000 AXNT20 KNHC 111728 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED FEB 11 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... A DEEPENING LOW ANALYZED AT 986 MB CENTERED NEAR 35N67W EXTENDS INFLUENCE INTO THE SW NORTH ATLC REGION N OF 20N BETWEEN 55W- 80W. WAVES OF ENERGY CONTINUE TO ROTATE CYCLONICALLY ACROSS THE SOUTHERN PERIPHERY OF THE LOW AS A PAIR OF COLD FRONTS EXTEND INTO THE DISCUSSION AREA. GIVEN THE OVERALL STRONG PRESSURE GRADIENT...GALE FORCE WINDS ARE OCCURRING GENERALLY N OF 29N BETWEEN 71W-76W...AS WELL AS N OF 28N BETWEEN 59W AND 62W. THIS AREA WILL TRANSLATE E-SE DURING THE NEXT 18 HOURS AS THE COMPLEX AREA OF LOW PRESSURE MOVES E-NE. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 09N13W TO 04N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N20W TO 01N30W TO 03N44W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION ARE FROM 03N-07N BETWEEN 09W-21W. SCATTERED MODERATE CONVECTION IS FROM 02S-03N BETWEEN 23W-37W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL RIDGING EXTENDS ACROSS THE GULF OF MEXICO. A VERY DRY AND STABLE AIRMASS COVERS THE BASIN WITH PATCHES OF STRATOCUMULUS DUE TO COOL AIR IN THE LOW LEVELS MAINLY OVER THE EASTERN BASIN. SURFACE HIGH PRESSURE WELL NORTH OF THE BASIN IS PROVIDING WEAK ANTICYCLONIC FLOW AT THE SURFACE. E TO NE WINDS OF 5 TO 10 KT COVER THE EASTERN GULF. E TO SE WINDS AROUND 10 KT COVER THE WESTERN GULF. RE-ENFORCING HIGH PRESSURE WILL BUILD ACROSS THE GULF FROM THE NW STARTING THURSDAY AND WILL DOMINATE THE BASIN THROUGH FRIDAY. CARIBBEAN SEA... WEST-SOUTHWESTERLY FLOW ALOFT PREVAILS OVER MUCH OF THE CARIBBEAN BASIN THIS MORNING WITH A PAIR OF COLD FRONTS ANALYZED ACROSS THE NW AND NORTH-CENTRAL CARIBBEAN. THESE FRONTS EXTEND FROM A STRONG LOW PRESSURE SYSTEM OVER THE WESTERN ATLANTIC. THE WESTERNMOST FRONT ENTERS THE CARIBBEAN THROUGH THE WINDWARD PASSAGE TO 18N83W. THE EASTERNMOST FRONT CROSSES THE DOMINICAN REPUBLIC NEAR 19N69W AND EXTENDS TO 15N77W. ISOLATED SHOWERS ARE WITHIN 50 NM OF EITHER SIDE OF THE COLD FRONTS. NW WINDS OF 15 TO 20 KT ARE ACROSS THE NW CARIBBEAN NW OF THE EASTERNMOST FRONT. SE TO SW WINDS OF 15 TO 20 KT COVER THE EASTERN CARIBBEAN. THE COLD FRONTS ARE FORECAST TO MERGE LATER TONIGHT. THE PORTIONS OF THE FRONTS OVER THE CARIBBEAN WILL DISSIPATE BY THURSDAY NIGHT. ...HISPANIOLA... A COLD FRONT IS PASSING OVER THE DOMINICAN REPUBLIC WHICH IS PROVIDING MOISTURE AND LIFT FOR ISOLATED SHOWERS ACROSS THE WESTERN PORTIONS OF THE ISLAND TODAY. ANOTHER COLD FRONT MOVING E ACROSS HAITI THIS EVENING WILL PROVIDE ADDITIONAL FOCUS FOR ISOLATED SHOWERS FOR THE ISLAND OVERNIGHT TONIGHT. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL LOW IS NOTED ON WATER VAPOR IMAGERY CENTERED NEAR 36N65W THAT SUPPORTS A COMPLEX AND LARGE AREA OF LOW PRESSURE OFF THE COAST OF THE CAROLINAS FOCUSED ON A 986 MB LOW CENTERED NEAR 35N67W. A PAIR OF COLD FRONTS EXTEND INTO THE DISCUSSION AREA...THE WESTERN-MOST FRONT EXTENDS FROM 31N65W TO 20N74W...AND THE EASTERN-MOST FRONT FROM 32N60W TO THE DOMINICAN REPUBLIC NEAR 19N69W. A SURFACE TROUGH EXTENDS FROM THE CENTER OF THE LOW TO 27N73W. THE SURFACE TROUGH AND WESTERN FRONT ARE DENOTED BY SURGES OF WINDS AND ARE MAINLY FREE OF CONVECTION. THE EASTERN FRONT REPRESENTS THE SHIFT FROM SOUTHERLY WINDS TO WESTERLIES WITH SCATTERED SHOWERS AND THUNDERSTORMS WITHIN 200 NM E OF THE FRONT. GALE FORCE WINDS ARE OCCURRING BEHIND THE WESTERNMOST FRONT...AND AHEAD OF THE EASTERNMOST FRONT. SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. FARTHER EAST...A 1012 MB SURFACE LOW CENTERED NEAR 27N34W SUPPORTS A SURFACE TROUGH FROM THE LOW TO 23N42W AND A DISSIPATING COLD FRONT TO 26N30W TO 20N36W TO 19N43W. THIS SYSTEM IS LOSING UPPER LEVEL SUPPORT AND ANY ASSOCIATED CONVECTION WITH THIS SYSTEM HAS WEAKENED TO MAINLY SHALLOW SHOWERS WITHIN 100 NM OF THE SURFACE FEATURES. OVER THE NEXT 24 HOURS THE COLD FRONTS OVER THE WESTERN ATLANTIC WILL MERGE INTO ONE COLD FRONT WITH A PRE-FRONTAL TROUGH E OF THE FRONT MOVING E INTO THE CENTRAL ATLANTIC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO