000
AXNT20 KNHC 170546
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT MAR 17 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 7N11W TO 4N19W. THE ITCZ CONTINUES FROM 4N19W ALONG 
2N30W CROSSING THE EQUATOR AT 37W TO 3S43W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS FROM 2N-4N BETWEEN 
18W-25W. 

...DISCUSSION...

THE GULF OF MEXICO...
AN UPPER LEVEL RIDGE IS MOVING ACROSS THE GULF OF MEXICO TONIGHT 
WITH AXIS EXTENDING FROM THE BAY OF CAMPECHE TO MISSISSIPPI. 
UPPER TROUGHING COVERS THE FAR ERN GULF WITH AXIS DOWN THE 
FLORIDA PENINSULA INTO THE WRN CARIBBEAN. AT THE 
SURFACE...MAINLY SURFACE RIDGING COVERS THE BASIN EXTENDING FROM 
A 1027 MB HIGH IN THE W ATLC NEAR 34N68W. A WEAK SURFACE TROUGH 
EXTENDS ACROSS THE YUCATAN PENINSULA ALONG 21N89W TO 16N93W...AS 
OF 0300 UTC. NO SIGNIFICANT WEATHER IS ASSOCIATED WITH THE 
TROUGH. MOSTLY CLEAR SKIES COVER THE MAJORITY OF THE BASIN  
BESIDES SOME UPPER LEVEL CLOUD COVER OVER THE WRN GULF WHERE 
UPPER LEVEL MOISTURE IS STREAMING TO THE NE AROUND THE W SIDE OF 
THE UPPER RIDGE. 10-15 KT E-SE SURFACE WINDS ARE AROUND THE 
SURFACE RIDGE. EXPECT THE SURFACE TROUGH OVER THE YUCATAN TO 
DRIFT WWD AS SURFACE RIDGING REMAINS ACROSS THE BASIN FOR THE 
NEXT SEVERAL DAYS. 

THE CARIBBEAN SEA...
MOSTLY FAIR CONDITIONS ARE ACROSS THE CARIBBEAN TONIGHT DUE TO 
DRY AIR ALOFT AROUND AN UPPER LEVEL TROUGH IN THE NW CARIBBEAN 
FROM CENTRAL CUBA TO HONDURAS. 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 A FEW 
OF THE ISLANDS INCLUDING HISPANIOLA AND WRN CUBA...AS WELL AS 
HONDURAS AND NRN NICARAGUA. 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...
AMPLE DRY AIR AND SUBSIDENCE ALOFT IS KEEPING THE FAR WRN ATLC 
UNDER MOSTLY CLEAR SKIES AND FAIR CONDITIONS. AN UPPER LEVEL 
RIDGE EXTENDS FROM THE NW BAHAMAS TO 34N75W CONTINUING TOWARDS 
THE NE. THE UPPER RIDGE SUPPORTS A 1027 MB SURFACE HIGH NEAR 
34N68W. SHORTWAVE UPPER TROUGHS ARE TO EITHER SIDE OF THE RIDGE 
ALL EMBEDDED WITHIN A LONGWAVE UPPER TROUGH OVER THE WRN 
CARIBBEAN AND THE BAHAMAS. THIS PATTERN IS SUPPORTING A PAIR OF 
SURFACE TROUGHS. THE FIRST EXTENDS OVER THE ERN BAHAMAS ALONG 
26N71W TO HAITI NEAR 19N73W. ISOLATED SHOWERS ARE NEAR THE NRN 
TIP OF THE TROUGH. THE SECOND TROUGH IS FARTHER ALONG 29N54W TO 
22N59W. SCATTERED SHOWERS ARE W OF THE AXIS FROM 19N-28N BETWEEN 
60W-65W...AND E OF THE AXIS FROM 23N-30N BETWEEN 51W-54W. ACROSS 
THE CENTRAL ATLC...A BROAD UPPER RIDGE IS S OF 33N WITH AN UPPER 
LEVEL TROUGH N OF 33N WITH AXIS ALONG 49W. AN UPPER RIDGE IS E 
OF THE UPPER TROUGH ALONG 36W SUPPORTING A 1027 MB HIGH NEAR 
34N46W WHICH IS PROVIDING FAIR WEATHER ACROSS THE REMAINDER OF 
THE AREA. AN UPPER LEVEL TROUGH COVERS THE FAR ERN ATLC WITH 
AXIS EXTENDING ACROSS THE MADEIRA ISLANDS TO W OF THE CANARY 
ISLANDS TO THE CAPE VERDE ISLANDS. THE UPPER TROUGH IS 
SUPPORTING A WEAK FRONTAL BOUNDARY N OF THE AREA.

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

$$
WALTON