000 AXNT20 KNHC 042351 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST FRI DEC 04 2015 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 2345 UTC. ...ITCZ/MONSOON TROUGH... THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 02N AND THE PRIME MERIDIAN TO 05N14W TO 04N20W TO 05N30W TO THE COAST OF BRAZIL NEAR 01N45W. SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 03N BETWEEN 05W-15W...AND FROM 02N-08N BETWEEN 13W- 19W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL SOUTHWESTERLY FLOW ALOFT IS COUPLED WITH MID-LEVEL ENERGY ASSOCIATED WITH A SHORTWAVE TROUGH AXIS EXTENDING OVER NE FLORIDA SW TO OVER EAST-CENTRAL MEXICO AS OF 04/2100 UTC. THESE CONDITIONS ARE SUPPORTING A SURFACE STATIONARY FRONT MEANDERING FROM THE SW TIP OF THE FLORIDA PENINSULA JUST N OF THE MIDDLE KEYS TO JUST N OF THE WESTERN TIP OF CUBA NEAR 23N85W. A CARIBBEAN SURFACE TROUGH STRETCHES FROM A 1015 MB LOW NEAR 17N86W NE TO THE STRAITS OF FLORIDA NEAR 23.5N83W. THE COMBINATION OF THE FRONT SERVING AS A FOCUSING MECHANISM FOR SURFACE CONVERGENCE...ALONG WITH DEEP MIDDLE AND UPPER LEVEL MOISTURE IN SW FLOW IS BRINGING AREAS OF RAIN WITH EMBEDDED SCATTERED TO SHOWERS AND TSTMS WHICH ARE CONFINED TO THE FAR SE PORTION OF THE GULF AND S FLORIDA BETWEEN THE MIDDLE LEVEL TROUGH AXIS AND THE FRONTAL BOUNDARY. MOST MIDDLE TO UPPER LEVEL CLEARING IS NOTED ON WATER VAPOR IMAGERY ACROSS THE REMAINDER OF THE GULF EARLY THIS EVENING. MAINLY FRESH TO STRONG N-NE WINDS PREVAIL TO NW OF THE FRONTAL BOUNDARY ACROSS THE SE HALF OF THE BASIN...WITH LIGHTER WINDS IN THE MODERATE BREEZE RANGE ACROSS THE NW HALF OF THE GULF TO THE TEXAS COAST. THE FRONT WILL BE SLOW TO SLIDE GRADUALLY EASTWARD THROUGH SATURDAY EXTENDING FROM THE STRAITS OF FLORIDA TO THE YUCATAN PENINSULA. A NEW COLD FRONT IS FORECAST TO ENTER THE NW GULF SUN MORNING...SWEEPING ACROSS THE BASIN THROUGH SUN EVENING. CARIBBEAN SEA... UPPER LEVEL RIDGING IS NOTED ON WATER VAPOR IMAGERY OVER THE WESTERN CARIBBEAN WITH THE AXIS ANCHORED NEAR 12N82W EXTENDING N- NE TO BEYOND CENTRAL CUBA NEAR 22N79W. UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE RIDGING ALOFT IN TANDEM WITH A WEAK 1015 MB SURFACE LOW AT 17N86W NE TO THE STRAITS OF FLORIDA NEAR 23.5N83W AS OF 04/2100 UTC CONTINUES TO PROVIDE THE FOCUS FOR SCATTERED SHOWERS AND TSTMS ACROSS THE NW CARIBBEAN N OF 18N BETWEEN 78W- 82W...AS WELL AS FROM 15N TO 18N BETWEEN 82W-84W. THIS AREA HAS EXPERIENCED PERSISTENT SURFACE TROUGHING ACROSS THE NW CARIBBEAN DURING THE PAST SEVERAL DAYS AS A FRONTAL BOUNDARY CONTINUES TO DRIFT ACROSS THE SE GULF OF MEXICO. FRESH NORTHERLY FLOW IS NOTED W OF THE SURFACE TROUGH AXIS UP ALONG AND OFFSHORE OF THE EASTERN COAST OF THE YUCATAN PENINSULA. ELSEWHERE...AN UPPER LEVEL LOW IS CENTERED OVER THE DOMINICAN REPUBLIC NEAR 15.5N70W WITH A RELATED TROUGH EXTENDING SSW TO 15N71W TO JUST N OF THE COAST OF COLOMBIA NEAR 13N72W. MIDDLE TO UPPER LEVEL MOISTURE ADVECTION IS OCCURRING ON SOUTHWESTERLY WINDS E OF THE TROUGH AXIS ALONG 70W-72W. SCATTERED SHOWERS AND ISOLATED TSTMS NOTED E OF THE TROUGH FROM 11N-17N. WITH THE DEEP MOISTURE IN PLACE E OF THE TROUGH CHANGING LITTLE THROUGH THE NEXT 48 HOURS...AND COMBINING WITH THE PREVAILING TRADES...EXPECT THE SHOWER AND TSTM ACTIVITY TO LAST THROUGH THE NEXT 48 HOURS OR SO. OTHERWISE...FRESH TO STRONG TRADES PREVAIL ACROSS MOST OF THE BASIN...EXCEPT W OF 80WAND E OF THE SURFACE TROUGH AXIS WHERE BROAD GENTLE CYCLONIC FLOW WILL PREVAIL. ...HISPANIOLA... THE AFOREMENTIONED UPPER LEVEL LOW OVER THE DOMINICAN REPUBLIC NEAR 15.5N70W CONTINUES TO PROVIDE FOR AMPLE LOW-LEVEL MOISTURE MAINLY E OF 70W-71W WITH DRIER AND MORE STABLE AIR IN PLACE W OF 71W. MODEL GUIDANCE SUGGESTS THAT THE UPPER LOW WILL SLOWLY DRIFT EASTWARD AND WEAKEN TO A TROUGH BY SUN EVENING AS UPPER LEVEL RIDGING SETTLES IN WITH A DRYING TREND SPREADING EASTWARD IN ITS WAKE. ATLANTIC OCEAN... UPPER LEVEL TROUGHING EXTENDS FROM OVER THE CANADIAN MARITIMES SW TO OVER THE U.S. MID-ATLANTIC REGION WITH SHORTWAVE TROUGHING AND VERY DRY AND STABLE AIR PREVAILING OVER THE CAROLINAS SW TO THE CENTRAL GULF OF MEXICO. AS OF 04/2100 UTC THE TROUGHING SUPPORTS A COLD FRONT ANALYZED FROM NEAR 31N63W SW TO A WEAK 1018 MB SURFACE LOW AT 28N77W...THEN STRADDLES THE SE FLORIDA COAST AS A STATIONARY FRONT AND SW TO JUST N OF THE FLORIDA KEYS. A JET STREAM BRANCH STRETCHES FROM THE SW GULF OF MEXICO NE TO ACROSS S FLORIDA...AND NE TO N OF THE AREA NEAR 32N65W. RIPPLES OF SHORTWAVE ENERGY ALONG THE JET STREAM ARE FLOWING NE IN THE VICINITY OF THE FRONT WHICH ARE RESULTING IN WIDESPREAD AREAS OF RAIN WITH EMBEDDED SCATTERED SHOWERS AND TSTMS OBSERVED FROM 26N-31N BETWEEN 70W-77W...AND ALSO S OF 28N W OF 77W TO JUST SE OF THE S FLORIDA COAST. SIMILAR ACTIVITY WITH POSSIBLE GUSTY WINDS IS VERY ACTIVE ACROSS THE STRAITS OF FLORIDA EARLY THIS EVENING. THE INTERACTION BETWEEN THE FRONT AND STRONG HIGH PRESSURE TO ITS N WILL BRING FRESH TO NEAR GALE FORCE NE-E WINDS OVER THE WATERS TO THE N OF THE FRONT INTO SUN BEFORE DIMINISHING. THE COLD FRONT PORTION OF THE BOUNDARY WILL REACH FROM NEAR 32N65W TO NEAR 28N73W BY SUN EVENING. OTHERWISE... SURFACE HIGH PRESSURE PREVAILS ACROSS THE REMAINDER OF THE CENTRAL AND EASTERN ATLC ANCHORED BY A 1033 MB HIGH CENTERED SW OF THE AZORES NEAR 37N29W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LEWITSKY