000
AXNT20 KNHC 031115
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SAT MAR 03 2012

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL 
ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1100 UTC.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH REMAINS INLAND ACROSS TROPICAL AFRICA AND 
EXITS THE WEST COAST THROUGH GUINEA NEAR 9N13W CONTINUING SW TO 
NEAR 6N21W...WHERE IT TRANSITIONS TO ITCZ CONTINUING WSW ALONG 
EQ30W TO THE NE COAST OF BRAZIL NEAR 2S43W. SCATTERED MODERATE 
CONVECTION IS WITHIN 125 NM ON EITHER SIDE OF THE ITCZ W OF 27W. 

...DISCUSSION...

GULF OF MEXICO...
DRY WESTERLY FLOW ALOFT COVERS MOST OF THE DISCUSSION AREA THIS 
MORNING...WITH SOME MID-UPPER LEVEL MOISTURE MOVING ACROSS THE 
NRN AND NW AREAS. AT SURFACE...LOW LEVEL RETURN FLOW UP TO 15 KT 
IS OBSERVED ACROSS THE AREA IN RESPONSE OF THE FRONTAL BOUNDARY 
SWEEPING ACROSS THE ERN AND SE CONUS. THIS SYSTEM IS SUPPORTED 
ALOFT BY A UPPER LEVEL TROUGH/LONGWAVE THAT COVERS MOST OF THE 
ERN CONUS ON WATER VAPOR IMAGERY. LATEST OBSERVATIONS SHOW THE 
FRONTAL BOUNDARY IS ENTERING THE NW WATERS. HOWEVER...THE 
CONVECTION ASSOCIATED TO IT REMAINS INLAND ON DOPPLER RADAR 
IMAGERY. THIS BOUNDARY IS EXPECTED TO PRODUCE MODERATE TO STRONG 
CONVECTION ALONG ITS AXIS THROUGHOUT THE DAY...AS WELL AS GALE 
FORCE WINDS S OF 25N W OF FRONT...GENERATING SEAS FROM 8 TO 12 
FT.

CARIBBEAN SEA...
A VERY DRY AND SUBSIDENT UPPER ATMOSPHERE DOMINATES THE ENTIRE 
CARIBBEAN BASIN THIS MORNING. THESE CONDITIONS ALOFT ARE KEEPING 
MOSTLY FAIR WEATHER CONDITIONS AND SUPPRESSING DEEP CONVECTION 
ACROSS THE AREA...ALLOWING FOR JUST A VERY FEW ISOLATED SHOWERS 
MOVING WITH THE EASTERLY TRADE WIND FLOW OF 15-20 KT E OF 80W. 
THIS FLOW IS DIVIDED W OF 80W...BECOMING SOUTH-EASTERLY N OF 15N 
AND NORTH-EASTERLY S OF 15N. AS THE FLOW TURNS CYCLONIC OVER THE 
FAR SW BASIN...IT PRODUCES A NEARLY STATIONARY AREA OF SCATTERED 
SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 15N W OF 
77W...WHICH IS ALSO BANKING LOW LEVEL MOISTURE AND SIMILAR 
CONVECTION OVER THE COASTAL WATERS OF PANAMA AND COSTA RICA. A 
RECENT ASCAT PASS REVEALED THIS FLOW INCREASES UP TO 30 KT 
BETWEEN 72W-77W S OF 15N. NO SIGNIFICANT CHANGES ARE EXPECTED 
OVER THE NEXT 24 HOURS. 

ATLANTIC OCEAN...
UPPER LEVEL RIDGING COVERS THE ATLC W OF 60W...SUPPORTING A WEAK 
1023 MB HIGH CENTERED NEAR 27N60W. AN UPPER LEVEL 
SHORTWAVE/TROUGH IS MOVING ACROSS THE CENTRAL ATLC SUPPORTING A 
COMPLEX LOW PRESSURE SYSTEM ANALYZED OVER THE WRN...CENTRAL... 
AND N-ERN ATLC BASINS N OF OUR DISCUSSION AREA. ALTHOUGH THE 
CONVECTION AND GALE WINDS ASSOCIATED TO THESE FEATURES REMAIN N 
OF THE AREA...THE SOUTHERN EXTENSION OF A SURFACE TROUGH BRIEFLY 
ENTERS THE AREA ALONG 32N47W TO 29N50W WITH A FEW ISOLATED 
SHOWERS AND THUNDERSTORMS WITHIN 35 NM ON EITHER SIDE OF IT. THE 
REMAINDER OF THE CENTRAL AND ERN ATLC BASINS ARE DOMINATED BY A 
BROAD AND STRONG SURFACE RIDGE ANCHORED BY A 1031 MB HIGH SW OF 
PORTUGAL NEAR 35N13W. A STRONG COLD FRONT WILL BEGIN TO AFFECT 
THE WRN ATLC WATERS OVER THE NEXT 24 HOURS WITH GUSTY WINDS AND 
MODERATE TO STRONG CONVECTION ALONG THE BOUNDARY.

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

$$

GARCIA