000 AXNT20 KNHC 021741 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON OCT 02 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE 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... TROPICAL STORM ISAAC WAS CENTERED NEAR 44.3N 55.0W OR ABOUT 165 NM SOUTH-SOUTHWEST OF CAPE RACE NEWFOUNDLAND AT 02/1500 UTC. ISAAC IS MOVING TOWARD THE NORTH-NORTHEAST AT 36 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 994 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. ISAAC IS LOSING TROPICAL CHARACTERISTICS AND IS EXPECTED TO BECOME AN EXTRATROPICAL LOW LATER TODAY. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A 1010 MB LOW IS ABOUT 585 NM SW OF THE CAPE VERDE ISLANDS NEAR 9N32W MOVING W 10-15 KT. SHOWER AND THUNDERSTORM ACTIVITY ASSOCIATED WITH THIS BROAD LOW REMAINS MINIMAL. UPPER LEVEL WINDS ARE NOT CONDUCIVE FOR DEVELOPMENT OF THIS SYSTEM AS IT MOVES SLOWLY WEST-NORTHWESTWARD. A LOW AMPLITUDE TROPICAL WAVE IS ALONG 45W S OF 17N MOVING W 10-15 KT. THERE IS SOME SUBTLE CYCLONIC TURNING OF THE LOW TO MID CLOUD FIELD FROM 10N-15N BETWEEN 40W-49W...BUT SHOWER AND TSTM ACTIVITY IS MINIMAL ASIDE FROM A SMALL CLUSTER OF SCATTERED MODERATE CONVECTION JUST E OF THE WAVE FROM 12N-13N BETWEEN 41W-44W. AN EASTERN CARIBBEAN SEA TROPICAL WAVE PREVIOUSLY ALONG 69W HAS BEEN REPOSITIONED TO 62W S OF 20N BASED ON THIS MORNINGS VISIBLE IMAGERY...ALONG WITH SOUNDING DATA FROM GUADELOUPE THAT SHOWS THE LOW LEVEL WINDS HAVE SHIFTED FROM NE TO E TO SE OVER THE PAST COUPLE OF DAYS. SEVERAL STATIONS IN THE LESSER ANTILLES ARE ALSO REPORTING SE WINDS. THIS WAVE IS ESTIMATED TO BE MOVING W 10-15 KT. AN INVERTED V PATTERN IS SEEN ON SATELLITE IMAGERY MOVING INTO THE FAR ERN CARIBBEAN...THOUGH SHOWER/TSTM ACTIVITY IS ISOLATED AT BEST WITHIN 100NM OF THE AXIS. TROPICAL WAVE IS ALONG 81W S OF 20N MOVING W AT 10-15 KT. ISOLATED SHOWERS WITH EMBEDDED TSTMS DOT THE SW CARIBBEAN AND COASTAL CENTRAL AMERICA FROM 9N-14N BETWEEN 78W-84W...AND IN THE NW CARIBBEAN FROM 16N-20N BETWEEN 82W-88W...THOUGH SOME OF THIS MAY BE MORE ASSOCIATED WITH UPPER DIFFLUENCE. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 12N16W 10N28W 9N36W 10N43W 11N60W. OUTSIDE OF THE TROPICAL WAVES AND THE LOW NEAR 9N32W...DEEP CONVECTION IS OVERALL MINIMAL WITHIN 200NM OF THE AXIS. SMALL CLUSTERS OF SCATTERED MODERATE CONVECTION ARE NOTED FROM 6N-7N BETWEEN 35W-38W...AND FROM 11N-13N BETWEEN 54W-56W. ...DISCUSSION... GULF OF MEXICO... ANTICYCLONIC FLOW AROUND A BROAD MID TO UPPER HIGH OVER SE MEXICO/S OF THE BAY OF CAMPECHE IS DOMINATING MUCH OF THE GULF THIS AFTERNOON. THERE IS A SHORT WAVE UPPER TROUGH WITH A POSITIVE TILT ALIGNED SW TO NE THROUGH CENTRAL MEXICO AND TEXAS. ASSOCIATED CLOUDINESS IS OVER THE NW GULF WITH HIGH CLOUDS STREAMING TO THE NE. THE ERN GULF IS DOMINATED BY DRY MID TO UPPER AIR ASIDE FROM A FEW ISOLATED SHOWERS IN THE FAR SE GULF FROM 23N-25N BETWEEN 83W-88W. AT THE SURFACE...CLOCKWISE EASTERLY FLOW IS OBSERVED AROUND THE SRN PERIPHERY OF A 1027MB HIGH NEAR BLACKSBURG VIRGINIA...MOSTLY IN THE 10 TO 20 KT RANGE. HIGH PRESSURE WILL REMAIN QUASI-STATIONARY NORTH OF THE AREA OVER THE NEXT FEW DAYS ALLOWING MODERATE E FLOW TO PERSIST...WITH E SWELL BUILDING FOR MAINLY THE WRN GULF WATERS AND AFFECTING COASTAL TX/NE MEXICO THROUGH THE SECOND HALF OF THE WEEK. CARIBBEAN SEA... THE UPPER HIGH OVER SRN MEXICO/S OF THE BAY OF CAMPECHE IS ALSO DOMINATING THE WRN CARIBBEAN. THERE IS SOME UPPER DIFFLUENCE NOTED BETWEEN THIS FEATURE AND THE TROUGHING OFF THE EASTERN SEABOARD OF THE UNITED STATES THAT MAY BE HELPING TO SUPPORT THE ISOLATED SHOWER/TSTM ACTIVITY IN THE NW CARIBBEAN...AS IT INTERACTS WITH THE TROPICAL WAVE MOVING THROUGH THE AREA. A MID TO UPPER LEVEL LOW IS SEEN JUST S OF THE DOMINICAN REPUBLIC NEAR 17N69W...THOUGH NOT MUCH SHOWER ACTIVITY IS NOTED IN THIS VICINITY IN THE MIDST OF DRY AIR PRESENT. HIGH CLOUDS ARE STREAMING NE THROUGH THE FAR ERN CARIBBEAN ON THE SE SIDE OF THIS UPPER LOW...THAT APPEARS TO BE INTERACTING WITH THE TROPICAL WAVE MOVING THROUGH THE AREA. ELSEWHERE AT THE SURFACE...TRADES 15 TO 20 KT DOMINATE AND WILL PERSIST THE NEXT COUPLE OF DAYS WITH HIGH PRESSURE N OF THE AREA AND LOWER PRESSURE NEAR THE COLOMBIAN COAST. ATLANTIC OCEAN... VERY DRY MID TO UPPER LEVEL AIR IS SEEN ON WV IMAGERY JUST OFF THE SE US AND FLORIDA COAST THIS AFTERNOON WITH DEEP LAYER TROUGHING PUSHING OFF THE EAST COAST. PERHAPS MORE INTERESTING WEATHER IS AT THE SURFACE WHERE FRESH NE FLOW IS DEVELOPING ACROSS SRN FLORIDA AND THE ADJACENT ATLC WATERS...WITH A 1027MB SURFACE HIGH BUILDING INTO THE AREA FROM ITS CENTER NEAR BLACKSBURG VIRGINIA. AVAILABLE CMAN/BUOY OBSERVATIONS OFF FLORIDA GENERALLY SHOW 15-20 KT ENE/NE WINDS. THIS IS EXPECTED TO PERSIST OVER THE NEXT FEW DAYS WITH HIGH PRESSURE REMAINING QUASI-STATIONARY N OF THE AREA. ASSOCIATED SHORT PERIOD NE WIND WAVES WILL BUILD ACROSS FL AND EXPOSED BEACHES IN THE BAHAMAS THROUGH MIDWEEK...SEE STATEMENTS FROM LOCAL WEATHER SERVICE OFFICES FOR MORE DETAILS. A SURFACE TROUGH CONTINUES TO EXTEND NE THROUGH THE TURKS/CAICOS INTO THE SW NORTH ATLC...ALONG 20N72W 32N64W. THIS IS HELPING TO SPARK PATCHES OF SCATTERED MODERATE CONVECTION FROM 20N-32N BETWEEN 66W-75W. THIS TROUGH IS ASSOCIATED WITH CONFLUENCE BETWEEN THE HIGH BUILDING DOWN THE SE US AND A 1031MB CENTRAL ATLC HIGH NEAR 40N40W. BROAD MID TO UPPER LEVEL HIGH PRESSURE IS DOMINATING THE AREA FROM 20N-40N BETWEEN 40W-68W WITH A FEW EMBEDDED HIGH CENTERS. A DRY UPPER LOW IS E OF THE WINDWARD ISLANDS NEAR 16N51W...WITH A STRONGER AND DEEPER LAYER LOW NEAR 30N30W THAT HAS A FRONTAL BOUNDARY EXTENDING S TO 22N31W FROM THE SURFACE LOW NEAR 32N29W. CLOUDINESS AND ISOLATED SHOWERS ASSOCIATED WITH THIS SYSTEM ARE FROM 24N-35N BETWEEN 20W-35W. THE SW FLOW BETWEEN THIS UPPER LOW AND THE UPPER HIGH OVER WRN AFRICA IS PRODUCING SHEAR OVER THE LOW NEAR 9N32W. $$ WILLIS