000 AXNT20 KNHC 211755 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... HURRICANE CHRIS IS CENTERED NEAR 41.1N 43.2W AT 21/1500 UTC OR ABOUT 540 NM SE OF CAPE RACE NEWFOUNDLAND MOVING NE AT 17 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 987 MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH GUSTS TO 80 KT. SCATTERED MODERATE CONVECTION IS FROM 40N-43N BETWEEN 42W-46W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. SOUTHWESTERLY UPPER LEVEL DIFFLUENT FLOW IS OVER MUCH OF THE GULF OF MEXICO THIS AFTERNOON BETWEEN AN UPPER LEVEL LOW CENTERED OVER NORTHERN MEXICO NEAR 27N100W AND AN UPPER LEVEL RIDGE TO THE SOUTHEAST WITH AXIS FROM SOUTHERN MEXICO NEAR 17N97W TO OVER THE SOUTHERN FLORIDA PENINSULA NEAR 26N81W. WHILE A MIDDLE TO UPPER LEVEL DIFFLUENT ENVIRONMENT REMAINS IN PLACE AND CONTINUES TO BECOME MORE FAVORABLE FOR TROPICAL CYCLONE DEVELOPMENT...AT THE SURFACE...A BROAD SURFACE TROUGH IS ANALYZED FROM THE NE GULF NEAR 29N84W INTO A WEAK 1008 MB LOW CENTERED NEAR 21N90W ON THE NORTHWESTERN TIP OF THE YUCATAN PENINSULA. MOST OF THE SIGNIFICANT DEEP CONVECTION WITH THIS SYSTEM IS LOCATED TO THE SE OF THE SURFACE TROUGH WITH SCATTERED STRONG CONVECTION OCCURRING FROM 20N-24N BETWEEN 81W-88W...AND FROM 17N-20N BETWEEN 86W-89W OFFSHORE OF THE EASTERN YUCATAN PENINSULA COAST. THIS SYSTEM IS EXPECTED TO REMAIN FAIRLY STATIONARY OVER THE NEXT FEW DAYS WITH A VERY BROAD SURFACE LOW FORECAST TO DRIFT NORTHEASTWARD TOWARDS THE FLORIDA BIG BEND REGION BY THE WEEKEND WITH A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. REGARDLESS OF DEVELOPMENT...HEAVY RAINS AND LOCALIZED FLOODING ARE POSSIBLE ACROSS THE YUCATAN PENINSULA...WESTERN CUBA...AND SOUTHERN FLORIDA THROUGH THE UPCOMING WEEKEND AHEAD. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 07N29W TO 14N24W MOVING W AT 15-20 KT. THE WAVE IS EMBEDDED WITHIN THE MONSOON TROUGH/ITCZ AXIS AND COINCIDES WITH A VERY WEAK 700-850 MB TROUGH THAT IS ALONG 25W. NO CONVECTION IS LOCATED IN THE VICINITY OF THE WAVE AXIS AT THIS TIME DUE TO SAHARAN DUST THAT COVERS MUCH OF THE TROPICAL NORTH ATLC WATERS PROVIDING OVERALL STABLE CONDITIONS. ANY CONVECTION TO THE SE OF THE WAVE AXIS IS LIKELY ASSOCIATED WITH MID-LEVEL DIFFLUENCE AND THE MONSOON TROUGH AXIS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO 08N27W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N27W TO 06N35W TO 08N43W TO 06N58W. SCATTERED MODERATE CONVECTION IS FROM 05N-11N BETWEEN 17W-24W. ...DISCUSSION... GULF OF MEXICO... ASIDE FROM THE SPECIAL FEATURES AREA DESCRIBED ABOVE...THE UPPER LEVEL LOW CENTERED OVER NORTHERN MEXICO NEAR 27N100W IS ALSO GENERATING SCATTERED SHOWERS AND TSTMS ACROSS THE WESTERN GULF N OF 22N W OF 93W DUE TO MAXIMIZED MIDDLE TO UPPER LEVEL DIFFLUENCE EAST OF THE UPPER LEVEL LOW. THIS UPPER LEVEL FEATURE IS EXPECTED TO DRIFT WESTWARD THROUGH FRIDAY BUT THEN MERGE NORTHEASTWARD WITH AN UPPER LEVEL TROUGH EXPECTED TO PROGRESS OVER THE CENTRAL CONUS INTO THE GREAT LAKES REGION AND LOWER MISSISSIPPI RIVER VALLEY BY SATURDAY. THE OVERALL WEATHER SCENARIO OVER THE UPCOMING WEEKEND THOUGH WILL BE DOMINATED BY THE SPECIAL FEATURES SURFACE TROUGH AND POTENTIAL SURFACE LOW PRESSURE AREA BRINGING STRONGER CYCLONIC WINDS TO THE EASTERN GULF OFFSHORE ZONES IN ADDITION TO PLENTY OF CONVECTIVE PRECIPITATION TO THE EASTERN GULF WATERS AND FLORIDA PENINSULA. CARIBBEAN SEA... AN UPPER LEVEL RIDGE AXIS EXTENDS FROM OVER SOUTHERN MEXICO NEAR 17N97W E-NE TO NEAR 23N81W OVER WESTERN CUBA. UPPER LEVEL DIFFLUENT FLOW MAXIMIZED OVER PORTIONS OF THE NW CARIBBEAN AND CUBA GENERATING SCATTERED STRONG CONVECTION NW OF A LINE FROM 17N88W TO 21N78W. THE REMAINDER OF THE CARIBBEAN BASIN IS UNDER THE INFLUENCE OF NORTH TO NORTHEASTERLY UPPER LEVEL FLOW WEST OF THE PREVIOUSLY MENTIONED UPPER LEVEL RIDGING. THIS FEATURE IS PROVIDING FOR AN OVERALL SUBSIDENT ENVIRONMENT OVER THE BASIN S OF 20N E OF 84W. THE ONLY AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS ARE IN THE VICINITY OF THE MONSOON TROUGH AXIS EXTENDING ALONG 09N/10N S OF 10N BETWEEN 75W-81W. ATLANTIC OCEAN... AN UPPER LEVEL LOW IS CENTERED OVER THE SW NORTH ATLC NEAR 28N70W AND SUPPORTS A WEAK SURFACE TROUGH ANALYZED FROM 27N74W TO 32N64W. WHILE THE SURFACE TROUGH HAS NO SIGNIFICANT CONVECTION NEAR ITS AXIS...TO THE SOUTH OF THE UPPER LEVEL LOW...MIDDLE TO UPPER LEVEL DIFFLUENCE IS MAXIMIZED GENERATING SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS FROM 21N-26N BETWEEN 67W-78W...AND FROM 22N-28N BETWEEN 63W-67W. TO THE NW OF THE SURFACE TROUGH...HIGH PRESSURE CONTINUES TO PROVIDE FAIR WEATHER CONDITIONS AS A 1019 MB HIGH IS CENTERED OFF THE CAROLINA COAST NEAR 33N72W. OTHERWISE THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1020 MB HIGH CENTERED NEAR 26N45W AND A 1022 MB HIGH CENTERED NEAR 31N28W. ONLY A FEW ISOLATED SHOWERS ARE OCCURRING ON THE NORTHERN PERIPHERY OF THE RIDGE ACROSS THE CENTRAL ATLC AS SURFACE TROUGHING STEMMING FROM HURRICANE CHRIS DIPS SOUTHWARD TO 28N WITH THE CONVECTION WITHIN 150 NM EITHER SIDE OF A LINE FROM 32N40W TO 26N53W. OF NOTE...EXAMINING THE GOES-R PROVING GROUND DUST PRODUCT IMAGERY...METEOSAT-9 VISIBLE IMAGERY...AND THE CIMSS SAHARAN AIR LAYER TRACKING PRODUCT...A LARGE AREA OF SAHARAN DUST IS ACROSS A LARGE PORTION OF THE TROPICAL ATLC FROM 09N-24N E OF 42W. ANOTHER AREA OF ENHANCED SUSPENDED DUST IS ACROSS THE EASTERN CARIBBEAN SEA AND ATLC WATERS NORTHEAST OF THE LESSER ANTILLES FROM 12N-23N BETWEEN 53W-68W. IMPACTS WILL CONTINUE TO BE HAZY SKY CONDITIONS OVER THE NEXT FEW DAYS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN