000 AXNT20 KNHC 241749 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON SEP 24 2012 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 1700 UTC. GOES-E IS CURRENTLY EXPERIENCING AN OUTAGE. GOES-W IS IN FULL DISK MODE TO PROVIDE IMAGERY OVER THE CONUS AND GULF OF MEXICO. ...SPECIAL FEATURES... TROPICAL STORM NADINE WAS LOCATED NEAR 31.7N 27.8W AT 24/1500 UTC. THIS POSITION IS LOCATED ABOUT 380 NM S OF THE AZORES ISLANDS. NADINE IS MOVING WNW NEAR 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 993 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUST TO 55 KT. PLEASE SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. SCATTERED MODERATE CONVECTION IS FROM 33N-34N BETWEEN 26N-28N...AND FROM 31N-32N BETWEEN 28W-30W. ...TROPICAL WAVES... TROPICAL WAVE IS E OF THE LESSER ANTILLES EXTENDING FROM 17N57W TO 11N59W MOVING W AT 15 KT. THE WAVE HAS LOST A LOT OF ITS ENERGY AS SOME OF THE ENERGY WAS SPREAD OUT HORIZONTALLY AHEAD OF IT...WHICH IS EVIDENT IN THE HIGH MOISTURE VALUES ACROSS THE SE CARIBBEAN. THERE IS ALSO A SMALL PATCH OF ENHANCED MOISTURE EAST OF THE WAVE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS WEST AFRICA TO THE COAST OF MAURITANIA AT 19N16W AND CONTINUES ACROSS THE ATLC ALONG 13N22W 9N28W 8N32W. THE ITCZ BEGINS AT 8N32W ALONG 10N40W 11N46W. SCATTERED MODERATE CONVECTION IS FROM 11N-13N BETWEEN 18W-20W. SIMILAR ACTIVITY IS FROM 7N-10N BETWEEN 21W-36W. ...DISCUSSION... GULF OF MEXICO... SATELLITE IMAGERY IS LIMITED ACROSS THE GULF OF MEXICO DUE TO THE GOES-E OUTAGE. MORE RELIANCE HAS BEEN PLACED ON BOTH SURFACE OBSERVATIONS AND MODEL DATA. THE COLD FRONT THAT HAS BEEN MOVING THROUGH THE BASIN HAS BECOME STATIONARY AS OF 1500 UTC. IT EXTENDS FROM NEAR LAKE OKEECHOBEE FLORIDA AT 27N81W TO 24N86W AND ENDING NEAR 25N92W. THE FRONT IS SUPPORTED BY A BROAD UPPER LEVEL TROUGH MOVING OFF THE EASTERN UNITED STATES SEABOARD. A SHORTWAVE UPPER TROUGH AXIS IS ALSO EXTENDING DOWN THE WESTERN GULF ALONG 94W. FROM THE AVAILABLE WATER VAPOR IMAGERY...DRY AIR ALOFT COVERS THE MAJORITY OF THE NORTHERN GULF WHERE CLEAR SKIES AND FAIR WEATHER ARE NOTED. MOIST CONDITIONS COVER THE REMAINDER OF THE BASIN NEAR THE FRONT AND NEAR A SURFACE TROUGH IN THE SW GULF ALONG 22N95W TO 18N93W. IT APPEARS THAT SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 25N ACROSS THE BASIN WITH RADAR IMAGERY INDICATING SIMILAR ACTIVITY THROUGH THE FLORIDA STRAITS. MODEL GUIDANCE INDICATES THAT THE FRONT WILL REMAIN STATIONARY AND EVENTUALLY DISSIPATE WITH THE MOISTURE ASSOCIATED WITH IT RETREATING NORTHWARD IN THE MIDDLE OF THE WEEK. CARIBBEAN SEA... THE CARIBBEAN IS HIT HARDEST WITH THE SATELLITE OUTAGE WITH ONLY A PORTION OF THE NW CARIBBEAN BEGIN COVERED BY THE GOES-W FULL DISK IMAGERY. SOME VERY LOW RESOLUTION DATA IS AVAILABLE ON THE WESTERN EDGE OF METEOSAT-9 IMAGERY...WHICH COVERS THE FAR EASTERN CARIBBEAN. THIS LEAVES THE CENTRAL CARIBBEAN MOSTLY IN THE DARK BESIDES SURFACE OBSERVATIONS AND MODEL GUIDANCE. LUCKILY...IT APPEARS THAT MOSTLY FAIR WEATHER PREVAILS ACROSS THE MAJORITY OF THE BASIN. THE NW CARIBBEAN AND MUCH OF CENTRAL AMERICA ARE UNDER MOSTLY CLEAR SKIES. THE MONSOON TROUGH EXTENDS FROM COSTA RICA TO NORTHERN COLOMBIA. EVEN WITHOUT SATELLITE IMAGERY...LIGHTNING DATA HELPS TO INDICATE THAT SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS PORTIONS OF COSTA RICA...PANAMA...AND NORTHERN COLOMBIA. TOTAL PRECIPITABLE WATER IMAGERY ALSO INDICATES HIGHER MOISTURE VALUES ARE ACROSS THIS AREA...AS WELL AS ACROSS THE SE CARIBBEAN. THE LOW RESOLUTION DATA AVAILABLE FROM METEOSAT-9 INDICATES THAT SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS THE SE CARIBBEAN S OF 15N BETWEEN 62W-66W. ASCAT SCATTEROMETER DATA INDICATES THAT TRADEWIND FLOW IS PRESENT ACROSS MUCH OF THE BASIN WITH SPEEDS OF 15-20 KTS. ALOFT...AN UPPER LEVEL RIDGE EXTENDS FROM GUATEMALA ACROSS CENTRAL CUBA INTO THE WEST ATLC. AN UPPER LEVEL TROUGH EXTENDS FROM PUERTO RICO TO COLOMBIA COVERING THE CENTRAL AND EASTERN CARIBBEAN. THIS IS BASED MAINLY ON MODEL GUIDANCE. MUCH OF THE SOUTHERN HALF OF THE CARIBBEAN WILL REMAIN MOIST FOR THE NEXT 24 HOURS. A TROPICAL WAVE EAST OF THE LESSER ANTILLES WILL APPROACH THE EASTERN CARIBBEAN WITHIN THE NEXT 24 HOURS. ATLANTIC OCEAN... THE WESTERN ATLC IS UNDER LIMITED SATELLITE IMAGERY TODAY. LUCKILY THE GOES-W FULL DISK IMAGERY DOES CAPTURE THE COLD FRONT DRAPED ACROSS THE BASIN. IT ENTERS THE DISCUSSION AREA NEAR 32N71W CONTINUING ALONG 28N76W TO THE COAST OF FLORIDA AT 27N80W. A SURFACE TROUGH IS AHEAD OF THE FRONT ALONG 27N76W. THE FRONT IS NEAR THE EDGE OF THE IMAGERY SO THE RESOLUTION IS NOT VERY GOOD...BUT IT APPEARS THAT SCATTERED SHOWERS/ISOLATED THUNDERSTORMS EXTEND 200 NM SE OF THE AXIS. THE FRONT IS SUPPORTED BY AN UPPER LEVEL TROUGH MOVING OFF THE EASTERN SEABOARD. AN UPPER LEVEL RIDGE IS TO THE E EXTENDING FROM CENTRAL CUBA TO NEAR 33N62W SUPPORTING SURFACE RIDGING ACROSS THE REMAINDER OF THE W ATLC EXTENDING FROM A HIGH CENTER IN THE N CENTRAL ATLC. NO SATELLITE IMAGERY IS AVAILABLE ACROSS THIS AREA...BUT THERE IS LIKELY LITTLE ACTIVE WEATHER. METEOSAT-9 CAPTURES THE CENTRAL ATLC ON THE EDGE OF ITS IMAGERY PROVIDING SOME INSIGHT OVER THIS AREA. AN UPPER LEVEL LOW IS SPINNING NEAR 27N58W AND IS SUPPORTING A FEW POSSIBLE SHOWERS N OF 25N BETWEEN 56W-58W. FARTHER E...A WEAK SURFACE TROUGH EXTENDS FROM 22N44W TO 20N47W WITH POSSIBLE ISOLATED SHOWERS WITHIN 100 NM EITHER SIDE OF ITS AXIS. THE REMAINDER OF THE E ATLC IS COVERED BY WEAK SURFACE RIDGING AROUND A 1016 MB HIGH NEAR 21N28W. TROPICAL STORM NADINE IS N OF THE HIGH CENTER. SEE SPECIAL FEATURES ABOVE. ALOFT...AN UPPER LEVEL TROUGH EXTENDS FROM NEAR 28N34W TO 12N46W. UPPER LEVEL RIDGING COVERS THE REMAINDER OF THE EAST ATLC CENTERED OVER NW AFRICA NEAR 22N12W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON