000 AXNT20 KNHC 271803 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED JUL 27 2011 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 1745 UTC. ...SPECIAL FEATURE... A TROPICAL WAVE MOVES ACROSS THE YUCATAN PENINSULA AND SE GULF OF MEXICO ANALYZED FROM 25N87W TO A 1008 MB LOW NEAR 22N87W TO INLAND OVER NORTHERN BELIZE NEAR 17N89W. TOTAL PRECIPITABLE WATER IMAGERY ALSO SHOWS A LARGE AREA OF ENHANCED DEEP LAYER MOISTURE ACROSS THE NW CARIBBEAN. SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS ARE OCCURRING FROM 17N-25N BETWEEN 81W-88W. BRIEF PERIODS OF LOCALLY HEAVY RAINFALL AND GUSTY WINDS ARE EXPECTED OVER THE NORTHERN YUCATAN PENINSULA AS THE SYSTEM MOVES WNW OVER THE NEXT 24 HOURS. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS CURRENTLY ENROUTE TO INVESTIGATE THIS SYSTEM ...AND IF IT CONFIRMS THE PRESENCE OF A CIRCULATION...ADVISORIES WILL BE INITIATED THIS AFTERNOON. INTERESTS IN THE CENTRAL AND WESTERN GULF OF MEXICO SHOULD MONITOR THIS SYSTEM. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE IS IN THE CENTRAL TROPICAL ATLC ANALYZED FROM 15N27W TO AN ELONGATED 1012 MB LOW NEAR 8N30W MOVING W AT ABOUT 10 KT. THE WAVE AND ASSOCIATED CONVECTION IS EMBEDDED IN A REGION OF DEEP MOISTURE ASSOCIATED TO THE MONSOON TROUGH. A TROPICAL WAVE MOVED OVER THE LESSER ANTILLES ABOUT 6 HOURS AGO...AND IT IS NOW ANALYZED FROM 21N61W TO 10N63W MOVING W AT 10-15 KT. VISIBLE SATELLITE IMAGERY AND DERIVED WINDS INDICATE BROAD CYCLONIC LOW-LEVEL FLOW IN THE VICINITY OF THE WAVE AXIS. THIS WAVE IS EMBEDDED WITHIN A DEEP MOISTURE SURGE ON TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION COVERS THE FAR SE BASIN INCLUDING THE LESSER ANTILLES S OF 16N BETWEEN 58W-63W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST OF GUINEA-BISSAU NEAR 12N16W TO 13N23W...SW ALONG 8N30W 5N35W THEN W TO NEAR 6N43W. NO ITCZ AXIS IS OBSERVED AT THE MOMENT. SCATTERED WEAK TO ISOLATED MODERATE CONVECTION IS FROM 4N-13N E OF 36W. THIS AREA OF CONVECTION IS ALSO ASSOCIATED WITH THE TROPICAL WAVE DISCUSSED ABOVE. A SURFACE TROUGH IS MOVING ACROSS THE COASTAL WATERS OF SURINAME IN SOUTH AMERICA...ANALYZED FROM 12N52W TO 6N57W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 150 NM W OF THE TROUGH AXIS. SIMILAR CONVECTION IS FROM 14N-20N BETWEEN 52W-57W...ASSOCIATED TO AN UPPER LEVEL LOW/TROUGH CENTERED OVER THE CENTRAL ATLC NEAR 25N53W ...DISCUSSION... THE GULF OF MEXICO... NE FLOW ALOFT COVER MUCH OF THE GULF ON WATER VAPOR IMAGERY THIS AFTERNOON...WITH THE STRONGEST SUBSIDENCE NOTICED OVER THE WRN HALF OF THE BASIN S OF 27N. HOWEVER...AN UPPER CYCLONIC CIRCULATION LINGERS NEAR THE COASTAL CITY OF VERACRUZ MEXICO WITHOUT ANY CONVECTION. MODERATE CONVECTION IS FOUND OVER THE NORTHERN GULF...AFFECTING THE COASTAL WATERS FROM TEXAS TO FLORIDA...AS INDICATED BY DOPPLER RADAR IMAGERY SHOWING SCATTERED SHOWERS AND THUNDERSTORMS WITHIN 140 NM ALONG THE NORTHERN COAST STATES BETWEEN 83W-95W. THIS AREA OF CONVECTION IS ASSOCIATED TO A MID-UPPER LEVEL TROUGH EXTENDING ACROSS THE SE CONUS. A TROPICAL WAVE MOVES ACROSS THE YUCATAN PENINSULA BRINGING SCATTERED STRONG CONVECTION TO THE FAR SE GULF INCLUDING THE YUCATAN CHANNEL S OF 25N E OF 88W. FOR MORE INFORMATION...READ THE SPECIAL FEATURE SECTION ABOVE. THE REMAINDER OF THE GULF CONTINUES FAIRLY DRY ON TPW PRODUCT. THE CARIBBEAN SEA... A TROPICAL WAVE IS MOVING ACROSS THE YUCATAN PENINSULA GENERATING SCATTERED HEAVY SHOWERS AND THUNDERSTORMS OVER THE WATERS N OF 18N W OF 82W INCLUDING INLAND PORTIONS CUBA AND THE NE YUCATAN PENINSULA. FOR MORE INFORMATION ABOUT THIS SYSTEM... READ THE SPECIAL FEATURE SECTION ABOVE. SIMILAR ACTIVITY IS OVER THE FAR SW BASIN...WITHIN 70 NM OFF THE COAST OF NICARAGUA... COSTA RICA AND PANAMA...DUE TO CLOSE PROXIMITY TO THE MONSOON TROUGH ANALYZED ACROSS CENTRAL AMERICA THROUGH SOUTHERN NICARAGUA INTO NORTHERN COLOMBIA. A SURFACE TROUGH MOVES ACROSS THE N CENTRAL BASIN WITH AXIS ANALYZED FROM THE MONA PASSAGE NEAR 18N68W TO 14N69W. SCATTERED MODERATE SHOWERS ARE WITHIN 100 NM ON EITHER SIDE OF THE TROUGH AXIS. A TROPICAL WAVE MOVED OVER THE LESSER ANTILLES ABOUT 6 HOURS AGO...AND IT IS NOW ANALYZED FROM 21N61W TO 10N63W...GENERATING SCATTERED MODERATE TO ISOLATED STRONG CONVECTION TO THE FAR SE BASIN INCLUDING THE LESSER ANTILLES S OF 16N E OF 63W. MODERATE SUBSIDENCE IS NOTICED ACROSS THE CENTRAL CARIBBEAN ON WATER VAPOR IMAGERY SUPPORTING FAIR WEATHER CONDITIONS ELSEWHERE ACROSS THE REMAINDER OF THE CARIBBEAN. THE ATLANTIC OCEAN... A BROAD SURFACE RIDGE DOMINATES THE ATLC DISCUSSION AREA N OF 20N WITH MOSTLY FAIR WEATHER CONDITIONS...ANCHORED BY A PAIR OF 1029 MB HIGHS CENTERED NEAR 40N28W AND 35N36W. THE RIDGE AXIS EXTENDS WEST-SOUTHWEST ACROSS THE DISCUSSION AREA REACHING THE FAR W ATLC. HOWEVER...SCATTERED SHOWERS ARE WITHIN 100-130 NM OFF THE EASTERN COAST OF THE FLORIDA PENINSULA GENERATED BY DIFFLUENCE FLOW IN THE UPPER LEVELS...BETWEEN THE UPPER TROUGH OVER THE SE CONUS AND THE UPPER ANTICYCLONIC CIRCULATION OVER THE FAR W ATLC. AN UPPER LEVEL CYCLONIC CIRCULATION IS OVER THE CENTRAL ATLC NEAR 25N53W WITH NO ASSOCIATED DEEP CONVECTION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA