000
AXNT20 KNHC 272342
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST SUN FEB 27 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ...

ITCZ AXIS ANALYZED ALONG 06N10W TO THE EQUATOR NEAR 27W THEN 
WESTWARD ALONG THE EQUATOR TO 39W THEN INTO NE BRAZIL NEAR 
03S43W. ISOLATED MODERATE CONVECTION IS FROM THE EQUATOR TO 06N 
BETWEEN 11W-19W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE NW 
CARIBBEAN SEA NEAR 19N85W EXTENDS A RIDGE AXIS NORTHWARD ALONG 
85W AND ACROSS THE SE CONUS TO THE OHIO RIVER VALLEY. WATER 
VAPOR INDICATES MOSTLY DRY AIR AND SUBSIDENCE IS ASSOCIATED WITH 
THIS UPPER LEVEL FEATURE AND IS MAINTAINING MOSTLY FAIR 
CONDITIONS THIS EVENING ACROSS MUCH OF THE GULF. AT THE 
SURFACE...SOUTHERLY WINDS IN THE RANGE OF 15 TO 20 KT ARE NOTED 
ON RECENT BUOY AND SHIP OBSERVATIONS...AHEAD OF THE NEXT 
APPROACHING COLD FRONT CURRENTLY ANALYZED ACROSS WEST TEXAS. THE 
COLD FRONT IS FORECAST TO IMPACT THE NW GULF WATERS BY EARLY 
MONDAY AND INTRODUCE STRONG N-NE WINDS WEST OF THE FRONT THROUGH 
MIDDAY TUESDAY WHEN NORTHERLY FLOW WILL GRADUALLY DECREASE AND 
MOST OF THE ENERGY ASSOCIATED WITH THE FRONT SHIFTS EASTWARD 
INTO THE SW NORTH ATLC REGION N OF 30N. 

CARIBBEAN SEA...
MOSTLY DRY AIR AND SUBSIDENCE ALOFT IS NOTED ON WATER VAPOR 
IMAGERY THIS EVENING OVER MUCH OF THE WESTERN CARIBBEAN AND 
CENTRAL AMERICA PROVIDING OVERALL FAIR CONDITIONS N OF 15N W OF 
75W. AT THE SURFACE...A 1025 MB HIGH IS CENTERED IN THE W ATLC 
NEAR 28N60W AND CONTINUES TO MAINTAIN FRESH TO STRONG TRADES 
OVER A LARGE PORTION OF THE BASIN THIS EVENING. WITH THE SURFACE 
RIDGE TO THE NORTH FORECAST TO REMAIN NEARLY STATIONARY OVER THE 
NEXT 48 HOURS...THE STRONG TRADES WILL PERSIST AND CONTINUE TO 
ADVECT LOW-LEVEL MOISTURE WESTWARD PROVIDING FOR AREAS OF 
ISOLATED SHOWERS. SATELLITE IMAGERY CURRENTLY INDICATES MOST OF 
THE POSSIBLE ISOLATED SHOWERS ACTIVITY REMAINS S OF 15N AS A 
SHEARLINE IS ANALYZED ACROSS TRINIDAD TO 11N66W. THE REMNANT 
BOUNDARY TRAILS WESTWARD TO 13N73W WITH ISOLATED SHOWERS OVER 
THE ABC ISLANDS THIS EVENING.      

ATLANTIC OCEAN...
A SURFACE RIDGE ANCHORED BY A 1025 MB HIGH CENTERED NEAR 28N60W 
CONTINUES TO INFLUENCE MUCH OF THE W ATLC DISCUSSION AREA W OF 
50W...INCLUDING THE BAHAMAS AND FLORIDA PENINSULA THIS EVENING. 
FARTHER EAST ACROSS THE CENTRAL ATLC...AN UPPER LEVEL LOW... 
LARGELY CUTOFF FROM THE WESTERLIES...IS CENTERED NEAR 27N37W AND 
SUPPORTS A COMPLEX LOW WITH MEAN 1009 MB CENTER NEAR 26N37W. 
THIS LOW REMAINS PARTIALLY OCCLUDED...WITH A STATIONARY FRONT 
EXTENDING SOUTH...THEN SOUTHWESTWARD FROM THE LOW ALONG 20N37W 
TO 11N47W. THE FRONTAL CHARACTERISTICS BECOME MORE DIFFUSE WEST 
OF 47W AND THE BOUNDARY IS ANALYZED AS A SHEARLINE EXTENDING 
WESTWARD ALONG 10N TO TRINIDAD AND INTO THE FAR SE CARIBBEAN SEA 
TO 11N66W. AN EARLY MORNING ASCAT PASS AROUND 27/1306 UTC 
CAPTURED THIS SHEARLINE WITH 10 TO 15 KT E-NE FLOW SOUTH OF THE 
BOUNDARY AND STRONGER 20 TO 25 KT NE FLOW NORTH OF THE BOUNDARY. 
ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE 
STATIONARY FRONT...AND WITHIN 90 NM EITHER SIDE OF THE 
SHEARLINE. CLOSER TO THE LOW CENTER AND BETTER UPPER LEVEL 
DYNAMICS...SCATTERED SHOWERS AND POSSIBLE ISOLATED TSTMS ARE 
OCCURRING N OF 23N BETWEEN 31W-42W. THE REMAINDER OF THE EASTERN 
ATLC IS UNDER THE INFLUENCE OF A WEAK SURFACE RIDGE WITH AXIS 
ALONG 32N23W TO 15N33W. 

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

$$
HUFFMAN