000
AXNT20 KNHC 030547
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0535 UTC.

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

MONSOON TROUGH REMAINS INLAND ACROSS TROPICAL AFRICA AND EXITS 
THE WEST COAST THROUGH SIERRA LEONE NEAR 7N12W CONTINUING SW TO 
NEAR 3N18W...WHERE IT TRANSITIONS TO ITCZ CONTINUING WSW ALONG 
EQ26W 2S34W EQ42W TO THE NE COAST OF BRAZIL NEAR 1S47W. 
SCATTERED MODERATE CONVECTION IS WITHIN 125 NM ON EITHER SIDE OF 
THE ITCZ W OF 25W. SCATTERED WEAK TO MODERATE CONVECTION IS 
WITHIN 120 NM S OF THE MONSOON TROUGH E OF 15W. 

...DISCUSSION...

GULF OF MEXICO...
DRY WESTERLY FLOW ALOFT COVERS MOST OF THE DISCUSSION AREA THIS 
EVENING...WITH SOME MID-UPPER LEVEL MOISTURE MOVING ACROSS THE 
NRN AND NW AREAS. AT SURFACE...LOW LEVEL RETURN FLOW UP TO 20 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. THE CONVECTION ASSOCIATED TO 
THIS FRONT REMAINS INLAND ON DOPPLER RADAR IMAGERY. HOWEVER... 
THIS BOUNDARY IS EXPECTED TO ENTER THE NW GULF DURING THE NEXT 9 
HOURS PRODUCING MODERATE TO STRONG CONVECTION ALONG THE BOUNDARY 
...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 EVENING. THESE CONDITIONS ALOFT ARE 
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 OBSERVED OVER THE ERN BASIN E OF 70W. A RECENT 
ASCAT PASS REVEALED THIS FLOW INCREASES UP TO 30 KT BETWEEN 
70W-80W S OF 17N. NO SIGNIFICANT CHANGES ARE EXPECTED OVER THE 
NEXT 24 HOURS. 

ATLANTIC OCEAN...
UPPER LEVEL RIDGING COVERS THE ATLC W OF 60W...SUPPORTING A WEAK 
1024 MB HIGH CENTERED NEAR 26N61W. A COMPLEX LOW PRESSURE SYSTEM 
COMPOSED OF MULTIPLE LOWS AND SEVERAL BOUNDARIES IS ANALYZED 
OVER THE WRN...CENTRAL...AND N-ERN ATLC BASINS N OF OUR 
DISCUSSION AREA. AN UPPER LEVEL SHORTWAVE/TROUGH MOVING ACROSS 
THE CENTRAL ATLC SUPPORT THIS SET OF BOUNDARIES AND LOWS. 
ALTHOUGH THE CONVECTION AND GALE WINDS ASSOCIATED TO THESE 
FEATURES REMAIN N OF THE AREA. A FEW ISOLATED SHOWERS AND 
THUNDERSTORMS POSSIBLE N OF 27N BETWEEN 47W-53W. THE REMAINDER 
OF THE CENTRAL AND ERN ATLC BASINS ARE DOMINATED BY A BROAD AND 
STRONG SURFACE RIDGE ANCHORED BY A 1032 MB HIGH OVER MADEIRA 
ISLAND. A STRONG COLD FRONT WILL BEGIN TO AFFECT THE WRN ATLC 
WATERS OVER THE NEXT 24-32 HOURS WITH GUSTY WINDS AND MODERATE 
TO STRONG CONVECTION ALONG THE BOUNDARY.

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

$$

GARCIA