000 AXNT20 KNHC 271127 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST SUN NOV 27 2005 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...SPECIAL FEATURE... THE CENTER OF TROPICAL STORM DELTA AT 27/0900 UTC IS NEAR 25.6N 32.8W OR ABOUT 945 MILES...1525 KM...WEST-SOUTHWEST OF LA PALMA IN THE CANARY ISLANDS MOVING NE 21 KT. THE MAXIMUM SUSTAINED WINDS ARE 35 KT WITH GUSTS TO 45 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 993 MB. PLEASE REFER TO THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC AND THE LATEST PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT3/ WTNT33 KNHC FOR MORE DETAILS. RECENTLY CIRRUS FROM NEARBY TSTMS HAVE COVERED THE CENTER OF DELTA... PERHAPS SUGGESTING THE STORM IS A LITTLE STRONGER. HOWEVER IT IS BEGINNING TO TAKE ON A COMMA-LIKE APPEARANCE ON SATELLITE AS ONE OF THE FIRST SIGNS OF EXTRATROPICAL TRANSITION. SHEAR IS FORECAST TO INCREASE SLOWLY IN ADDITION TO GRADUALLY COOLING WATERS... WHICH SHOULD START THE EXTRATROPICAL PROCESS LATER TODAY. STRONG WINDS TO NEAR GALE FORCE APPEAR POSSIBLE IN THE CANARY ISLANDS STARTING EARLY MON WITH EXTRATROPICAL VERSION OF DELTA. SCATTERED MODERATE CONVECTION IS FROM 25.5N-29N BETWEEN 25W-33W. ...ITCZ... ITCZ IS CENTERED ALONG 9N13W 9N40W 4N51W. ISOLATED MODERATE CONVECTION IS FROM 2N-5N BETWEEN 10W-20W AND FROM 8N-10N BETWEEN W AFRICA AND 20W. A FEW SHOWERS ARE ALSO WITHIN 90 NM OF 8.5N42W. ...DISCUSSION... GULF OF MEXICO... WEAK WARM FRONT PREVIOUSLY ALONG THE LOUISIANA COAST HAS DISSIPATED. 60-90 NM WIDE BAND OF SHOWERS EXTENDS FROM NEAR 28N87W IN THE NE GULF TO NEAR PENSACOLA FLORIDA. THIS ACTIVITY IS OCCURRING AHEAD OF A WEAK SHORTWAVE SHOOTING NEWARD ACROSS NE TEXAS INTO ARKANSAS. OTHERWISE THE SUBTROPICAL JET EXTENDS FROM SE MEXICO NEAR 21N97W NE INTO THE FLORIDA PANHANDLE NEAR TALLAHASSEE WITH SCATTERED HIGH CLOUDS AND INCREASING MOISTURE WITHIN 120 NM OF THE JET. OVERCAST LOW CLOUDS AND ISOLATED SHOWERS ARE IN THE SRN GULF OF MEXICO S OF 27N E OF 88W DIMINISHING OVER THE STRAITS OF FLORIDA. THESE CLOUDS ARE ASSOCIATED WITH A SURGE IN LOW-LEVEL MOISTURE FROM A CARIBBEAN SURFACE TROUGH. THIS AREA OF CLOUDS IS EXPECTED TO CONTINUE MOVING NORTHWARD AND COULD ADD TO THE CLOUDINESS OVER SW FLORIDA TODAY AND SOME SHOWERS OVER CENTRAL FLORIDA NORTHWARD THRU N FLORIDA INCLUDING THE W COAST OVERNIGHT TONIGHT. A COLD FRONT IS EXPECTED TO MOVE INTO THE NW GULF ON MON...THOUGH LIMITED UPPER DYNAMICS AND MOISTURE SHOULD KEEP THE WESTERN GULF MOSTLY DRY DURING THE FRONTAL PASSAGE. A FEW TSTMS WILL LIKELY BREAK OUT BY TUE IN THE E GULF AS THE FRONT ENCOUNTERS DEEPER MOISTURE. CARIBBEAN SEA... WEAK SURFACE TROUGH EXTENDS FROM E HONDURAS NEAR 15N85W TO THE YUCATAN CHANNEL NEAR 22N86W MOVING NW. ISOLATED MODERATE CONVECTION IS FROM 16N-22N BETWEEN 78W-85W. RAIN IS EXPECTED FOR W CUBA LATER TODAY... POSSIBLY SPREADING INTO THE NE TIP OF YUCATAN THIS AFTERNOON. FURTHER E...15-20 KT TRADEWINDS ARE NOTED E OF 78W ALONG WITH ISOLATED SHOWERS FROM 13.5N-16N BETWEEN 68W-77W. DRIER AIR IS FILTERING INTO THE NE CARIBBEAN.. WITH DEWPOINTS BELOW 70F OBSERVED AT A FEW STATIONS IN THE LEEWARD ISLANDS. A CONTINUATION OF NLY WINDS SHOULD OCCUR OVER THE E CARIBBEAN WITH DEWPOINTS PERHAPS INTO THE MIDDLE 60S FILTERING IN BY EARLY WEEK AS A LARGE LOW PRESSURE AREA FORMS OVER THE CENTRAL ATLC. IN THE UPPER LEVELS... UPPER RIDGING DOMINATES THE AREA WITH A HIGH CENTER NEAR JAMAICA. STRONG SUBSIDENCE IS PRACTICALLY EVERYWHERE SAVE NEAR THE WEAK SURFACE TROUGH IN THE NW CARIBBEAN. SHOWERS MAY BEGIN TO RETURN TO CENTRAL AMERICA BY MID-WEEK AS DEEP-LAYERED MOISTURE INCREASES. WEAK LOW-LEVEL TROUGH IS N OF PUERTO RICO ALONG 19N59W TO 21N64W AND COULD ENHANCE LOW-TOPPED SHOWERS LATER TODAY FOR THE LEEWARD ISLANDS INTO PUERTO RICO. ATLANTIC OCEAN... SCATTERED STRATOCUMULUS CLOUDS DOT ALMOST THE ENTIRE AREA N OF 20N W OF 40W WITH BROKEN HIGH CLOUDS N OF 28N W OF BERMUDA. OTHER HIGH CLOUDS N OF 26N BETWEEN 50W-60W ARE OCCURRING AHEAD OF AN UPPER LOW DROPPING INTO THE AREA NEAR 33N57W. THIS UPPER LOW SHOULD MOVE SE AND INTERACT WITH A WEAK TROUGH LOCATED NW OF DELTA IN ADDITION TO A SMALL UPPER LOW NEAR 32N46W... AND FORM INTO AN EXTRATROPICAL LOW. COMPUTER MODELS ARE SUGGESTING THAT AROUND TUE/WED... SOME TRANSITION TO A SUBTROPICAL CYCLONE MIGHT OCCUR OVER MARGINAL SST'S. HOWEVER MODELS ARE NOT CONSISTENT ON WHETHER THE SYSTEM WILL EVENTUALLY ACQUIRE SOME SUBTROPICAL (OR EVEN TROPICAL) CHARACTERISTICS. BLOCKING AT HIGH LATITUDES SEEMS TO FAVOR ANOTHER SUBTROPICAL CYCLONE EFFORT THOUGH. ELSEWHERE...TROUGH IS SWINGING THRU THE CENTRAL ATLC NEAR 24N45W TO 17N53W WITH SOME COLD-AIR INSTABILITY NEAR THE TROUGH PRODUCING ISOLATED TSTMS WITHIN 90 NM OF 23N46W... PLUS ISOLATED TSTMS N OF 28N BETWEEN 40W-50W. SHOWERS NEAR 13N38W HAVE DISSIPATING THOUGH LIFT FROM AN ASSOCIATED LARGE MEAN TROUGH COVERING THE CENTRAL ATLC FROM ITS EASTERN EXTENT NEAR DELTA RANGING WESTWARD TO ABOUT 65W COULD ALLOW FOR A COMEBACK LATER TODAY. UPPER RIDGING CONTINUES OVER THE E ATLC NEAR THE CAPE VERDE ISLANDS NNE INTO WESTERN SAHARA. LARGE AREA OF CIRRUS DEBRIS CLOUDS IS N OF 22N BETWEEN DELTA AND AFRICA FROM THE TROPICAL CYCLONE'S TSTMS AND UPPER LIFT FROM THE TROUGH. OTHERWISE IN THE TROPICAL ATLC STRONG SUBSIDENCE IS ALLOWING ONLY A FEW CLOUDS S OF 20N W OF 30W. $$ BLAKE