000 AXNT20 KNHC 210303 RRA TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON SEP 20 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... HURRICANE IGOR IS CENTERED NEAR 39.0N 60.5W AT 21/0000 UTC OR ABOUT 565 NM SW OF CAPE RACE NEWFOUNDLAND MOVING NE AT 25 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 968 MB. MAXIMUM SUSTAINED WINDS REMAIN 65 KT WITH GUSTS TO 80 KT. IGOR IS EMBEDDED WITHIN INCREASING SOUTHWESTERLY SHEAR WITH ALL THE DEEP CONVECTION DISPLACED 90 NM TO THE N OF THE CENTER. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 90 TO 360 NM IN THE N SEMICIRCLE OF IGOR. IGOR IS EXPECTED TO BECOME EXTRA-TROPICAL WITHIN THE NEXT 12-24 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. THE REMNANT GALE CENTER OF FORMER TROPICAL STORM JULIA IS CENTERED NEAR 35N46W OR ABOUT 875 NM WSW OF THE AZORES ISLANDS. THE GALE CENTER WAS MOVING E ABOUT 10 KT WITH AN ESTIMATED CENTRAL PRESSURE OF 1000 MB. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN THE HIGH SEAS FORECAST ISSUED BY THE OCEAN PREDICTION CENTER UNDER AWIPS/WMO HEADERS HFDHSFAT1/FZNT01 KWBC. A 1007 MB LOW IS LOCATED W OF THE CAPE VERDE ISLANDS NEAR 16N32W DRIFTING TO THE NE. A BURST OF SCATTERED TO NUMEROUS STRONG CONVECTION HAS DEVELOPED NEAR THE LOW LEVEL CENTER WITH CLOUD TOP TEMPERATURES OF -85C. IN ADDITION CONVECTION WAS ORGANIZED IN A BAND WHICH CURVED FROM 18N30W TO 16N30W TO 14N32W. ENVIRONMENTAL CONDITIONS ARE FAVORABLE FOR FURTHER DEVELOPMENT OF THIS SYSTEM OVER THE NEXT COUPLE OF DAYS AND THERE IS A HIGH PROBABILITY OF TROPICAL CYCLONE FORMATION. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG THE W AFRICAN COAST EXTENDING FROM 9N18W TO 20N16W WITH A 1007 MB LOW ANALYZED AT THE FAR N END OF THE WAVE. THE WAVE WAS MOVING W NEAR 10 KT. SATELLITE IMAGERY INDICATES BROAD CYCLONIC FLOW AROUND THE WAVE AXIS WITH A SURGE OF DEEP LAYER MOISTURE JUST OFF THE COAST EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS NOTED FROM 12N-15N BETWEEN 17W-21W. ...ITCZ... A MONSOONAL TROUGH IS ANALYZED FROM 11N19W TO LOW PRESSURE SYSTEM NEAR 16N32W TO 11N40W TO 10N45W. SCATTERED MODERATE CONVECTION IS FROM 12N-16N BETWEEN 27W-33W. THE TRADITIONAL ITCZ AXIS PICKS UP NEAR 10N45W TO 13N58W. A SURFACE TROUGH IS E OF THE WINDWARD ISLANDS ALONG 13N59W TO 08N60W ENHANCING SCATTERED MODERATE CONVECTION IS FROM 10N-16N BETWEEN 59W-62W. ...DISCUSSION... GULF OF MEXICO... WEAK SURFACE RIDGING IS NOTED OVER THE GULF OF MEXICO WITH EASTERLY FLOW OVER THE REGION WHICH TURNED MORE TO THE SE ALONG THE TEXAS COAST IN THE VICINITY OF A WEAK RETURN FLOW TROUGH. THIS TROUGH WAS AIDING IN THE MAINTENANCE OF SCATTERED MODERATE CONVECTION ALONG THE COAST OF NE MEXICO AND TEXAS FROM 24N-29N BETWEEN 94W-98W. SKIES WERE GENERALLY CLEAR OVER FLORIDA AND THE E GULF E OF 85W AS DRY AIR IS BEING ADVECTED SOUTHWARD IN THE WAKE OF DEPARTING HURRICANE IGOR. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH IS CENTERED OVER MEXICO NEAR 23N104W. NORTHERLY FLOW AROUND THE HIGH WAS ADVECTING UPPER LEVEL MOISTURE OVER THE GULF W OF 84W. VERY STRONG SUBSIDENCE IN THE WAKE OF HURRICANE IGOR WAS PRESSING SWD ACROSS FLORIDA TOWARD CUBA RESULTING IN RATHER COMFORTABLE CONDITIONS. CARIBBEAN SEA... WIDELY SCATTERED MODERATE CONVECTION IS OVER THE WINDWARD ISLANDS FROM 10N-16N BETWEEN 60W-64W DUE TO THE SURFACE TROUGH JUST E OF THE ISLANDS. ELSEWHERE...SCATTERED MODERATE ISOLATED STRONG CONVECTION IS N OF COLOMBIA FROM 10N-13N BETWEEN 73W-82W...WEAK 10-15 KT SURFACE WINDS COVERS MOST OF THE CARIBBEAN. IN THE UPPER LEVELS...STRONG SUBSIDENCE IS OVER THE NORTH CENTRAL CARIBBEAN N OF 15N BETWEEN 73W-80W. CONSIDERABLE UPPER LEVEL MOISTURE IS OVER THE REMAINDER OF THE CARIBBEAN AND CENTRAL AMERICA. EXPECT...CONTINUED SHOWERS AND CONVECTION OVER THE E CARIBBEAN E OF 75W AND OVER THE S CARIBBEAN S OF 15N OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... THE DOMINANT FEATURE OVER THE ATLANTIC S OF 31N IS THE AREA OF LOW PRESSURE NEAR 16N32W WHICH CONTINUES TO SHOW INCREASING ORGANIZATION WITH TIME. THIS LOW IS EMBEDDED WITHIN A MUCH LARGER MONSOONAL TROUGH WHICH GOVERNS THE SYNOPTIC PATTERN IN THE ATLANTIC E OF 45W. AS INDICATED ABOVE THERE IS A HIGH PROBABILITY OF TROPICAL CYCLONE FORMATION WITH THIS LOW OVER THE NEXT 48 HOURS. AT THE UPPER LEVEL A LARGE ANTICYCLONE NEAR 30N50W DOMINATES MOST OF THE REGION. A SHEAR AXIS EXTENDS TO THE S OF THE HIGH FROM 23N30W TO 18N40W TO 17N55W. THE LOW WAS SITUATED TO THE E OF THIS SHEAR AXIS. ELSEWHERE A SHARP UPPER TROUGH EXTENDS FROM 31N72W SWD TO THE STRAITS OF FLORIDA AND WAS ACCOMPANIED BY STRONG DRY AIR ALOFT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ COBB