Home

000
AXNT20 KNHC 151114
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST THU JAN 15 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...THE ITCZ...

FROM LIBERIA NEAR 7N11W TO 1N24W TO 1N32W...CROSSING THE
EQUATOR ALONG 38W...INTO NORTHEASTERN BRAZIL NEAR 3S46W.
SCATTERED STRONG SHOWERS AND THUNDERSTORMS FROM 1N TO 4N
BETWEEN 1W AND 15W...SOUTH OF 3N BETWEEN 17W AND 24W...
AND FROM 2N TO 4N BETWEEN 28W AND 35W

...DISCUSSION...

THE GULF OF MEXICO...
UPPER LEVEL SOUTHWESTERLY WIND FLOW COVERS THE AREA. MOISTURE
AT SEVERAL LEVELS IN THE ATMOSPHERE COVERS MOST OF THE AREA.
THE ONLY AMOUNTS OF DRY AIR IN SUBSIDENCE ARE NORTH OF 28N.
SURFACE HIGH PRESSURE HAS SETTLED INTO THE AREA. GALE-FORCE
WIND CONDITIONS ARE BEING EXPERIENCED IN THE GULF OF
TEHUANTEPEC ON THE EASTERN PACIFIC OCEAN SIDE OF MEXICO.

THE CARIBBEAN SEA...
MIDDLE TO UPPER LEVEL DRY AIR IN SUBSIDENCE COVERS THE AREA
EAST OF 80W. BROAD UPPER LEVEL ANTICYCLONIC FLOW IS IN PLACE
AS MIDDLE TO UPPER LEVEL CYCLONIC FLOW STARTS TO MOVE INTO THE
AREA EAST OF 65W. THE CYCLONIC FLOW IS AROUND A CUT-OFF CYCLONIC
CIRCULATION CENTER IN THE ATLANTIC OCEAN NEAR 15N50W. A TROUGH
EXTENDS FROM THE CYCLONIC CENTER TO 12N64W. THE SOUTHERN END OF
AN ATLANTIC OCEAN-TO-CARIBBEAN SEA STATIONARY FRONT PASSES
OVER CUBA NEAR 21N78W TO THE CAYMAN ISLANDS...CONTINUING AS
A STATIONARY FRONT FROM THE CAYMAN ISLANDS TO THE ISLAS DE
LA BAHIA OFF THE COAST OF HONDURAS. SCATTERED MODERATE SHOWERS
AND POSSIBLE THUNDERSTORMS ARE FROM THE NORTHEASTERN COAST OF
THE YUCATAN PENINSULA INTO THE YUCATAN CHANNEL. WINDS FROM THE
NORTHEAST TO EAST RANGING FROM 20 TO 30 KTS AND SEA HEIGHTS
RANGING FROM 8 TO 12 FT ARE FORECAST FOR THE NEXT 48 HOURS
FROM 10N TO 18N EAST OF 84W. THE WINDS AND SEAS ARE RELATED
TO A TIGHT SURFACE PRESSURE GRADIENT BETWEEN HIGH PRESSURE
NORTH OF THE AREA AND THE SEMI-PERMANENT SURFACE LOW PRESSURE
IN COLOMBIA AND PANAMA.

THE ATLANTIC OCEAN...
THE DEEP LAYER TROUGH THAT BROUGHT THE MOST RECENT COLD FRONT
TO THE GULF OF MEXICO HAS MOVED OUT OF THE AREA...TO THE
ATLANTIC OCEAN...ALONG THE U.S.A. EAST COAST. THE TROUGH HAS
BECOME ELONGATED...STRETCHED OUT ALONG A NORTHEAST-TO-SOUTHWEST
LINE. A STATIONARY FRONT PASSES THROUGH A POINT JUST TO THE EAST
OF BERMUDA TO 28N70W TO THE BAHAMAS NEAR 23N75W TO CUBA NEAR
21N78W. AN UPPER LEVEL RIDGE IS ALONG THE LINE FROM THE MONA
PASSAGE BEYOND 32N43W. A MIDDLE TO UPPER LEVEL CYCLONIC
CIRCULATION CENTER IS NEAR 15N50W. A TROUGH EXTENDS FROM THIS
CENTER TO 12N64W IN THE SOUTHEASTERN CARIBBEAN SEA. CYCLONIC
FLOW AROUND THIS CENTER COVERS THE ATLANTIC OCEAN FROM 8N TO 23N
BETWEEN 45W AND 60W ON CURRENT WATER VAPOR SATELLITE IMAGERY.
A SURFACE TROUGH IS ALONG 49W/50W FROM 9N TO 19N. SCATTERED
MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE FROM 14N
TO 19N BETWEEN 43W AND 55W...AND FROM 16N TO 18N BETWEEN 36W
AND 40W. A DEEP LAYER TROUGH IS DIGGING SOUTHWARD TO THE CANARY
ISLANDS. THIS TROUGH SUPPORTS A COLD FRONT THAT ENDS AT 31N16W.
A TROUGH CONTINUES FROM 31N16W TO 28N26W 29N34W. PRECIPITATION
IS POSSIBLE NORTH OF 29N BETWEEN 10W AND 15W. A SURFACE RIDGE
PASSES THROUGH 32N40W TO 30N51W TO 27N60W 26N68W.

$$
MT





Home