000 AXNT20 KNHC 050557 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST SAT DEC 05 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... A STRENGTHENED PRESSURE GRADIENT IS EXPECTED TO MATERIALIZE ACROSS THE SW CARIBBEAN SEA WITHIN CLOSE PROXIMITY TO THE COAST OF COLOMBIA BY 06/0000 UTC. THESE NEAR GALE TO GALE FORCE WINDS ARE EXPECTED TO PERSIST FOR 12 HOURS AND THEN DECREASE TO A RANGE OF 20 TO 30 KT. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N AT THE PRIME MERIDIAN TO 05N17W TO 04N35W TO 01N45W. SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 07N BETWEEN 07W-22W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER LEVEL TROUGHING OVER THE SE CONUS IS SUPPORTING A WEAK AREA OF LOW PRESSURE ACROSS THE SW NORTH ATLC THE STRETCHES ACROSS THE SE GULF WATERS AND REMAINS FOCUSED ALONG A FRONTAL BOUNDARY EXTENDING FROM THE EXTREME SOUTHERN FLORIDA PENINSULA NEAR 25N81W AS STATIONARY TO 23N85W. A SURFACE TROUGH BOUNDARY THEN EXTENDS FROM THE TAIL END OF THE FRONT ACROSS THE YUCATAN CHANNEL INTO A 1013 MB LOW CENTERED IN THE GULF OF HONDURAS. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING GENERALLY S OF 26N E OF 86W...INCLUDING THE APPROACH TO THE YUCATAN CHANNEL. OTHERWISE...THE REMAINDER OF THE BASIN IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1038 MB HIGH CENTERED ACROSS THE OHIO VALLEY EXTENDING AN AXIS S-SW TO COASTAL TEXAS THEN SOUTHWARD TO A 1029 MB HIGH CENTERED NEAR TAMPICO MEXICO. UPPER LEVEL DRYING HAS OCCURRED DURING THE PAST 24 HOURS ACROSS MUCH OF THE GULF WITH PRIMARY CLOUD COVER CONTINUING TO BE A BROKEN TO OVERCAST STRATOCUMULUS DECK INDICATING RELATIVELY STABLE CONDITIONS. FRESH TO STRONG NE WINDS PREVAIL E OF 90W WHILE MODERATE TO FRESH NE WINDS CONTINUE W OF 90W THIS EVENING. THIS OVERALL WIND REGIME IS EXPECTED TO PERSIST THROUGH EARLY SUNDAY. CARIBBEAN SEA... UPPER LEVEL RIDGING IS NOTED ON WATER VAPOR IMAGERY OVER THE WESTERN CARIBBEAN WITH AXIS ANCHORED NEAR 13N80W EXTENDING N-NE TO BEYOND EASTERN CUBA NEAR 25N77W. UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE RIDGING ALOFT IN TANDEM WITH A SURFACE TROUGH ANALYZED FROM THE YUCATAN CHANNEL NEAR 22N85W SOUTHWARD INTO A 1013 MB LOW CENTERED NEAR 17N86W IS PROVIDING FOCUS FOR SCATTERED SHOWERS AND TSTMS ACROSS THE NW CARIBBEAN N OF 16N BETWEEN 78W-88W. SCATTERED SHOWERS AND TSTMS CONTINUE TO THE SE ALONG THE NICARAGUA TO PANAMA COAST FROM 09N-16N BETWEEN 81W- 84W. ELSEWHERE...A NORTH-SOUTH ELONGATED UPPER LEVEL LOW IS CENTERED NEAR 17N70W WITH MIDDLE TO UPPER LEVEL MOISTURE NOTED ON WATER VAPOR IMAGERY ACROSS THE EASTERN CARIBBEAN E OF 71W. ISOLATED SHOWERS ARE POSSIBLE FROM 10N-19N BETWEEN 63W-72W. OTHERWISE...FRESH TO STRONG TRADES PREVAIL ACROSS MOST OF THE BASIN EXCEPT W OF 82W WHERE THE SURFACE TROUGH AXIS IS GENERATING BROAD GENTLE CYCLONIC FLOW. THE STRONGEST TRADES ARE NOTED WITHIN CLOSE PROXIMITY TO THE COAST OF COLOMBIA THIS EVENING. ...HISPANIOLA... AN UPPER LEVEL LOW IS CENTERED NEAR 17N70W THAT CONTINUES TO PROVIDE MOSTLY CLEAR SKIES THIS EVENING WITH POSSIBLE ISOLATED SHOWERS OCCURRING ACROSS THE EASTERN PORTION OF THE REGION. THE UPPER LEVEL FEATURE WILL SLOWLY DRIFT EASTWARD BY LATE SUNDAY AND WEAKEN E OF 68W AS UPPER LEVEL RIDGING SETTLES IN AND THE OVERALL DRYING TREND CONTINUES. ATLANTIC OCEAN... UPPER LEVEL TROUGHING EXTENDS FROM OFFSHORE OF THE CANADIAN MARITIMES SW TO OVER THE CAROLINAS. THE TROUGHING SUPPORTS A STATIONARY FRONT ANALYZED FROM 30N64W WESTWARD INTO A 1019 MB LOW NEAR 29N76W THEN AS A COLD FRONT SW TO THE EXTREME SOUTHERN FLORIDA PENINSULA AND INTO THE SE GULF OF MEXICO. SCATTERED TO WIDESPREAD SHOWERS AND WIDELY SCATTERED TSTMS ARE OCCURRING GENERALLY FROM 22N-31N BETWEEN 71W-80W...AND WITHIN 150 NM NORTH OF THE FRONT E OF 71W. STRONG TO NEAR GALE NE WINDS PERSIST AS A STRONG RIDGE ANCHORS ITSELF ACROSS THE MID-ATLC AND NEW ENGLAND STATES. OTHERWISE...SURFACE RIDGING PREVAILS ACROSS THE CENTRAL ATLC ANCHORED BY A 1033 MB HIGH CENTERED S OF THE AZORES NEAR 36N29W. FINALLY...ACROSS THE EASTERN ATLC...A MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 25N32W THAT SUPPORTS A SURFACE TROUGH EXTENDING SOUTHWARD INTO THE DISCUSSION AREA ALONG 32N23W TO 27N24W. EXTENSIVE CLOUDINESS COVERS THE EASTERN ATLC FROM 10N- 32N E OF 30W DUE TO DIFFLUENT SOUTHWESTERLY FLOW ALOFT. ISOLATED SHOWERS AND TSTMS ARE POSSIBLE ACROSS THIS AREA THROUGH THE OVERNIGHT INTO SATURDAY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN