000
AXNT20 KNHC 101746
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST THU JAN 10 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 
1645 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH THE SOUTHERN COAST OF LIBERIA 
FROM 5N8W TO 6N12W WHERE IT TRANSITIONS INTO ITCZ AND CONTINUES 
ALONG 6N20W 4N30W 1N43W. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION IS FROM 1N-2N BETWEEN 25W-30W...AND FROM 1N-3N 
BETWEEN 34W-39W.  

...DISCUSSION...

GULF OF MEXICO...
ACTIVE WEATHER IS IMPACTING THE NW GULF OF MEXICO TODAY AS A 
COLD FRONT AND VERY ACTIVE SQUALL LINE PUSH THROUGH THE AREA. AS 
OF 1500 UTC...A COLD FRONT EXTENDS FROM WESTERN LOUISIANA NEAR 
30N93W TO NEAR 26N95W WHERE IT TRANSITIONS INTO A STATIONARY 
FRONT TO THE MEXICO COAST AT 23N98W. A VERY ACTIVE SQUALL LINE 
IS EAST OF THE FRONT CURRENTLY ALONG 31N91W 27N93W 23N94W. 
STRONG SHOWERS/THUNDERSTORMS ARE WITHIN 50 NM OF THE SQUALL 
AXIS. NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS ALSO EXTEND 
WESTWARD FROM THE SQUALL AXIS TO THE COLD FRONT. SCATTERED 
SHOWERS/ISOLATED THUNDERSTORMS CONTINUE 50 NM WEST OF THE FRONT. 
A NARROW UPPER LEVEL TROUGH OVER TEXAS AND EASTERN MEXICO IS 
SUPPORTING THE FRONTAL SYSTEM. DIFFLUENCE ALOFT AROUND THE EAST 
SIDE OF THE UPPER TROUGH IS HELPING CONTRIBUTE TO THE LARGE AREA 
OF THUNDERSTORM ACTIVITY. THE REMAINDER OF THE BASIN REMAINS 
UNDER FAIR CONDITIONS DUE TO DRY AIR ALOFT AROUND A BROAD UPPER 
RIDGE COVERING THE REST OF THE GULF AS WELL AS THE CARIBBEAN AND 
WEST ATLC. SOUTHEAST WINDS OF 15-20 KT SPREAD OVER MUCH OF THE 
EASTERN GULF INCREASING TO 25 KT JUST EAST OF THE SQUALL LINE. 
LIGHTER NORTHWEST WINDS UP TO 10 KT ARE WEST OF THE FRONT. THE 
FRONT IS EXPECTED TO CONTINUE SLOWLY EAST BEFORE STALLING AND 
DISSIPATING WITHIN 48 HOURS. STRONG SHOWERS/THUNDERSTORMS WILL 
CONTINUE NEAR THE FRONT AND SQUALL LINE FOR LIKELY THE NEXT 24 
HOURS.  

CARIBBEAN SEA...
THE CARIBBEAN IS EXPERIENCING FAIR WEATHER BASIN-WIDE ASSOCIATED 
WITH SURFACE RIDGING TO THE NORTH SUPPORTED BY A BROAD UPPER 
LEVEL RIDGE COVERING THE BASIN ACCOMPANIED BY DRY AIR ALOFT. A 
TIGHT PRESSURE GRADIENT DUE TO THE SURFACE RIDGE TO THE NORTH IS 
HELPING SUPPORT GALE FORCE WINDS NORTH OF COLOMBIA ALONG WITH 
MAINLY 20-25 KT TRADEWIND FLOW ACROSS THE EASTERN AND CENTRAL 
CARIBBEAN. PATCHES OF LOW-LEVEL CLOUDS WITH ISOLATED SHOWERS ARE 
MOVING QUICKLY ACROSS THE AREA MAINLY IN THE EASTERN AND CENTRAL 
PORTIONS. THE GALE FORCE WINDS ARE EXPECTED TO REMAIN FOR THE 
NEXT 24 HOURS WITH LITTLE CHANGE ELSEWHERE. 

ATLANTIC OCEAN...
A SURFACE RIDGE COVERING THE EASTERN CONUS EXTENDS INTO THE WEST 
ATLC PROVIDING FAIR CONDITIONS ACROSS MUCH OF THE AREA. THE 
RIDGE IS SUPPORTED BY A BROAD UPPER LEVEL RIDGE COVERING THE 
EASTERN GULF OF MEXICO...THE CARIBBEAN AND THE ATLC WEST OF 55W. 
BROAD UPPER TROUGHING COVERS THE REMAINDER OF THE CENTRAL AND 
EASTERN ATLC WITH A SHARPER AXIS ALONG 41W. THIS NARROWER AXIS 
SUPPORTS A SPOT 1021 MB SURFACE LOW NEAR 29N39W AND A STATIONARY 
FRONT THAT EXTENDS THROUGH THE LOW ALONG 31N37W 25N40W 25N51W 
BECOMING DISSIPATING ALONG 25N57W 30N62W. SCATTERED SHOWERS ARE 
MAINLY EAST OF THE FRONT WITHIN 150 NM NORTH OF 39N. FAIR 
WEATHER IS NOTED ELSEWHERE. 

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

$$
WALTON