOW CLOUDS
STILL HOLDING ACROSS MUCH OF THE REGION ATTM BUT MODEL GUIDANCE
SUGGESTS THAT SKIES WILL BEGIN TO CLEAR OVERNIGHT SO HAVE TRENDED
SKIES MORE OPTIMISTIC TOWARD DAYBREAK. INCREASING SUBSIDENCE
TOMORROW SHOULD RESULT IN M/SUNNY DAY ACROSS MUCH OF THE REGION
ALONG WITH WARMER TEMPERATURES. MODELS SHOW DEEP DRYING AND A
STRONG SUBSIDENCE CAP THAT WILL BE DIFFICULT TO OVERCOME SO HAVE
REMOVED ALL POPS FOR TOMORROW. SHOULD BE A REALLY NICE DAY.

[b]MAJOR ERUPTION OF THE MONSERATT VOLCANO OCCURRED EARLIER TODAY.
WINDS FCST TO SWITCH TO THE SOUTHEAST TOMORROW AND COULD ADVECT
SOME ASH TOWARD SOUTHEAST PR ESPECIALLY TOWARD VIEQUES AND ST.
CROIX. ADDED VOLCANIC ASH TO THE GRIDS FOR THESE AREAS.

WE ARE CURRENTLY UNABLE TO GENERATE TEXT/DIGITAL PRODUCTS LIKE THE
ZONE AND COASTAL WATERS FORECAST. NCF IS CURRENTLY TROUBLESHOOTING
THESE PROBLEMS. DON`T HAVE AN ESTIMATED TIME WHEN THIS WILL BE
FIXED. MAY ASK MIAMI TO GENERATE THESE PRODUCTS FOR US.


&&

.AVIATION...SKIES FCST TO CLEAR TOWARD MORNING AS DRIER AIR MOVES
IN FROM THE SOUTHEAST SO VFR CONDITIONS EXPECTED. VOLCANIC ASH
WILL BE A CONCERN ESPECIALLY FOR ST. CROIX NEXT 24 HRS AS WINDS
SWITCH TO THE SOUTHEAST.


&&

.MARINE...NNW SWELLS WILL CONTINUE TO SLOWLY SUBSIDE OVER THE NEXT
24 HRS. SEAS STILL HAZARDOUS FOR SMALL CRAFT OPERATORS ACROSS
AMZ710 AND THE NEAR SHORE WATERS BUT CONDITIONS EXPECTED TO
IMPROVE RAPIDLY TOMORROW.

[/b]

[cycloneye]

Good morning to all.The warm spell returns this weekend and also the Soufriere volcano will continue to be a big story for us.More about that on the Soufriere thread at Geology subforum as part of Global Weather forum.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
459 AM AST SAT JAN 9 2010

.SYNOPSIS...EXPECT MID TO UPPER LEVEL RIDGE TO BE THE DOMINANT
WEATHER FEATURE LOCALLY THROUGH THE WEEKEND AND POSSIBLY
BEYOND...PRODUCING A GENERALLY FAIR AND MAINLY DRY WEATHER
PATTERN ACROSS THE LOCAL ISLANDS.

&&

.DISCUSSION...REMNANTS OF OLD FRONTAL BOUNDARY/SHEAR LINE CONTINUE
TO MOVE WEST NORTHWEST AND AWAY FROM THE LOCAL AREA AT THIS TIME...
WHILE SLOWLY DISSIPATING. BEHIND THIS FEATURE A MUCH DRIER AND
MORE STABLE AIR MASS IS ON TAP FOR TODAY AND SUNDAY. ALTHOUGH
CANNOT COMPLETELY RULE OUT SOME PASSING CLOUDS AND ISOLATED
SHOWERS...PARTICULARLY ON SUNDAY...MOST OF THIS WEEKEND SHOULD
REMAIN PRETTY DRY. EAST SOUTHEAST TO SOUTHEAST SURFACE WINDS AND
PLENTIFUL SUNSHINE SHOULD ALLOW NORTH COASTAL HIGH TEMPERATURES TO
ONCE AGAIN CLIMB TO WELL ABOVE NORMAL LEVELS BUT DO NOT FORESEE
ANY RECORDS AT THIS TIME...AT LEAST NOT FOR TODAY. LOOKING
AHEAD...HEALTHY UPPER LEVEL SHORT WAVE IS FORECAST TO PASS ACROSS
OR JUST NORTH OF THE LOCAL ISLANDS MONDAY...WITHOUT MUCH FANFARE.
AT THE SAME TIME...NEXT COLD FRONTAL BOUNDARY WILL APPROACH THE
LOCAL AREA FROM THE NORTHWEST AND ALTHOUGH IT APPEARS THAT IT WILL
GET HUNG UP TO THE NORTHWEST OF THE LOCAL ISLANDS...THIS IS NOT
YET ETCHED IN STONE. AS PREVIOUS FORECASTERS HAVE ALLUDED TO...WE
MAY WELL SEE THE WEAKENING LOW LEVEL BOUNDARY OR SHEAR LINE MOVE
INTO OR ACROSS THE FA AS THE LAST COUPLE HAVE DONE. STAY TUNED
FOR FURTHER DETAILS ON THIS AS WE GO THROUGH THE WEEKEND.

&&

.AVIATION...LARGE VA EXPLOSION LAST NIGHT AT MONTSERRAT WITH ASH
CLOUD LIKELY OVER USVI AND EASTERN PR ATTM. LATEST SIGMET PUTS
USVI SITES AND TJSJ IN VA UNTIL AROUND 15Z. WENT WITH SAME LINE OF
THINKING IN TAFS UNTIL FIRST FEW FRAMES OF VIS SATELLITE CAN BE
ANALYZED AFTER SUNRISE.

&&

.MARINE...NORTH NORTHWEST SWELLS WILL CONTINUE TO SLOWLY SUBSIDE
ACROSS THE ATLANTIC WATERS AND THE CARIBBEAN PASSAGES TODAY. A
SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE ATLANTIC OFF SHORE
WATERS THROUGH THIS EVENING AND FOR THE NEAR SHORE WATERS OF
NORTHERN PUERTO RICO...THE NORTHERN USVI AND THE MONA PASSAGE
UNTIL 6 AM AST. OTHERWISE...SMALL BOAT OPERATORS SHOULD EXERCISE
CAUTION ACROSS THE ATLANTIC WATERS AND THE CARIBBEAN PASSAGES.
NEW...NORTH NORTHWEST SWELLS ARE EXPECTED TO INVADE THE LOCAL
ATLANTIC WATERS AND THE CARIBBEAN PASSAGES TUESDAY AND THEN
CONTINUE THROUGH WEDNESDAY.

[cycloneye]

Afternoon Discussion by NWS San Juan

For information about the ash you can go to the Soufriere thread at Geology subforum as part of Global Weather forum.Link to Soufriere thread below.

viewtopic.php?f=67&t=107244&start=0


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
258 PM AST SAT JAN 9 2010

.SYNOPSIS...AT UPPER LEVELS...HIGH PRESSURE CONTINUES ACROSS THE
CARIBBEAN AND NORTHERN SOUTH AMERICA. FLOW BECOMES WEST SOUTHWEST
OVERHEAD AS MID LATITUDE TROUGH PUSHES ACROSS THE EASTERN
ATLANTIC SEABOARD LATE IN THE WEEKEND. FLOW BECOMES NORTHWEST
AGAIN ON THURSDAY.

AT MID LEVELS...A RIDGE OF HIGH PRESSURE EXTENDS FROM THE
CARIBBEAN INTO THE TROPICAL ATLANTIC UNTIL THE SUNDAY AFTER NEXT.
LITTLE IF ANY MOISTURE APPEARS ABOVE 600 MB.

AT LOWER LEVELS...A LARGE AREA OF PATCHY MOISTURE IS MOVING INTO
THE CARIBBEAN AND DISSIPATING. AN OLD FRONTAL BOUNDARY WILL
CONTINUE TO MOVE NORTHWEST...BUT WILL RETURN TO THE VICINITY
TUESDAY AND WEDNESDAY.

&&

.DISCUSSION...SOUNDER DATA SHOWS THE ATMOSPHERE IS EXCEPTIONALLY
DRY WITH THE PRECIPITABLE WATER NOW BELOW ONE INCH. FOR THE NEXT 7
DAYS MOST WEATHER MAKERS REMAIN NORTH OF THE AREA...BUT THE FRONT
MAY RETURN CLOSE ENOUGH TO BRING SOME SHOWERS MONDAY THROUGH
WEDNESDAY. THESE WILL MAINLY AFFECT THE NORTH COAST OF PUERTO RICO
AND THE NORTHERN VIRGIN ISLANDS.

CURRENT SATELLITE IMAGERY SHOWS A WELL-DEVELOPED BAROCLINIC LEAF
JUST OFF THE EASTERN COAST OF THE UNITED STATES AND MODELS ARE
EXPECTING CYCLOGENESIS OFF THE COAST OF GEORGIA. THE LOW THAT
DEVELOPS UNDERNEATH THE BAROCLINIC LEAF IS EXPECTED TO PROGRESS
RAPIDLY TO THE EAST NORTHEAST AND REMAIN NORTH OF THE SUBTROPICAL
RIDGE...BUT WILL SEND SOME SWELL INTO THE AREA TUESDAY AND
WEDNESDAY...MORE DETAILS BELOW. THAT SAME RIDGE DOMINATES THE
WEATHER PATTERN OVER PUERTO RICO AND THE U.S. VIRGIN ISLANDS FOR
THE NEXT 10 DAYS...ALBEIT WITH WEAKENING TOWARD THE END.

&&

.AVIATION...
PREVAILING VFR CONDS EXPECTED ACROSS FLYING AREA FOR
NEXT 24 HOURS. LATEST VISIBLE SATELLITE IMAGERY SUGGESTED THAT
VA IF ANY ACROSS PR AND THE USVI THIS AFTERNOON HAD BECOME VERY
DIFFUSE AND LIGHT...AND NOT VISIBLE ATTM FROM SFC AT TJSJ OR BY
PILOTS LANDING AT TISX. THEREFORE...DO NOT EXPECT ANY OPERATIONAL
IMPACTS IN LOCAL FLYING AREA FOR NOW. HOWEVER A PLUME WAS CLEARLY
VISIBLE EXTENDING SOME 100 MILES OR SO WEST NORTHWEST OF TRPG...AND
JUST WSW OF TKPK AND TKPN. WITH THE PRESENT EAST SOUTHEAST LOW LVL
WINDS...ANOTHER PATCH OF VA MAY ONCE AGAIN DRIFT ACROSS THE LOCAL
FLYING AREA LATE EVENING AND OVERNIGHT. THEREFORE PLEASE REFER TO
LATEST SIGMETS FOR UPDATES.

&&

.MARINE...SWELL ARE BELOW 6 FEET NOW AND WILL CONTINUE TO DIMINISH
THROUGH MONDAY. NEW SWELL FROM A NEW LOW DEVELOPING IN THE
WESTERN ATLANTIC TONIGHT WILL BE PRODUCED AND WILL PEAK LATE
TUESDAY EVENING AT BUOY 41043. OTHERWISE ALL SMALL CRAFT WILL BE
DOWN TONIGHT AT MIDNIGHT.

[Macrocane]

The government of El Salvador has declared "green alert" because of the strong winds that are already affecting the country. Green alert is declared when a natural phenomenon represents a possible threat to people's lives and infrastructure. El Salvador's Civil Protection has adviced that:
- People in old age and children must be prtected from the cold air and the strong winds.
- Unstable roofs must be repared.
- Stay away from trees and fragile structures that may collapse due to the strong winds.
- Do not start bonfires or other type of outdoor fires.
- Beggining on Sunday January 10 sea sports, lake sports, navigation and artisan fishing are prohibited.
- Conventional eyeglasses or sunglasses are recommended to protect the eys from possible infections.

[cycloneye]

The government of El Salvador has declared "green alert" because of the strong winds that are already affecting the country. Green alert is declared when a natural phenomenon represents a possible threat to people's lives and infrastructure. El Salvador's Civil Protection has adviced that:
- People in old age and children must be prtected from the cold air and the strong winds.
- Unstable roofs must be repared.
- Stay away from trees and fragile structures that may collapse due to the strong winds.
- Do not start bonfires or other type of outdoor fires.
- Beggining on Sunday January 10 sea sports, lake sports, navigation and artisan fishing are prohibited.
- Conventional eyeglasses or sunglasses are recommended to protect the eys from possible infections.

When you can,keep us informed of any news regarding the effects of the strong winds.

[Gustywind]

[Macrocane]

When you can,keep us informed of any news regarding the effects of the strong winds.

Yes I will, and if I find other important information from other centralamerican countries I will post them too.

[cycloneye]

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
937 PM AST SAT JAN 9 2010

.SYNOPSIS...SUBTROPICAL RIDGE WILL MAINTAIN A DRY PATTERN ACROSS
THE ERN CARIBBEAN THROUGH MUCH OF NEXT WEEK.

&&

.DISCUSSION...ATMOSPHERE BONE DRY AND STRONGLY CAPPED ATTM PER
00Z JSJ SOUNDING. HOWEVER...MOISTURE IS MUCH HIGHER OVER THE
LEEWARD ISLANDS THIS EVENING WHERE TPW IMAGERY SHOWS PWAT VALUES
AROUND 2.0 INCHES. SOME OF THIS MOISTURE WILL ADVECT WWD OVERNIGHT
WHICH COULD RESULT IN A FEW SPOTTY SHOWERS ACROSS THE
USVI...VIEQUES AND SURROUNDING WATERS. SO HAVE PUT IN ISOLD POPS
FOR THOSE AREAS.

MOISTURE STILL EXPECTED TO BE LIMITED TOMORROW BUT MODELS SHOW CAP
WEAKENING/LIFTING TO AROUND 700 MB. THE INCREASED INSTABILITY
COULD LEAD TO A COUPLE OF LOW-TOPPED SHOWERS ACROSS NW PR
TOMORROW. OVERALL STILL A NICE DAY.

SUBTROPICAL RIDGE APPEARS TO HOLD STRONG ACROSS THE ERN CARIBBEAN
THROUGH MUCH OF NEXT WEEK PREVENTING ANY FRONTS FROM GETTING THIS
FAR SOUTH. GUIDANCE SUGGESTS A FRONT WILL STALL ONCE IT GETS TO
AROUND 20N MIDDLE OF NEXT WEEK. WITH FRONT FCST TO WEAKEN
SIGNFICANTLY HAVE TRENDED FCST DRIER MIDDLE OF NEXT WEEK.

&&

.AVIATION...NO SIG WX NEXT FIVE DAYS WITH VFR CONDITIONS
EXPECTED. SOUTHEAST WINDS MAY STEER ANY VOLCANIC ASH TOWARD
ST. CROIX TOMORROW BUT HAVE KEPT OUT OF TAFS FOR NOW.

&&

.MARINE...SEAS WILL CONTINUE TO IMPROVE THROUGH MONDAY. A NEW SET
OF NW SWELLS WILL RAISE SEAS TO 7-8 FT ACROSS THE ATLC WATERS TUE
NIGHT AND WED. SCA WILL LIKELY BE NEEDED AGAIN.

[cycloneye]

Good morning to all.The big story continues to be the Soufriere Volcano.Go to the Soufriere thread at Geology subforum to see the latest.

[b]AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
421 AM AST SUN JAN 10 2010

.SYNOPSIS...MID LEVEL HIGH PRESSURE WILL MAINTAIN FAIR WEATHER
CONDITIONS ACROSS THE LOCAL REGION THROUGH MUCH OF NEXT WEEK. A
WEAK COLD FRONT IS EXPECTED TO STALL ALONG LATITUDE 20 NORTH
MIDDLE OF NEXT WEEK.

&&

.DISCUSSION...SATELLITE IMAGES ARE SHOWING PATCHES OF LOW LEVEL
MOISTURE MOVING ACROSS THE ANEGADA PASSAGE...THE DOPPLER RADAR IS
NOT REPORTING SIGNIFICANT SHOWERS ASSOCIATED TO THESE PATCHES. AT
THIS MOMENT THE DOPPLER RADAR IS SHOWING A FEW ISOLATED SHOWERS
MOVING ACROSS THE LOCAL CARIBBEAN WATERS. A FEW OF THESE SHOWERS
COULD AFFECT THE EAST AND SOUTHEAST PORTIONS OF PUERTO RICO AND
ADJACENT ISLANDS. NO SIGNIFICANT RAIN FROM THESE SHOWERS ARE
EXPECTED.

DRY CONDITIONS WILL CONTINUE TODAY BUT ENOUGH MOISTURE WILL BE
AVAILABLE TO GENERATE ISOLATED TO LOCALLY SCATTERED SHOWERS OVER
THE INTERIOR AND NORTHWEST PORTIONS OF PUERTO RICO. A RELATIVELY
GOOD CONDITIONS WILL PREVAIL ACROSS THE LOCAL FORECAST AREA. A
SLIGHTLY MORE UNSTABLE CONDITIONS WILL PREVAILED BETWEEN MONDAY
AND WEDNESDAY INCREASING THE CHANCES OF SHOWERS ACROSS THE
REGION.


&&

.AVIATION...ANOTHER VERY SIGNIFICANT VOLCANIC EVENT FROM MONTSERRAT
DURING THE OVERNIGHT...VERY OBVIOUS EVEN ON IR IMAGERY. ASH PLUME
HEADED STRAIGHT NW AT A VERY RAPID PACE...CURRENTLY (08Z) ABOUT
50-100 NM NW OF TRPG (MONTSERRAT). SIMPLE TRAJECTORY CALCULATIONS PUT
THE VA CLOUD IN THE AREA OF TIST AND TJSJ BEGINNING 12Z. JUST TO BE
SAFE...INCLUDED VA IN THE FORECAST AT THOSE TWO SITES BETWEEN 10Z
AND 15Z. BACK SIDE OF ASH PLUME MAY BECOME MORE EXTENDED
OVERTIME...AS VOLCANO STILL ERUPTING AS OF 08Z. EXPECTING PLUME TO
REACH TJSJ BY ABOUT 11Z AND LASTING UNTIL AT LEAST 15Z. AS WITH ALL
OF THESE EVENTS...THE TIMING AND FORECASTING OF A VA CLOUD IS HIGHLY
PRONE TO ERROR. THE CLOUD MAY DISSIPATE...OR MISS ALL OF THESE
SITES. ITS VERY HARD TO TRACK WITHOUT PIREPS OR DAYTIME IMAGERY. BUT
FOR NOW...WILL GO WITH ASH IMPACTING TJSJ...TIST AND TISX DURING THE
EARLY MORNING.
[b]