000 AXNT20 KNHC 200004 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT APR 19 2014 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 2345 UTC. ...SPECIAL FEATURE... N-NE GALE FORCE WINDS ARE FORECAST TO BEGIN SUN MORNING ON THE SW N ATLANTIC WATERS N OF 29N BETWEEN 20 AND 60 NM OF SHORE ASSOCIATED WITH A FRONTAL SYSTEM. GALE WINDS ARE EXPECTED TO SUBSIDE BY SUN AFTERNOON. PLEASE SEE THE HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/ FZNT02 KNHC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA WITH THE WESTERNMOST PART OF THE AXIS BEING AT SW SENEGAL. THE ITCZ BEGINS NEAR 05N11W AND CONTINUES ALONG 01N25W 01N36W TO THE NORTHERN COAST OF BRAZIL NEAR 0N50W. CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 02S-05N BETWEEN 14W-26W. SCATTERED MODERATE CONVECTION IS ELSEWHERE WITHIN 150 NM N AND S OF THE ITCZ W OF 26W. ...DISCUSSION... GULF OF MEXICO... SURFACE AND UPPER LEVEL RIDGING AS WELL AS DRY AIR SUBSIDENCE DOMINATE ACROSS THE GULF WATERS...THUS SUPPORTING STABILITY AND FAIR WEATHER CONDITIONS. THE SURFACE RIDGE IS ANCHORED BY A 1021 MB HIGH S OF THE BORDER BETWEEN TEXAS AND LOUISIANA NEAR 29N93W AND PROVIDES THE GULF WITH N-NE WIND FLOW OF 10-15 KT. SURFACE RIDGING IS EXPECTED TO PREVAIL THROUGH MONDAY. BY TUE MORNING...A HIGH PRESSURE CENTER IS EXPECTED TO DEVELOP OVER THE NW GULF AHEAD OF THE NEXT COLD FRONT WHICH IS EXPECTED TO ENTER THIS REGION OF THE BASIN TUE AFTERNOON. CARIBBEAN SEA... NEARLY WESTERLY FLOW AND DRY AIR DOMINATE THE CARIBBEAN AT THE UPPER LEVELS. A BROAD SURFACE RIDGE COVERING MUCH OF THE ATLC EXTENDS INTO THE NORTHERN BASIN THUS INCREASING THE PRESSURE GRADIENT TO SUPPORT TRADE WINDS OF 20 KT ACROSS THE CENTRAL AND EASTERN CARIBBEAN. A RELAXED PRESSURE GRADIENT OVER THE NW AND SW CARIBBEAN SEA SUPPORT LIGHTER NE WINDS RANGING FROM 5-15 KT. A WESTWARD-MOVING MOIST AIRMASS HAS REACHED JAMAICA AND CENTRAL- EASTERN CUBA WHERE IT IS SUPPORTING SHOWERS AND TSTMS. WET TRADES ARE ALSO ACROSS THE EASTERN CARIBBEAN WHICH MAY ENHANCE SCATTERED SHOWERS TONIGHT. ...HISPANIOLA... CURRENTLY FAIR WEATHER IS ACROSS THE ISLAND SUPPORTED BY DRY AIR AT THE LOWER LEVELS AND ALOFT. EXCEPT FOR THE TYPICAL AFTERNOON SHOWERS...FAIR WEATHER IS EXPECTED THE NEXT TWO DAYS. ATLANTIC OCEAN... A DEEP LAYER CYCLONIC CIRCULATION IS OVER THE SOUTHEASTERN U.S. WITH AN ASSOCIATED TROUGH EXTENDING SOUTHWARD TO N OF CUBA. TROUGHINESS ALOFT IS SUPPORTING A FRONTAL SYSTEM ASSOCIATED WITH A 1011 MB LOW OVER JACKSONVILLE NEAR 30N81W. A COLD FRONT EXTENDS FROM A TRIPLE POINT ALONG 30N79W 26N79W TO THE STRAITS OF FLORIDA NEAR 23N82W. AHEAD OF THE FRONT...A SQUALL LINE EXTENDS FROM 30N74W TO 27N75W TO EASTERN-CENTRAL ANDROS NEAR 24N77W. SATELLITE IMAGERY AND LIGHTING DATA INDICATE THERE ARE SHOWERS AND TSTMS WITHIN 80 NM E OF THE FRONT N OF 26N AND WITHIN 160 NM E OF THE SQUALL LINE N OF 24N. BOTH LOW LEVEL MOISTURE CONVERGENCE AND UPPER LEVEL DIFFLUENCE SUPPORT THIS CONVECTION. GALE FORCE WINDS ASSOCIATED WITH THIS FRONTAL SYSTEM ARE FORECAST TO BEGIN SUN MORNING AND SUBSIDE SUN AFTERNOON. PLEASE SEE SPECIAL FEATURE SECTION. THE LOW WILL CONTINUE TO SHIFT NE AND THE ASSOCIATED COLD FRONT WILL CONTINUE TO DRIFT EASTWARD ACROSS THE SW N ATLC THROUGH TUE MORNING. OTHERWISE...THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1029 MB HIGH NEAR 32N53W WHICH IS EXPECTED TO DRIFT SE INTO THE AREA OF DISCUSSION BY SUN AFTERNOON. FAIR WEATHER IS OVER THE CENTRAL AND EASTERN ATLC BEING SUPPORTED BY DRY AIR SUBSIDENCE FROM THE MIDDLE LEVELS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR