000 AXNT20 KNHC 111733 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED APR 11 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1700 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH THE COASTAL BORDER AREA OF SIERRA LEONE AND LIBERIA NEAR 7N11W TO THE EQUATOR AT 27W. THE ITCZ CONTINUES FROM 0N27W TO THE NORTHEAST COAST OF BRAZIL NEAR 4S40W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTIVE PRECIPITATION LIES FROM 7N TO THE EQUATOR BETWEEN 10W AND 23W. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS ELSEWHERE TO THE SOUTH OF 10N TO THE EAST OF 60W. ...DISCUSSION... THE GULF OF MEXICO... WEST-NORTHWESTERLY UPPER LEVEL WINDS ARE CURRENTLY OVER MUCH OF THE GULF ARE CARRYING MID TO UPPER LEVEL MOISTURE ACROSS THE REGION PRIMARILY N OF 23N. THESE WINDS ARE BEGINNING TO SHIFT NORTHWESTERLY AS THE MEAN UPPER TROUGH CENTERED JUST EAST OF FLORIDA AMPLIFIES. A COLD FRONT ASSOCIATED WITH THIS TROUGH ALOFT IS MAKING ITS WAY THROUGH NORTH FLORIDA AND THE NORTHEASTERN GULF OF MEXICO. A 1020 MB SURFACE HIGH IS CENTERED NEAR 28N91W AND LIGHT TO MODERATE ANTICYCLONIC FLOW IS FOUND AT THE SURFACE OVER THE GULF AROUND THE HIGH...WITH WINDS IN THE NORTHEAST GULF VEERING MORE NORTHERLY BEHIND THE COLD FRONT. THE FRONT WILL DISSIPATE ACROSS THE NORTHEASTERN GULF BY TONIGHT AND THE SURFACE HIGH WILL MERGE WITH STRONGER HIGH PRESSURE BEHIND THE FRONT OVER THE OHIO VALLEY. THE LIGHT TO MODERATE WIND REGIME WITH PREVAILING WINDS FROM THE NORTHEAST IN THE EASTERN GULF AND SOUTHEAST IN THE WESTERN GULF WILL CONTINUE FOR THE NEXT FEW DAYS. THE CARIBBEAN SEA... WATER VAPOR IMAGERY SHOWS SOUTHWESTERLY WINDS ALOFT ARE TRANSPORTING MID TO UPPER LEVEL MOISTURE FROM THE PACIFIC AND SOUTH AMERICA ACROSS THE CARIBBEAN...WITH WIDELY SCATTERED CIRRUS FOUND PRIMARILY SOUTH OF 14N EAST OF 80W. THE SUBTROPICAL HIGH AT THE SURFACE IS WELL NORTHEAST OF THE CARIBBEAN NEAR 37N37W AND RIDGING IS FURTHER WEAKENED BY A SURFACE TROUGH THAT LIES NORTH OF HISPANIOLA. WINDS ARE LIGHT OVER THE CARIBBEAN AS A RESULT OF THE DIMINISHED PRESSURE GRADIENT BETWEEN THE SUBTROPICAL HIGH AND TROUGHING OVER SOUTH AMERICA. A SURFACE TROUGH LIES FROM THE WINDWARD PASSAGE NEAR 19N75W TO 13N76W. LIGHT TO MODERATE EAST-NORTHEASTERLY TRADE WINDS CAN BE FOUND OVER MUCH OF THE AREA...WITH NORTH-NORTHEAST WINDS FOUND EAST OF THE TROUGH IN THE SOUTHWEST CARIBBEAN. THIS WEAK TROUGH IS EXPECTED TO DISSIPATE OVER THE NEXT 24 HOURS. SCATTERED SHOWERS ARE MOST PREVALENT NEAR THE CENTRAL AMERICAN COAST AS WELL AS IN THE REGION NORTH OF 17N BETWEEN 68W AND 82W WHERE SOME ISOLATED THUNDERSTORMS CAN ALSO BE FOUND. PRECIPITABLE WATER IMAGERY SHOWS LOW LEVEL MOISTURE HAS POOLED IN THE CARIBBEAN NORTH OF 16N EAST OF 80W AS WELL AS NORTH OF THE CARIBBEAN NEAR THE TROUGH FOUND NORTH OF HISPANIOLA. THE AVAILABLE MOISTURE SHOULD BEGIN TO THIN OUT HERE ON THURSDAY AS A COLD FRONT SWEEPS THROUGH THE BAHAMAS AND THE MOISTURE IS SPREAD NORTHWARD ALONG THE FRONT. THE ATLANTIC OCEAN... A BROAD UPPER LEVEL TROUGH LIES OVER THE WESTERN ATLANTIC. THE LEADING EDGE OF THIS TROUGH SUPPORTS A DISSIPATING STATIONARY FRONT AT THE SURFACE FROM 32N53W TO 27N58W. SCATTERED MODERATE CONVECTIVE PRECIPITATION LIES NORTH OF 30N NEAR THIS DISSIPATING FRONT. A SURFACE TROUGH EXTENDS FROM 27N66W TO 20N71W. SCATTERED MODERATE CONVECTIVE PRECIPITATION CAN GENERALLY BE FOUND WITHIN 270 NM ON EITHER SIDE OF THIS TROUGH. THE UPPER PATTERN IS BEGINNING TO AMPLIFY AS ENERGY IS MOVING INTO THE BACKSIDE OF THE BROAD TROUGH FROM NORTH AMERICA AND RIDGING AHEAD OF THE TROUGH IS BUILDING OVER THE CENTRAL ATLANTIC. A NEW COLD FRONT ASSOCIATED WITH THIS ENERGY LIES FROM 32N77W THROUGH SAINT AUGUSTINE...FLORIDA. THE FRONT WILL SWEEP SOUTHEASTWARD INTO THE BAHAMAS THURSDAY AND LIFT THE AFOREMENTIONED SURFACE TROUGH NEAR EASTERN HISPANIOLA NORTHWARD. FARTHER EAST...DEEP LAYER RIDGING IS BUILDING OVER THE CENTRAL ATLANTIC. THE 1032 MB SUBTROPICAL HIGH CURRENTLY LIES NEAR 37N37W. THE PRESSURE GRADIENT BETWEEN THE HIGH AND THE ITCZ TO THE SOUTH IS FORCING AN AREA OF FRESH NORTHEASTERLY TRADE WINDS FOUND GENERALLY OVER THE AREA SOUTH OF 24N EAST OF 57W. THE HIGH IS FORECAST TO DRIFT A FEW DEGREES EASTWARD OVER THE NEXT DAY OR TWO. ELSEWHERE...SCATTERED MODERATE CONVECTIVE PRECIPITATION CAN BE FOUND FROM 04N TO 09N BETWEEN 50W AND 60W INCLUDING NORTHERN GUYANA...SURINAME...AND FRENCH GUIANA. OTHERWISE...SIGNIFICANT CONVECTIVE PRECIPITATION IS CONFINED TO THE AREA DESCRIBED IN THE ITCZ SECTION ABOVE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SCHAUER