000 AXNT20 KNHC 180551 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST WED FEB 18 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 0545 UTC. ...SPECIAL FEATURES... ...GALE WARNING FOR THE W ATLC... A GALE WARNING GOES INTO EFFECT AS OF 0600 UTC THIS MORNING N OF 28.5N WITHIN 90 NM SE OF A COLD FRONT OVER THE SOUTHWESTERN N ATLC. THE GALE FORCE WINDS ARE FORECAST TO SHIFT EAST AHEAD OF THE EASTWARD ADVANCING COLD FRONT UNTIL 0600 UTC THURSDAY...WHEN WINDS ARE EXPECTED TO DECREASE BELOW GALE FORCE. PLEASE SEE THE LATEST HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/ FZNT02 KNHC FOR MORE DETAILS. ...GALE WARNING FOR THE GULF OF MEXICO... A GALE WARNING IS IN EFFECT AS OF 0400 UTC THIS MORNING S OF 21N W OF 95W ASSOCIATED WITH THE TIGHT PRESSURE GRADIENT BEHIND THE COLD FRONT PRESENTLY ACROSS THE GULF. THE GALE WINDS ARE FORECAST TO DIMINISH TO BELOW GALE FORCE AT 1800 UTC TODAY. PLEASE SEE THE LATEST HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/ FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 08N13W TO 04N19W WHERE THE ITCZ BEGINS AND CONTINUES TO S OF THE EQUATOR AT 24W TO 2S31W. NO SIGNIFICANT CONVECTION IS NOTED. ...DISCUSSION... GULF OF MEXICO... A STRONG UPPER TROUGH IS SWINGING EASTWARD ACROSS EASTERN TEXAS AND THE NW GULF. THIS TROUGH SUPPORTS A COLD FRONT THAT EXTENDS ACROSS CENTRAL FL NEAR 28N82W AND ACROSS THE GULF TO 25N89W TO THE COAST OF MEXICO NEAR 18N94W. NUMEROUS SHOWERS ARE WITHIN 120 NM OF EITHER SIDE OF THE COLD FRONT. ADDITIONAL UPPER LEVEL ENERGY ROUNDING THE BASE OF THE TROUGH OVER THE GULF IS SUPPORTING SCATTERED MODERATE CONVECTION WITH THUNDERSTORMS FROM 22N TO 25N BETWEEN 82W AND 87W. HIGH PRESSURE BUILDING ACROSS THE GULF NW OF THE FRONT IS PRODUCING GALE FORCE WINDS OVER PORTIONS OF THE SW GULF. SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. N TO NW WINDS OF 15 TO 20 KT ARE ELSEWHERE NW OF THE FRONT OVER THE GULF. SOUTHERLY WINDS OF 5 TO 15 KT ARE SE OF THE FRONT. OVER THE NEXT 24 HOURS THE FRONT WILL MOVE SE AND WILL EXIT THE SE GULF AND MOVE OVER THE NW CARIBBEAN AND FL STRAITS WITH SHOWERS AND POSSIBLE CONVECTION. CARIBBEAN SEA... A LARGE UPPER LEVEL RIDGE CENTERED OVER CENTRAL AMERICA EXTENDS A RIDGE AXIS OVER THE CARIBBEAN BASIN TO HISPANIOLA AND OVER THE WESTERN ATLC. SUBSIDENCE FROM THE RIDGE IS SUPPORTING MAINLY FAIR WEATHER ACROSS THE BASIN THIS MORNING...OTHER THAN SCATTERED SHOWERS OVER THE E CARIBBEAN AND NW CARIBBEAN. 20 TO 25 KT EASTERLY TRADE WINDS COVER THE CENTRAL AND EASTERN CARIBBEAN. MAINLY SE WINDS OF 15 TO 20 KT COVER THE W CARIBBEAN. SHOWERS AND THUNDERSTORMS WILL ENTER THE NW CARIBBEAN LATER THIS MORNING AHEAD OF A SE ADVANCING COLD FRONT CURRENTLY CROSSING THE GULF OF MEXICO. THE FRONT WILL ENTER THE CARIBBEAN TONIGHT AND WILL EXTEND FROM CENTRAL CUBA TO BELIZE BY THURSDAY MORNING WITH SHOWERS AND POSSIBLY THUNDERSTORMS. ...HISPANIOLA... ISOLATED TRADE WIND SHOWERS IN THE LOW LEVEL MOISTURE ARE OVER THE ISLAND TONIGHT. ISOLATED SHOWERS WILL CONTINUE TO BE POSSIBLE THROUGH TONIGHT WITH AN INCREASE IN SHOWER ACTIVITY ON THURSDAY AS A COLD FRONT APPROACHES THE ISLAND FROM THE NW. ATLANTIC OCEAN... UPPER LEVEL RIDGING OVER THE WESTERN ATLC IS SHIFTING EASTWARD AS A DEEP TROUGH OVER THE US SLIDES EAST. THE UPPER TROUGH SUPPORTS A 1008 MB LOW OVER THE W ATLC NEAR 33N74W. A COLD FRONT EXTENDS SW FROM THE LOW TO CENTRAL FL NEAR 28N82W. NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 100 NM NW OF THE FRONT AND 150 NM SE OF THE FRONT. AS OF 0600 UTC...GALE FORCE WINDS ARE FORECAST TO DEVELOP E OF THE FRONT. SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. TO THE EAST OF THE UPPER LEVEL RIDGE...AN UPPER TROUGH ALONG 45W SUPPORTS A STATIONARY FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N43W TO 27N51W TO 24N63W. A SURFACE TROUGH EXTENDS FROM 28N48W TO 23N58W. SCATTERED SHOWERS ARE POSSIBLE WITHIN 75 NM OF THE FRONT AND TROUGH. A LARGE AREA HIGH PRESSURE CENTERED JUST OFF THE COAST OF FRANCE EXTENDS ACROSS THE EASTERN ATLC WITH ANTICYCLONIC FLOW AND GENERALLY FAIR WEATHER. OVER THE NEXT 24 HOURS THE COLD FRONT WILL MOVE E TO NEAR 30N72W TO THE BAHAMAS WITH SHOWERS AND ISOLATED THUNDERSTORMS. THE STATIONARY FRONT AND SURFACE TROUGH OVER THE CENTRAL ATLANTIC ARE FORECAST TO GRADUALLY DISSIPATE TODAY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO