000
AXNT20 KNHC 180538
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SUN MAR 18 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 0515 UTC.

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

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF 
LIBERIA NEAR 6N10W TO 2N19W. THE ITCZ CONTINUES FROM 2N19W ALONG 
2N30W CROSSING THE EQUATOR AT 39W TO THE COAST OF BRAZIL AT 
2S45W. NUMEROUS MODERATE/STRONG CONVECTION IS S OF W AFRICA FROM 
EQ-5N BETWEEN THE PRIME MERIDIAN AND 16W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS FROM 2N-4N BETWEEN 
22W-27W. 

...DISCUSSION...

THE GULF OF MEXICO...
UPPER LEVEL RIDGING COVERS THE GULF OF MEXICO TONIGHT WITH AXIS 
ALONG 90W. MOISTURE IS STREAMING ACROSS THE WRN GULF AROUND THE 
W SIDE OF THE UPPER RIDGE PROVIDING SOME UPPER LEVEL CLOUD 
COVER. THE UPPER RIDGE ALSO SUPPORTS SURFACE RIDGING EXTENDING 
FROM THE NE CORNER TO SW CORNER OF THE GULF. MOSTLY FAIR 
CONDITIONS AND MODERATE 10-15 KT ANTI-CYCLONIC FLOW IS PRESENT 
ACROSS THE BASIN. RADAR IMAGERY INDICATES A FEW ISOLATED SHOWERS 
OVER S FLORIDA AND THE FLORIDA STRAITS. LITTLE CHANGE IS 
EXPECTED OVER THE NEXT 24 HOURS. 

THE CARIBBEAN SEA...
MOSTLY FAIR CONDITIONS REMAIN ACROSS THE CARIBBEAN DUE TO DRY 
AIR ALOFT AROUND A BROAD UPPER LEVEL TROUGH IN THE WRN 
CARIBBEAN. SOME UPPER LEVEL MOISTURE IS STREAMING OVER THE ERN 
CARIBBEAN AROUND THE E SIDE OF THE UPPER TROUGH SUPPORTING SOME 
UPPER LEVEL CLOUDS. THE REMAINDER OF THE BASIN HAS CLEAR SKIES 
BESIDES A FEW ISOLATED SHOWERS OVER HISPANIOLA. TRADEWIND FLOW 
OF 15-20 KTS IS ACROSS MUCH OF THE AREA WITH SOME STRONGER WINDS 
AROUND THE COAST OF COLOMBIA. EXPECT LITTLE CHANGE OVER THE NEXT 
COUPLE OF DAYS. 

THE ATLANTIC OCEAN...
DRY AIR ALOFT AROUND AN UPPER LEVEL TROUGH OVER THE W ATLC IS 
HELPING PROVIDE FAIR CONDITIONS W OF 68W. A WEAK SURFACE TROUGH 
IS NEAR THE NW BAHAMAS FROM 29N77W TO 25N74W...BUT CAUSING NO 
SIGNIFICANT WEATHER. A SECOND SURFACE TROUGH IS FARTHER E ALONG 
60W FROM 23N-29N. SCATTERED SHOWERS ARE WITHIN 250 NM W OF THE 
AXIS...AND WITHIN 180 NM TO THE E. THE UPPER TROUGH IS ALSO 
PROVIDING LIFT FOR ANOTHER AREA OF SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS N OF 27N BETWEEN 48W-55W. AN UPPER LEVEL RIDGE 
COVERS THE CENTRAL ATLC AND PART OF THE ERN ATLC SUPPORTING 
SURFACE RIDGING ANCHORED BY A 1034 MB AZORES HIGH NEAR 40N25W 
WHICH IS PROVIDING MOSTLY FAIR CONDITIONS ACROSS THE REMAINDER 
OF THE BASIN. GOES-R SATELLITE ENHANCED IMAGERY ALONG WITH THE 
LAST VISIBLE SATELLITE IMAGES FROM YESTERDAY INDICATE AN AREA OF 
DUST EMERGING OFF NW AFRICA EXTENDING TO 33W. AN UPPER LEVEL 
TROUGH COVERS THE FAR ERN ATLC WITH AXIS ALONG 21W CAUSING NO 
SIGNIFICANT WEATHER IN THE DISCUSSION AREA. 

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

$$
WALTON