000 AXNT20 KNHC 310003 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT AUG 30 2008 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... HURRICANE GUSTAV IS CENTERED NEAR 22.7N 83.4W AT 31/0000 UTC OR OVER WESTERN CUBA NEAR LOS PALACIOS AND 55 NM WEST-SOUTHWEST OF HAVANA CUBA MOVING NW AT 13 KT. THE MINIMUM CENTRAL PRESSURE RECENTLY REPORTED BY A NOAA RECONNAISSANCE AIRCRAFT AS GUSTAV WAS MAKING LANDFALL ACROSS WRN CUBA WAS 941 MB. MAXIMUM SUSTAINED WIND SPEED IS 130 KT WITH HIGHER GUSTS. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/ WTNT22 KNHC AND/OR THE PUBLIC ADVISORY MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS. GUSTAV IS BEGINNING TO TRACK ACROSS WRN CUBA AND REMAINS AN EXTREMELY DANGEROUS CATEGORY FOUR HURRICANE ON THE SAFFIR-SIMPSON HURRICANE SCALE. FURTHER STRENGTHENING IS FORECAST ONCE GUSTAV REACHES THE WARMER WATERS OF THE SE GULF OF MEXICO. OUTFLOW REMAINS GOOD IN ALL QUADRANTS WITH SCATTERED/ NUMEROUS STRONG CONVECTION WITHIN 90 NM OF THE CENTER IN ALL QUADRANTS. SCATTERED MODERATE/STRONG CONVECTION COVERS THE REMAINDER OF THE AREA FROM 18N-30N BETWEEN 78W-87W...INCLUDING OUTER RAINBANDS OF SCATTERED SHOWERS/ISOLATED TSTMS ACROSS THE FLORIDA PENINSULA AND ERN GULF OF MEXICO. TROPICAL STORM HANNA IS CENTERED NEAR 22.8N 67.3W AT 31/0000 UTC OR ABOUT 230 NM EAST-NORTHEAST OF GRAND TURK ISLAND MOVING WNW AT 5 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC AND/OR THE PUBLIC ADVISORY MIATCPAT3/ WTNT33 KNHC FOR MORE DETAILS. HANNA CONTINUES TO EXPERIENCE WLY SHEAR RESULTING WITH MUCH OF THE CONVECTION LOCATED IN THE NE QUADRANT OF THE STORM. SCATTERED/NUMEROUS STRONG CONVECTION IS FROM 22N-25N BETWEEN 63W-67W WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION COVERING THE REMAINDER OF THE AREA FROM 17N-22N BETWEEN 61W-65W...INCLUDING THE US/UK VIRGIN ISLANDS AND THE NRN LEEWARD ISLANDS NORTH OF GUADELOUPE. TROPICAL WAVE IS ALONG 26W/27W S OF 20N WITH A 1008 MB SURFACE LOW ALONG THE WAVE NEAR 14.5N MOVING W 10-15 KT. A BROAD MID LEVEL CYCLONIC ROTATION IS OBSERVED ON SATELLITE IMAGERY WITH ASSOCIATED CONVECTION MOSTLY LOCATED NORTH OF THE LOW. SCATTERED MODERATE CONVECTION IS FROM 15N-18N BETWEEN 25W-28W. SCATTERED SHOWERS COVER THE REMAINDER OF THE AREA FROM 14N-22N BETWEEN 21W-30W. CONDITIONS APPEAR CONDUCIVE FOR DEVELOPMENT AND THIS SYSTEM COULD BECOME A TROPICAL DEPRESSION DURING THE NEXT COUPLE OF DAYS. ...TROPICAL WAVES... TROPICAL WAVE IS FROM 25N46W THROUGH A 1009 MB LOW NEAR 21N46W TO 15N47W MOVING WNW NEAR 10 KT. INVERTED-V SATELLITE SIGNATURE IS OBSERVED WELL N OF THE ITCZ. CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE FROM 19N-24N BETWEEN 42W-46W AND ARE BEING ENHANCED BY UPPER LEVEL DIFFLUENCE E OF A MID-UPPER TROUGH OVER THE ATLC. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 19N16W 18N24W...DISRUPTED BY THE TROPICAL WAVE ALONG 26W/27W TO...11N28W 12N44W 10N61W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ALONG THE W AFRICAN COAST FROM 8N-11N BETWEEN 11W-15W. SCATTERED SHOWERS AND POSSIBLE ISOLATED TSTMS ARE WITHIN 120 NM OF A LINE FROM 9N23W TO 9N39W. ...DISCUSSION... GULF OF MEXICO... HURRICANE GUSTAV IS THE FOCUS FOR THE SE GULF...STRAITS OF FLORIDA AND FLORIDA PENINSULA AS IT CONTINUES TRACKING NW ACROSS WRN CUBA...SEE SPECIAL FEATURES ABOVE. BROAD UPPER TROUGH DOMINATES MOST OF THE GULF EXTENDING S FROM NEAR NEW ORLEANS LOUISIANA TO THE YUCATAN PENINSULA AND BELIZE. UPPER RIDGE OVER NE MEXICO EXTENDS ACROSS THE WRN GULF W OF 94W AND IS PROVIDING UPPER LEVEL DIFFLUENCE TO GENERATE CLUSTERS OF SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE FAR WRN GULF W OF A LINE FROM BROWNSVILLE TEXAS TO OVER THE ISTHMUS OF TEHUANTEPEC IN SRN MEXICO. THE UPPER RIDGE ASSOCIATED WITH HURRICANE GUSTAV IS PROVIDING VERY FAVORABLE UPPER LEVEL DIFFLUENCE E OF THE UPPER TROUGH GENERATING SCATTERED SHOWERS AND TSTMS S OF 31N E OF 87W TO OVER THE FLORIDA PENINSULA. MODERATE SUBSIDENCE/DRY AIR IS NOTED WITHIN 120 NM OF THE UPPER TROUGH AXIS ALONG 92W N OF THE YUCATAN PENINSULA TO OVER LOUISIANA AND FAR ERN TEXAS. CARIBBEAN SEA... THE MAIN CONCERN CONTINUES TO BE HURRICANE GUSTAV FOR THE NW CARIBBEAN...SEE SPECIAL FEATURES ABOVE. SCATTERED SHOWERS REMAIN OVER THE NRN LEEWARD ISLANDS AND THE VIRGIN ISLANDS ASSOCIATED WITH OUTER RAINBANDS OF T.S. HANNA. BROAD UPPER HIGH ASSOCIATED WITH GUSTAV IS DOMINATING THE CARIBBEAN W OF 72W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ASSOCIATED WITH UPPER DIFFLUENCE ARE OVER THE WRN CARIBBEAN FROM 12N-15N BETWEEN 74W-77W AND AN AREA OVER THE GULF OF HONDURAS W OF 85W. AN UPPER HIGH IS CENTERED IN THE NE CARIBBEAN NEAR 16N64W EXTENDING A RIDGE OVER THE ERN CARIBBEAN TO 72W. MODERATE SUBSIDENCE AND DRY AIR CONTROL THE ERN CARIBBEAN LIMITING SHOWERS OVER THE AREA INCLUDING THE WINDWARD ISLANDS...EXCEPTION BEING THE ACTIVITY IN ASSOCIATION WITH T.S. HANNA OVER THE LEEWARD AND VIRGIN ISLANDS. ATLANTIC OCEAN... MAIN FOCUS FOR THE ATLC IS OVER THE SW ATLC IN ASSOCIATION WITH HURRICANE GUSTAV AND IN THE VICINITY N OF PUERTO RICO WITH T.S. HANNA...SEE SPECIAL FEATURES ABOVE. THE UPPER HIGH ASSOCIATED WITH HURRICANE GUSTAV IN THE CARIBBEAN EXTENDS ACROSS CUBA AND THE BAHAMAS OVER THE FAR W ATLC PROVIDING UPPER LEVEL DIFFLUENCE TO GENERATE SCATTERED SHOWERS/ISOLATED TSTMS S OF 31N W OF 76W ACROSS THE NW BAHAMA ISLANDS AND CUBA TO OVER THE FLORIDA PENINSULA AND THE STRAITS OF FLORIDA. A WEAKENING UPPER LOW REMAINS N OF HISPANIOLA NEAR 21N69W AND IS PROVIDING T.S. HANNA WITH JUST ENOUGH UPPER LEVEL SHEAR TO LIMIT CONVECTION ON THE WRN SIDE OF THE STORM. SCATTERED STRONG CONVECTION HAS FLARED UP OVER THE PAST 3-6 HOURS SW OF THE CENTER FROM 21N-23N BETWEEN 67W-70W. A SHARP UPPER TROUGH IS IN THE CENTRAL ATLC EXTENDING THROUGH 32N48W S TO 19N48W. ANOTHER UPPER TROUGH CONTINUES TO SLIDE EWD OVER THE NE ATLC N OF 24N FROM 14W-28W INDUCING AN AMPLIFYING UPPER RIDGE TO THE W WHICH IS ENHANCING THE SCATTERED SHOWERS ASSOCIATED WITH THE TROPICAL WAVE IN THE CENTRAL ATLC. AN UPPER RIDGE IS CENTERED N OF THE CAPE VERDE ISLANDS AND IS AIDING IN GENERATING THE CONVECTIVE ACTIVITY ASSOCIATED WITH THE TROPICAL WAVE IN THE SPECIAL FEATURES. ALSO AT THE SURFACE...A SURFACE RIDGE OF HIGH PRESSURE REMAINS OVER MUCH OF THE ATLC N OF 26N E OF 55W AND N OF 30N E OF 75W ANCHORED BY A SERIES OF HIGHS N OF THE REGION. $$ HUFFMAN