000 AXNT20 KNHC 220005 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU JUN 21 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...SPECIAL FEATURES... HURRICANE CHRIS BECAME A TROPICAL STORM AT 21/2100 UTC CENTERED NEAR 42.4N 42.9W OR ABOUT 585 NM ESE OF CAPE RACE NEWFOUNDLAND MOVING NNE AT 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB. MAXIMUM SUSTAINED WIND SPEED IS 60 KT WITH GUSTS TO 75 KT. SCATTERED MODERATE CONVECTION IS OCCURRING WITHIN 120 NM OF CENTER IN ALL QUADRANTS. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. AN ELONGATED SURFACE TROUGH EXTENDS FROM THE NE GULF OF MEXICO ALONG A 1007 MB LOW CENTERED NEAR THE NRN COAST OF THE YUCATAN PENINSULA NEAR 22N89W INTO INLAND PORTIONS OF THE YUCATAN PENINSULA AROUND 18N90W. MARINE AND SURFACE OBSERVATIONS REGISTER A SHARP CYCLONIC TURNING ALONG THE TROUGH AXIS WITH SE WINDS ON THE ERN SIDE OF THE AXIS GUSTING TO NEAR GALE FORCE CRITERIA. DOPPLER RADAR AND INFRA-RED SATELLITE IMAGERY INDICATED SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS OVER MUCH OF THE CENTRAL AND EASTERN GULF OF MEXICO AND THE NORTHWESTERN CARIBBEAN SEA...AND ALSO OVER THE YUCATAN PENINSULA...WESTERN AND CENTRAL CUBA...SOUTHERN FLORIDA...AND THE NORTHWESTERN BAHAMAS FROM 18N-28N BETWEEN 75W-90W. THIS SYSTEM IS GRADUALLY BECOMING BETTER DEFINED AND SURFACE PRESSURES ARE SLOWLY FALLING ACROSS THE AREA. UPPER-LEVEL WINDS ARE ALSO IMPROVING AND ARE FORECAST TO BECOME MORE CONDUCIVE FOR DEVELOPMENT OF A TROPICAL DEPRESSION DURING THE NEXT DAY OR SO. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES SLOWLY NORTHWARD INTO THE CENTRAL GULF OF MEXICO. INTERESTS ALONG THE ENTIRE UNITED STATES GULF COAST SHOULD MONITOR THE PROGRESS OF THIS LARGE DISTURBANCE THROUGH THE WEEKEND. HEAVY RAINS AND LOCALIZED FLOODING ARE POSSIBLE ACROSS THE YUCATAN PENINSULA...WESTERN CUBA...AND SOUTHERN FLORIDA THROUGH SATURDAY. AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT IS SCHEDULED TO INVESTIGATE THE SYSTEM TOMORROW AFTERNOON...IF NECESSARY. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM NEAR THE CAPE VERDE ISLANDS NEAR 15N25W TO 7N30W MOVING W AT 5-10 KT. THE WAVE PRECEDES A SURGE OF DEEP MOISTURE ON TOTAL PRECIPITABLE WATER IMAGERY. HOWEVER...NO SIGNIFICANT CONVECTION IS ASSOCIATED WITH THE WAVE AT THIS TIME...DUE TO SAHARAN DUST COVERING MUCH OF THE TROPICAL NORTH ATLC WATERS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE WESTERN AFRICAN COAST OF GUINEA-BISSAU NEAR 12N16W ALONG 8N22W TO 7N29W. THE ITCZ BEGINS W OF A TROPICAL WAVE NEAR 6N32W ALONG 7N43W TO 5N55W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 160 NM ON EITHER SIDE OF THE MONSOON TROUGH BETWEEN 17W-29W. SCATTERED WEAK SHOWERS ARE WITHIN 150 NM N OF THE ITCZ. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LOW SPINNING OVER SRN TEXAS PROVIDING MIDDLE TO UPPER LEVEL LIFTING TO THE WESTERN GULF AS WELL AS TROPICAL MOISTURE FROM THE ERN TROPICAL PACIFIC REGION...GENERATING SCATTERED SHOWERS AND THUNDERSTORMS N OF 21N W OF 92W. THE SECOND REGION OF ACTIVE WEATHER OVER THE GULF IS ASSOCIATED TO A BROAD/ELONGATED LOW PRESSURE SYSTEM DISCUSSED IN THE SPECIAL FEATURES SECTION ABOVE. COMPUTER MODELS SUGGEST THIS SYSTEM WILL CONTINUE TO GENERATE STRONG CONVECTION OVER A GREAT PORTION OF THE ERN GULF DURING THE NEXT 24 HOURS...WITH THE POTENTIAL OF FURTHER DEVELOPMENT DURING THE FORECAST PERIOD. CARIBBEAN SEA... SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS REMAIN OVER THE NW CARIBBEAN WATERS N OF 18N W OF 79W...ASSOCIATED TO THE BROAD SURFACE CYCLONIC WIND FIELD FROM THE SPECIAL FEATURE LOW PRESSURE SYSTEM CENTERED NEAR THE NRN COAST OF THE YUCATAN PENINSULA. PERSISTENT CONVECTION IS FORECAST TO CONTINUE ACROSS THE NW CARIBBEAN DURING THE NEXT FEW DAYS. LOCALLY HEAVY RAINFALL WITH THE HIGH POTENTIAL FOR FLOODING AND MUDSLIDES IS LIKELY OVER PORTIONS OF CUBA AND THE YUCATAN PENINSULA DURING THE FORECAST PERIOD. OTHERWISE...FAIR WEATHER CONDITIONS ARE ACROSS THE REMAINDER OF THE CARIBBEAN THIS EVENING...WITH 10-20 KT EASTERLY TRADES OBSERVED E OF 80W. JUST A PORTION OF THE MONSOON TROUGH EXTENDS ACROSS THE FAR SW CARIBBEAN FROM NRN COLOMBIA TO WRN PANAMA. HOWEVER...THE CONVECTION REMAINS OUT OF THE DISCUSSION AREA OVER THE ERN TROPICAL PACIFIC WATERS. AN AREA OF ENHANCED SUSPENDED SAHARAN DUST IS ACROSS THE EASTERN CARIBBEAN SEA. IMPACTS WILL CONTINUE TO BE HAZY SKY CONDITIONS OVER THE NEXT FEW DAYS. ATLANTIC OCEAN... WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LOW SPINNING NEAR 28N70W SUPPORTING A SURFACE TROUGH ANALYZED FROM 31N67W TO 24N73W. WHILE SCATTERED WEAK SHOWERS ARE IN THE VICINITY OF THE SURFACE TROUGH...MOST OF THE HEAVIEST CONVECTION ASSOCIATED TO THIS SYSTEM IS WELL OUTSIDE THE LOCATION OF THE SURFACE FEATURE ...DUE TO STRONG DIFFLUENCE ALOFT TO THE S AND SE...GENERATING A BROAD AREA OF SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS FROM 21N-27N BETWEEN 62W-70W...AS WELL AS FROM 21N-25N BETWEEN 70W-80W. HEAVY RAINS AND LOCALIZED FLOODING ARE POSSIBLE ACROSS THE CENTRAL AND NW BAHAMAS THROUGH SATURDAY. OTHERWISE THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE AXIS EXTENDING ACROSS THE DISCUSSION AREA ANCHORED BY A 1021 MB HIGH NEAR 31N27W AND A 1026 MB HIGH AROUND 39N17W. THE FAIR WEATHER OVER THIS REGION IS ALSO ASSOCIATED TO SAHARAN DUST DEPICTED ON THE METEOSAT-9 SAHARAN AIR LAYER TRACKING PRODUCT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA