[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200615
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SUN JAN 20 2008

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0545 UTC

...THE ITCZ...
FROM 7N11W TO 4N24W 4N35W...CROSSING THE EQUATOR AT 50W...AND
CONTINUING INTO NORTHEASTERN BRAZIL NEAR 1S53W. ISOLATED
MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS FROM 3N TO 7N
BETWEEN 16W AND 23W...FROM 1S TO 1N BETWEEN 33W AND 35W.
SCATTERED MODERATE TO STRONG SHOWERS/THUNDERSTORMS FROM THE
EQUATOR TO 3N BETWEEN 46W AND 51W.

...DISCUSSION...

THE GULF OF MEXICO...
BROAD MIDDLE TO UPPER LEVEL CYCLONIC FLOW FROM A TROUGH SWEEPS
ACROSS MEXICO INTO THE GULF OF MEXICO. THIS TROUGH SUPPORTS THE
COLD FRONT FROM NORTHEASTERN FLORIDA TO WEST CENTRAL FLORIDA
TO THE NORTHWESTERN YUCATAN PENINSULA TO MEXICO EAST OF THE
ISTHMUS OF TEHUANTEPEC. THE PASS AREA IS OPEN...WITHOUT A FRONT.
A STATIONARY FRONT CONTINUES FROM THE WESTERN SIDE OF THE
ISTHMUS TO 20N98W. SURFACE HIGH PRESSURE IS BUILDING FROM DEEP
SOUTH TEXAS ALONG THE EASTERN COAST OF MEXICO. A GALE WARNING
EXISTS IN THE GULF OF TEHUANTEPEC. A 1008 MB GALE LOW PRESSURE
CENTER IS ALONG THE COLD FRONT ALONG THE WEST CENTRAL FLORIDA
COAST. TEMPERATURES IN NORTHERN FLORIDA ARE IN THE 30S FAHRENHEIT
AND IN THE LOW 70S FAHRENHEIT IN SOUTH FLORIDA. ISOLATED MODERATE
RAINSHOWERS ARE WITHIN 30 NM TO 60 NM ON EITHER SIDE OF THE LINE
FROM NORTHERN BELIZE TO THE NORTHEASTERN YUCATAN PENINSULA...INTO
THE SOUTHEASTERN GULF OF MEXICO...TO FLORIDA SOUTH OF 29N...AND
INTO THE ATLANTIC OCEAN BEYOND 31N77W.

THE CARIBBEAN SEA...
BROAD UPPER LEVEL ANTICYCLONIC FLOW COVERS THE ATLANTIC OCEAN
SOUTH OF 32N WEST OF 55W...AND INCLUDING IN THE CARIBBEAN SEA.
A MIDDLE LEVEL ANTICYCLONIC CIRCULATION CENTER IS SUPPOSED
TO BE ABOUT 90 NM NORTH OF EASTERN HISPANIOLA ACCORDING TO THE
GFS MODEL. SUCH A CENTER IS NOT EASY TO SEE WITH THE NAKED EYE
ON SATELLITE IMAGERY. MIDDLE TO UPPER LEVEL DRY AIR/SUBSIDENCE
COVERS THE ENTIRE AREA. SURFACE EASTERLY WIND FLOW IS LOOSELY
RELATED TO LARGE SCALE ATLANTIC OCEAN ANTICYCLONIC FLOW.
A SURFACE ANTICYCLONIC CIRCULATION CENTER IS ABOUT 700 NM EAST
OF BERMUDA IN THE ATLANTIC OCEAN. LARGE-SCALE ANTICYCLONIC FLOW
FROM THIS ATLANTIC OCEAN HIGH PRESSURE CENTER REACHES THE
CARIBBEAN SEA. THE ISOBARS ON THE SURFACE MAP DO NOT APPEAR
TO SHOW A STRONG PRESSURE GRADIENT. THAT DOES NOT MEAN THAT
A SLIGHT CHANGE IN THE PRESSURE FIELD IS NOT ABLE TO GENERATE
COMPARATIVELY FASTER WIND SPEEDS ACROSS THE OPEN WATERS OF
THE CARIBBEAN SEA. AN EXAMPLE OF FAST WINDS FROM WHAT DOES NOT
APPEAR TO BE SUCH A STRONG GRADIENT ACCORDING TO THE ISOBARIC
ANALYSIS IS FROM 10N TO 19N EAST OF 82W BETWEEN 70W AND 80W
EASTERLY WINDS FROM 20 KT TO 30 KT AND SEAS FROM 9 TO 13 FT
CURRENTLY AND IN THE MIAHSFAT2 FORECAST FOR THE NEXT 48 HOURS.
PLEASE REFER TO THE MIAHSFAT2 HIGH SEAS FORECAST FOR SPECIFIC
DETAILS. POSSIBLE SHOWERS IN CLUSTERS OF LOW CLOUDS ARE NORTH OF
11N65W 14N75W 14N80W. SHOWERS ARE POSSIBLE SOUTH OF 15N WEST OF
80W IN THE WATERS EAST OF CENTRAL AMERICA...AND NORTH OF 15N
WEST OF 80W.

THE ATLANTIC OCEAN...
A WESTERN ATLANTIC STATIONARY FRONT PASSES THROUGH 32N76W TO
30N80W TO A 1008 MB GALE LOW PRESSURE CENTER NEAR 29N83W ALONG
THE WEST CENTRAL FLORIDA COAST. ISOLATED MODERATE RAINSHOWERS
ARE WITHIN 30 NM TO 60 NM ON EITHER SIDE OF THE LINE FROM
THE SOUTHEASTERN GULF OF MEXICO TO FLORIDA SOUTH OF 29N...AND
INTO THE ATLANTIC OCEAN BEYOND 31N77W. BROAD MIDDLE TO UPPER
LEVEL ANTICYCLONIC WIND FLOW IS ON TOP OF THE AREA OF THIS
FRONT. AN ATLANTIC OCEAN COLD FRONT EXTENDS FROM AN EAST-CENTRAL
ATLANTIC OCEAN 1010 MB PRESSURE CENTER/DEVELOPING GALE LOW
CENTER NEAR 34N28W TO 26N30W AND 22N35W. A DISSIPATING FRONTAL
BOUNDARY CONTINUES FROM 22N35W TO 20N50W. A MIDDLE TO UPPER LEVEL
EAST CENTRAL ATLANTIC OCEAN TROUGH SUPPORTS THIS COLD FRONT.
SHOWERS AND POSSIBLE THUNDERSTORMS ARE NORTH OF 27N BETWEEN 24W
AND 30W. A 1027 MB HIGH PRESSURE CENTER IS ABOUT 700 NM EAST OF
BERMUDA. THIS HIGH PRESSURE CENTER AND ITS ASSOCIATED
FLUCTUATIONS IN THE PRESSURE GRADIENT ARE PRODUCING 20 KT
TO 30 KT WIND SPEEDS IN THE SOUTH CENTRAL CARIBBEAN SEA. PLEASE
REFER TO THE MIAHSFAT2 HIGH SEAS FORECAST FOR SPECIFIC FORECAST
INFORMATION REGARDING WIND AND SEAS NEAR THE FRONTAL BOUNDARIES.

$$
MT

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