000 AXNT20 KNHC 210559 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE SEP 21 2010 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... HURRICANE IGOR IS CENTERED NEAR 41.3N 57.5W AT 21/0600 UTC OR ABOUT 325 NM SSW OF CAPE RACE NEWFOUNDLAND MOVING NE AT 26 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 968 MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH GUSTS TO 80 KT. IGOR IS EMBEDDED WITHIN INCREASING SOUTHWESTERLY SHEAR WITH DEEP CONVECTION DISPLACED WELL N OF THE CENTER. SCATTERED MODERATE CONVECTION IS FROM 41N-47N BETWEEN 54W-61W. IGOR IS EXPECTED TO BECOME EXTRA- TROPICAL WITHIN THE NEXT 24 HOURS. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 AND THE FULL FORECAST ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. TROPICAL DEPRESSION FOURTEEN IS CENTERED NEAR 17.1N 31.9W AT 21/0300 UTC OR ABOUT 460 NM W OF THE CAPE VERDE ISLANDS MOVING N AT 5 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. GRADUAL STRENGTHENING IS FORECAST OVER THE NEXT FEW DAYS AS THE TROPICAL CYCLONE REMAINS SOUTH OF AN EASTERN ATLC TROUGH IN A MINIMAL VERTICAL SHEAR ENVIRONMENT. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 13N-19N BETWEEN 27W-33W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 09N19W TO 19N16W MOVING W AT 10-15 KT. A 1009 MB LOW IS ANALYZED ALONG THE WAVE AXIS NEAR 17N17W. CIMSS WAVETRAK MODEL GUIDANCE INDICATES A NARROW AREA OF 850 MB RELATIVE VORTICITY IS ASSOCIATED WITH THE WAVE AXIS LOCATED ALONG THE W AFRICA COAST FROM 09N-20N. A SURGE OF DEEP LAYER MOISTURE JUST OFF THE COAST IS ALSO EVIDENT IN TPW IMAGERY. ISOLATED MODERATE CONVECTION IS FROM 13N-17N BETWEEN 18W-21W. TROPICAL WAVE EXTENDS FROM 07N60W TO 17N61W MOVING W AT 10-15 KT. ENERGY ASSOCIATED WITH THIS WAVE HAS TRACKED WESTWARD ACROSS THE TROPICAL ATLC OVER THE PAST SEVERAL DAYS AND CONTINUES TO EXHIBIT BROAD CYCLONIC LOW-LEVEL FLOW OVER THE EASTERN CARIBBEAN. TOTAL PRECIPITABLE WATER VALUES REMAIN HIGH FROM 08N-15N BETWEEN 56W-63W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 11N-15N BETWEEN 59W-62W AND WEST OF THE WAVE AXIS FROM 12N-17N BETWEEN 63W-65W. ...ITCZ... A MONSOONAL TROUGH IS ANALYZED FROM SW OF T.D. FOURTEEN NEAR 16N33W TO 11N45W. THE ITCZ AXIS THEN RESUMES NEAR 12N46W AND EXTENDS TO 13N60W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 06N-09N BETWEEN 24W-28W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE EXTENDS ACROSS THE GULF OF MEXICO AND FLORIDA PENINSULA STEMMING FROM AN UPPER LEVEL ANTICYCLONE CENTERED OVER NORTHERN MEXICO NEAR 24N105W. THIS ANTICYCLONE IS PROVIDING THE GULF WITH NW TO N UPPER LEVEL FLOW AND PRIMARILY STABLE CONDITIONS ALOFT WHILE SUPPORTING BROAD SURFACE RIDGING. WIDELY SCATTERED SHOWERS ARE OCCURRING IN THE WESTERN GULF N OF 22N W OF 90W DUE TO LOW-LEVEL WARM AIR ADVECTION AND WEAK SURFACE TROUGHING EXTENDING ALONG THE TEXAS AND MEXICO GULF COASTS. CARIBBEAN SEA... WHILE UPPER LEVEL NORTHERLY FLOW IS OVER THE NW CARIBBEAN AND PORTIONS OF CENTRAL AMERICA W OF 83W...AN UPPER LEVEL TROUGH EXTENDS FROM THE W ATLC ACROSS CENTRAL CUBA TO NEAR 13N83W. DRY AIR ALOFT ASSOCIATED WITH THE TROUGHING IS PROVIDING FAIR CONDITIONS OVER CUBA TONIGHT...HOWEVER AS THE TROUGH CONTINUES TO DIP INTO THE WESTERN CARIBBEAN WATERS...ISOLATED SHOWERS ARE FROM 15N-20N BETWEEN 76W-84W. FARTHER EAST...AHEAD OF THE TROUGH AXIS...MOIST SW UPPER LEVEL FLOW IS GENERATING AN EXTENSIVE AREA OF LOW-LEVEL CLOUDINESS AND POSSIBLE ISOLATED SHOWERS FROM 13N-20N BETWEEN 67W-74W...INCLUDING MOST OF HISPANIOLA. THIS AREA STRETCHES NORTHWARD INTO THE SW NORTH ATLC BETWEEN 65W-72W WHERE A WEAKNESS IN THE SUBTROPICAL RIDGE IS LOCATED. THE REMAINDER OF THE EASTERN CARIBBEAN IS INFLUENCED BY THE TROPICAL WAVE ALONG 61W THAT CONTINUES MOVING WESTWARD AND GENERATING SCATTERED SHOWERS AND TSTMS OVER THE LESSER ANTILLES AND AN AREA FROM 12N-17N BETWEEN 63W-65W. ANOTHER AREA OF INTEREST IN THE CARIBBEAN SEA BASIN IS A SURFACE TROUGH ANALYZED FROM 13N73W TO THE COAST OF NICARAGUA NEAR 13N83W AND INLAND OVER INTERIOR PORTIONS OF CENTRAL AMERICA TO CENTRAL GUATEMALA NEAR 16N90W. THIS MONSOON TROUGH DENOTES THE BOUNDARY BETWEEN SOUTHWESTERLY FLOW ORIGINATING IN THE E PACIFIC REGION AND EAST-NORTHEASTERLY FLOW OVER THE WESTERN CARIBBEAN. SCATTERED SHOWERS AND ISOLATED TSTMS ARE FROM 08N-13N BETWEEN 69W-79W AND OVER CENTRAL AMERICA WITHIN 90 NM EITHER SIDE OF THE MONSOON TROUGH AXIS. ATLANTIC OCEAN... A SHARP UPPER LEVEL TROUGH AXIS EXTENDS ACROSS THE W ATLC FROM 32N71W TO CENTRAL CUBA NEAR 22N80W AND INTO THE WESTERN CARIBBEAN SEA. THIS TROUGHING IS SUPPORTING THE ADVECTION OF MID-LEVEL MOISTURE AND POSSIBLE ISOLATED SHOWERS FROM 20N-23N BETWEEN 65W-75W. THE TROUGHING ALSO COINCIDES WITH AN OVERALL WEAKNESS IN THE SUBTROPICAL RIDGE BETWEEN 65W-72W...HOWEVER WEATHER CONDITIONS IN THIS AREA REMAIN FAIRLY BENIGN. ELSEWHERE ACROSS THE CENTRAL AND EASTERN ATLC...A SURFACE RIDGE DOMINATES ANCHORED BY A 1017 MB HIGH CENTERED NEAR 27N49W. THE RIDGE AXIS EXTENDS FROM THE HIGH CENTER E-NE TO 32N30W AND FROM THE HIGH CENTER SW TO 22N65W. THIS SURFACE HIGH IS SUPPORTED ALOFT BY A LARGE UPPER LEVEL ANTICYCLONE CENTERED NEAR 30N50W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN