000
AXNT20 KNHC 230534
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST MON FEB 23 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0515 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 7N12W 1N17W 0N25W 1S36W 3S43W. 
SCATTERED MODERATE CONVECTION IS FROM 1N-3N BETWEEN 25W-27W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS S OF 1N BETWEEN 
30W-43W.

...DISCUSSION...

GULF OF MEXICO...
A DEEP LAYER TROUGH IS PRESENT ACROSS THE GULF OF MEXICO...WITH 
AN ASSOCIATED SURFACE COLD FRONT EXTENDING FROM THE W FLORIDA 
PENINSULA NEAR 28N83W TO THE CENTRAL GULF NEAR 24N90W ACROSS THE 
BAY OF CAMPECHE TO THE COAST OF MEXICO NEAR 19N94W. LOW LEVEL 
CONVERGENCE IS SUPPORTING SCATTERED SHOWERS WITHIN 60 NM EITHER 
SIDE OF THIS FRONT. TO THE N AND W OF THE FRONT...GENERALLY FAIR 
WEATHER IS PRESENT WHERE NORTHWESTERLY FLOW ALOFT IS SUPPORTING 
ATMOSPHERIC SUBSIDENCE AND STABLE ATMOSPHERIC CONDITIONS. THIS 
SUBSIDENCE IS ALSO BEING SUPPORTED BY A 1032 MB SURFACE HIGH 
OVER SE TEXAS NEAR 29N96W. INCREASED NORTHERLY SURFACE WINDS IN 
THE WAKE OF THE COLD FRONT ARE USHERING IN A RELATIVELY COOLER 
AND DRIER AIRMASS ACROSS THE N AND W GULF...WITH GALE FORCE 
WINDS OCCURRING ACROSS PORTIONS OF THE SW GULF. ADDITIONALLY... 
STRONG N TO NE SURFACE WINDS ARE BLOWING THROUGH THE ISTHMUS OF 
TEHUANTEPEC RESULTING IN STORM FORCE WINDS IN THE E PACIFIC 
REGION.

CARIBBEAN SEA...
STRONG TRADE WINDS ARE OCCURRING ACROSS THE CARIBBEAN...WHERE AN 
INCREASED SURFACE PRESSURE GRADIENT IS PRESENT. THE STRONGEST 
WINDS ARE FOUND NEAR THE COAST OF COLOMBIA...WHERE A GALE 
WARNING IS IN EFFECT. GENERALLY FAIR WEATHER CONDITIONS ARE 
OCCURRING ACROSS THE CARIBBEAN REGION...WHERE AN UPPER LEVEL 
RIDGE IS PRESENT. PATCHES OF LOW LEVEL MOISTURE CONTINUE TO BE 
ADVECTED WESTWARD ACROSS THE CARIBBEAN BY THE TRADE WINDS...WITH 
SCATTERED SHOWERS EMBEDDED WITHIN THESE PATCHES OF LOW LEVEL 
MOISTURE. THE GREATEST CONCENTRATION OF THESE SHOWERS IS E OF 
65W.

ATLANTIC OCEAN...
A DEEP TROUGH OVER THE W ATLC IS ASSOCIATED WITH A SURFACE COLD 
FRONT THAT EXTENDS FROM THE E FLORIDA PENINSULA NEAR 29N81W TO 
31N77W TO 32N75W TO NE OF THE DISCUSSION AREA. LOW LEVEL 
CONVERGENCE IS SUPPORTING SCATTERED SHOWERS WITHIN 60 NM EITHER 
SIDE OF THIS FRONT. TO THE E...A DEVELOPING SURFACE COLD FRONT 
EXTENDS FROM 28N71W TO 30N69W TO 32N67W TO NE OF THE DISCUSSION 
AREA...AND A SURFACE STATIONARY FRONT EXTENDS FROM 31N60W TO 
30N54W TO 31N47W. LOW LEVEL CONVERGENCE IS SUPPORTING SCATTERED 
SHOWERS WITHIN 60 NM EITHER SIDE OF THESE FRONTS. ACROSS THE 
CENTRAL AND E ATLC TO THE SE OF THESE FRONTS...SUBSIDENCE 
ASSOCIATED WITH A SURFACE RIDGE IS SUPPORTING FAIR WEATHER 
CONDITIONS. HOWEVER...AN UPPER TROUGH IS PRESENT WITH AN AXIS 
THAT EXTENDS FROM 14N39W TO 25N27W TO 32N19W TO NE OF THE 
DISCUSSION AREA. TO THE E OF THIS UPPER TROUGH AXIS...UPPER 
LEVEL DIVERGENCE ASSOCIATED WITH AN UPPER LEVEL WIND SPEED 
MAXIMUM IS SUPPORTING SCATTERED SHOWERS N OF 28N E OF 23W. 
ACROSS THE TROPICAL ATLC...DIFFLUENCE IN WESTERLY FLOW ALOFT IS 
ENHANCING THE CONVECTION ASSOCIATED WITH THE ITCZ.

$$
COHEN