000 AXNT20 KNHC 180001 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU JUN 17 2010 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC... ...TROPICAL WAVES... A TROUGH OF LOW PRESSURE IS APPROACHING THE LESSER ANTILLES ALONG 22N57W TO 13N59W. LOW-LEVEL CYCLONIC FLOW REMAINS CONCENTRATED NEAR A 1012 MB LOW ALONG THE AXIS NEAR 16N. SEVERAL DAYS AGO THIS SYSTEM HAD A HIGHER CHANCE OF DEVELOPING INTO A TROPICAL CYCLONE...BUT DUE TO STRONG UPPER LEVEL WINDS THERE IS CURRENTLY A LOW PROBABILITY OF DEVELOPMENT. HOWEVER...THIS SYSTEM CONTINUES TO BE EMBEDDED IN A LARGE AREA OF ENHANCED DEEP LAYER MOISTURE BETWEEN 50W-62W SUPPORTING WIDESPREAD SHOWER ACTIVITY. NUMEROUS STRONG CONVECTION IS NEAR THE LOW CENTER FROM 15N-18N BETWEEN 56W-59W WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 14N-22N BETWEEN 53W-56W. AS THIS SYSTEM MOVES WWD...LOCALLY HEAVY RAINFALL IS POSSIBLE OVER THE LEEWARD ISLANDS...THE VIRGIN ISLANDS...AND PUERTO RICO. TROPICAL WAVE EXTENDS FROM 10N23W TO 3N25W MOVING W 10-15 KT. LAST VISIBLE SATELLITE IMAGES OF THE DAY INDICATE CYCLONIC FLOW ABOUT THE WAVE AXIS CONFIRMED BY SATELLITE DERIVED WINDS. THE WAVE ALSO LIES AHEAD OF A MAXIMUM IN DEEP LAYER MOISTURE SEEN IN TOTAL PRECIPITABLE WATER IMAGERY...WHICH COINCIDES WITH A NWD CLEARING OF THE SAHARAN AIR LAYER. ISOLATED CLUSTERS OF MODERATE CONVECTION ARE WITHIN 150 NM EITHER SIDE OF THE WAVE AXIS. TROPICAL WAVE EXTENDS FROM 11N40W TO 2N42W MOVING W NEAR 15 KT. THE WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. BROAD CYCLONIC FLOW IS IN THE VICINITY OF THE WAVE INDICATED BY SATELLITE IMAGERY. SCATTERED STRONG CONVECTION IS E OF THE WAVE AXIS FROM 5N-10N BETWEEN 35W-41W. TROPICAL WAVE EXTENDS FROM THE MONA PASSAGE NEAR 19N68W TO NW VENEZUELA NEAR 11N72W MOVING W NEAR 15 KT. THE WAVE CONTINUES TO TRACK ALONG AN AREA OF ENHANCED MOISTURE IN TOTAL PRECIPITABLE WATER IMAGERY. HOWEVER...DRY AIR TO THE N CONTINUES TO SUPPRESS CONVECTION. CURRENTLY ISOLATED SHOWERS/THUNDERSTORMS ARE FROM 16N-20N BETWEEN 65W-71W AFFECTING PORTIONS OF PUERTO RICO AND HISPANIOLA. SCATTERED MODERATE/STRONG CONVECTION IS INLAND OVER VENEZUELA/COLOMBIA FROM 9N-12N BETWEEN 70W-75W. CONVECTION ASSOCIATED WITH THIS WAVE HAS THE POTENTIAL TO INCREASE AS IT MOVES WWD UNDER AN UPPER LEVEL TROUGH CURRENTLY ACROSS THE CENTRAL CARIBBEAN. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 10N11W 8N22W 6N33W 7N44W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 8N-13N BETWEEN 13W-17W. ISOLATED MODERATE/STRONG CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 29W-36W. AN EMBEDDED SURFACE TROUGH EXTENDS ALONG 48W S OF 10N COINCIDING WITH A BROAD AREA OF CYCLONIC FLOW. SCATTERED MODERATE/ISOLATED STRONG CONVECTION COVERS THE AREA FROM 2N-10N BETWEEN 43W-57W. ...DISCUSSION... GULF OF MEXICO... A WEAK UPPER LEVEL TROUGH CONTINUES TO IMPACT THE NE GULF EXTENDING DOWN THE ERN U.S. SEABOARD TO THE BIG BEND OF FLORIDA SUPPORTING A SURFACE TROUGH EXTENDING DOWN THE ERN COAST OF FLORIDA S OF CAPE CANAVERAL. RADAR IMAGERY INDICATES SCATTERED SHOWERS/THUNDERSTORMS...SOME LOCALLY HEAVY...ACROSS THE PENINSULA E OF 83W. ISOLATED SHOWERS/THUNDERSTORMS AREA ALSO ACROSS THE FLORIDA PANHANDLE AND THE GULF STATES. A SECOND SURFACE TROUGH LINES THE WRN COAST OF THE YUCATAN PENINSULA FROM 23N90W TO 19N91W. SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 150 NM E OF THE AXIS. ELSEWHERE...UPPER LEVEL RIDGING COVERS THE REMAINDER OF THE WRN BASIN CENTERED OVER SE TEXAS NEAR 28N97W KEEPING CONDITIONS FAIR ACROSS THE REMAINDER OF THE BASIN. THE UPPER LEVEL RIDGE SUPPORTS A WEAK SURFACE RIDGE ANCHORED BY A 1020 MB HIGH S OF MOBILE ALABAMA NEAR 28N88W. LIGHT ANTI-CYCLONIC FLOW IS AROUND THE SURFACE RIDGE. A SECOND UPPER LEVEL TROUGH COVERS THE SE GULF EXTENDING FROM THE CARIBBEAN FURTHER SUPPORTING CONVECTION ACROSS THE FLORIDA PENINSULA. EXPECT WEAK SURFACE RIDGING TO REMAIN ACROSS THE BASIN. CARIBBEAN SEA... AN UPPER LEVEL TROUGH CONTINUES TO COVER THE WRN HALF OF THE CARIBBEAN WITH AXIS EXTENDING FROM JUST E OF NICARAGUA TO THE NW BAHAMAS. UPPER LEVEL DIFFLUENCE AROUND THE BASE OF THE TROUGH IS ENHANCING SHOWERS/THUNDERSTORMS ACROSS THE SW CARIBBEAN S OF 13N W OF 76W AFFECTING PORTIONS OF PANAMA...COSTA RICA...AND NICARAGUA. THE REMAINDER OF THE WRN CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER UNDER THE INFLUENCE OF DRY AIR ALOFT. ISOLATED SHOWERS/THUNDERSTORMS ARE ACROSS THE NE CARIBBEAN NEAR A TROPICAL WAVE EXTENDING FROM THE MONA PASSAGE TO THE NW VENEZUELA COAST. SEE TROPICAL WAVE SECTION ABOVE. AN UPPER LEVEL RIDGE COVERS THE REMAINDER OF THE ERN CARIBBEAN CENTERED OVER THE SRN LESSER ANTILLES NEAR 13N61W KEEPING CONDITIONS FAIR. EXPECT CONVECTION TO INCREASE NEAR THE TROPICAL WAVE AS IT MOVES WWD AND UNDER THE INFLUENCE OF THE UPPER LEVEL TROUGH. ALSO EXPECT SHOWERS/THUNDERSTORMS TO BEGIN IMPACTING THE LEEWARD ISLANDS AS AN ACTIVE SURFACE TROUGH IN THE ATLC MOVES WWD. MORE DETAILS ON THIS FEATURE CAN BE FOUND IN THE TROPICAL WAVE SECTION. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH EXTENDING FROM THE WRN CARIBBEAN TO THE NW BAHAMAS IS ENHANCING ISOLATED SHOWERS/THUNDERSTORMS ACROSS THE ISLANDS FROM 23N-27N BETWEEN 75W-79W. THE REMAINDER OF THE W ATLC IS INFLUENCED BY DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE CENTERED NEAR 29N60W KEEPING CONDITIONS FAIR. AN UPPER LEVEL TROUGH TO THE NE OF THE UPPER RIDGE SUPPORTS A STATIONARY FRONT THAT LINES THE DISCUSSION AREA ALONG 30N/31N BETWEEN 42W-64W. POSSIBLE ISOLATED SHOWERS ARE WITHIN 30 NM EITHER SIDE OF THE AXIS. A DRY UPPER LEVEL LOW IS S OF THE RIDGE AND N OF THE CARIBBEAN CENTERED NEAR 23N64W. UPPER LEVEL DIFFLUENCE BETWEEN THIS UPPER LEVEL LOW AND AN UPPER LEVEL RIDGE TO THE S CENTERED OVER THE SRN LESSER ANTILLES NEAR 13N61W IS ENHANCING CONVECTION NEAR A SURFACE TROUGH/LOW E OF THE LEEWARD ISLANDS. NUMEROUS STRONG CONVECTION IS NEAR THE LOW CENTER FROM 15N-18N BETWEEN 56W-59W WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 14N-22N BETWEEN 53W-56W. SEE TROPICAL WAVE SECTION ABOVE FOR MORE DETAILS ON THIS SYSTEM. FARTHER E...SURFACE RIDGING DOMINATES ANCHORED BY A 1028 MB HIGH N OF THE AZORES ISLANDS NEAR 43N21W PROVIDING GENERALLY FAIR WEATHER ACROSS THE ERN ATLC. ALOFT...AN UPPER LEVEL TROUGH EXTENDS FROM PORTUGAL TO NEAR 19N30W. A BROAD UPPER LEVEL RIDGE EXTENDING FROM THE SRN LESSER ANTILLES COVERS THE TROPICAL ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON