000 AXNT20 KNHC 290546 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN APR 29 2012 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 0515 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 08N13W TO 05N14W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 05N14W TO 02N26W TO 03N41W TO 01N50W. ISOLATED MODERATE CONVECTION IS FROM 02N-06N BETWEEN 12W-32W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL TROUGH EXTENDS OVER THE EASTERN GULF ALONG 85W SOUTHWARD INTO THE NW CARIBBEAN SEA SUPPORTING A MIDDLE TO UPPER LEVEL LOW CENTERED NEAR 21N83W. MIDDLE TO UPPER LEVEL DIFFLUENCE IS MAXIMIZED NORTH AND EAST OF THE LOW AND ASSOCIATED TROUGHING GENERATING NUMEROUS SHOWERS OVER THE FAR SE GULF AND FLORIDA STRAITS. MOSAIC DOPPLER RADAR IMAGERY FROM KEY WEST AND MIAMI INDICATE THE PRECIPITATION IS OCCURRING S OF 25N E OF 83W. THE REMAINDER OF THE GULF IS UNDER THE INFLUENCE OF MOSTLY DRY AIR ALOFT AND A SURFACE RIDGE AXIS EXTENDING FROM THE SW NORTH ATLC ACROSS THE NORTHERN FLORIDA PENINSULA TO THE TEXAS GULF COAST NEAR 29N95W. SKIES ARE CLEAR W OF 84W WITH E TO SE WINDS OBSERVED IN THE RANGE OF 10 TO 20 KT...STRONGEST OVER THE FAR WESTERN GULF DUE TO AN ENHANCED PRESSURE GRADIENT. LOOKING AHEAD...CONSENSUS OF GLOBAL MODEL GUIDANCE SUGGESTS THAT ENERGY ASSOCIATED WITH THE UPPER LEVEL TROUGHING WILL SLIDE WESTWARD ACROSS THE SOUTH-CENTRAL GULF AS A SURFACE TROUGH THROUGH THE EARLY PART OF NEXT WEEK. THE GFS REMAINS THE MOST AGGRESSIVE IN DEVELOPING A WEAK SURFACE LOW ACROSS WESTERN CUBA THAT MOVES INTO THE SOUTH-CENTRAL GULF...HOWEVER THE NAM...ECMWF...AND UKMET KEEP A SURFACE TROUGH FEATURE PROGRESSING WESTWARD ON THE SOUTHWESTERN PERIPHERY OF THE RIDGE. CARIBBEAN SEA... A MIDDLE TO UPPER LEVEL LOW IS CENTERED SOUTH OF WESTERN CUBA IN THE NW CARIBBEAN NEAR 21N83W AND EXTENDS AN UPPER LEVEL TROUGH AXIS FROM THE LOW TO 14N88W. SOUTH-SOUTHWESTERLY UPPER LEVEL FLOW IS OCCURRING OVER MUCH OF THE CARIBBEAN BETWEEN THE TROUGH AND AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER EASTERN VENEZUELA NEAR 08N62W. MIDDLE TO UPPER LEVEL DIFFLUENCE IS MAXIMIZED CLOSER TO THE TROUGH AXIS AND COUPLED WITH A SURFACE TROUGH EXTENDING FROM 22N80W TO 17N81W...SCATTERED SHOWERS AND TSTMS ARE OCCURRING FROM 10N-22N BETWEEN 76W-82W. WHILE THE REMAINDER OF THE NW CARIBBEAN REMAINS FAIRLY DRY ALOFT WITH CLEAR SKIES WEST OF THE TROUGH AXIS...THE REMAINDER OF THE EASTERN CARIBBEAN IS UNDER FRESH EASTERLIES AND A FEW ISOLATED QUICK-PASSING LOW-TOPPED SHOWERS. MOST OF THE ACTIVE CONVECTION OCCURRING OVER THE WESTERN CARIBBEAN THIS EVENING IS EXPECTED TO DRIFT WEST-NORTHWESTWARD OVER THE NEXT 24 TO 36 HOURS AND INTO THE SOUTH-CENTRAL GULF OF MEXICO. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL LOW AND ASSOCIATED TROUGH IS CENTERED IN THE NW CARIBBEAN SEA NEAR 21N83W AND IS PROVIDING MOST OF THE SW NORTH ATLC WITH PLENTY OF MOISTURE AND OVERCAST CLOUDINESS W OF 62W. MOSAIC DOPPLER RADAR IMAGERY INDICATES THAT NUMEROUS SHOWERS ARE OCCURRING S OF 27N W OF 74W AND THAT POSSIBLE SCATTERED SHOWERS ARE ELSEWHERE S OF 30N W OF 70W. OTHERWISE... THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE AXIS EXTENDING ALONG 30N TO THE NORTHERN FLORIDA PENINSULA AND INTO THE GULF OF MEXICO. MUCH OF THIS RIDGING AT THE SURFACE IS SUPPORTED ALOFT BY AN AMPLIFIED UPPER LEVEL RIDGE WITH AXIS ALONG 67W. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 25N40W AND SUPPORTS WEAK SURFACE TROUGHING ACROSS THE CENTRAL ATLC FROM 27N43W TO 16N44W TO 10N50W. LOW TO MIDDLE LEVEL MOISTURE IS MOST PREVALENT EAST OF THIS TROUGH AXIS WITH POSSIBLE ISOLATED SHOWERS OCCURRING OVER A LARGE AREA FROM 15N-30N BETWEEN 27W-43W. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1032 MB HIGH CENTERED NW OF THE AZORES NEAR 43N33W. THE RIDGE AXIS EXTENDS SOUTHWARD ALONG 33W TO 10N. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN