000 AXNT20 KNHC 130535 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST SUN JAN 13 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 8N13W 3N25W 1N140W CROSSING THE EQUATOR NEAR 45W TO 1S47W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 45-60 NM OF THE AXIS BETWEEN 21W AND 24W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM OF THE AXIS BETWEEN 28W-32W AND FROM THE EQUATOR TO 3N BETWEEN 10W-18W. ...DISCUSSION... THE GULF OF MEXICO... A WEAK FRONTAL BOUNDARY REMAINS STALLED FROM CEDAR KEY FLORIDA THROUGH 26N90W TO THE EAST COAST OF MEXICO NEAR TAMPICO. COMBINATION OF MOSAIC DOPPLER RADAR AND LIGHTNING DATA SUGGEST SCATTERED SHOWERS AND TSTMS ARE WITHIN 60 NM N OF THE STATIONARY FRONT. THE FRONT HAS LITTLE UPPER SUPPORT AT THE MOMENT AS WATER VAPOR IMAGES AND DERIVED UPPER WINDS SHOW WIDESPREAD SWLY FLOW AREA-WIDE. HOWEVER...SUPPORT IS ON THE WAY AS A LARGE UPPER TROUGH OVER THE SOUTH-CENTRAL U.S. SHIFTS E. THIS TROUGH IS SUPPORTING A COLD FRONT WHICH HAS NOW MOVED OFF THE CENTRAL TEXAS COAST. MODEL GUIDANCE SHOWS THESE BOUNDARIES MERGING AND SWEEPING THROUGH THE MAJORITY OF THE AREA WITHIN THE NEXT 24-36 HOURS BRINGING COOLER CONDITIONS TO THE REGION. THE CARIBBEAN SEA... LARGE SUBSIDENT MID TO UPPER RIDGE LIES ABOVE THE ENTIRE ZONE LIMITING THE DEVELOPMENT OF CONVECTION OR DEEP CLOUDINESS. PATCHES OF LOW LEVEL CLOUDS ARE STREAMING FROM W TO E ACROSS THE AREA IN MODERATE TRADE WIND FLOW. THE MOST CONCENTRATED PATCHES ARE S OF 17N E OF 70W AND FROM 14N-20N BETWEEN 80W-84W AND MOVING ONSHORE OVER NE NICARAGUA AND FAR EASTERN HONDURAS. OVERALL...LITTLE CHANGE IS EXPECTED UNTIL A FRONT MOVES INTO THE NW CORNER ON MON. THE ATLANTIC OCEAN... A WEAK 1013 MB LOW PRES SYSTEM IS DRIFTING N AND WAS CENTERED NEAR 27N60W. WHILE THE LOW-LEVEL CIRCULATION IS EASILY EVIDENT...THE SYSTEM IS DEVOID OF DEEP CONVECTION. A 0044 UTC ASCAT PASS CAPTURED THE CIRCULATION WELL REVEALING WINDS OF UP TO 20 KT MAINLY IN THE EASTERN SEMICIRCLE. NWP MODELS SHOW A CONTINUED NORTH-NORTHWEST DRIFT AS IT OPENS INTO A TROUGH OVER THE NEXT DAY OR TWO... EVENTUALLY BEING ABSORBED BY A MUCH LARGER EXTRATROPICAL LOW. OVERCAST MULTILAYERED CLOUDS WITH EMBEDDED SCATTERED SHOWERS/ ISOLATED TSTMS LIE WELL TO THE E OF THE SFC LOW FROM 22N-30N BETWEEN 45W-51W IN AN UPPER DIFFLUENT ZONE. THE W ATLC W OF 65W IS UNDER SWLY UPPER FLOW AND WEAK SFC RIDGING. THIS PATTERN IS PRODUCING SCATTERED LOW CLOUDS NE OF THE BAHAMAS. RADAR AND LIGHTNING DATA INDICATES THAT A LINE OF SCATTERED THUNDERSTORMS HAVE DEVELOPED WITHIN 60-75 NM E OF THE FLORIDA E COAST FROM VERO BEACH TO JACKSONVILLE. FURTHER E...MUCH STRONGER SFC RIDGING LIES OVER THE E ATLC WITH A FAIRLY WELL DEFINED TROUGH ALOFT EXTENDING FROM THE MADEIRA ISLANDS NEAR 32N17W TO 25N35W. SWIFT MID TO UPPER ZONAL FLOW LIES OVER THE TROPICAL BELT. THIS OVERALL PATTERN IS ALSO NOT AMOUNTING TO MUCH SENSIBLE WEATHER WITH ONLY A SWATH OF MID-HIGH LEVEL CLOUDS AND POSSIBLE SHOWERS FROM 10N-16N E OF 50W. $$ COBB