000
AXNT20 KNHC 121808
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SAT JAN 12 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 
SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE 
AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION 
IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS... 
WEATHER OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 8N13W 3N33W 2S44W. SCATTERED 
MODERATE CONVECTION FROM THE EQUATOR TO 8N BETWEEN 20W AND 30W. 

...DISCUSSION...

THE GULF OF MEXICO...
A STATIONARY FRONT EXTENDS FROM THE FLORIDA PANHANDLE THROUGH 26N90W 
TO THE BAY OF CAMPECHE NEAR 20N97W. WIDESPREAD LIGHT TO MODERATE 
SHOWERS ARE WITHIN 60 NM OF THE FRONTAL BOUNDARY. NO THUNDERSTORMS 
ARE ASSOCIATED WITH THE FRONT. LIGHT SWLY WINDS ARE EVIDENT SE OF 
THE FRONT...WITH NE WINDS 10 KT OR LESS NW OF THE FRONT. IN THE 
UPPER LEVELS...NEARLY ZONAL WEST WINDS OVER THE ENTIRE BASIN IS 
PARALLEL TO THE STATIONARY FRONT...PROVIDING VERY LITTLE SUPPORT TO 
THE FRONT. A PATCH OF UPPER LEVEL MOISTURE S OF 28N IS BEING CAPPED 
BY AN UPPER LEVEL WIND MAX WITH SATELLITE DERIVED WINDS OF 60-70 KT. 
THIS AREA OF MOISTURE IS LIFTING NORTHWARD AS UPPER LEVEL FLOW BACKS 
IN ADVANCE OF A DIGGING TROUGH OVER TEXAS. THE STATIONARY FRONT WILL 
BEGIN MOVING SLOWLY SE WITHIN THE NEXT 24 HOURS WITH SHOWER ACTIVITY 
INCREASING AS GOOD UPPER LEVEL SUPPORT ARRIVES FROM TEXAS...ALLOWING 
LOW PRESSURE TO DEVELOP OFF THE GEORGIA/SOUTH CAROLINA COAST SUNDAY.

THE CARIBBEAN SEA...
LIGHT TO MODERATE TRADE WINDS ARE OVER THE ENTIRE BASIN. A PATCH OF 
LOW CLOUDS AND SHOWERS IS OVER THE WEST CENTRAL CARIBBEAN EXTENDING 
NORTHWARD W OF JAMAICA TO CUBA. A CONCENTRATED AREA OF SHOWERS ARE 
NOTED E OF 68W EXTENDING ACROSS THE WINDWARD ISLANDS. IN THE UPPER 
LEVELS...CONFLUENT WSWLY FLOW OVER CENTRAL AMERICA AND THE CARIBBEAN 
IS CAUSING A LARGE AREA OF STRONG SUBSIDENCE...MOST PRONOUNCED E OF 
75W. A WEAK SURFACE TROUGH PREVIOUSLY ANALYZED E OF THE WINDWARD 
ISLANDS HAS DISSIPATED. SOME SHOWER ACTIVITY WILL PERSIST OVER THE 
WINDWARD ISLANDS FOR THE NEXT 24 HOURS OR SO.

THE ATLANTIC OCEAN...
A 1012 MB LOW IS NEARLY STATIONARY NEAR 27N60W. A SURFACE RIDGE SPANS
THE SUBTROPICAL ATLANTIC N AND W OF THE SURFACE LOW. A 1030 MB HIGH 
NEAR 34N34W DOMINATES THE E ATLANTIC...INCLUDING LOW LEVEL FLOW N OF 
THE ITCZ AND E OF 46W. IN THE UPPER LEVELS...A NARROW RIDGE IS N OF 
20N W OF 62W WITH AN AXIS ALONG 67W. A WELL DEFINED UPPER LEVEL LOW 
IS VERTICALLY STACKED WITH THE SURFACE LOW NOTED ABOVE NEAR 27N60W 
AND AN UPPER TROUGH IS DIGGING SWD TO 20N OVER THE CENTRAL ATLANTIC 
BETWEEN 50W AND 62W. UPPER LEVEL DIFFLUENCE E OF THE TROUGH AND 
UPPER LOW PRODUCING A LARGE AREA OF MULTI-LAYERED CLOUDS WITH 
SCATTERED SHOWERS FROM 20N TO 31N BETWEEN 45W AND 52W...WITH SHOWERS 
WITHIN 120-150 NM SE SEMICIRCLE OF THE STACKED LOW. AN UPPER RIDGE 
IS N OF 17N BETWEEN 30W-50W. MOSTLY ZONAL FLOW IS E OF 30W WITH A 
TROPICAL WIND MAX NOTED ALONG 15N WHICH WAS CAPPING AN EXTENSIVE 
AREA OF MAINLY MID AND UPPER LEVEL CLOUDS. 

$$
MUNDELL