000
AXNT20 KNHC 251752
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL  
105 PM EST FRI FEB 25 2011

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ...

ITCZ AXIS ANALYZED ALONG 05N09W TO 03N18W TO 02N27W CROSSING 
EQUATOR AT 36W AND INTO NE BRAZIL NEAR 03S40W.  SCATTERED 
MODERATE ISOLATED STRONG CONVECTION FROM 02N-04N BETWEEN 17W TO 
20W. SCATTERED MODERATE CONVECTION S OF EQUATOR FROM 32W TO 38W. 

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL RIDGE AXIS AT EASTERN EDGE OF BASIN FORCED OUT BY 
INCOMING LONGWAVE TROUGH N OF AREA.  WEAK COLD FRONT ENTERED 
EARLIER THIS MORNING INTO WESTERN GULF AFFECTING WIND AND SEAS 
MAINLY N OF 25N.  PATTERN ALOFT BECOMES MOSTLY WESTERLY ZONAL 
BEHIND TROUGH.  QUICKLY WEAKENING LINE OF SCATTERED MODERATE AND 
ISOLATED STRONG CONVECTION RUNS AHEAD OF COLD FRONT PRESENTLY 
EXTENDING FROM 30N85W TO 27N91W.   OTHERWISE...PERSISTENT AREAS 
OF LOW STRATUS CLOUDS AND LOW VISIBILITIES IN SEA FOG WERE ALONG 
TEXAS SE COAST EARLIER AND SLOWLY LIFTING BY NOON TODAY AS NE 
WINDS BEHIND COLD FRONT MIXES AIR MASS.

CARIBBEAN SEA...
TAIL END OF UPPER LEVEL TROUGH CROSSES CARIBBEAN SEA FROM 
NORTHEAST TO SOUTHWEST BRINGING VERY DRY AND STABLE AIR MASS 
INTO ENTIRE BASIN.  ONLY EXTREME SE CORNER LEFT WITH LINGERING 
MOISTURE AND ISOLATED MODERATE SHOWERS SOUTH OF 15N.  MINOR 
AMOUNT OF MOISTURE BROUGHT BY WEAK STATIONARY FRONT BARELY 
INCHES INSIDE ANEGADA CHANNEL AT THIS TIME.  AT THE SURFACE... 
FRESH NE TO E BREEZE PERSIST THROUGH WEEKEND AS HIGH PRESSURE 
OVER SOUTHWEST NORTH ATLANTIC BEHIND STATIONARY FRONT BUILDS.

ATLANTIC OCEAN...
SOUTHWEST NORTH ATLANTIC REMAINS UNDER BROAD RIDGE THAT SUPPORTS 
LARGE HIGH PRESSURE CENTERED JUST NORTH OF BASIN.  SURFACE 
ANTICYCLONE 1027 MB IS FORCED SOUTHEAST BY APPROACHING COLD 
FRONT PRESENTLY CROSSING EASTERN CONUS.  FAIR SKIES WITH 
ISOLATED DOT MOST OF BASIN AS CLOUD LINES ASSOCIATED WITH FRONT 
MOVE CLOSER TO ITS NORTHEASTERN CORNER.  CLOUDS AND CONVECTION 
EXPECTED TO INCREASE FROM NW TO SOUTHEAST TONIGHT THROUGH SUN. 

FARTHER EAST...LONGWAVE UPPER LEVEL TROUGH DIPS SOUTHWEST ALONG 
CENTRAL ATLANTIC SUPPORTING STATIONARY FRONT WHICH STRETCHES 
FROM 31N41W TO NORTHEAST OF LEEWARD ISLANDS.  ISOLATED SHOWERS 
IN LINES OCCUR WITHIN 90 NM EAST AND 120 NM WEST OF FRONT. 

ELSEWHERE...REMAINDER OF EASTERN ATLANTIC REMAINS UNDER THE  
INFLUENCE OF SURFACE RIDGE ANCHORED BY 1032 MB HIGH PRESSURE 
CENTERED JUST WEST OF PORTUGAL NEAR 38N16W.  RIDGE CAP PREVENTS 
MOST VERTICAL DEVELOPMENT SO LOW LEVEL STRATIFORM CLOUDS ARE 
MAIN FEATURE E OF 35W.

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

$$
WALLY BARNES