000 AXNT20 KNHC 241759 TWDAT TROPICAL WEATHER DISCUSSION... NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN JUN 24 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 1715 UTC. ...SPECIAL FEATURES... AS OF 1800 UTC...TROPICAL STORM DEBBY IS CENTERED NEAR 28.3N 85.9W...OR ABOUT 175 NM ESE OF THE MOUTH OF MISSISSIPPI RIVER...MOVING NE AT 5 KT. THE ESTIMATED MINIMUM PRESSURE IS 993 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS FROM 26N-31N BETWEEN 79W-85W INCLUDING MUCH OF THE FLORIDA PENINSULA...WHICH IS CONFIRMED BY RADAR IMAGERY. SIMILAR ACTIVITY IS ALSO N OF THE STORM CENTER FROM 29N-31N BETWEEN 85W-88W. A LINE OF SHOWERS/THUNDERSTORMS ALSO EXTENDS FROM THE MAIN AREA OF CONVECTION TOWARDS THE SW GULF ALONG 26N85W TO 21N95W. ANOTHER AREA OF NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS IN THE NW CARIBBEAN FROM 17N-23N BETWEEN 84W-88W. EVEN THOUGH THIS AREA OF CONVECTION IS REMOVED FROM THE STORM CENTER...IT IS STILL WITHIN THE LARGE AREA OF CYCLONIC FLOW PRESENT AROUND THE STORM WHICH SPREADS ACROSS THE ENTIRE GULF OF MEXICO AND THE FAR NW CARIBBEAN. THERE IS A LOT OF UNCERTAINTY IN THE TRACK FORECAST...AND ALL AREAS OF THE GULF COAST SHOULD CONTINUE TO MONITOR THE PROGRESS OF DEBBY. PLEASE READ THE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT43/WTNT24 KNHC AND THE PUBLIC ADVISORY MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE HAS MOVED OFF THE COAST OF AFRICA AND IS ALONG 16N20W TO 8N24W MOVING W NEAR 10-15 KT. UPPER AIR SOUNDINGS FROM DAKAR SENEGAL INDICATE THAT THE WAVE PASSED THE STATION BETWEEN 23/0000 UTC AND 23/1200 UTC. THERE IS ALSO A CLEARING IN THE SAHARAN AIR LAYER AROUND THE WAVE ALONG WITH A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 4N-11N BETWEEN 21W-28W. A TROPICAL WAVE IS ALONG 17N46W TO 8N47W MOVING W NEAR 20 KT. THE WAVE LIES ON THE WRN SIDE OF A NARROW SURGE IN DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. VISIBLE SATELLITE IMAGERY ALSO INDICATES A CLEARING IN A LARGE AREA OF SAHARAN DUST THAT EXISTS BOTH E AND W OF THE WAVE AXIS. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE DUE TO THE DRY AIR SURROUNDING IT. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF AFRICA NEAR 19N16W ALONG 13N23W 6N29W. THE ITCZ CONTINUES FROM 6N29W ALONG 4N38W 6N46W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 8N-14N BETWEEN 15W-17W. SIMILAR ACTIVITY IS FROM 5N-8N BETWEEN 28W-36W. ...DISCUSSION... THE GULF OF MEXICO... TROPICAL STORM DEBBY IS DOMINATING THE WEATHER PATTERN ACROSS THE GULF OF MEXICO TODAY. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. MOST OF THE SHOWER/THUNDERSTORM ACTIVITY IS E AND N OF THE STORM CENTER LEAVING MUCH OF THE WRN GULF DRY AND CLEAR. DRY AIR ALOFT AROUND AN UPPER LEVEL TROUGH OVER THE WRN GULF ALONG 93W IS HELPING MAINTAIN THESE FAIR CONDITIONS. AN UPPER LEVEL RIDGE IS ALONG THE FLORIDA PENINSULA AND ACROSS MUCH OF THE CARIBBEAN. THE FUTURE TRACK OF DEBBY IS SOMEWHAT UNCERTAIN AS MODEL GUIDANCE HAS BEEN YIELDING CONFLICTING TRACK FORECASTS. THE ENTIRE GULF COAST SHOULD MONITOR THE PROGRESS OF DEBBY DUE TO THE LOW CONFIDENCE IN TRACK FORECAST. THE CARIBBEAN SEA... SHOWERS/THUNDERSTORMS ARE ACROSS THE FAR NW CARIBBEAN IN ASSOCIATION WITH THE CIRCULATION AROUND TROPICAL STORM DEBBY IN THE GULF OF MEXICO. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. THE REMAINDER OF THE CARIBBEAN IS UNDER MOSTLY CLEAR SKIES DUE TO DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE COVERING FLORIDA AND THE CENTRAL AND WRN CARIBBEAN. A WEAK UPPER TROUGH COVERS THE ERN CARIBBEAN ALSO ACCOMPANIED BY DRY AIR. TRADEWIND FLOW OF 15-20 KT IS ACROSS MUCH OF THE BASIN. SURFACE OBSERVATIONS INDICATE THE PRESENCE OF DUST ACROSS BOTH THE LESSER ANTILLES AND THE NRN CARIBBEAN ISLANDS INCLUDING HISPANIOLA POSSIBLY ALL THE WAY TO CUBA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. THE ATLANTIC OCEAN... SHOWERS/THUNDERSTORMS ASSOCIATED WITH TROPICAL STORM DEBBY SPREAD ACROSS FLORIDA AND INTO THE WRN ATLC TO 79W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALSO FARTHER E FROM 23N-29N BETWEEN 69W-75W...AND FROM 24N-26N BETWEEN 63W-65W. ALOFT...AN UPPER LEVEL RIDGE COVERS THE W ATLC W OF 69W SUPPORTING A WEAK 1021 MB SURFACE HIGH NEAR 26N62W. AN UPPER TROUGH IS ALONG 64W LIKELY SUPPORTING SOME OF THE SHOWERS/THUNDERSTORMS NEAR THE SURFACE HIGH CENTER. A SECOND UPPER RIDGE IS ALONG 52W WITH A BROAD UPPER TROUGH COVERS THE N CENTRAL ATLC ALONG 40W. THIS UPPER RIDGE SUPPORTS A STATIONARY FRONT ALONG 31N40W 28N47W DISSIPATING TO 28N58W. A PRE-FRONTAL SURFACE TROUGH IS ALONG 31N38W 26N46W 24N55W. ISOLATED SHOWERS ARE ALONG THE FRONTAL BOUNDARY WHILE SCATTERED SHOWERS ARE ALONG THE TROUGH AXIS. UPPER LEVEL RIDGING COVERS BOTH THE TROPICAL ATLC AND ERN ATLC AROUND TWO ANTI-CYCLONIC CENTERS NEAR 17N43W AND 31N21W. VISIBLE SATELLITE IMAGERY INDICATES A LARGE AREA OF SAHARAN DUST EXTENDS FROM THE COAST OF AFRICA ALL THE WAY TO THE ERN CARIBBEAN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON