000
AXNT20 KNHC 291738
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST TUE JAN 29 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1715 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH SOUTHERN COASTAL LIBERIA NEAR 
5N9W TO 5N13W. THE ITCZ CONTINUES FROM 5N14W 3N20W 2N30W 2N40W 
TO 2N46W. ISOLATED SHOWERS ARE WITHIN 200 NM EITHER SIDE OF THE 
MONSOON TROUGH AND ITCZ AXES.

...DISCUSSION...

THE GULF OF MEXICO...
RETURN FLOW SPREADS OVER THE ENTIRE GULF DUE TO A 1028 MB HIGH 
PRESSURE POSITIONED OVER THE WEST ATLC. SOUTHEASTERLY WINDS OF 15 
KT DOMAIN MOST OF THE REGION. STRONGER WINDS OF 20-25 KT ARE 
PRESENT OVER THE SE AND NW AREAS OF THE GULF. PATCHES OF BROKEN 
LOW LEVEL CLOUDS CAN BE FOUND OVER THE REGION. HOWEVER THERE IS 
NO CONVECTIVE PRECIPITATION ASSOCIATED TO THEM. FAIR WEATHER 
CONDITIONS ARE BEING SUPPORTED BY AN UPPER LEVEL RIDGE THAT 
EXTENDS OVER THE EASTERN CONUS DOWN TO THE GULF AND DRY AIR 
SUBSIDENCE. WITHIN 24 HOURS...GALE FORCE WINDS ARE EXPECTED TO 
DEVELOP S OF 22N W OF 93W IN ASSOCIATION TO A COLD FRONT THAT 
WILL ENTER THE NW GULF. EAST OF THE FRONT...RETURN FLOW WILL 
CONTINUE AS THE HIGH PRESSURE OVER THE WEST ATLC REMAINS 
STATIONARY. HOWEVER SOUTHERLY/SOUTHEASTERLY WINDS ARE EXPECTED 
TO INCREASE TO 20-25 KT.  

THE CARIBBEAN SEA...
EASTERLY TRADE WINDS OF 15-25 KT COVER THE WEST...CENTRAL AND 
EASTERN CARIBBEAN THIS AFTERNOON. IN THE SOUTHERN CARIBBEAN 
SOUTH OF 13N GALE FORCE WINDS ARE PRESENT DUE TO A TIGHTER 
PRESSURE GRADIENT. PATCHES OF BROKEN LOW LEVEL CLOUDS ARE 
DISPERSED OVER THE REGION BUT THERE IS NO CONVECTIVE 
PRECIPITATION ASSOCIATED TO IT. WATER VAPOR IMAGERY INDICATE DRY 
AIR SUBSIDENCE ALOFT ALLOWING FAIR WEATHER OVER THE BASIN. 
HOWEVER OVER PUERTO RICO AND LA HISPANIOLA SCATTERED SHOWERS ARE 
POSSIBLE IN ASSOCIATION TO A DISSIPATING COLD FRONT RUNNING 
ACROSS THESE ISLANDS. NO SIGNIFICANT CHANGES ARE EXPECTED WITHIN 
THE NEXT 24 HOURS.   

THE ATLANTIC OCEAN...
OVER THE WEST ATLC...A 1026 MB HIGH IS POSITIONED NEAR 30N69W. 
FAIR WEATHER CONDITIONS ARE BEING SUPPORTED BY AN UPPER LEVEL 
RIDGE WITH AXIS OVER THE EASTERN CONUS AND DRY AIR SUBSIDENCE. 
OVER THE CENTRAL ATLC...A COLD FRONT ENTERS THE REGION NEAR 
30N33W AND EXTENDS TO 25N41W 21N50W 19N63W WHERE A DISSIPATING 
COLD FRONT CONTINUES TO 19N71W. EAST OF THE FRONT A SURFACE 
TROUGH EXTENDS FROM 25N37W TO 20N45W. BOTH THE FRONT AND THE 
TROUGH ARE BEING SUPPORTED BY A BROAD UPPER LEVEL TROUGH 
POSITIONED OVER THE CENTRAL ATLC N OF 26N. SCATTERED SHOWERS CAN 
BE FOUND WEST OF THE FRONT TO 44W FROM 27N-30N. OVER THE EAST 
ATLC...ANTICYCLONIC FLOW SPREADS N OF 21N EAST OF THE COLD FRONT 
IN ASSOCIATION TO A SURFACE HIGH PRESSURE SYSTEM POSITIONED OVER 
SPAIN AND N AFRICA. UPPER LEVEL RIDGING AND DRY AIR SUBSIDENCE 
SUPPORT CLEAR SKIES OVER THIS REGION. NO SIGNIFICANT CHANGES ARE 
EXPECTED OVER THE NEXT 24 HOURS. 

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

$$
NR