000 AXNT20 KNHC 172354 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST TUE DEC 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ/MONSOON TROUGH... THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM THE AFRICAN COAST NEAR 08N13W TO 04N30W TO 0N49W. SCATTERED MODERATE CONVECTION IS WITHIN 200 NM EITHER SIDE OF THE AXIS E OF 24W AND WITHIN 170 NM BETWEEN 24W-39W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY DEPICT A BROAD MIDDLE TO UPPER LEVEL TROUGH OVER THE EASTERN CONUS WITH A BASE EXTENDING TO THE SW GULF AND IS PROVIDING MOSTLY DRY AIR AND STABLE CONDITIONS ALOFT TO MUCH OF THE BASIN. AT THE SURFACE...RIDGING FURTHER SUPPORTS THE STABILITY ALOFT ANCHORED BY A 1025 MB HIGH ON THE NW GULF NEAR 28N94W. THE RIDGE PROVIDES NORTHEASTERLY WINDS UP TO 15 KT WHICH ARE EXPECTED TO PREVAIL THROUGH WEDNESDAY AFTERNOON. AS THE HIGH PRESSURE AREA IS REINFORCED AND BEGINS TO SHIFT EASTWARD LATE WEDNESDAY INTO EARLY THURSDAY...E-SE FLOW WILL ESTABLISH ACROSS THE BASIN. AN AREA OF LOW PRESSURE IS FORECAST ACROSS THE WESTERN GULF ON FRI AFTERNOON ASSOCIATED WITH THE NEXT COLD FRONT EXPECTED TO EMERGE OFF THE TEXAS AND LOUISIANA COASTS EARLY SUNDAY. CARIBBEAN SEA... A BROAD MIDDLE TO UPPER LEVEL TROUGH EXTENDING ACROSS THE EASTERN CONUS TO THE WESTERN N ATLC W OF 60W SUPPORTS A FRONTAL SYSTEM ANALYZED AS A STATIONARY FRONT FROM CENTRAL CUBA NEAR 21N80W TO 19N85W TO THE COASTLINE OF NORTHERN HONDURAS NEAR 16N86W. LOW-LEVEL MOISTURE CONVERGENCE ALONG THE FRONTAL BOUNDARY AND ALONG THE COASTLINES FROM HONDURAS TO COSTA RICA SUPPORT SCATTERED SHOWERS AND ISOLATED TSTMS N OF 10N W OF 78W. IN THE SW BASIN S OF 10N...SCATTERED SHOWERS AND ISOLATED TSTMS ARE BEING ENHANCED BY THE MONSOON TROUGH THAT EXTENDS ACROSS SOUTHERN PANAMA TO A 1006 MB LOW NEAR 08N74W. BOTH SSMI TPW AND WATER VAPOR IMAGERY DEPICT DRY AIR ACROSS THE CENTRAL AND EASTERN BASIN WHICH CONTINUES TO SUPPORT FAIR WEATHER CONDITIONS. THE STATIONARY FRONT OVER THE NW BASIN IS EXPECTED TO DISSIPATE BY WED AFTERNOON. HISPANIOLA... CURRENTLY RELATIVELY DRY AIR AND STABLE CONDITIONS AT THE MIDDLE AND LOWER LEVELS AS DEPICTED IN WATER VAPOR AND SSMI TPW IMAGERY...RESPECTIVELY. TRADEWINDS ARE EXPECTED TO CONTINUE ACROSS THE ISLAND WITH WINDS INCREASING SLIGHTLY THURSDAY INTO FRIDAY DUE TO A STRENGTHENING PRESSURE GRADIENT ACROSS THE REGION. FAIR WEATHER IS EXPECTED THROUGHOUT EARLY WED...HOWEVER CONDITIONS MAY DEGRADE IN THE AFTERNOON AS A VERY MOIST AIRMASS IS EXPECTED TO MOVE ACROSS THE ISLAND. ATLANTIC OCEAN... A BROAD MIDDLE TO UPPER LEVEL LONGWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER THE EASTERN CONUS THAT SUPPORTS A STATIONARY FRONT ANALYZED INTO THE DISCUSSION AREA NEAR 30N63W EXTENDING SW TO THE BAHAMAS NEAR 24N75W THEN ACROSS CENTRAL CUBA AND INTO THE NW CARIBBEAN SEA. ISOLATED SHOWERS ARE OCCURRING WITHIN 100 NM EITHER SIDE OF THE FRONT. THE FRONT IS FORECAST TO GRADUALLY WEAKEN AND BECOME DIFFUSE BY EARLY WEDNESDAY ACROSS THE SW NORTH ATLC. FARTHER EAST...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A LARGE AREAL SURFACE RIDGE ANCHORED BY A 1031 MB HIGH CENTERED NEAR 34N28W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR