000 AXNT20 KNHC 300003 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT MAR 29 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. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL LIBERIA NEAR 6N10W TO 3N14W. THE ITCZ CONTINUES FROM 3N14W...THROUGH THE EQUATOR ALONG 20W...TO 3S30W...AND TO THE COAST OF BRAZIL NEAR 5S37W. CONVECTIVE PRECIPITATION...ISOLATED MODERATE TO THE SOUTH OF 5N TO THE EAST OF 40W...AND TO THE SOUTH OF 10N BETWEEN 40W AND 60W. ...DISCUSSION... ...THE GULF OF MEXICO... A DEEP LAYER TROUGH EXTENDS FROM A MID-TO UPPER LEVEL CYCLONE LIFTING TO THE NNE OVER SW PENNSYLVANIA SOUTHWARD OVER THE DEEP SOUTH INTO THE GULF E OF 90W...WITH VERY STRONG SUBSIDENCE IN ITS WAKE OVER THE DEEP SOUTH. THE TROUGH IS SUPPORTING A COLD FRONT THAT EXTENDING FROM THE FLORIDA BIG BEND THROUGH 25N90W TO NEAR THE E COAST OF MEXICO NE OF TAMPICO. A PRE-FRONTAL TROUGH WAS WITHIN 90 NM OF THE FRONT...EXTENDING FROM CEDAR KEY THROUGH 25N87W TO 22N93W. FURTHER E...A SQUALL LINE EXTENDED FROM JUST S OF FORT MYERS FLORIDA AND INTERSECTED THE SURFACE TROUGH NEAR 25.5N86.5W. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WERE NOTED ALONG AND WITHIN 60-75 NM NW OF THE SQUALL LINE. SCATTERED TO BROKEN LOW CLOUDS WERE NOTED ELSEWHERE OVER THE GULF TO THE NW OF THE FRONT WITH THE EXCEPTION OF LOW CLOUD CEILINGS BEING REPORTED AT THE FOLLOWING ICAO PLATFORM SITES...KGBK AND KATP. BROKEN TO OVERCAST HIGH CLOUDS WERE WERE SWEEPING EWD OVER THE GULF N OF 25N AND W OF 90W WITHIN A FLAT SHORTWAVE RIDGE WITH AXIS ALONG 93W. THE COLD FRONT IS EXPECTED TO SWEEP RAPIDLY SE AND CLEAR THE GULF OF MEXICO ON SUN WITH HIGH PRESSURE BUILDING OVER THE N-CENTRAL GULF. ...THE CARIBBEAN SEA... A SHARP MID-TO UPPER LEVEL TROUGH EXTENDS FROM THE ATLANTIC OCEAN THROUGH 31N58W...TO A CYCLONIC CIRCULATION CENTER NEAR 23N63W...TO A BASE NEAR 14N63W IN THE EASTERN CARIBBEAN SEA. MID-TO UPPER LEVEL NORTHWESTERLY WINDS SPAN THE CARIBBEAN SEA W OF THE TROUGH AXIS IN GENERALLY ANTICYCLONIC FLOW. STRONG SUBSIDENCE PREVAILED OVER MOST OF THE CARIBBEAN W OF THE TROUGH AXIS. BROKEN TO OVERCAST LOW LEVEL AND MIDDLE LEVEL CLOUDS AND POSSIBLE RAINSHOWERS ARE MOVING THROUGH THE CARIBBEAN SEA IN THE TRADE WIND FLOW. GALE CONDITIONS OVER THE SW CARIBBEAN NEAR THE COLOMBIAN COAST HAVE ENDED AS OF 1800 UTC WITH A 1448 UTC ASCAT PASS INDICATED 25-30 KT WINDS CLOSE TO THE COAST OF COLOMBIA. 15- 20 KT TRADES WERE NOTED ELSEWHERE E OF 75W...WITH LIGHTER WINDS...10-15 KT NOTED W OF 75W. LITTLE CHANGE IN OVERALL CONDITIONS EXPECTED INTO EARLY NEXT WEEK. ...HISPANIOLA... THE MID-TO UPPER LEVEL TROUGH EXTENDING FROM THE ATLANTIC OCEAN INTO THE CARIBBEAN IS WELL E OF HISPANIOLA AND THEREFORE HAVING A LIMITED IMPACT ON THE WEATHER CONDITIONS AS THE ISLAND IS SITUATED IN NW FLOW ALOFT CHARACTERIZED BY STRONG SUBSIDING AIR. AS SUCH CURRENT CONDITIONS INCLUDE SCATTERED TO BROKEN LOW CLOUDS REPORTED IN SANTO DOMINGO...LA ROMANA...AND SANTIAGO. FEW LOW CLOUDS WERE BEING REPORTED IN BARAHONA AND IN PUNTA CANA. FEW LOW CLOUDS ARE BEING OBSERVED IN PORT-AU-PRINCE IN HAITI. OVERALL LITTLE CHANGE EXPECTED IN THE GENERAL SYNOPTIC PATTERN PER THE GFS GLOBAL MODEL FORECAST. ...THE ATLANTIC OCEAN... A MID-TO UPPER LEVEL TROUGH IS ALONG 31N58W...TO A CYCLONIC CIRCULATION CENTER NEAR 23N63W...TO 20N63W...AND TO 15N64W IN THE EASTERN CARIBBEAN SEA. AN AMPLIFIED RIDGE WAS SITUATED TO THE W OF THE TROUGH WITH MEAN AXIS ALONG 70W. AN AREA OF STRONG UPPER LEVEL DIFFLUENCE EXISTED OVER THE ATLANTIC BETWEEN THE RIDGE AND THE SHARP TROUGH MOVING OFF THE EAST COAST. THIS FLOW WAS ENHANCING SCATTERED THUNDERSTORMS ALONG AND WITHIN 60 NM OF A SQUALL LINE EXTENDING FROM 30N78W TO THE E COAST OF FLORIDA NEAR STUART. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE NOTED ELSEWHERE N OF 27N BETWEEN 73W AND THE SQUALL LINE. MID-TO UPPER LEVEL CYCLONIC WIND FLOW COVERED THE ATLANTIC OCEAN FROM 9N TO 24N BETWEEN 40W AND 58W. COMPARATIVELY DRIER AIR IN SUBSIDENCE...APPARENT IN WATER VAPOR IMAGERY...WAS NOTED WITHIN THE AREA OF CYCLONIC WIND FLOW. A SURFACE TROUGH ALONG 24N53W TO 17N55W IS MOVING WESTWARD AT 15 TO 20 KNOTS DURING THE LAST 24 HOURS. IT HAS SHOWN UP WELL IN A LONG-TERM LOOP OF SATELLITE IMAGERY. A 1033 MB HIGH PRESSURE CENTER IS NEAR 36N51W. ONE SURFACE RIDGE EXTENDS FROM THE 1036 MB HIGH CENTER THROUGH 32N44W TO 27N38W. A SECOND SURFACE RIDGE EXTENDS FROM THE 1036 MB HIGH CENTER THROUGH 36N59W...ACROSS BERMUDA...TO 29N73W. A COLD FRONT...VOID OF ANY SHOWER ACTIVITY EXTENDED INTO THE DISCUSSION AREA THROUGH 32N23W TO 28N32W..WHERE IT BECAME DIFFUSE TO 28N41W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ COBB