000
AXNT20 KNHC 031132
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SUN MAR 03 2013

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 
1045 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM NORTHERN GUINEA NEAR 11N15W INTO 
THE TROPICAL EAST ATLC ALONG 5N17W 4N19W. THE ITCZ CONTINUES 
FROM 4N19W TO 1N31W 1N47W. SCATTERED STRONG CONVECTION IS FROM 
3N-6N BETWEEN 8W-13W. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 
21W-40W.  

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL TROUGH REMAINS OVER THE EASTERN CONUS AND GULF OF 
MEXICO EXTENDING FROM ALABAMA TO NORTHERN MEXICO CONTINUING TO 
ADVECT COOLER AIR ACROSS THE BASIN. DRY AIR ALOFT IS KEEPING THE 
WESTERN GULF WEST OF 94W FAIR WITH CLEAR SKIES...WHILE OVERCAST 
CONDITIONS AND ISOLATED SHOWERS REMAIN OVER THE EASTERN PORTIONS 
OF THE AREA. MORE WIDESPREAD...BUT LIGHT...SHOWERS COVER MUCH OF 
SOUTH FLORIDA. A TIGHT PRESSURE GRADIENT BETWEEN HIGHER PRESSURE 
OVER THE FAR WESTERN GULF...AND LOWER PRESSURE ACROSS THE WEST 
ATLC CONTINUES TO SUPPORT STRONG NORTHWEST TO NORTH WINDS OF 
20-25 KT. THE UPPER TROUGH IS EXPECTED TO MOVE EAST AND WILL 
ALLOW SURFACE RIDGING TO BUILD IN AND DOMINATE THE GULF. AS THE 
RIDGE BUILDS IN WIND SPEEDS WILL DECREASE BEFORE ANOTHER COLD 
FRONT MOVES IN THE AREA IN THE MIDDLE OF NEXT WEEK. 

CARIBBEAN SEA...
A SLOW-MOVING COLD FRONT EXTENDS THROUGH THE NW CARIBBEAN FROM 
EASTERN CUBA NEAR 20N75W TO EAST OF NICARAGUA ALONG 17N80W 
11N82W. STRONG NORTHERLY WINDS ARE BEHIND THE FRONT REACHING 
20-25 KT IN MOST SPOTS WITH A SMALL AREA OF GALE FORCE WINDS OFF 
THE COAST OF HONDURAS FROM 10N-17N BETWEEN 82W-85W. OVERCAST 
SKIES AND ISOLATED SHOWERS ARE BOTH AHEAD AND BEHIND THE FRONT 
BETWEEN 75W-82W. A SURFACE TROUGH IS ALSO ANALYZED EAST OF THE 
FRONT ALONG 18N76W TO 11N79W. THE EASTERN CARIBBEAN REMAINS 
UNDER CLEAR SKIES DUE TO DRY AIR ALOFT AROUND A BROAD UPPER 
LEVEL RIDGE WITH AXIS ALONG 55W. TRADEWIND FLOW OF 15-20 KT IS 
PRESENT OVER THIS AREA. EXPECT THE FRONT TO CONTINUE MOVING 
SLOWLY EAST. ISOLATED SHOWERS ARE LIKELY ACROSS MUCH OF THE 
CENTRAL CARIBBEAN AS THE FRONT MOVES EAST. 

ATLANTIC OCEAN...
THE FRONTAL BOUNDARY THAT PREVIOUSLY SPREAD ACROSS MUCH OF THE 
NORTHERN PART OF THE DISCUSSION AREA HAS SPLIT INTO TWO SEPARATE 
COLD FRONTS. THE ONE FARTHEST WEST ENTERS THE DISCUSSION AREA 
NEAR 32N65W AND CONTINUES ACROSS THE BAHAMAS TO EASTERN CUBA 
NEAR 21N75W. THE FRONT IS SUPPORTED BY AN UPPER LEVEL TROUGH 
COVERING THE EASTERN CONUS AND THE GULF OF MEXICO. A SURFACE 
TROUGH TRAILS BEHIND IT ALONG 32N71W TO 29N78W. OVERCAST SKIES 
AND ISOLATED SHOWERS ARE WITHIN 220 NM EITHER SIDE OF THE FRONT 
AXIS ENHANCED BY DIFFLUENCE ALOFT BETWEEN THE UPPER TROUGH AND 
AN UPPER LEVEL RIDGE COVERING THE WEST AND CENTRAL ATLC ALONG 
55W. THE UPPER RIDGE SUPPORTS A SURFACE RIDGE AROUND A PAIR OF 
HIGH CENTERS IN THE CENTRAL AND EASTERN ATLC. A 1018 MB HIGH IS 
NEAR 22N52W...WHILE A 1016 MB HIGH IS NEAR 20N27W. THE TWO HIGH 
CENTERS ARE KEEPING MUCH OF THE CENTRAL AND EASTERN TROPICAL 
ATLC UNDER FAIR CONDITIONS. AN UPPER LEVEL TROUGH IS OVER THE 
FAR EASTERN ATLC FROM THE AZORES ISLANDS TO NEAR THE CAPE VERDE 
ISLANDS BEFORE CHANGING DIRECTIONS WITH THE AXIS HEADING 
SOUTHWEST INTO THE TROPICAL ATLC ACROSS THE CAPE VERDE ISLANDS 
TO NEAR 9N48W. THE NORTHERN PORTION OF THE UPPER TROUGH SUPPORTS 
THE SECOND COLD FRONT THAT DRAPES ACROSS THE NORTHERN PORTION OF 
THE DISCUSSION AREA NORTH OF THE SURFACE RIDGE ALONG 32N24W 
27N33W 26N49W. SCATTERED SHOWERS ARE EAST OF THE AXIS NORTH OF 
29N BETWEEN 12W-26W. POSSIBLE ISOLATED SHOWERS ARE ALONG THE 
AXIS ELSEWHERE. GALE FORCE WINDS ARE ALSO PRESENT BOTH AHEAD AND 
BEHIND THE FRONT NORTH OF 28N. 

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

$$
WALTON