000 AXNT20 KNHC 121123 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 8N13W 4N25W 2N35W 2S46W. SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 4N BETWEEN 14W AND 25W AND ALSO FROM 5N TO 7N BETWEEN 27W AND 30W. ...DISCUSSION... THE GULF OF MEXICO... A STATIONARY FRONT EXTENDS FROM THE FLORIDA PANHANDLE IN THE VICINITY OF APALACHEE BAY THROUGH 25N90W TO THE BAY OF CAMPECHE NEAR 18N95W. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 60 NM EAST OF THE FRONT NEAR CEDAR KEY FLORIDA WITH MORE EXTENSIVE ACTIVITY OVER NORTH FLORIDA. ADDITIONAL SHOWER AND ISOLATED THUNDERSTORM ACTIVITY IS JUST TO THE WEST OF THE DRY TORTUGAS. LIGHT SWLY WINDS OF 5-10 KT ARE NOTED IN ADVANCE OF THE FRONT WITH LIGHT N TO NE WINDS OF 10 KT OR LESS W OF THE FRONT. IN THE UPPER LEVELS...WSWLY FLOW COVERS THE ENTIRE GULF OF MEXICO AND IS MOSTLY PARALLEL TO THE STATIONARY FRONT IN ADDITION TO PROVIDING VERY LITTLE SUPPORT TO THE FRONT ITSELF. A PATCH OF UPPER LEVEL MOISTURE IS OVER THE GULF S OF 28N AND WAS CAPPED BY AN UPPER LEVEL WIND MAX WITH SATELLITE DERIVED WINDS OF 60-70 KT NOTED. THIS AREA OF MOISTURE WAS LIFTING NORTHWARD AS THE UPPER LEVEL FLOW WAS BACKING IN ADVANCE OF A DIGGING TROUGH OVER TEXAS. STRONG SUBSIDENCE WAS EXITING THE FAR NE CORNER OF THE GULF. THE STATIONARY FRONT WILL BEGIN MOVING SLOWLY EASTWARD WITHIN THE NEXT 24 HOURS WITH SHOWER ACTIVITY IN THE INCREASE AS STRONG UPPER LEVEL SUPPORT ARRIVES FROM TEXAS ALLOWING LOW PRESSURE TO DEVELOP OFF THE GEORGIA SOUTH CAROLINA COAST ON SUNDAY. THE CARIBBEAN SEA... LIGHT TO MODERATE TRADEWINDS ARE OVER THE ENTIRE CARIBBEAN SEA WITH PATCHES OF BROKEN LOW CLOUDS AND SCATTERED SHOWERS OVER PANAMA AND COSTA RICA. ANOTHER PATCH OF LOW CLOUDS/SHOWERS WAS NOTED OVER THE W-CENTRAL CARIBBEAN EXTENDING NORTHWARD OVER JAMAICA AND CUBA. A MORE CONCENTRATED AREA OF SHOWERS ARE NOTED OVER THE CARIBBEAN E OF 65W AND EXTENDING EASTWARD OVER THE WINDWARD ISLANDS. IN THE UPPER LEVELS...CONFLUENT WSWLY FLOW IS OVER CENTRAL AMERICA AND THE CARIBBEAN AND WAS RESULTING IN A LARGE AREA OF STRONG SUBSIDENCE WHICH WAS MOST PRONOUNCED EAST OF 75W. THE SURFACE TROUGH JUST TO THE EAST OF THE WINDWARD ISLANDS HAS BECOME DIFFUSE AND EXPECTED TO DISSIPATE OVER THE NEXT SEVERAL HOURS...HOWEVER SHOWER ACTIVITY IS EXPECTED TO PERSIST OVER THE WINDWARD ISLANDS FOR THE NEXT 24 HOURS OR SO. THE ATLANTIC OCEAN... A 1013 MB LOW IS OVER THE CENTRAL ATLANTIC NEAR 27N59.5W. THE LOW WAS ALONG A SURFACE TROUGH WHICH EXTENDED FROM 31N60W S TO 22N59W. SURFACE RIDGE COVERED THE ATLANTIC N AND W OF THE SURFACE LOW. FURTHER EAST A QUASI-STATIONARY 1029 MB HIGH IS OVER THE E ATLANTIC NEAR 34N34W AND DOMINATES THE LOW LEVEL FLOW OVER THE ATLANTIC N OF THE ITCZ AND E OF 46W. IN THE UPPER LEVELS...A NARROW RIDGE IS OVER THE NW ATLANTIC N OF 20N W OF 62W WITH AXIS ALONG 67W. A WELL DEFINED UPPER LEVEL LOW WHICH IS NEARLY VERTICALLY STACKED WITH THE SURFACE LOW NOTED ABOVE NEAR 27N59W IS BEGINNING TO DRIFT TO THE SE. ASSOCIATED TROUGH DIGS SWD TO 20N OVER THE CENTRAL ATLANTIC BETWEEN 50W AND 62W. UPPER LEVEL DIFFLUENCE IS E OF THE TROUGH AND UPPER LOW PRODUCING A LARGE AREA OF MULTI-LAYERED CLOUDS WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM 20N-31N BETWEEN 45W-54W...AND WITHIN 120-150 NM IN THE SE SEMICIRCLE OF THE STACKED UPPER/SURFACE 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. $$ COBB