000 AXNT20 KNHC 252341 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST FRI JAN 25 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 6N10W CONTINUING TO 4N19W WHERE THE ITCZ CONTINUES ALONG 2N23W ACROSS THE EQUATOR NEAR 28W. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 2N-5N BETWEEN 2W-21W INCLUDING SW AFRICA. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE EXTENDS FROM SW MEXICO TO OVER THE CENTRAL PLAIN STATES INCLUDING THE W GULF OF MEXICO. A BROAD UPPER TROUGH OVER THE W ATLC NARROWS SIGNIFICANTLY AS IT EXTENDS ACROSS THE NW CARIBBEAN FORMING A SECONDARY UPPER RIDGE AXIS FROM TAMPICO MEXICO TO ACROSS S FLORIDA NEAR NAPLES TO OVER THE N BAHAMA ISLANDS. WATER VAPOR IMAGERY INDICATES THAT STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT COVERS THE GULF EXCEPT ALONG THE LOUISIANA AND TEXAS COASTS. HOWEVER AT THE SURFACE THERE IS MOSTLY CLEAR SKIES ACROSS THE ENTIRE GULF WITH A POSSIBLE STRAY ISOLATED SHOWER S OF THE FLORIDA KEYS. A SURFACE RIDGE REMAINS OVER THE GULF ANCHORED BY A 1026 MB HIGH OFF THE FLORIDA PANHANDLE NEAR 29N85W. HIGH PRESSURE WILL WEAKEN ON SUN ALLOWING A WEAK FRONT TO MOVE INTO THE NE GULF BECOMING STATIONARY SUN NIGHT AND DISSIPATING ON MON. HIGH PRESSURE WILL THEN BUILD AGAIN BEHIND THE FRONT. ANOTHER COLD FRONT WILL MOVE INTO THE NW GULF ON WED. CARIBBEAN SEA... THE NARROW UPPER TROUGH EXTENDS FROM A BROAD UPPER TROUGH OVER THE W ATLC ENTERING THE NW CARIBBEAN ACROSS CENTRAL CUBA NEAR SANTA CLARA TO AN UPPER LOW OVER BELIZE. THE REMAINED OF THE CARIBBEAN IS UNDER SW FLOW ALOFT. WATER VAPOR IMAGERY INDICATES THAT STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT COVERS ALL BUT THE NW CARIBBEAN WHERE INCREASED INSTABILITY AND SCATTERED SHOWERS ARE MAINLY S OF 20N W OF 84W TO INLAND OVER THE YUCATAN PENINSULA. FRESH TO STRONG TRADE WINDS ARE ACROSS THE S/CENTRAL CARIBBEAN WITH LIGHT TO MODERATE TRADES ACROSS THE REMAINDER OF THE AREA. REMNANT MOISTURE COUPLED WITH THE EASTERLY SURFACE FLOW ARE GENERATING ISOLATED SHOWERS FROM 15N-21N BETWEEN 76W-84W INCLUDING JAMAICA. TRADE WINDS WILL PERSIST UNTIL THE W ATLC SURFACE RIDGE STRENGTHENS LATE IN THE WEEKEND RESULTING IN FRESH TO STRONG TRADES THROUGHOUT THE AREA. ATLANTIC OCEAN... A BROAD UPPER TROUGH COVERS THE AREA N OF 25N W OF 50W THEN NARROWS DRAMATICALLY AS IT ENTERS THE NW CARIBBEAN ACROSS CENTRAL CUBA NEAR SANTA CLARA. INCREASED INSTABILITY AND SCATTERED SHOWERS ARE FROM OVER THE S BAHAMA ISLANDS TO OVER THE GREATER ANTILLES BETWEEN 70W-79W INCLUDING THE TURKS AND CAICOS. THE BROAD UPPER TROUGH IS SUPPORTING A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N52W EXTENDING ALONG 27N61W TO 25N68W WHERE IT DISSIPATES ALONG 25N74W THEN ACROSS THE N BAHAMA ISLANDS TO OVER FLORIDA NEAR CAPE CANAVERAL. ISOLATED SHOWERS ARE POSSIBLE WITHIN 60 NM W OF THE FRONT. A REMNANT STATIONARY FRONT REMAINS ACROSS THE CENTRAL ATLC ENTERING THE DISCUSSION AREA NEAR 32N49W CONTINUING ALONG 25N59W TO 22N66W WHERE IT DISSIPATES S OF THE TURKS AND CAICOS NEAR 21N73W. A SURFACE RIDGE IS BUILDING ACROSS THE W ATLC W OF THESE FRONTS ANCHORED BY A 1027 MB HIGH OFF NORTH CAROLINA. A SURFACE RIDGE DOMINATES THE E ATLC E OF THE ABOVE FRONTS ANCHORED BY A 1031 MB HIGH NEAR 32N26W GIVING THE REMAINDER OF THE ATLC FAIR WEATHER THIS EVENING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW