000
AXNT20 KNHC 072343
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST MON MAR 07 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ...

ITCZ AXIS IS ANALYZED ALONG 06N11W CROSSING THE EQUATOR NEAR 33W 
AND INTO NE BRAZIL NEAR 02S44W. ISOLATED MODERATE CONVECTION IS 
FROM THE EQUATOR TO 05N BETWEEN 12W-30W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL RIDGE IS LOCATED ACROSS MUCH OF THE GULF BASIN 
THIS EVENING WITH MOSTLY DRY AIR NOTED ON WATER VAPOR IMAGERY S 
OF 25N. THIS UPPER LEVEL FEATURE IS LARGELY SUPPORTIVE OF A 
SURFACE RIDGE ACROSS THE GULF WITH AXIS STEMMING FROM THE SE 
CONUS ALONG 85W INTO THE NW CARIBBEAN SEA. ON THE SOUTHWESTERN 
PERIPHERY OF THE SURFACE RIDGE...STRONG WARM AIR ADVECTION AND 
SE SURFACE WINDS IN THE RANGE OF 10 TO 20 KT ARE CONTINUING TO 
STREAM NORTHWARD INTO A DEVELOPING AREA OF SURFACE LOW PRESSURE 
CURRENTLY LOCATED OVER THE TEXAS AND OKLAHOMA PANHANDLES...AS 
WELL AS THE DESERT SOUTHWEST. THIS AREA OF LOW PRESSURE IS 
FORECAST TO MOVE NE OVER THE GREAT LAKES REGION BY WEDNESDAY 
WITH THE ATTENDANT COLD FRONT EMERGING OFF THE TEXAS GULF COAST 
AND INTO THE NW GULF WATERS BY MID-DAY WEDNESDAY. CURRENTLY... 
THE RELATIVELY COOLER AND DRIER AIRMASS ASSOCIATED WITH THE 
SURFACE RIDGE OVER FLORIDA AND THE SE CONUS CONTINUES TO 
GRADUALLY MODIFY...HOWEVER...AN AIRMASS DIFFERENCE IS NOTED IN 
SURFACE OBSERVATIONS AND UPPER LEVEL FORECAST SOUNDINGS
ALONG A REMNANT FRONTAL BOUNDARY ALONG A LINE FROM 26N86W TO 
28N91W. WEAK LOW-LEVEL CONVERGENCE AND MARGINAL INSTABILITIES 
ARE PROVIDING FOR ISOLATED SHOWERS THIS EVENING WITHIN 120 NM SW 
OF THE LINE ACROSS THE CENTRAL GULF.

CARIBBEAN SEA...
WATER VAPOR IMAGERY INDICATES STRONG SUBSIDENCE AND MOSTLY DRY 
AIR COVERS MUCH OF THE CARIBBEAN SEA BASIN UNDER GENERALLY 
WESTERLY FLOW ALOFT THIS EVENING. THIS IS PROVIDING THE BASIN 
WITH OVERALL RATHER TRANQUIL CONDITIONS AND A LACK OF ANY 
SIGNIFICANT DEEP CONVECTION. MAXIMUM DAYTIME HEATING AND 
INSTABILITY IS GENERATING A FEW ISOLATED SHOWERS AND TSTMS OVER 
THE NE YUCATAN PENINSULA AND CUBA...HOWEVER THIS ACTIVITY IS 
EXPECTED TO DIMINISH THROUGH THE NEXT SEVERAL HOURS. 
ELSEWHERE...THE REMAINDER OF THE CARIBBEAN IS UNDER THE 
INFLUENCE OF MODERATE TO FRESH TRADE WINDS. THE TRADES ARE 
FORECAST TO PERSIST THROUGH EARLY WEDNESDAY. ISOLATED SHOWERS 
ARE NOTED ON SATELLITE IMAGERY IN THE SW CARIBBEAN S OF 13N W OF 
80W...INCLUDING INLAND PORTIONS OF WESTERN PANAMA...COSTA 
RICA...AND SE NICARAGUA.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY WITH AXIS 
EXTENDING FROM NEW ENGLAND TO 32N72W TO A BASE OVER CUBA. THIS 
UPPER LEVEL FEATURE CONTINUES TO SUPPORT A COLD FRONT ANALYZED 
INTO THE DISCUSSION AREA NEAR 32N71W TO THE CENTRAL BAHAMAS NEAR 
25N76W TO WESTERN CUBA NEAR 23N81W. SCATTERED SHOWERS AND 
ISOLATED TSTMS ARE OCCURRING N OF 24N WITHIN 210 NM EAST OF THE 
FRONT. THE FRONT IS FORECAST TO SWEEP NE OF THE DISCUSSION AREA 
THROUGH LATE TUESDAY WITH A STRONG SURFACE RIDGE BUILDING ACROSS 
MUCH OF THE SW NORTH ATLC BY EARLY WEDNESDAY. FARTHER EAST...A 
1011 MB LOW IS CENTERED IN THE CENTRAL ATLC NEAR 26N53W. A 
SURFACE TROUGH IS ANALYZED FROM THE LOW CENTER SW TO 18N61W WITH 
SCATTERED SHOWERS AND ISOLATED TSTMS DISPLACED EAST OF THE 
SURFACE LOW. THIS IS LARGELY THE RESULT OF AN ELONGATED UPPER 
LEVEL TROUGH AND CUT-OFF LOW IN THE VICINITY OF 31N55W. UPPER 
LEVEL DIFFLUENCE EAST OF THIS FEATURE IS GENERATING SCATTERED 
SHOWERS AND POSSIBLE ISOLATED TSTMS COVERING A LARGE AREA FROM 
23N-34N BETWEEN 35W-51W. ELSEWHERE...THE REMAINDER OF THE 
EASTERN ATLC REMAINS FAIRLY QUIET THIS EVENING WITH A SURFACE 
RIDGE AXIS EXTENDING FROM 32N35W TO 16N18W. A DEEP LAYER LOW IS 
CENTERED SE OF THE IBERIAN PENINSULA WITH A 1003 MB LOW CENTERED 
NEAR 35N19W. A WEAK COLD FRONT EXTENDS S OF 32N ALONG 32N11W TO 
THE EASTERNMOST CANARY ISLANDS NEAR 28N15W. ISOLATED SHOWERS ARE 
OCCURRING WITHIN 75 NM EAST OF THE COLD FRONT.

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

$$
HUFFMAN