000 AXNT20 KNHC 182351 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE MAY 18 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... TROPICAL WAVE IS ALONG 22W S OF 9N MOVING W AT 10-15 KT AND IS BASED ON ANALYSIS OF THE HOVMOLLER DIAGRAM ACROSS THE EASTERN TROPICAL ATLC AND PREVIOUS CONTINUITY. THE WAVE COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE EVIDENT ON TOTAL PRECIPITABLE WATER IMAGERY. ALSO OF NOTE...A STRONG SAHARAN AIR LAYER (SAL) IS DETECTED NORTH OF 11N E OF 30W...MAINLY NORTH OF THE WAVE AXIS. SCATTERED MODERATE CONVECTION IS EMBEDDED WITHIN THE ITCZ AND IS FROM 3N-8N BETWEEN 17W-24W. TROPICAL WAVE IS ALONG 41W S OF 11N MOVING W AT 10-15 KT. THE WAVE IS EMBEDDED IN A BROAD AREA OF DEEP LAYER MOISTURE AS NOTED IN TOTAL PRECIPITABLE WATER IMAGERY. WITH ELEVATED AREAS OF TPW AND CLOSE PROXIMITY TO THE ITCZ AXIS...SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 3N-8N BETWEEN 36W-45W. TROPICAL WAVE EXTENDS FROM 14N65W TO 2N67W MOVING W AT 10-15 KT. THE WAVE COINCIDES WITH AN AREA OF MAXIMUM DEEP LAYER MOISTURE LOCATED OVER THE SE CARIBBEAN SEA. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS OCCURRING E OF THE WAVE AXIS FROM 6N-11N BETWEEN 59W-65W. TROPICAL WAVE IS ALONG 76W S OF 11N MOVING W AT 10-15 KT. SCATTERED MODERATE TO STRONG CONVECTION IS E OF THE WAVE AXIS FROM 6N-11N BETWEEN 68W-75W AND WITHIN 90 NM OF THE AXIS FROM 2N-8N. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 10N14W 6N22W 5N41W AND INTO NORTHERN S AMERICA ALONG 4N51W TO 6N65W. SCATTERED MODERATE CONVECTION IS S OF 6N BETWEEN 24W-36W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL SHORTWAVE TROUGH IS PROGRESSING ACROSS THE NW GULF WITH AXIS FROM THE LOUISIANA COAST TO 22N93W. THIS UPPER LEVEL FEATURE ALONG WITH MOIST S-SW SURFACE FLOW SOUTH OF AN STATIONARY FRONT LOCATED ACROSS EASTERN TEXAS...NORTHERN LOUISIANA...AND CENTRAL MISSISSIPPI IS GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS ALONG THE GULF COAST FROM THE FLORIDA PANHANDLE NEAR PANAMA CITY WESTWARD TO SE LOUISIANA THEN SW OVER THE NW GULF WATERS N OF 25N W OF 90W. EAST OF THE CONVECTIVE ACTIVITY...A WEAK 1016 MB HIGH IS CENTERED OVER THE CENTRAL GULF NEAR 27N89W. THE SURFACE RIDGE EXTENDS ALONG 26N EASTWARD INTO THE W ATLC REGION...HOWEVER A MID-LEVEL WEAKNESS EXTENDS ACROSS THE FLORIDA PENINSULA TO THE YUCATAN PENINSULA AND SUPPORTS SURFACE TROUGHING OVER PORTIONS OF THE SOUTHERN FLORIDA PENINSULA AND EASTERN BAY OF CAMPECHE. A SURFACE TROUGH IS ANALYZED FROM 23N90W TO 17N91W AND CONTINUES TO PROVIDE FOCUS FOR ISOLATED SHOWERS OVER THE SE GULF S OF 25N E OF 92W... INCLUDING PORTIONS OF WESTERN CUBA AND THE YUCATAN PENINSULA THIS EVENING. CARIBBEAN SEA... DIFFLUENT FLOW ALOFT BETWEEN AN UPPER LEVEL SHORTWAVE TROUGH ACROSS THE WESTERN GULF OF MEXICO AND AN UPPER LEVEL RIDGE AXIS FROM HONDURAS TO NW VENEZUELA IS SUPPORTING SCATTERED SHOWERS AND TSTMS OVER A MAJORITY OF THE NW CARIBBEAN...YUCATAN PENINSULA...AND CUBA. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS COVER THE REMAINDER OF THE AREA NW OF A LINE FROM THE MONA PASSAGE TO SOUTHERN NICARAGUA NEAR 12N84W. A SURFACE TROUGH... EMBEDDED WITHIN THE EASTERLY TRADEWIND FLOW...ANALYZED FROM 21N68W TO 17N71W...CONTINUES TO BRING INCREASED MOISTURE... SCATTERED SHOWERS AND ISOLATED TSTMS TO THE ISLAND OF HISPANIOLA THIS EVENING. ALSO LOCATED WITHIN MID-LEVEL TROUGHING ACROSS THE NORTH-CENTRAL CARIBBEAN...THIS FEATURE HAS CONTINUED TO PROVIDE PLENTIFUL PRECIPITATION OVER PUERTO RICO AND HISPANIOLA OVER THE LAST 24-36 HOURS. THE REMAINDER OF THE CARIBBEAN E OF 70W IS EXPERIENCING MODERATE TO FRESH TRADEWINDS WITH GENERALLY FAIR SKIES ACROSS THE LESSER ANTILLES. ATLANTIC OCEAN... MID-LEVEL TROUGHING EXTENDS ACROSS THE W ATLC THAT SUPPORTS A SURFACE TROUGH ANALYZED FROM THE SOUTHERN FLORIDA PENINSULA ALONG 29N78W TO BEYOND 32N76W. AS A MAJORITY OF THE ENERGY ASSOCIATED WITH THE UPPER LEVEL TROUGH MOVE NE OF THE AREA... CONVECTIVE ACTIVITY CONTINUES TO DIMINISH THIS EVENING...HOWEVER ISOLATED SHOWERS LINGER WITHIN 90 NM E OF THE SURFACE TROUGH N OF 31N. FARTHER SE...ANOTHER SURFACE TROUGH IS FROM 20N-27N ALONG 60W AND CONTINUES TO GENERATE ISOLATED SHOWERS WITHIN 250 NM EITHER SIDE OF THE TROUGH AXIS. THE REMAINDER THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1030 MB HIGH CENTERED EAST OF THE AZORES NEAR 40N18W. THE SURFACE RIDGE AXIS EXTENDS SW FROM THE HIGH TO 28N40W AND THEN WESTWARD TO 28N75W. A STATIONARY FRONT REMAINS ALONG 32N BETWEEN 45W-65W WITH POSSIBLE ISOLATED SHOWERS WITHIN 90 NM OF THE FRONTAL BOUNDARY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN