000 AXNT20 KNHC 250000 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI SEP 24 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. ...SPECIAL FEATURES... TROPICAL STORM MATTHEW IS CENTERED NEAR 14.9N 84.4W AT 25/0000 UTC OR ABOUT 70 NM W OF CABO GRACIAS A DIOS ON NICARAGUA/ HONDURAS BORDER MOVING W AT 13 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 998 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT5/WTNT35 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. MATTHEW MADE LANDFALL THIS AFTERNOON ALONG THE NE COAST OF NICARAGUA. NUMEROUS STRONG CONVECTION IS INLAND OVER NE NICARAGUA/NW HONDURAS WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION COVERING THE REMAINDER OF THE AREA FROM 12N-20N BETWEEN 80W-88W. MATTHEW CAN CONTINUE TO PRODUCE HEAVY RAINS WITH TOTAL RAIN ACCUMULATIONS OF 6 TO 10 INCHES OVER PORTIONS OF NICARAGUA AND HONDURAS AND ISOLATED MAXIMUM AMOUNTS OF UP TO 15 INCHES ARE POSSIBLE OVER THE NEXT COUPLE OF DAYS. THESE RAINS COULD PRODUCE LIFE THREATENING FLASH FLOODS AND MUD SLIDES. TROPICAL STORM LISA WAS UPGRADED TO HURRICANE AT 24/2300 UTC. HURRICANE LISA IS CENTERED NEAR 20.2N 27.8W AT 24/2300 UTC OR ABOUT 335 NM NW OF THE CAPE VERDE ISLANDS MOVING N AT 7 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 989 MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH GUSTS TO 80 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. SATELLITE IMAGERY SHOWS THAT ALTHOUGH LISA IS A SMALL STORM IN RELATION TO THE CONVECTION AND HAS INCREASED IN INTENSITY TO BECOME A HURRICANE WITH A VERY SMALL EYE FEATURE. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 19N21N BETWEEN 26W-29W. ...ITCZ... THE ITCZ IS ANALYZED SW OF HURRICANE LISA NEAR 11N34W 11N43W 13N54W 12N60W. SMALL CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 3N-8N BETWEEN 20W-30W AND FROM 5N-9N BETWEEN 35W-45W. ...DISCUSSION... GULF OF MEXICO... A NARROWING UPPER RIDGE EXTENDS FROM N/CENTRAL MEXICO ACROSS TEXAS TO THE LOWER MISSISSIPPI VALLEY NEAR THE LOUISIANA/ ARKANSAS BORDER COVERING THE FAR NW GULF ALONG THE COAST OF TEXAS. THIS UPPER RIDGE IS FOLLOWED CLOSELY BY A DEEP LAYERED TROUGH AND ASSOCIATED FRONTAL BOUNDARY WITH STRONG SUBSIDENCE AND VERY DRY AIR IN WAKE OF THE FRONT. A SECOND UPPER RIDGE COVERS THE S GULF S OF 26N AND ANCHORED OVER THE YUCATAN CHANNEL. THESE UPPER RIDGES ARE INDUCING AN UPPER TROUGH THAT EXTENDS THROUGH AN UPPER LOW OVER SE LOUISIANA NEAR NEW ORLEANS SW TO BETWEEN TAMPICO MEXICO AND BROWNSVILLE TEXAS. A SQUALL LINE/SEABREEZE SURFACE TROUGH IS MOVING OFFSHORE ALONG THE FLORIDA PENINSULA FROM 24N-29N ALONG 83W AT 24/2100 UTC GENERATING A NARROW BAND OF HEAVY SHOWERS/NUMEROUS THUNDERSTORMS WITHIN 45 NM ALONG THE TROUGH AXIS. THE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 120/150 NM OF A LINE FROM THE N GULF COAST NEAR THE ALABAMA/MISSISSIPPI BORDER TO 25N94W AND S OF 25N TO THE YUCATAN CHANNEL BETWEEN 83W-86W. CARIBBEAN SEA... THE MAIN CONCERN THIS EVENING IS TROPICAL STORM MATTHEW AS IT CONTINUES ACROSS PORTIONS OF CENTRAL AMERICA...SEE SURFACE FEATURES ABOVE. BROAD UPPER RIDGE COVERS THE CARIBBEAN W OF 76W ANCHORED OVER THE YUCATAN CHANNEL AND IS PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 11N ACROSS JAMAICA AND OVER CUBA BETWEEN 75W-80W. AN UPPER LOW IS CENTERED OVER HISPANIOLA NEAR 19N72W COVERING THE AREA N OF 15N BETWEEN 66W-75W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 14N BETWEEN 66W-74W TO OVER HISPANIOLA. NORTHERLY FLOW ALOFT COVERS THE S CARIBBEAN WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 14N BETWEEN 68-77W TO INLAND OVER COLOMBIA. THIS IS LEAVING THE LESSER ANTILLES UNDER MOSTLY CLEAR SKIES THIS EVENING. ATLANTIC OCEAN... A CONCERN FOR THE FAR E ATLC IS HURRICANE LISA...SEE SPECIAL FEATURES ABOVE. THE UPPER RIDGE ANCHORED OVER THE YUCATAN CHANNEL EXTENDS AN UPPER RIDGE AXIS NE ALONG 25N80W TO 30N75W PROVIDING DIFFLUENCE ALOFT TO GENERATE ISOLATED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FROM 23N-27N BETWEEN 76W-80W TO THE COAST OF THE FLORIDA PENINSULA. AN UPPER LOW CENTERED OVER HISPANIOLA COVERS THE W ATLC S OF 24N BETWEEN 66W-74W. BROAD UPPER RIDGE ANCHORED NEAR 23N54W DOMINATES THE REMAINDER OF THE W ATLC AND THE CENTRAL ATLC WITH MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR. A REMNANT 1014 MB SURFACE LOW IS CENTERED NEAR 31N44W WITH A SURFACE TROUGH EXTENDING FROM 31N42W 28N41W TO 24N42W WITH SCATTERED SHOWERS WITHIN 60 NM OF THE SURFACE LOW. A LARGE UPPER RIDGE REMAINS ANCHORED INLAND OVER AFRICA EXTENDING INTO THE E ATLC TO NEAR 20W AND DRAWING TROPICAL MOISTURE N AND NE FROM HURRICANE LISA WITH ISOLATED SHOWERS WITHIN 150 NM OF LINE FROM 23N28W 26N25W TO BEYOND 32N16W INCLUDING THE CANARY ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW