000
AXNT20 KNHC 311105
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT MAR 31 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 
1030 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS SW FORM THE COAST OF WEST AFRICA OVER 
THE COAST OF SIERRA LEONE NEAR 7N12W TO 2N20W. THE ITCZ THEN 
CONTINUES FROM 3N18W CROSSING THE EQUATOR AT 30W TO THE COAST OF 
BRAZIL NEAR 3S40W. SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION IS WITHIN 100-170 NM ON EITHER SIDE OF BOTH THE 
MONSOON TROUGH AND ITCZ AXIS.

...DISCUSSION...

GULF OF MEXICO...
MOSTLY SW FLOW ALOFT ACROSS THE GULF IS NOTICED ON WATER VAPOR 
IMAGERY. EMBEDDED WITHIN THIS FLOW...A MID-ATMOSPHERIC CYCLONIC 
CIRCULATION MOVES ACROSS THE N CENTRAL GULF SUPPORTING A LINE OF 
MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS OVER THE MISSISSIPPI 
...ALABAMA...FLORIDA COASTAL WATERS WITHIN 75 NM BETWEEN 
85W-90W. DEBRIS BLOW-OFF HIGH LEVEL CLOUDS FROM WIDESPREAD TSTM 
ACTIVITY OVER ERN MEXICO IS SPREADING EWD INTO THE WRN GULF WITH 
LIMITED SHOWER ACTIVITY. OTHERWISE...FAIR WEATHER CONDITIONS ARE 
ELSEWHERE ACROSS THE AREA DUE TO A SURFACE RIDGE AXIS EXTENDING 
ACROSS THE GULF FROM A WEAK HIGH PRESSURE SYSTEM OVER THE WRN 
ATLC. THE WIND FLOW AROUND THE RIDGE AXIS IS MAINLY SSE 10-15 
KT. SOUTHERLY FLOW WILL INCREASE OVER THE WRN GULF LATE SUN INTO 
MON IN ADVANCE OF AN APPROACHING COLD FRONT.

CARIBBEAN SEA...
DRY SUBSIDENT AIR ALOFT IS PRESENT ACROSS MOST OF THE BASIN THIS 
EVENING...SUPPRESSING DEEP CONVECTION AND KEEPING FAIR WEATHER 
CONDITIONS ACROSS THE AREA. A FEW CLUSTERS OF LOW LEVEL WEAK 
SHOWERS ARE NOTED ON DOPPLER RADAR OVER THE NE WATERS E OF 67W N 
OF MARTINIQUE. SOME OF THE MOST ACTIVE AREAS ARE SEEN S OF 
PUERTO RICO AND THE US/UK VIRGIN ISLANDS. TRADE WIND FLOW OF 
15-20 KT IS OBSERVED ACROSS THE DISCUSSION AREA WITH THE 
STRONGEST FLOW TURNING NEAR THE COAST OF COLOMBIA...AND CAUSING 
SOME WEAK LOW LEVEL CONVERGENCE IN THE SW CARIBBEAN...GENERATING 
SOME POSSIBLE SHOWERS S OF 15N BETWEEN 76W-81W. SHORT RANGE 
COMPUTER MODELS SUGGEST NO SIGNIFICANT CHANGES DURING THE NEXT 
24 HOURS.

ATLANTIC OCEAN...
WATER VAPOR IMAGERY SHOWS A BROAD UPPER LEVEL RIDGE MOVING OFF 
THE ERN CONUS...SUPPORTING WEAK 1022 MB HIGH OVER THE WRN ATLC 
NEAR 26N65W. THIS FEATURE IS KEEPING QUIET WEATHER CONDITIONS 
OVER THIS PORTION OF THE ATLC...WITH THE EXCEPTION OF A WEAK 
COLD FRONTAL BOUNDARY THAT BRIEFLY DIPS DOWN IN OUR NRN LIMIT OF 
THE DISCUSSION AREA ALONG 32N52W TO 29N61W TO 32N67W. ISOLATED 
SHOWERS ARE POSSIBLE ALONG THE BOUNDARY E OF 60W. TO THE E OF 
THIS BOUNDARY...A NEARLY STATIONARY 1023 MB HIGH IS CENTERED 
AROUND 27N43W. A COLD FRONT ENTERS THE DISCUSSION AREA THROUGH 
32N25W TO 28N32W...WHERE IT TRANSITIONS TO A DISSIPATING 
STATIONARY FRONT EXTENDING SW TO 20N50W AND BECOMES A TROUGH TO 
17N53W. ISOLATED WEAK SHOWERS ARE WITHIN 55 NM ON EITHER SIDE OF 
THE FRONTAL BOUNDARY. A DISSIPATING 1023 MB HIGH IS E OF THE 
COLD FRONT NEAR 23N34W.

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

$$

GARCIA