000 AXNT20 KNHC 210602 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN APR 21 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS THE SOUTHERN COAST OF GUINEA NEAR 9N13W TO 4N19W. THE ITCZ BEGINS AT 4N19W AND CONTINUES ALONG 3N31W 4N42W 2N52W. SCATTERED STRONG CONVECTION IS FROM EQ- 3N BETWEEN 12W-14W. SIMILAR ACTIVITY IS FROM 3N-5N BETWEEN 16W- 19W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER LEVEL TROUGH COVERS THE MAJORITY OF THE GULF OF MEXICO WITH AXIS ALONG 87W. THE UPPER TROUGH CONTINUES TO SUPPORT A NOW STATIONARY FRONT THAT EXTENDS FROM SOUTH FLORIDA NEAR 25N81W TO 25N86W 22N90W 18N90W...AS OF 0300 UTC. A SWATH OF SHOWERS/ISOLATED THUNDERSTORMS IS NORTH OF THE FRONT ACROSS CENTRAL FLORIDA FROM 26N-28N...WHICH CONTINUES WEST OF THE FLORIDA PENINSULA TO 87W. POSSIBLE ISOLATED SHOWERS EXTEND UP TO 300 NM NORTH AND WEST OF THE AXIS ELSEWHERE. SCATTERED SHOWERS/THUNDERSTORMS ALSO EXTEND SOUTH OF THE AXIS THROUGH THE STRAITS OF FLORIDA TO NW CUBA. NORTHEAST WINDS OF 15-20 KT ARE NORTH OF THE FRONTAL BOUNDARY BECOMING EASTERLY ACROSS THE WESTERN GULF AS THEY WRAP AROUND THE SOUTHERN EDGE OF A SURFACE RIDGE COVERING MUCH OF THE EASTERN CONUS. DRY AIR ALOFT AROUND THE WEST SIDE OF THE UPPER TROUGH IS KEEPING THE FAR NW GULF UNDER CLEAR SKIES. THE WESTERN PORTION OF THE FRONT IS EXPECTED TO SPLIT FROM THE MAIN FRONT OVER THE NEXT 24 HOURS AND WILL DRIFT WEST AS EITHER A SURFACE TROUGH OR POSSIBLE WEAK SURFACE LOW. SURFACE RIDGING WILL DOMINATE THE REMAINDER OF THE BASIN FOR THE NEXT SEVERAL DAYS. SHOWERS AND THUNDERSTORMS WILL LIKELY REMAIN ACROSS THE EASTERN GULF AND FLORIDA THROUGH AT LEAST MONDAY. CARIBBEAN SEA... UPPER LEVEL RIDGING COVERS THE WESTERN CARIBBEAN EXTENDING FROM SOUTH OF MEXICO ACROSS GUATEMALA TO CENTRAL CUBA CONTINUING INTO THE WEST ATLC. DRY AIR ALOFT ACROSS THIS AREA IS HELPING PROVIDE FAIR CONDITIONS AT THE SURFACE. ONLY A FEW SHOWERS HAVE POPPED UP OVER HONDURAS AND SOUTH OF EASTERN CUBA WITH A FEW POSSIBLE SHOWERS OVER HISPANIOLA. HOWEVER...AN UPPER LEVEL TROUGH WITH AXIS NEAR 67W IS PROVIDING SOME UPPER LEVEL MOISTURE ACROSS THE FAR EASTERN CARIBBEAN ALONG WITH SOME DIFFLUENCE ALOFT SUPPORTING SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS NORTH OF 13N EAST OF 67W. TRADEWIND FLOW OF 15-20 KT SPREADS ACROSS MUCH OF THE CENTRAL AND EASTERN CARIBBEAN. LITTLE CHANGE IS EXPECTED OVER THE NEXT 24 HOURS. MOISTURE AND LIKELY SHOWERS WILL REMAIN OVER THE EASTERN CARIBBEAN AS THE UPPER TROUGH DRIFTS SLOWLY EAST. ATLANTIC OCEAN... THE STATIONARY FRONT OVER THE SE GULF OF MEXICO EXTENDS INTO THE WEST ATLC ALONG 25N80W TO 31N75W...AS OF 0300 UTC. SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS EXTEND UP TO 100 NM EITHER SIDE OF THE AXIS. THE SYSTEM IS SUPPORTED BY A BROAD UPPER TROUGH COVERING MUCH OF THE EASTERN CONUS. AN UPPER LEVEL RIDGE IS TO THE EAST EXTENDING FROM CENTRAL CUBA TO NEAR 31N70W. A LARGER SCALE UPPER RIDGE IS CENTERED NEAR 30N59W...BUT A WEAK UPPER LOW IS TO THE SOUTH NEAR 21N66W WITH AXIS CONTINUING INTO THE CARIBBEAN. THE UPPER LOW/TROUGH IS SUPPORTING SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS FROM 13N-18N WEST OF 57W INTO THE EASTERN CARIBBEAN. THE UPPER RIDGE TO THE NORTH SUPPORTS SURFACE RIDGING ACROSS THE REMAINDER OF THE WEST ATLC ANCHORED BY A 1034 MB HIGH NEAR 42N45W. FARTHER EAST...AN UPPER LEVEL LOW NEAR 30N41W SUPPORTS BROAD SURFACE TROUGHING ALONG 30N35W TO 23N42W. A DISSIPATING COLD FRONT IS TO THE EAST ALONG 32N35W TO 25N46W. AN EARLIER ASCAT PASS INDICATES THAT A SURFACE LOW MAY BE FORMING NEAR THE SURFACE TROUGH. ISOLATED SHOWERS ARE FROM 26N- 30N BETWEEN 32W-36W. AN UPPER LEVEL RIDGE ALONG 17W COVERS THE REMAINDER OF THE EAST ATLC SUPPORTING A WEAK 1015 MB HIGH NEAR 24N32W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON