000 AXNT20 KNHC 261747 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED JAN 26 2011 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 5N10W 5N22W 3N30W 3N40W CROSSING THE EQUATOR AT 50W. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE NOTED S OF THE ITCZ AXIS TO 1N BETWEEN 6W AND 15W. SCATTERED MODERATE CONVECTION IS WITHIN 90-100 NM N OF AXIS FROM 22W TO 33W. SIMILAR CONVECTION IS S OF AXIS TO THE COAST OF SOUTH AMERICA BETWEEN 44W AND 47W. ...DISCUSSION... GULF OF MEXICO... AT 26/1500 UTC...A COLD FRONT EXTENDS FROM FORT MYERS SW FLORIDA ACROSS THE SE PORTION OF THE GULF CROSSING THE YUCATAN PENINSULA TO NEAR 18N93W. MOST OF THE STRONG SHOWER AND TSTMS ACTIVITY NOTED AHEAD OF THE FRONT SINCE YESTERDAY HAS DIMINISHED AND THE THREAT OF SEVERE TSTMS HAS ENDED OVER THE STATE OF FLORIDA. HOWEVER...ADDITIONAL SHOWERS AND A COUPLE OF TSTMS ARE STILL POSSIBLE WITH THE FRONTAL PASSAGE ACROSS SOUTH FLORIDA THIS AFTERNOON. A PRE-FRONTAL THROUGH IS OVER THE YUCATAN CHANNEL AND EXTENDS FROM 24N84W TO 18N86W. THE 1212 UTC WINDSAT PASS PROVIDED OBSERVATIONS OF NW TO N WINDS OF 20 TO 30 BEHIND THE COLD FRONT E OF 90W. COLD AIR STRATOCUMULUS CLOUDS ARE SEEN COVERING MOST THE GULF WATERS BEHIND THE FRONT DUE TO THE ADVECTION OF COLD AIR OVER RELATIVELY WARM WATERS. PERSISTENT LOW CLOUDINESS ARE ALSO BANKED UP ALONG THE E SLOPES OF THE SIERRA MADRE MOUNTAINS. THE FRONT WILL QUICKLY MOVE SE OF THE GULF BY LATE THIS AFTERNOON. HIGH PRES WILL BUILD IN ITS WAKE FROM W TO E ACROSS THE REGION THROUGH SUN. AS A RESULT...WINDS AND SEAS WILL GRADUALLY DIMINISH ACROSS THE REGION. ALOFT...A STRONG SHORT WAVE TROUGH MOVING E OVER THE SE CONUS SUPPORTS THE AFOREMENTIONED COLD FRONT WITH SW TO W UPPER LEVEL FLOW DOMINATING THE GULF REGION. CARIBBEAN SEA... BROAD UPPER RIDGE DOMINATES THE CARIBBEAN SEA ANCHORED OVER EASTERN COLOMBIA. STRONG UPPER LEVEL SUBSIDENCE WITH THE IMPLIED DRY AIR MASS COVERS MOST THE BASIN WITH THE EXCEPTION OF SOME MID/UPPER LEVEL MOISTURE OVER THE FAR NW CARIBBEAN ASSOCIATED WITH A PRE-FRONTAL TROUGH. FRESH TO STRONG TRADE WINDS CONTINUE TO BLOW ACROSS THE EASTERN AND CENTRAL CARIBBEAN WITH THE STRONGEST WINDS UP TO 30 KT NEAR THE COAST OF COLOMBIA DUE TO THE PRESSURE GRADIENT BETWEEN THE RIDGE N OF AREA AND THE COLOMBIAN/PANAMANIAN LOW THAT USUALLY RESIDES IN THIS REGION. THE 1032 UTC WINDSAT PASS AND THE 1408 UTC ASCAT PASS ALONG WITH SOME SHIP OBSERVATIONS VERIFIED THESE WIND SPEEDS. THESE WINDS ARE EXPECTED TO DIMINISH THROUGH THU NIGHT BUT RETURN SUN AS HIGH PRES BUILDS SE INTO NORTHERN CARIBBEAN BEHIND A COLD FRONT FORECAST TO BECOME STATIONARY FROM CENTRAL CUBA TO THE GULF OF HONDURAS TONIGHT THROUGH THU AND DISSIPATE EARLY FRI. PATCHES OF LOW LEVEL MOISTURE REMAIN EMBEDDED WITHIN THE TRADE WIND FLOW AS SEEN ON VISIBLE SATELLITE IMAGERY USHERING IN ISOLATED TO SCATTERED PASSING SHOWERS. ATLANTIC OCEAN... A COLD FRONT IS JUST ENTERING THE NW PORTION OF THE SW N ATLC AND EXTENDS FROM 31N78W TO SW FLORIDA INTO THE GULF OF MEXICO. A NARROW BAND OF SHOWERS AND TSTMS IS AHEAD OF THE FRONT AND IS CURRENTLY AFFECTING THE NW BAHAMAS. GALE FORCE WINDS ARE EXPECTED AHEAD OF THE FRONT THROUGH EARLY TONIGHT...AND A GALE WARNING REMAINS IN EFFECT N OF 29N W OF 75W. ANOTHER COLD FRONT ENTERS THE FORECAST AREA NEAR 31N38W THEN CONTINUES SW AND THEN W TO NEAR 23N53W WHERE IT BEGINS TO DISSIPATE AS A STATIONARY FRONT ALONG 22N65W TO THE TURKS AND CAICOS NEAR 21N72W. SOME SHOWERS ARE ALONG THE FRONTAL BOUNDARY. A BELT OF 20-25 KT NE WINDS IS NOTED PER AN EARLIER WINDSAT PASS WITHIN AROUND 180 NM N OF THE DISSIPATING FRONT BETWEEN 57W AND 67W. NLY WINDS IN THE 20 TO 25 KT RANGE ARE ALSO OBSERVED BEHIND THE COLD FRONT E OF 47W. A THIRD COLD FRONT IS MOVING ACROSS THE CANARY ISLANDS FOLLOWED BY FRESH TO STRONG WINDS. IN THE UPPER LEVELS...A HIGH AMPLIFIED RIDGE/TROUGH PATTERN DOMINATES THE AREA. THE BROAD UPPER RIDGE THAT COVERS THE CARIBBEAN SEA EXTENDS NWD OVER THE W ATLC TO BEYOND 31N70W. AN UPPER TROUGH IS OVER THE E-CENTRAL ATLC AND RUNS FROM 31N18W TO 17N37W TO 10N50W. A JET STREAM BRANCH WITH CORE WINDS OF 70-90 KT ROUNDS THE BASE OF THE TROUGH AND EXTENDS NE THEN E INTO NORTHERN AFRICA. THE REMAINDER OF THE E AND CENTRAL ATLC IS UNDER THE INFLUENCE OF HIGH PRES WITH MOSTLY FAIR CONDITIONS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR