000
AXNT20 KNHC 061134
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST TUE MAR 06 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 
1115 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO A 1009 MB LOW NEAR 
13N16W CONTINUING SW TO 4N23W. THE ITCZ CONTINUES FROM 4N23W TO 
1N30W CROSSING THE EQUATOR AT 39W TO THE COAST OF BRAZIL NEAR 
3S45W. SCATTERED MODERATE CONVECTION IS FROM 2S-3N BETWEEN 
25W-28W. ISOLATED MODERATE CONVECTION IS FROM 2S-3N BETWEEN 
32W-36W.   

...DISCUSSION...

GULF OF MEXICO...
A DRY AND STABLE AIRMASS CONTINUES TO SIT OVER THE GULF OF 
MEXICO THIS MORNING PROVIDING MOSTLY FAIR WEATHER BASIN-WIDE. 
SURFACE RIDGING DOMINATES ANCHORED BY A 1029 MB HIGH S OF 
LOUISIANA NEAR 28N90W. LIGHT ANTI-CYCLONIC FLOW IS AROUND THE 
HIGH WITH WIND SPEEDS INCREASING RADIALLY FROM THE CENTER 
REACHING 20 KTS IN THE SE GULF. THE SURFACE RIDGE IS SUPPORTED 
BY AN UPPER LEVEL RIDGE OVER MEXICO AND THE CENTRAL CONUS ALONG 
99W. WATER VAPOR IMAGERY INDICATES DRY AIR ALOFT AND STRONG 
SUBSIDENCE OVER THE BASIN...WHICH ARE HELPING SUPPORT CLEAR 
SKIES ACROSS THE MAJORITY OF THE AREA BESIDES A FEW PATCHES OF 
STRATOCUMULUS CLOUDS IN THE SW GULF. BROAD UPPER TROUGHING 
COVERS THE ERN HALF OF THE BASIN SUPPORTING A SECONDARY COLD 
FRONT IN THE W ATLC. EXPECT THE SURFACE HIGH TO MERGE WITH A 
HIGH TO THE N AND STRENGTHEN...WHICH WILL INCREASE SURFACE 
RETURN FLOW ACROSS THE GULF. 

CARIBBEAN SEA...
A SHEAR AXIS...REMNANTS OF A FRONTAL BOUNDARY...CONTINUE TO 
IMPACT THE NW CARIBBEAN. THE AXIS EXTENDS FROM CENTRAL CUBA NEAR 
22N79W TO NRN HONDURAS AT 15N87W. ISOLATED SHOWERS ARE WITHIN 
200 NM NW OF THE AXIS. A FEW ISOLATED SHOWERS ARE ALSO ACROSS 
JAMAICA. BESIDES MOISTURE IN THE NW CARIBBEAN...THE REMAINDER OF 
THE BASIN IS UNDER DRY AIR ALOFT AROUND A BROAD UPPER LEVEL 
RIDGE OVER THE CENTRAL AND ERN CARIBBEAN...WHICH IS HELPING 
MAINTAIN CLEAR SKIES AND FAIR CONDITIONS BESIDES SOME LOW-LEVEL 
CLOUD COVER ACROSS THE SW CARIBBEAN. TRADEWIND FLOW OF 20-25 KTS 
IS ACROSS THE ERN AND CENTRAL CARIBBEAN REACHING GALE FORCE NEAR 
THE COAST OF COLOMBIA. EXPECT THE SHEAR AXIS TO REMAIN 
STATIONARY BEFORE DISSIPATING LATER TODAY. 

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH IS OVER THE W ATLC ALONG 67W SUPPORTING A 
PAIR OF FRONTAL BOUNDARIES. THE PRIMARY FRONT HAS BECOME 
STATIONARY AND ENTERS THE DISCUSSION AREA NEAR 32N60W EXTENDING 
TO 24N73W WHERE IT TRANSITIONS INTO A SHEAR AXIS TO ERN CUBA AT 
22N79W. ISOLATED SHOWERS ARE WITHIN 90 NM BEHIND THE FRONT AND 
SHEAR AXIS. THE SECONDARY COLD FRONT ENTERS THE AREA NEAR 32N69W 
TO 29N80W. POSSIBLE ISOLATED SHOWERS ARE ALONG 
THE AXIS. THE CENTRAL ATLC IS DOMINATED BY SURFACE RIDGING 
AROUND A 1029 MB HIGH NEAR 34N44W. THE RIDGE IS SUPPORTED BY AN 
UPPER LEVEL RIDGE EXTENDING FROM THE NE CARIBBEAN TOWARD THE NE 
TO N OF THE AZORES ISLANDS. AN UPPER LEVEL LOW IS TO THE S OF 
THE AZORES CENTERED NEAR 31N30W WITH AXIS EXTENDING TOWARDS THE 
WINDWARD ISLANDS. THE UPPER LOW IS SUPPORTING ISOLATED SHOWERS 
FROM 28N-32N BETWEEN 29W-32W. BROAD UPPER LEVEL RIDGING COVERS 
THE TROPICAL ATLC CENTERED NEAR 7N20W.  

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

$$
WALTON