000 AXNT20 KNHC 052357 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... A COLD FRONT EXTENDS FROM 32N48W TO 29N60W WHERE IT BECOMES STATIONARY AND CONTINUES THROUGH 29N73W TO 27N76W TO THE STRAITS OF FLORIDA. NORTH OF THE FRONT...A STRONG PRESSURE GRADIENT PERSISTS BETWEEN LOWER PRESSURE ACROSS THE GREATER ANTILLES AND BAHAMAS...AND A STRONG HIGH PRESSURE SYSTEM AT 1040 MB CENTERED OVER CENTRAL PENNSYLVANIA. LATE MORNING SCATTEROMETER DATA CONTINUED TO INDICATE A 120 NM WIDE SWATH OF GALE FORCE WINDS DIRECTLY NORTH OF THE FRONT. THESE CONDITIONS ARE EXPECTED TO PERSIST THROUGH 06/0600 UTC. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. A STRENGTHENED PRESSURE GRADIENT IS EXPECTED TO MATERIALIZE ACROSS THE SW CARIBBEAN SEA WITHIN CLOSE PROXIMITY TO THE COAST OF COLOMBIA BY 06/0600 UTC. THESE NEAR GALE TO GALE FORCE WINDS ARE EXPECTED TO PERSIST FOR 6-12 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 02N AND THE PRIME MERIDIAN TO 03N10W TO LOW PRES NEAR 05N25W 1011 MB TO 05N35W. SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 03N BETWEEN 06W-20W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER LEVEL TROUGHING OVER THE SE CONUS IS SUPPORTING A STATIONARY FRONT WHICH EXTENDS FROM THE STRAITS OF FLORIDA TO JUST N OF THE WESTERN COAST OF CUBA TO THE YUCATAN CHANNEL. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING GENERALLY WITHIN 60-90 NM EITHER SIDE OF THE FRONT INCLUDING THE APPROACH TO THE YUCATAN CHANNEL. OTHERWISE...THE REMAINDER OF THE BASIN IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1040 MB HIGH CENTERED ACROSS CENTRAL PENNSYLVANIA EXTENDING AN AXIS S-SW TO THE TEXAS COASTAL PLAIN THEN SOUTHWARD TO A 1028 MB HIGH CENTERED NEAR TAMPICO MEXICO. UPPER LEVEL DRYING AND MANY STABLE CONDITIONS DOMINATE THE BASIN AWAY FROM THE STATIONARY FRONT. PRIMARY CLOUD COVER IS CONTINUING TO BE A BROKEN TO OVERCAST STRATOCUMULUS DECK UNDER THE RELATIVELY STABLE CONDITIONS. FRESH TO STRONG NE WINDS PREVAIL E OF 90W WHILE MAINLY MODERATE NE-E WINDS CONTINUE W OF 90W. THIS OVERALL WIND REGIME IS EXPECTED TO PERSIST THROUGH EARLY SUNDAY. EXPECT MODERATE TO FRESH N-NE WINDS ACROSS THE BASIN BY SUN NIGHT THROUGH MONDAY AFTERNOON... EXCEPT NEAR GALE FORCE ALONG AND OFFSHORE OF THE COAST OF VERACRUZ SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON. CARIBBEAN SEA... UPPER LEVEL RIDGING IS NOTED ON WATER VAPOR IMAGERY OVER THE WESTERN CARIBBEAN WITH AXIS ANCHORED NEAR 13N84W EXTENDING N-NE TO BEYOND EASTERN CUBA NEAR 22N78W. UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE RIDGING ALOFT IN TANDEM WITH A STATIONARY FRONT ANALYZED FROM THE YUCATAN CHANNEL NEAR 22N85.5W TO THE GULF OF HONDURAS NEAR 16N87W IS PROVIDING FOCUS FOR SCATTERED SHOWERS AND TSTMS ACROSS THE NW CARIBBEAN N OF 15N W OF 81W. SCATTERED SHOWERS AND TSTMS CONTINUE TO THE SE ALONG THE EASTERN HONDURAS...NICARAGUA AND WESTERN PANAMA COASTS FROM 09N-16N WHERE A SURFACE TROUGH STRETCHES. ELSEWHERE...A NORTH-SOUTH ELONGATED UPPER LEVEL LOW IS CENTERED NEAR 15.5N70W WITH MIDDLE TO UPPER LEVEL MOISTURE NOTED ON WATER VAPOR IMAGERY ACROSS THE EASTERN CARIBBEAN E OF 72W. ISOLATED SHOWERS ARE OCCURRING FROM 11N-19N E OF 72W. OTHERWISE...FRESH TO STRONG TRADES PREVAIL ACROSS MOST OF THE BASIN...EXCEPT W OF 82W WHERE THE STATIONARY FRONT IS GENERATING BROAD MODERATE TO FRESH CYCLONIC FLOW. THE STRONGEST TRADES ARE NOTED WITHIN CLOSE PROXIMITY OF THE COAST OF COLOMBIA WITH WINDS INCREASING TO GALE FORCE AS IS DISCUSSED IN THE SPECIAL FEATURES SECTION. ...HISPANIOLA... AN UPPER LEVEL LOW IS CENTERED NEAR 15.5N70W. SATELLITE AND LIGHTNING DATA INDICATE SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS THE ISLAND WITH E-SE FLOW ALOFT AROUND THE UPPER LOW COMBINING WITH OROGRAPHIC LIFTING. THIS ACTIVITY IS LIKELY TO DIMINISH LATER THIS EVENING WITH THE LOSS OF DAYTIME HEATING. THE UPPER LEVEL FEATURE WILL SLOWLY DRIFT EASTWARD BY LATE SUNDAY AND WEAKEN E OF 68W AS UPPER LEVEL RIDGING SETTLES IN WITH AN OVERALL DRYING TREND EXPECTED. ATLANTIC OCEAN... UPPER LEVEL TROUGHING EXTENDS FROM WELL N OF THE AREA NEAR 40N40W TO THE W-SW THROUGH 36N65W THEN TO THE SW TO CENTRAL FLORIDA. THIS TROUGHING SUPPORTS A COLD FRONT ANALYZED FROM 32N48W TO 29N60W WHERE IT BECOMES STATIONARY AND CONTINUES THROUGH 29N73W TO 27N76W TO THE STRAITS OF FLORIDA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING GENERALLY WITHIN 60-120 NM EITHER SIDE OF THE FRONT. STRONG TO GALE NE-E WINDS PERSIST N OF THE FRONT AS IS DESCRIBED IN THE SPECIAL FEATURES SECTION. OTHERWISE...SURFACE RIDGING PREVAILS ACROSS THE CENTRAL ATLC ANCHORED BY A 1024 MB HIGH CENTERED S OF THE AZORES NEAR 32N28W. ACROSS THE EASTERN ATLC...A MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 22N31W SUPPORTING A SURFACE TROUGH FROM 24N30W TO 19N35W. EXTENSIVE CLOUDINESS COVERS THE EASTERN ATLC FROM 14N- 32N E OF 28W DUE TO DIFFLUENT SOUTHWESTERLY FLOW ALOFT. ISOLATED SHOWERS AND TSTMS ARE POSSIBLE ACROSS THIS AREA THROUGH AT LEAST EARLY SUNDAY. 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