000
AXNT20 KNHC 031749
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL  
105 PM EST THU MAR 03 2011

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ...

ITCZ AXIS ALONG THE COAST OF LIBERIA NEAR 06N10W TO 01N27W TO 
03N33W TO S OF THE EQUATOR ALONG THE COAST OF BRAZIL NEAR 
01S45W. ISOLATED MODERATE TO STRONG CONVECTION IS WITHIN 120 NM 
EITHER SIDE OF THE AXIS E OF 22W AND FROM 00N TO 03N BETWEEN 25W 
AND 30W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 180 
NM N OF THE AXIS W OF 42W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL TROUGH EXTENDS ACROSS THE STATE OF FLORIDA FROM 
NEAR TAMPA BAY TO JUST N OF THE YUCATAN CHANNEL. A STATIONARY 
FRONT AT THE SURFACE IS SUPPORTED BY THIS UPPER LEVEL FEATURE 
EXTENDING FROM 1016 MB LOW PRES NEAR 27N91W TO THE WESTERN TIP 
OF CUBA. SURFACE OBSERVATIONS AND VISIBLE SATELLITE IMAGERY 
INDICATE THAT THE LOW IS WEAKENING WITH SURFACE PRESSURES 
RISING. NUMEROUS SHOWERS AND SCATTERED TSTMS ARE OCCURRING NE OF 
THE FRONT. A WEAK SURFACE TROUGH ALSO EXTENDS FROM THE LOW TO 
THE YUCATAN COAST NEAR 22N91W WITH SCATTERED SHOWERS OCCURRING 
IN ITS VICINITY. THE LOW AND FRONT WILL DISSIPATE TONIGHT AS 
HIGH PRES RIDGING IN FROM THE ATLANTIC STRENGTHENS THROUGH FRI. 
SOUTHERLY RETURN FLOW WILL BE THE STRONGEST IN THE E AND CENTRAL 
GULF WHERE THE PRES GRADIENT WILL BE THE TIGHTEST. A STRONG COLD 
FRONT WILL APPROACH THE NW GULF SAT MORNING...MOVING OFF THE 
TEXAS COAST SAT AFTERNOON. GALE FORCE CONDITIONS ARE EXPECTED 
BEHIND THE FRONT IN THE SW GULF SAT NIGHT INTO SUN.

CARIBBEAN SEA...
THE STATIONARY FRONT MENTIONED IN THE GULF OF MEXICO EXTENDS 
INTO THE FAR NW CARIBBEAN REACHING FROM THE FAR WESTERN TIP OF 
CUBA JUST S OF THE ISLE OF YOUTH AND CONTINUING E-SE TO THE 
EASTERN TIP OF CUBA NEAR THE WINDWARD PASSAGE. SCATTERED SHOWERS 
AND ISOLATED TSTMS ARE OCCURRING WITHIN 90 NM S OF THE FRONT 
WITH ADDITIONAL SHOWERS ALSO OCCURRING BEHIND THE FRONT OVER 
CUBA WITH ENHANCED UPSLOPE FLOW. THIS FRONT WILL DISSIPATE 
TONIGHT AS STRONG HIGH PRES IN THE ATLC BUILDS IN FROM THE NE. 
WATER VAPOR SATELLITE IMAGERY INDICATES THAT VERY DRY AIR EXISTS 
ACROSS THE CARIBBEAN WITH WEAK TROUGHING ALOFT IN THE E 
CARIBBEAN BETWEEN UPPER RIDGING OVER THE FAR W CARIBBEAN AND TO 
THE E IN THE TROPICAL N ATLANTIC. A SURFACE TROUGH IS IN THE E 
CARIBBEAN SUPPORTED BY ITS UPPER LEVEL COUNTERPART REACHING FROM 
NEAR BARBUDA SW TO JUST N OF THE CENTRAL VENEZUELAN COAST. 
SCATTERED SHOWERS ARE OCCURRING WITHIN 180 NM OF THE TROUGH. 
THIS TROUGH WILL WEAKEN AND BECOME ILL-DEFINED TONIGHT AS THE 
RIDGING BUILDS N OF THE AREA. TRADE WINDS AND SEAS WILL DECREASE 
AND SUBSIDE BEGINNING SUN AS THE HIGH NE OF THE AREA RETREATS 
AND WEAKENS.

ATLANTIC OCEAN...
A DEEP LAYERED TROUGH ENTERS THE AREA NEAR 32N67W EXTENDING SW 
INTO THE E GULF OF MEXICO. THIS TROUGH IS SUPPORTING A SURFACE 
COLD FRONT WHICH STRETCHES FROM SE OF BERMUDA NEAR 32N61W TO THE 
WINDWARD PASSAGE. SCATTERED SHOWERS ARE WITHIN 210-300 NM E OF 
THE FRONT N OF 23N WITH ISOLATED TSTMS N OF 27N. THIS FRONT WILL 
GRADUALLY WEAKEN INTO A FRONTAL TROUGH FRI MORNING THROUGH SAT 
AS STRONG HIGH PRES E OF THE CAROLINAS BUILDS DOWN ACROSS THE 
AREA FROM THE N. A TIGHT PRES GRADIENT GENERATED BY THIS 
BUILDING HIGH WILL RESULT IN BUILDING SEAS AND INCREASING 
EASTERLY WINDS ACROSS THE NW PORTION OF THE AREA FRI AND SAT 
WEAKENING SAT NIGHT AND SUN AS THE HIGH SHIFTS E AND PRESSURES 
FALL. A COLD FRONT WILL APPROACH THE WESTERN PORTION OF THE AREA 
SUN FROM THE GULF OF MEXICO. 1018 MB LOW PRES IS STATIONARY NEAR 
30N37W WITH A STATIONARY FRONT EXTENDING FROM THE LOW TO 26N36W 
TO 17N47W. SCATTERED SHOWERS ARE OCCURRING WITHIN 90-180 NM OF 
THE FRONT AND LOW. THE LOW WILL REMAIN NEARLY STATIONARY THROUGH 
THE NEXT FEW DAYS WHILE THE FRONT DISSIPATES. BROAD UPPER 
RIDGING EXISTS ACROSS THE SE PORTION OF THE AREA EXTENDING FROM 
AN UPPER ANTICYCLONE LOCATED NEAR 06N03E WESTWARD ALONG 06/07N. 
CONVECTION IS BEING ENHANCED ALONG THE ITCZ ON THE SOUTHERN SIDE 
OF THE UPPER RIDGING.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
LEWITSKY