000 AXNT20 KNHC 282316 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU MAR 28 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 2245 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH THE COAST OF SOUTHERN GUINEA AT 9N13W INTO THE EASTERN TROPICAL ATLC ALONG 3N17W 1N20W. THE ITCZ BEGINS AT 1N20W AND CONTINUES ALONG 1S25W EQ34W 3S43W. A CLUSTER OF STRONG CONVECTION IS FROM EQ-1N BETWEEN 17W-20W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 1N-3N BETWEEN 31W- 37W. ...DISCUSSION... THE GULF OF MEXICO... SURFACE RIDGING CONTINUES TO DOMINATE THE GULF OF MEXICO ANCHORED BY A 1028 MB HIGH OVER ALABAMA NEAR 32N88W. THIS PATTERN IS PROVIDING 10-15 KT ANTI-CYCLONIC FLOW ACROSS THE AREA. SKIES ARE MOSTLY CLEAR EXCEPT FOR SOME OVERCAST AREAS ALONG THE NE COAST OF MEXICO AND TEXAS. ALOFT...MAINLY ZONAL WESTERLY FLOW IS PRESENT ALTHOUGH AN UPPER LEVEL RIDGE IS APPROACHING FROM THE WEST SUPPORTING THE SURFACE RIDGE. DRY AIR ALOFT IS ALSO HELPING MAINTAIN THE FAIR WEATHER ACROSS THE BASIN. THE SURFACE RIDGE IS EXPECTED TO BEGIN SHIFTING EAST OVER THE NEXT SEVERAL DAYS. THE CARIBBEAN SEA... A WEAK SHEAR AXIS CONTINUES TO EXTEND FROM WESTERN HISPANIOLA TO SOUTH OF JAMAICA ALONG 19N72W TO 16N77W. POSSIBLE ISOLATED SHOWERS EXTEND UP TO 120 NM NW OF THE AXIS WITH ISOLATED SHOWERS ALSO POSSIBLE FARTHER SOUTH OFF THE EASTERN COAST OF NICARAGUA AND HONDURAS. SCATTERED SHOWERS ARE PRESENT OVER NORTHERN HISPANIOLA DUE TO A COLD FRONT IN THE ATLC THAT EXTENDS JUST TO THIS PORTION OF THE ISLAND. NORTHEAST WINDS OF 20 KT COVER THE MAJORITY OF THE NW CARIBBEAN CONTINUING INTO THE SW CARIBBEAN OFF THE COAST OF CENTRAL AMERICA. THE REMAINDER OF THE BASIN IS DOMINATED BY TRADEWIND FLOW RANGING FROM 10-15 KT WITH 20-25 KT WINDS NEAR THE COAST OF COLOMBIA. CLEARS SKIES SPREAD THROUGHOUT THE CENTRAL AND EASTERN CARIBBEAN DUE TO DRY AIR ALOFT AROUND A BROAD UPPER LEVEL RIDGE WITH AXIS EAST OF THE LESSER ANTILLES ALONG 49W. THE SHEAR AXIS IS EXPECTED TO DISSIPATE OVER THE NEXT 24 HOURS WITH LITTLE CHANGE ELSEWHERE. THE ATLANTIC OCEAN... SURFACE RIDGING ACROSS THE GULF OF MEXICO IS BEGINNING TO SPREAD OVER INTO THE WEST ATLC AND WILL CONTINUE TO DO SO OVER THE NEXT FEW DAYS. A COLD FRONT CONTINUES TO SPREAD ACROSS THE CENTRAL ATLC ENTERING THE DISCUSSION AREA NEAR 32N34W AND TRAILING SW TO HISPANIOLA ALONG 24N54W 19N70W. ISOLATED TO SCATTERED SHOWERS ARE WITHIN 60 NM EAST...AND 100 NM WEST OF THE AXIS. THE SYSTEM IS SUPPORTED BY BROAD UPPER LEVEL TROUGHING COVERING THE NW ATLC. AN UPPER LEVEL RIDGE ALONG 49W SUPPORTS A BROAD SURFACE RIDGE COVERING THE REMAINDER OF THE CENTRAL AND EASTERN ATLC ANCHORED BY A 1019 MB HIGH NEAR 26N24W. FAIR WEATHER DOMINATES THIS AREA. AN UPPER LEVEL TROUGH EXTENDS THROUGH NW AFRICA INTO THE TROPICAL ATLC FROM THE CAPE VERDE ISLANDS TO 4N45W...BUT IS NOT SUPPORTING ANY ACTIVE WEATHER. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON