Caribbean - Central America Weather

[Macrocane]

It's a chilly morning here in San Salvador, the temperature this morning is 16 °C (61 °F) and the winds are in the 30-40 km/h range (19-25 mph) range. But what impresses me more is the cloud field that is over us at this time, it's a very unusual view, you can see it in the webcam on the first page, maybe I will upload a photo with this beautiful skies sometime this week. I will post updates on the system later in the day.

Here is the infrared image of this morning:

[Gustywind]

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]

Thanks for the info Cycloneye .

[cycloneye]

This is a small version of a discussion but contains all about the story of the day,the Soufriere Volcano.Go to the Soufriere thread at Geology subforum to see the latest.

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
1222 PM AST SUN JAN 10 2010

.UPDATE...A COINCIDENTAL VOLCANIC ERUPTION FROM MONTSERRAT SENT
ASH INTO A BAND OF SHOWERS THAT WAS OVER MONTSERRAT AT AROUND 0530Z.
THE BAND AND THE ASH HAS BEEN MOVING NORTHWEST AT 18 KNOTS. ASH IS
VISIBLE IN THE SATELLITE IMAGERY AND SHOWERS ARE NOTED ON THE
RADAR NORTHWEST OF SAINT THOMAS AND WEST NORTHWEST OF SAINT CROIX
AS OF 16Z. ASH WAS ALSO NOTED IN TORTOLA COVERING CARS WITH A FINE
LAYER. THE ASH CLOUD WAS NOTED BETWEEN FL080 AND FL200 AND IS
EXPECTED TO MOVE OVER TSJU BY 1730Z...BECOMING MORE DIFFUSE AS IT
GOES. MINOR CHANGES WERE MADE TO THE GRIDS THROUGHOUT BUT WILL
MAKE LITTLE DIFFERENCE IN THE INDIVIDUAL POP FORECASTS. AS
CONDITIONS REMAIN SOMEWHAT DRY AND ISOLATED SHOWERS WILL BE THE
RULE EXCEPT WHEN FLOW BECOMES EAST TO NORTHEAST THEN SHOWERS MAY
BECOME SCATTERED ON THE NORTHEAST COAST WEDNESDAY THROUGH FRIDAY.

[Macrocane]

No doubt that this cold front has been the strongest so far this season. It's 1:00 pm in El Salvador it's completely sunny but we have only reached 26 °C (79 °F), in other cold events we've had at this hour 30 °C (86 °F) and without cold events we would have reached 32 °C (90 °F). Very strong gusts have been reported, later today I will post some of the observations.

[cycloneye]

Afternoon Discussion by NWS San Juan

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
224 PM AST SUN JAN 10 2010

.SYNOPSIS...PASSING TROUGHS AND A STRONG SUB TROPICAL JET ARE
HELD NORTH OF THE AREA BY A HIGH OVER THE CARIBBEAN AND THE NORTH
COAST OF SOUTH AMERICA.

AT MID LEVELS...HIGH PRESSURE NEAR 21 NORTH 52 WEST WILL STRETCH
INTO THE CENTRAL ATLANTIC TOMORROW AND TUESDAY WHILE MAINTAINING A
RIDGE OVER THE CARIBBEAN. RIDGING WILL SINK SOUTH OVER THE CENTRAL
ATLANTIC KEEPING AN EAST-WEST RIDGE OVER THE CARIBBEAN THROUGH
MONDAY OF NEXT WEEK. HIGH PRESSURE WILL THEN SHIFT SLOWLY TOWARD
THE DOMINICAN REPUBLIC.

AT LOWER LEVELS...A COLD FRONT NEAR THE TIP OF FLORIDA AT THIS
TIME WILL MOVE SLOWLY ACROSS CUBA TONIGHT AND TOMORROW AND THEN
LEAN OVER VERY SLOWLY MONDAY THROUGH FRIDAY UNTIL IT IS NEARLY
PARALLEL WITH LATITUDE 21 NORTH. AFTER FRIDAY THE FRONT LIFTS TO
THE NORTH AND PEELS BACK TO THE NORTHEAST


&&

.DISCUSSION...THE BIGGEST WEATHER STORY CONTINUES TO BE ASH FROM
MONTSERRAT WHICH HAS BEEN DRIFTING NORTHWEST AT 18 KNOTS. IT WAS
LAST SIGHTED PASSING TORTOLA AND SAINT CROIX AND IS EXPECTED TO
PASS OVER SAN JUAN DIFFUSELY AFTER 2 PM AST. A THIN COLUMN OF
EMISSION...MAINLY STREAM...CAN BE SEEN CONTINUING FROM THE
MOUNTAIN. VISIBILITY AT SAN JUAN DROPPED BELOW 10 MILES AS OF 2 PM
AST. A FRONT...CURRENTLY OVER THE TIP OF FLORIDA WILL MOVE ACROSS
CUBA BUT DOES NOT GET AS CLOSE AS THE MONA CHANNEL ACCORDING TO
THE GFS. THIS LEAVES THE AREA RELATIVELY DRY FOR THE NEXT 10 DAYS
WITH NO MAJOR PRECIPITATION EVENTS FORESEEN.


&&

.AVIATION...
EXPECT PREVAILING VFR CONDITIONS ACROSS THE LOCAL ISLANDS AND AT
ALL LOCAL TAF SITES THROUGH TONIGHT...WITH LOCAL MVFR CEILINGS AND
BRIEF MOUNTAIN OBSCURATIONS POSSIBLE OVER PARTS OF PUERTO RICO
THROUGH 10/22Z. BASED ON LATEST VISIBLE SATELLITE DATA...VOLCANIC
ASH ADVISORY AND SIGMET...EXPECT LEFTOVER VOLCANIC ASH PATCH/CLOUD
FROM OVERNIGHT SIGNIFICANT MONTSERRAT EVENT TO CONTINUE TO IMPACT
TISX THROUGH ABOUT 10/1830Z...TIST THROUGH ABOUT 10/1900Z...TJSJ
THROUGH ABOUT 10/2000Z AND TJPS THROUGH ABOUT 10/2030Z...BUT THESE
MAY NEED TO BE UPDATED/EXTENDED ON THE FLY. ADDITIONALLY...LOW TO
MID LEVEL WIND FLOW ACROSS THE NORTHEAST CARIBBEAN REMAINS
SOUTHEAST TO SOUTH...SO ANY NEW VOLCANIC ASH EMISSIONS FROM
MONTSERRAT COULD AGAIN IMPACT LOCAL TAF SITES.

&&

.MARINE...SEAS HAVE COME DOWN SUCH THAT...SMALL CRAFT EXERCISE
CAUTION...WILL NOT APPEAR IN THE COASTAL WATERS FORECAST TONIGHT AND
A SMALL CRAFT ADVISORY IS NOT EXPECTED UNTIL THURSDAY MORNING IN
THE ATLANTIC.

[Macrocane]

Yellow alert has been declared in El Salvador, it was upgraded because there has been some wind damage. Here is the link (in Spanish) to the official declaratory: Yellow Alert in El Salvador

This is the list of the emergencies attended:
- The collapse of a Billboard
- Roof damage in a touristic complex building in La Libertad.
- 2 Fallen tress, on of them damaged a home in San Miguel.
- 14 houses have been damaged in Olocuilta.
- 2 Wildfires have been registered.

Also a new special report has been issued by the Met Office: http://www.snet.gob.sv/ver/meteorologia/informes+especiales/?evento=167

Description: The 1040 mb High pressure system is producing strong to very strong northerly winds in the country. On Sunday dawn wind gusts up to 72 km/h (45 mph) were registered in La Union. A minimum temperature of 7.2 °C (45 °F) was registered in Planes de Montecristo, Santa Ana.

Forecast
Sunday afternoon and night: Strong to very strong northerly winds will persist with speed in the 40-50 km/h range (25-31 mph) and gusts in the 70-80 km/h range (44-50 mph). Stronger gusts cannot be discarded.

Monday January 11: Moderate to strong northerly winds are expected in the 30-50 km/h range (19-31 mph) and gusts up to 65 km/h (41 mph).

Tuesday January 12: Moderate northerly winds continue to affect the country, in the 30-40 km/h range (19-25 mph) and gusts upto 50 km/h (31 mph).

The temperatures will be sensibly diminished between 5-10 °C (41-50 °F) in high areas and mountains, between 14-16 °C (57-61 °F) in the valleys and between 17-18 °C (62-64 °F) in the coast.

[cycloneye]

That is a monster high down there causing all kinds of problems as noted by the news.The good news is no fatalities nor injuries have occured and hopefully that continues.

[Macrocane]

I hope so too. I've found this news from Honduras: Cold front causes problems in Honduras It says that 4 communities in Santa Fe municipality in Honduras are inaccessible because of the rise on the water level in two rivers. Usually cold fronts don't bring rains to El Salvador but they do it to Honduras and that's why the rivers have risen.
By the way, it's 7:00 pm here and temperature have dropped down to 17 °C (63 °F) yesterday at this hour the temperature was 21 °C (70 °F) that's a 4 °C drop I guess this will be a cold night.

[cycloneye]

Updated Discussion by NWS San Juan

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

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
945 PM AST SUN JAN 10 2010

.SYNOPSIS...SUBTROPICAL HIGH WILL BE THE DOMINANT WX FEATURE FOR
THE REST OF THE WEEK AND MAINTAIN FAIR WX CONDITIONS. A WEAK CDFNT
WILL APPROACH THE AREA LATE IN THE WORK WEEK.

&&

.DISCUSSION...DESPITE STRONG MID-LVL RIDGING/CAP A COUPLE OF
SHOWERS MANAGED TO DEVELOP AROUND THE SAN JUAN AREA TODAY.
GFS SHOWS SUBSIDENCE CAP WEAKENING/LIFTING TO AROUND 700 MB AND K
INDEX RISING TO NEAR 30 TOMORROW WHICH SHOULD RESULT IN MORE SHRA
ACTIVITY THAN TODAY. WINDS WILL ALSO BE RELATIVELY LIGHT FROM THE
SOUTH WHICH SHOULD RESULT IN STRONGER SEA BREEZE CONVERGENCE. HAVE
BUMPED POPS TO SCT RANGE TOMORROW ALONG THE NORTH COAST.

SUBSIDENCE CAP FCST TO HOVER BETWEEN 700-650 MB THROUGH THE REST
OF THE WEEK. THIS SHOULD ALLOW FOR ISOLD TO SCT AFTERNOON SHOWERS
TO DEVELOP EACH DAY.

NCEP GUIDANCE BRINGS A CDFNT THROUGH THE AREA BETWEEN THU AND FRI
THEN SHOWS DISSIPATING BY SAT. HOWEVER...LATEST GFS GUIDANCE
SHOWS BEST THICKNESS PACKING STAYS JUST TO THE NORTH OF THE AREA.
IN ANY CASE...PROXIMITY OF BDRY AND EAST NORTHEAST FLOW SHOULD
RESULT IN A CONTINUED CHANCE OF SHRAS BUT NO REAL SIGNIFICANT
HEAVY RAIN EVENTS ARE FORESEEN AT THIS TIME.

&&

.AVIATION...NO SIG WX NEXT FIVE DAYS WITH NO MORE THAN VCSH
EXPECTED. VOLCANIC ASH FCST FOR TKPK THROUGH 11/1330Z BASED ON
VAAC GUIDANCE.

&&

.MARINE...SCA MAY BE REQUIRED ONCE AGAIN TOMORROW FOR AMZ710 AS A
NEW SET OF NW SWELLS BEGINS TO ARRIVE INTO OUR LOCAL ATLC WATERS.
NAH MODELS BRINGS 8 FT SWELLS AT 11 SECS TUE NIGHT.

[Macrocane]

What a nice morning, it's windy and cold, San Salvador is at this hour (7:00 am) 14 °C (57 °F)
This is today's forecast: http://www.snet.gob.sv/ver/meteorologia/pronostico/24+horas/

Moderate to strong northerly winds persist today with speeds in the 30-40 km/h (19-25 mph) range and gusts up to 60 km/h (38 mph), especially in high areas and mountains. Windspeed diminish in the midday and afternoon hours but they re-intensify in night, dawn and morning hours.

Clear skies are expected and the temperatures will be lowered in diurnal and nocturnal hours.

Comments about dominant systems: The 1038 mb high pressure system is extending a ridge over Central America allowing moderate to stron northerly winds to persist. Lowered temperatures are expected during the whole day. Temperatures down to 4-8 °C (39-46 °F) in high areas and down to 12-14 °C (54-57 °F) in the valleys.

Aditional information: Temperatures may drop 2°C (3.6 °F) less than those forecasted today, that means that the coldest period of this event will be on Monday and Tuesday dawn.

So according to the official forecast tomorrow's morning San Salvador may have a 12 °C (54°F) temperature! Let's see if that verifies.

[Macrocane]

I've found this article from a Honduras newspaper, it's long and it's on Spanish: http://www.elheraldo.hn/Ediciones/2010/01/11/Noticias/Se-mantiene-alerta-por-frente-frio-en-Honduras

The most important information says that Tegucigalpa registered 10 °C (50 °F) this morning, and the lowest temperature in that country was in La Esperanza with 5°C (41 °F). In Colon (department of Honduras) the cold front produced rainfall amounts between 60-100 mm (2.4-3.9 inches) and that caused some rivers to rise. Northerly winds in the 50-80 km/h (31-50 mph) have been registered.

[cycloneye]

I am posting this graphic of how the sst anomalies in the Tropical Atlantic are as of now because,if this were August or September,the MDR road would be favorable to fuel those tropical waves that emerge Africa but its January.However,remember that the ssta's are only one factor of many that determine how a season will be in terms of activity.

[Gustywind]

[cycloneye]

Afternoon Discussion by NWS San Juan

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


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
300 PM AST MON JAN 11 2010

.SYNOPSIS...AT UPPER LEVELS...SHORT WAVES AND UPPER LEVEL JETS PASS TO THE
NORTH OF THE AREA AS HIGH PRESSURE HOLDS ITS PLACE OVER THE
CARIBBEAN AND NORTHERN SOUTH AMERICA.

AT MID LEVELS...HIGH PRESSURE STRETCHES FROM AFRICA IN THE EASTERN
ATLANTIC TO THE SOUTHWEST CARIBBEAN. HIGH PRESSURE RE-BUILDS WEAKLY
OVER THE CARIBBEAN AFTER THE WEEKEND AND DOMINATES THE CARIBBEAN
AFTERWARD. THE MID LEVELS OF THE ATMOSPHERE REMAIN DRY THROUGHOUT
THE PERIOD.

AT LOWER LEVELS...A COLD FRONT IS STILL SLOWLY MOVING TOWARD THE
LOCAL AREA WITH A BAND OF SOLID CLOUDS AND SOME SHOWERS...BUT IS MEETING
MORE RESISTANCE FROM THE FLOW OUT OF THE HIGH AND WILL STALL
BEFORE IT GETS HERE. THE FRONT IS EXPECTED TO LEAN OVER UNTIL IT
IS ALMOST OVER 21 DEGREES NORTH.

&&

.DISCUSSION...A SOLID BAND OF CLOUDS IS VISIBLE OVER THE DOMINICAN
REPUBLIC AND THE WINDWARD PASSAGE. SOME CLOUDS AND A FEW SHOWERS
FORMED IN THE CONVERGENCE ZONE OVER THE SOUTHWEST PORTION OF THE
ISLAND OF PUERTO RICO AND ALSO A FEW SHOWERS FORMED JUST
NORTHWEST OF SAINT CROIX. MODELS HAVE NOT CHANGED MUCH DURING THE
PAST 24 HOURS AND ARE STILL HOLDING THE FRONT NORTH OF THE LOCAL
AREA AND SHOW CONVERGENCE BANDS MOVING WEST NORTHWEST THROUGH THE
AREA FOR THE ADDITIONAL SHOWERS THAT ARE SUPPOSED TO EMERGE MID
WEEK. AS THE FRONTAL BAND ROTATES IT MAY CLIP PUERTO RICO AND THE
U.S. VIRGIN ISLANDS AGAIN ON SATURDAY NIGHT. NONE OF THESE PORTEND
ANY WIDESPREAD HEAVY RAINFALL EVENTS IN THE NEXT 10 DAYS...SO
LITTLE CHANGE IN THE FORECAST WILL BE NOTED.

&&

.AVIATION...
EXPECT PREVAILING VFR CONDITIONS ALL TAF SITES FOR NEXT
24 HOURS...WITH THE CHANCE OF AN MVFR CIG/VSBY IN A VCSH OR PASSING
SHRA ACROSS TJSJ...TJMZ AND TJBQ THROUGH 12/00Z. VA WILL LIKELY
REMAIN SOUTH OF ALL TAF SITES...BUT NEAR SAINT CROIX DURING THE LATE
EVENING AND OVERNIGHT HOURS.

&&

.MARINE...ATLANTIC SEAS ARE EXPECTED TO PEAK ON WEDNESDAY MORNING
AND THEN QUIET DOWN AGAIN. SMALL CRAFT ADVISORIES WILL CONTINUE
FOR SOME TIME THERE. SEAS REMAIN BELOW ADVISORY CRITERIA IN THE CARIBBEAN.

[Macrocane]

It's unbelievable how cool is here, it's 2:00 p.m and the temperature has only risen to 25 °C (75 °F) in San Salvador and it's sunny. A new special report has been issued: http://www.snet.gob.sv/ver/meteorologia/informes+especiales/?evento=167

Description:The 1036 mb high pressure system is still producing moderate to strong northerly winds in the country. On sunday night and monday dawn wind gusts up to 84 km/h were registered in La Union (in the Gulf of Fonseca). The lowest temperature this morning was 4.8 °C (40.6 °F) in Planes de Montecristo and Los Andes (in western El Salvador).

Forecast

Monday afternoon: moderate to strong northerly winds are expected, windspeeds in the 30-40 km/h range (19-25 mph) and gusts in the 50-60 km/h range (31-38 mph). Higher gusts cannot be discarded.

Tuesday January 12: Moderate winds in the 25-40 km/h range (15-25 mph) and gusts up to 50 km/h (31 mph) are expected. Stronger wind gusts are possible.

Wednesday January 13: Northerly winds will gradually weaken, windspeed in the 20-30 km/h range (12-19 mph) and gusts up to 45 km/h (28 mph).

A significantly drop in temperatures is forecasted, they will be between 4-8 °C (39-46 °F) in high areas and mountains, 10-16 °C (50-60°F) in the valleys and 17-18 °C (62-64 °F) in the coast.

The yellow alert continues in El Salvador. The new balance of damages is: 20 homes and one building damaged, 5 fallen trees, 1 Billboard destroyed and 34 fires (most of them small bushfires).

[Macrocane]

In this link you can see the low temperatures and the max wind gusts for different locations in El Salvador since January 1: http://www.snet.gob.sv/ver/meteorologia/informes+especiales/verificacion/
San Salvador's station is "Aeropuerto Ilopango", according to this data the temperature this morning was not 14 °C like I've said earlier but 12.6 °C (54.7 °F) that is the lowest temperature in San Salvador since november 2006.

[cycloneye]

Small Craft Advisory in effect

http://forecast.weather.gov/wwamap/wwat ... 20advisory

URGENT - MARINE WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN JUAN PR
1016 PM AST MON JAN 11 2010

...NORTHWEST SWELLS EXPECTED BEGINNING TUESDAY NIGHT...

.A TRAIN OF NORTHWEST SWELLS FROM A PREVIOUS STORM SYSTEM OF THE
EAST COAST OF THE UNITED STATES WILL ENTER THE ATLANTIC WATERS
BEGINNING TUESDAY NIGHT.

AMZ710-121030-
/O.CON.TJSJ.SC.Y.0005.100112T1600Z-100114T0400Z/
ATLC WATERS OF PUERTO RICO AND USVI FROM 10NM TO 19.5N-
1016 PM AST MON JAN 11 2010

...SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM NOON TUESDAY TO
MIDNIGHT AST WEDNESDAY NIGHT...

A SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM NOON TUESDAY TO
MIDNIGHT AST WEDNESDAY NIGHT.

NORTHWEST SWELLS ARE SET TO ENTER THE AREA TUESDAY NIGHT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SMALL CRAFT ADVISORY MEANS THAT WINDS OF 22 TO 33 KNOTS AND
SEAS OF 7 FEET AND GREATER ARE EXPECTED TO PRODUCE HAZARDOUS
MARINE CONDITIONS FOR SMALL CRAFT. INEXPERIENCED MARINERS...
ESPECIALLY THOSE OPERATING SMALLER VESSELS...SHOULD AVOID
NAVIGATING IN THESE CONDITIONS.

[cycloneye]

Afternoon Discussion by NWS San Juan

Winter-type weather will be with us during the next few days.

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

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
314 PM AST TUE JAN 12 2010

.SYNOPSIS...AT UPPER LEVELS...HIGH PRESSURE OVER THE CARIBBEAN AND
NORTHERN SOUTH AMERICA WILL PERSIST THROUGH THE FORECAST PERIOD.
ZONAL FLOW WILL HOLD OVER PUERTO RICO AND THE U.S. VIRGIN ISLANDS
UNTIL LATE NEXT WEEK WHEN IT BECOMES MORE NORTHWESTERLY.

AT MID LEVELS...HIGH PRESSURE OVER THE EASTERN ATLANTIC RIDGES
BACK INTO THE CARIBBEAN AND FORMS ANOTHER HIGH CENTER JUST
SOUTHEAST OF PUERTO RICO BY THE WEEKEND...BUT WEAKENS SLIGHTLY
LATE IN THE FOLLOWING WEEK.

AT LOWER LEVELS...HIGH PRESSURE OVER THE EASTERN UNITED STATES
MOVES INTO THE WESTERN ATLANTIC EARLY IN THE WEEKEND AND RECEDES
INTO THE EASTERN ATLANTIC BY MID WEEK NEXT WEEK. AN OLD COLD FRONT
SAGS CLOSE TO THE AREA THURSDAY THROUGH SATURDAY...BUT THEN PULLS
BACK.


&&

.DISCUSSION...SHOWERS CONTINUED OVER THE ATLANTIC WATERS OFF THE
NORTHWEST CORNER OF PUERTO RICO TODAY AS CONVERGENCE AHEAD OF THE
OLD FRONTAL BOUNDARY CONTINUES. THIS BOUNDARY IS EXPECTED TO MOVE
CLOSER TO THE AREA AND SPREAD RAIN OR SHOWERS ACROSS THE ATLANTIC
COASTAL WATERS THAT WILL INCREASE THROUGH FRIDAY. CURRENTLY MODELS
ARE EXPECTING DRIER WEATHER AFTER SUNDAY. MOST CHANGES TO THE
GRIDS HAVE BEEN MADE TONIGHT THROUGH SATURDAY NIGHT WITH FEW
CHANGES AFTERWARD. DIFFERENCES BETWEEN THE GFS AND THE SUBSEQUENT
FORECAST WERE NOT VERY LARGE AND THE MODEL FORECASTS DID NOT LOOK
AS REASONABLE AS THE FORECAST MADE BY NWS FORECASTERS FROM SUNDAY
OUT. TEMPERATURES IN THE MODELS WERE COOLED QUITE A BIT THURSDAY
AND FRIDAY...OSTENSIBLY DUE TO THE PROXIMITY OF THE CLOUDINESS
FROM THE OLD FRONTAL BOUNDARY AND MUST AGREE THAT THIS LOOKS GOOD
AT THIS TIME.

&&

.AVIATION...
EXPECT PREVAILING VFR CONDITIONS ACROSS MOST OF THE LOCAL ISLANDS
AND TAF SITES THROUGH TONIGHT. HOWEVER...OCCASIONAL MVFR
CONDITIONS WILL CONTINUE FROM THE NORTHERN MONA PASSAGE AND THE
NORTHWEST THIRD OF THE LOCAL ATLANTIC OFF SHORE WATERS WEST AND
NORTHWEST IN SHOWERS. IN ADDITION...LESS FREQUENT MVFR CONDITIONS
ARE ALSO EXPECTED ACROSS TKPK AND TNCM IN PASSING CLOUD BANDS AND
SHOWERS. THE SMALL PLUME OF VOLCANIC ASH FROM MONTSERRAT IS
EXPECTED TO CONTINUE MOVING WEST SOUTHWEST THROUGH LATE THIS
AFTERNOON...BUT SHOULD TURN MORE WEST THIS EVENING AND THEN
CONTINUE OVERNIGHT. HOWEVER...MOST ASH SHOULD REMAIN AWAY FROM THE
LOCAL ISLANDS AND TAF SITES.

&&

.MARINE...SMALL CRAFT ADVISORIES WILL GO INTO EFFECT FOR THE
ATLANTIC WATERS AND THE MONA PASSAGE. SWELLS DECREASE WEDNESDAY NIGHT
BUT WINDS INCREASE TONIGHT AND TOMORROW AND WAVES ARE STEEP AND
HAZARDOUS THROUGH FRIDAY FOR THESE WATERS. THE CARIBBEAN REMAINS
LESS AFFECTED AND MORE TRANQUIL.

[msbee]

The winds have definitely increased here today
currently they are from the E at 13 MPH according to the airport Met Office.

Yesterday at this time they were from the SSE at 5 MPH.

[msbee]

Luis
I don't know where to post this but I just received notice of a 7.0 earthquake in Haiti.

7.0 Mw - HAITI REGION
Preliminary Earthquake Report Magnitude 7.0 Mw
Date-Time 12 Jan 2010 21:53:09 UTC
12 Jan 2010 16:53:09 near epicenter
12 Jan 2010 17:53:09 standard time in your timezone

Location 18.451N 72.445W
Depth 10 km
Distances 9 km (6 miles) SSW (197 degrees) of Carrefour, Ouest, Haiti
16 km (10 miles) SW (227 degrees) of PORT-AU-PRINCE, Haiti
18 km (11 miles) WSW (245 degrees) of Pétionville, Ouest, Haiti

Location Uncertainty Horizontal: 8.3 km; Vertical
Parameters Nph = 103; Dmin = 365.7 km; Rmss = 1.14 seconds; Gp = 93°
M-type = Mw; Version = 7
Event ID US 2010rja6 ***This event supersedes event AT00333319.