000 AXNT20 KNHC 192345 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE JUN 19 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 2315 UTC. ...SPECIAL FEATURES... THE GALE FORCE LOW IN THE NW ATLC HAS NOW GAINED ENOUGH CONVECTION AND ORGANIZATION TO BE CLASSIFIED AS TROPICAL STORM CHRIS. AS OF 2100 UTC...T.S. CHRIS IS LOCATED AT 39.3N 57.7W...OR ABOUT 490 NM SSW OF CAPE RACE NEWFOUNDLAND. MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. CHRIS IS MOVING E AT 7 KT. MODERATE CONVECTION IS WITHIN 100 NM OF THE STORM CENTER. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 15N54W TO 7N57W MOVING W AT 20-25 KT. THE WAVE IS BEST INDICATED IN 700 MB STREAMLINES. THERE IS ALSO A CLEARING IN AN AREA OF AFRICAN DUST TO THE N AND E OF THE WAVE INDICATING ITS PRESENCE. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 7N-11N BETWEEN 53W-62W. TROPICAL WAVE IS ALONG 20N66W TO 13N70W MOVING WNW NEAR 20-25 KT. THE MOISTURE SIGNAL PREVIOUSLY ASSOCIATED WITH THIS WAVE APPEARS TO HAVE BEEN ABSORBED INTO THE WIDESPREAD MOISTURE OVER THE NW CARIBBEAN. THIS WAVE WILL LIKELY BE DROPPED FROM THE NEXT ANALYSIS. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM A 1008 MB SURFACE LOW OVER W AFRICA AT 18N15W CONTINUING SW ALONG 11N20W 7N27W. THE ITCZ CONTINUES AT 7N27W ALONG 5N42W 8N53W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 4N-6N BETWEEN 13W-17W. SIMILAR ACTIVITY IS FROM 5N-9N BETWEEN 19W-24W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-7N BETWEEN 39W-44W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING IS ACROSS THE GULF OF MEXICO TODAY AROUND A 1023 MB HIGH OVER SW NORTH CAROLINA. E-SE WINDS OF 15-20 KTS ARE PRESENT AROUND THE RIDGE. HOWEVER...A PAIR OF UPPER TROUGHS ARE CAUSING ACTIVE WEATHER ACROSS PORTIONS OF THE BASIN. THE MAIN UPPER TROUGH IS ACROSS SRN TEXAS AND ERN MEXICO CAUSING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ACROSS THE WRN GULF W OF 94W S OF 26N...AND ALONG THE TEXAS COASTLINE. SIMILAR ACTIVITY IS ALSO ACROSS THE YUCATAN PENINSULA. A SHORTWAVE UPPER TROUGH IS ALSO OVER THE ERN GULF. THIS IN COMBINATION WITH A BROAD AREA OF SURFACE TROUGHING IN THE NW CARIBBEAN IS GENERATING SCATTERED SHOWERS IN THE SE GULF INCLUDING THE FLORIDA STRAITS AND CUBA. THE SURFACE TROUGH IN THE NW CARIBBEAN IS EXPECTED TO DRIFT NW OVER THE NEXT SEVERAL DAYS WHICH WILL CONTINUE TO BRING MOIST CONDITIONS ACROSS THE SE GULF INCLUDING S FLORIDA. WIND OF 15-20 KTS WILL ALSO PERSIST DUE TO THE TIGHTENED PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE TO THE N AND THE LOWER PRESSURES MOVING INTO THE BASIN. CARIBBEAN SEA... BROAD CYCLONIC SURFACE FLOW ALONG WITH A LARGE AREA OF SHOWERS/THUNDERSTORMS COVER PORTIONS OF THE NW CARIBBEAN. A SURFACE TROUGH MARKS THE AXIS OF CYCLONIC FLOW FROM THE FLORIDA STRAITS NEAR 24N80W ACROSS WRN CUBA TO BELIZE AT 18N88W. A LARGE AREA OF STRONG SHOWERS/SCATTERED THUNDERSTORMS IS CROSS THE CAYMAN ISLANDS AND CUBA FROM 17N-23N BETWEEN 77W-82W. THESE AREAS HAVE ALREADY BEEN RECEIVING LARGE AMOUNTS OF RAIN OVER THE PAST SEVERAL DAYS MEANING FLOODING AND MUDSLIDES ARE POSSIBLE. THE REMAINDER OF THE BASIN IS COVERED BY DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE EXTENDING FROM HONDURAS TO HISPANIOLA AND INTO THE CENTRAL ATLC. THE DRY AIR IS HELPING MAINTAIN FAIR CONDITIONS ACROSS THE CENTRAL AND ERN CARIBBEAN. A TROPICAL WAVE IS ACROSS PUERTO RICO AND THE ERN CARIBBEAN...BUT IT IS NOT CAUSING ANY SIGNIFICANT WEATHER. IT WILL LIKELY BE DROPPED ON THE NEXT ANALYSIS. TRADEWIND FLOW OF 20-25 KTS IS ACROSS MUCH OF THE ERN AND CENTRAL CARIBBEAN. THE SURFACE TROUGH IN THE NW CARIBBEAN IS EXPECTED TO CONTINUE DRIFTING NW INTO THE SE GULF. MOIST CONDITIONS WILL LIKELY CONTINUE ACROSS THE NW CARIBBEAN FOR THE NEXT COUPLE OF DAYS. AN AREA OF SAHARAN DUST JUST E OF THE LESSER ANTILLES MAY BEGIN TO IMPACT THE ERN CARIBBEAN ISLANDS SHORTLY CAUSING HAZY CONDITIONS. ATLANTIC OCEAN... T.S. CHRIS IS N OF THE DISCUSSION AREA. SEE SPECIAL FEATURES ABOVE. A SURFACE TROUGH EXTENDS FROM 30N63W TO 24N76W DEPICTING A BROAD AREA OF CYCLONIC FLOW ACROSS THE W ATLC. THIS AREA OF TROUGHING IS A LEFT BEHIND AFTER THE SURFACE LOW THAT IS NOW T.S. CHRIS MOVED TOWARDS THE NE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE MAINLY ACROSS THE BAHAMAS FROM 22N-26N BETWEEN 73W-80W. SCATTERED SHOWERS ARE ALSO FROM 24N-29N BETWEEN 62W-70W. ALOFT...AN UPPER LEVEL RIDGE IS ACROSS THE FAR W ATLC ALONG 76W SUPPORTING A WEAK 1022 MB HIGH NEAR 34N73W WITH UPPER LEVEL TROUGHING TO THE NE NEAR CHRIS. A SECOND UPPER LEVEL RIDGE EXTENDS FROM THE NE CARIBBEAN TO NEAR 43N42W SUPPORTING A 1025 MB SURFACE HIGH NEAR 29N45W WHICH IS PROVIDING MOSTLY FAIR CONDITIONS ACROSS THE CENTRAL AND ERN ATLC. UPPER LEVEL RIDGING ALSO COVERS THE TROPICAL ATLC. THE LAST VISIBLE SATELLITE IMAGES OF THE DAY ALONG WITH GOES-R IMAGERY ENHANCEMENT INDICATES A LARGE AREA OF SAHARAN DUST EXTENDS FROM THE COAST OF AFRICA AROUND THE TROPICAL WAVE TO NEAR 60W. THIS DUST MAY REACH THE ERN CARIBBEAN SHORTLY CAUSING HAZY CONDITIONS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON