[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 142312
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SAT FEB 14 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2245 UTC.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 5N2W 3N15W 1N27W CROSSING THE
EQUATOR NEAR 39W...AND INTO NE BRAZIL NEAR 2S49W. SCATTERED
MODERATE CONVECTION IS FROM 4N-6N BETWEEN 15W-17W. SCATTERED
MODERATE CONVECTION IS ALSO S OF 3N BETWEEN 28W-35W.

...DISCUSSION...

GULF OF MEXICO...
STRONG WESTERLY FLOW ALOFT IS PRESENT ACROSS THE N GULF. ALSO...
A SURFACE COLD FRONT IS PRESENT ACROSS THE NW GULF...EXTENDING
FROM SE LOUISIANA NEAR 29N91W TO 28N94W TO S TEXAS NEAR 27N98W.
LOW LEVEL CONVERGENCE NEAR THIS COLD FRONT IS SUPPORTING
SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE N GULF N OF 28N.
THIS ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIVERGENCE IN THE
SW QUADRANT OF AN UPPER LEVEL JET MAXIMUM CENTERED OVER THE SE
CONUS. NORTHERLY SURFACE WINDS AND A RELATIVELY COOLER AND DRIER
AIRMASS ARE PRESENT N OF THE FRONT. ACROSS THE S GULF...
SUBSIDENCE...STABLE ATMOSPHERIC CONDITIONS...AND DEEP LAYER DRY
AIR ARE RESULTING IN GENERALLY FAIR WEATHER CONDITIONS. THIS
SUBSIDENCE IS BEING ENHANCED NEAR A SURFACE RIDGE EXTENDING INTO
THE SE GULF FROM A 1019 MB SURFACE HIGH IN THE W ATLC NEAR
29N70W...AND NEAR A SURFACE HIGH W OF THE FLORIDA PENINSULA NEAR
26N83W. SOUTHERLY RETURN SURFACE FLOW IS PRESENT AROUND THE
SURFACE HIGHS AND SURFACE RIDGE ACROSS THE S GULF.

CARIBBEAN SEA...
DEEP LAYER DRY AIR AND SUBSIDENCE IN WESTERLY AND NORTHWESTERLY
FLOW ALOFT ARE RESULTING IN FAIR WEATHER CONDITIONS ACROSS MUCH
OF THE CARIBBEAN REGION. HOWEVER...LOW LEVEL MOISTURE IS BEING
TRANSPORTED WESTWARD ACROSS THE E AND CENTRAL CARIBBEAN...WITH
ISOLATED SHOWERS OCCURRING S OF 17N E OF 67W. NE SURFACE WINDS
OF 20 TO 25 KT ARE OCCURRING ACROSS THE SW AND E CARIBBEAN...
WITH E SURFACE WINDS OF 15 TO 20 KT ACROSS THE NW CARIBBEAN.

ATLANTIC OCEAN...
STRONG WESTERLY FLOW ALOFT IS PRESENT ACROSS THE SW NORTH ATLC.
A SURFACE TROUGH EXTENDS FROM 30N81W TO 31N79W TO 32N79W. LOW
LEVEL CONVERGENCE IS SUPPORTING SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS N OF 29N W OF 79W INCLUDING PORTIONS OF THE NE
FLORIDA PENINSULA. FARTHER TO THE E...DEEP LAYER DRY AIR AND
SUBSIDENCE ARE PRESENT IN THE VICINITY OF A 1019 MB SURFACE HIGH
NEAR 29N70W. ACROSS THE CENTRAL ATLC...A DEEP LAYER TROUGH IS
PRESENT WITH AN ASSOCIATED DISSIPATING SURFACE STATIONARY FRONT
EXTENDING FROM E OF THE BAHAMAS NEAR 25N73W TO 24N66W TO 24N61W
AND A SURFACE COLD FRONT EXTENDING FROM 24N61W TO 28N52W TO
32N47W TO N OF THE DISCUSSION AREA. LOW-LEVEL CONVERGENCE IS
SUPPORTING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF EACH OF
THESE FRONTS. TO THE SOUTH...A SURFACE TROUGH EXTENDS FROM 8N50W
TO 3N51W CROSSING THE EQUATOR NEAR 51W AND INTO NE BRAZIL NEAR
1S51W. LOW LEVEL CONVERGENCE AND UPPER LEVEL DIFFLUENCE ARE
RESULTING IN SCATTERED SHOWERS AND THUNDERSTORMS WITHIN 120 NM
EITHER SIDE OF THIS SURFACE TROUGH. TO THE E...SUBSIDENCE
ASSOCIATED WITH A SURFACE RIDGE AND A 1022 MB SURFACE HIGH NEAR
29N32W IS RESULTING IN FAIR WEATHER CONDITIONS ACROSS MUCH OF
THE E ATLC. ACROSS THE TROPICAL ATLC...AN UPPER RIDGE IS PRESENT
WITH AN AXIS EXTENDING FROM 6N2W TO 4N19W TO 1N35W. UPPER LEVEL
DIVERGENCE ASSOCIATED WITH THIS UPPER RIDGE IS ENHANCING THE
CONVECTION ASSOCIATED WITH THE ITCZ.

$$
COHEN




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