000 AXNT20 KNHC 011758 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI NOV 01 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURE... ...GALE WARNING... NORTHERLY WINDS ARE FORECAST TO INCREASE TO GALE FORCE ON SAT AFTERNOON TO THE S OF 22N W OF 96W AND NW OF A COLD FRONT EXTENDING FROM 26N82W TO 22N88W TO 19N96W. THE FRONT WILL EXTEND FROM 24N80W TO 20N91W TO 18N93W AROUND SUNRISE ON SUN WITH THE AREA OF GALE CONDITIONS NW OF THE FRONT TO 21N WITH THE FRONT EXTENDING FROM 24N80W TO 20N91W TO 18N93W. ...TROPICAL WAVES... .NONE. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS SW OFF THE AFRICAN COAST AT 10N13W TO 06N21W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN INTER-TROPICAL CONVERGENCE ZONE...WHICH THEN TURNS NW TO 07N37W...THEN SW TO THE COAST OF S AMERICA NEAR 05N52W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS NOTED OVER/ALONG THE AFRICAN COAST WITHIN 30 NM EITHER SIDE OF A LINE FROM 03N10E TO 07N02E TO 04N07W. SIMILAR CONVECTION IS OBSERVED TO THE S OF THE MONSOON TROUGH WITHIN 120 NM EITHER SIDE OF A LINE FROM THE AFRICAN COAST AT 06N11W TO 02N22W. SCATTERED MODERATE CONVECTION IS NOTED N OF THE ITCZ WITHIN 30 NM OF A LINE FROM 09N26W TO 07N31W... AND ALSO WELL N OF THE ITCZ WITHIN 45 NM OF 12N27W. ...DISCUSSION... GULF OF MEXICO... AN UPPER SHORTWAVE TROUGH IS ADVANCING ACROSS THE EASTERN CONUS TRAILING THE TROUGH FROM CENTRAL LOUISIANA SW ACROSS NE TEXAS. AN UPPER LEVEL ANTICYCLONE IS OVER CENTRAL MEXICO AT 22N99W WITH AN UPPER RIDGE EXTENDING NE TO A CREST OVER THE CENTRAL GULF OF MEXICO AT 26N87W. THIS SETS UP AN AREA OF UPPER DIFFLUENCE JUST AHEAD OF THE ASSOCIATED SURFACE COLD FRONT THAT EXTENDS FROM THE EXTREME WESTERN PANHANDLE TO EXTREME SE TEXAS. THE COLD FRONT IS PRECEDED BY A PRE-FRONTAL TROUGH...AND A SW-W 15-25 KT WIND SHIFT ROUGHLY 60 NM AHEAD OF THE FRONT. CONVECTION BURST NEAR 26N94W AROUND SUNRISE THIS MORNING WITH EVIDENCE OF A MESO- HIGH FORMING TO THE NE OF THE OF THE TSTMS AT 27N93W...THUS A SQUALL LINE WAS ANALYZED. MULTI-LAYERED BROKEN TO OVERCAST CLOUDS ARE OBSERVED WITHIN 420 NM E OF THE FRONT. DEEP LAYERED DRY AIR IS INDICATED TO THE W OF THE UPPER SHORTWAVE. REFER TO THE SPECIAL FEATURES PARAGRAPH FOR GALE CONDITIONS EXPECTED ON SAT. FURTHER S...THE NORTHERN EXTENSION OF A TROUGH IS ANALYZED TO THE S OF 23N ALONG 90.5W AND IS MOVING SLOWLY W. CONVECTION IS CURRENTLY ENHANCED ONLY OVER THE PACIFIC WATERS ALONG THIS TROUGH. CARIBBEAN SEA... A TROPICAL UPPER TROPOSPHERIC TROUGH OR TUTT...EXTENDS FROM THE SUBTROPICAL ATLC SW INTO THE CARIBBEAN FROM EASTERN CUBA INTO AN EMBEDDED UPPER CYCLONE AT 13N78W...WITH THE TROUGH CONTINUING S ACROSS PANAMA. VERY DRY UPPER AIR IS INDICATED TO THE W OF THIS TROUGH AND IS SUPPRESSING CLOUDS AND CONVECTION TO ONLY SMALL CLUSTERS ACROSS THE NW WATERS FROM 18-22N BETWEEN 80-88W. AN UPPER ANTICYCLONE IS OBSERVED OVER THE ATLC AT 07N56W...WITH AN UPPER RIDGE EXTENDING NW ACROSS THE EASTERN CARIBBEAN TO A GENTLE CREST OVER THE SE BAHAMAS. AT THE LOWER LEVELS A SURFACE TROUGH IS ANALYZED TO THE N OF 16N ALONG 66W AND ACROSS CENTRAL PUERTO RICO. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS ENHANCED ACROSS THE CENTRAL CARIBBEAN BETWEEN 63-76W. A SECOND LOW LEVEL TROUGH IS APPROACHING THE E CARIBBEAN ALONG 60W...WITH SCATTERED MODERATE ISOLATED STRONG CONVECTION OBSERVED WITHIN 60 NM W AND WITHIN 150 NM E OF THE TROUGH AXIS. THE RESULTANT DEBRIS MOISTURE FROM THE CONVECTIVE AREAS IS ADVECTED NE AND E WITHIN THE UPPER RIDGE...BASICALLY ACROSS THE AREA E OF 76W. HISPANIOLA... BROKEN TO LOCALLY OVERCAST MULTILAYERED CLOUDS WITH ISOLATED SHOWERS AND TSTMS...WILL CONTINUE ACROSS HISPANIOLA AND THE ADJACENT COASTAL WATERS TODAY AND SAT. CONVECTION MAY INCREASE TONIGHT AS A LOW LEVEL TROUGH CURRENTLY OVER PUERTO RICO MOVES W THROUGH THE MONA PASSAGE AND ACROSS EASTERN HISPANIOLA. IF THE CONVECTIVE CELLS TRAIN ACROSS ANY EASTERN PORTION OF THE ISLAND...LOCALIZED FLOODING AND LANDSLIDES MAY OCCUR. ATLANTIC OCEAN... A VIGOROUS UPPER SHORTWAVE IS APPROACHING THE SE CONUS PRECEDED BY STRONG UPPER SOUTHWESTERLY FLOW ADVECTING DENSE UPPER MOISTURE ACROSS THE DISCUSSION AREA TO THE W OF A LINE FROM 27N80W TO 32N75W. A MID TO UPPER LEVEL TROUGH DISSECTS THE SUBTROPICAL ATLC FROM 34N54W THROUGH AN EMBEDDED UPPER CYCLONE AT 31N60W TO 27N63W...WITH THE TROUGH CONTINUING SW ACROSS EASTERN CUBA. AN UPPER ANTICYCLONE IS CENTERED W OF THE TROUGH NEAR 29N71W WITH AN UPPER RIDGE EXTENDING SW ACROSS SE FLORIDA. VERY DRY UPPER AIR IS INDICATED ACROSS THE DISCUSSION AREA BETWEEN THESE TWO UPPER TROUGHS. AN UPPER ANTICYCLONE IS CENTERED NEAR 29N35W WITH ITS ANTICYCLONIC ENVELOPE...AND DRY UPPER AIR...DOMINATING THE AREA N OF 22N BETWEEN 24-40W WITH ONLY THIS LINES OF CUMULUS OBSERVED. TO THE W IS A VERY DENSE UPPER LEVEL MOISTURE PLUME ADVECTED NE FROM THE CARIBBEAN WITHIN 420 NM EITHER SIDE OF A LINE FROM 17N65W TO BEYOND 32N45W. THE UPPER LEVELS OF THE EASTERN ATLC IS DOMINATED BY ANOTHER UPPER TROUGH EXTENDING THROUGH UPPER CYCLONES AT 32N02W...21N19W AND 14N33W. THE UPPER LEVEL CYCLONE AT 14N33W IS PROGRESSING W ACROSS THE TROPICS ACCOMPANIED DRY UPPER AIR FROM 10-22N BETWEEN 35-50W. A BROAD UPPER RIDGE EXTENDS NW ACROSS WESTERN AFRICA. UPPER MOISTURE ORIGINATING OVER S AMERICA AND REINFORCED WITH CONVECTIVE MOISTURE OVER THE CENTRAL AND E CARIBBEAN...IS ADVECTED E ACROSS THE TROPICS S OF 10N BETWEEN 48-28W...THEN IT MERGES WITH DEBRIS MOISTURE ASSOCIATED WITH THE MONSOON TROUGH CONVECTION PREVIOUSLY MENTIONED...WITH THE DENSE PLUME ADVECTED E AND NE ACROSS MOST OF CENTRAL AFRICA. AT THE LOWER LEVELS A RIDGE EXTENDS ACROSS THE AREA N OF 15N BETWEEN 15-45W WITH LOCALLY BROKEN OBSERVED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NELSON