000 AXNT20 KNHC 221145 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN AUG 22 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION SIX IS CENTERED NEAR 12.1N 33.4W AT 22/0900 UTC...OR LOCATED ABOUT 600 MILES WEST-SOUTHWEST OF THE SOUTHERNMOST CAPE VERDE ISLANDS MOVING W-NW AT 08 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. STRENGTHENING IS FORECAST OVER THE NEXT FEW DAYS AS THE CYCLONE REMAINS OVER WARM SEA SURFACE TEMPERATURES AND WITHIN A RELATIVELY LOW NORTHEASTERLY SHEAR ENVIRONMENT. THIS IS EXPECTED TO PROVIDE AN OVERALL FAVORABLE UPPER LEVEL DIFFLUENT ENVIRONMENT FOR THE SYSTEM TO MAINTAIN ORGANIZED CONVECTION AND PROVIDE FOR MINIMAL WIND SHEAR. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 10N-15N BETWEEN 34W-39W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 11N49W TO 17N52W TO 24N51W MOVING W AT 15-20 KT. WEAK CYCLONIC FLOW IS NOTED IN THE LOW-LEVEL CLOUD FIELD ALONG THE WAVE AXIS. THIS SYSTEM MOVES ALONG WITH AN AREA OF MODERATE VALUES OF DEEP LAYER MOISTURE OBSERVED ON THE TPW IMAGERY. HOWEVER...MUCH OF THE MOISTURE TO THE EAST OF THE WAVE IS POSITIONED BENEATH A STABLE SAHARAN AIR LAYER THAT COVERS MUCH OF THE CENTRAL ATLC. HOWEVER...SCATTERED SHOWERS ARE WITHIN 40 NM ON EITHER SIDE OF THE WAVE AXIS. TROPICAL WAVE EXTENDS FROM 18N69W TO 26N67W MOVING WNW AT 15-20 KT. THE WAVE COINCIDES WITH A MID-LEVEL TROUGH OVER THE W ATLC BETWEEN 65W-74W. MAXIMUM TOTAL PRECIPITABLE WATER VALUES ARE HIGHEST N OF 20N BETWEEN 61W-69W AS THIS MOISTURE CONTINUES TO ADVECT NORTHWARD DUE TO A WEAKNESS IN THE SUBTROPICAL RIDGE BETWEEN 70W-80W. ISOLATED MODERATE CONVECTION AND WIDELY SCATTERED SHOWERS ARE OCCURRING FROM 20N-29N BETWEEN 62W-70W. ...ITCZ... ITCZ AXIS IS ANALYZED FROM THE WEST COAST OF AFRICA OVER SIERRA LEONE NEAR 8N13W TO 10N20W. THEN RESUMES OVER NEAR 8N39W 10N49W 8N55W AND CONTINUES OVER NORTHERN SOUTH AMERICA. THE GRADUAL DISSIPATION OF THE MONSOON TROUGH THAT HAS PERSISTED OVER THE PAST SEVERAL DAYS OVER THE TROPICAL EASTERN ATLC...IS ANALYZED AS A SURFACE TROUGH FROM NE OF T.D. SIX NEAR 14N30W TO 17N21W. HOWEVER...MOST OF THE CONVECTION IS ASSOCIATED TO T.D. SIX. A BROAD AREA OF SCATTERED MODERATE TO STRONG CONVECTION IS MOVING OFF THE WESTERN AFRICA COAST E OF 24W FROM 6N-15N. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION COVERS THE BASIN. THIS UPPER LEVEL FEATURE IS PROVIDING A DRY EASTERLY FLOW ALOFT OVER MUCH OF THE GULF. LOW TO MID-LEVEL INSTABILITY AND UPPER LEVEL DIFFLUENCE PROVIDED BY THE UPPER LEVEL RIDGE IS GENERATING SCATTERED SHOWERS AND TSTMS OVER THE EASTERN GULF E OF 88W...INCLUDING THE FLORIDA PENINSULA AND FLORIDA STRAITS. SCATTERED SHOWERS AND THUNDERSTORMS ARE ALSO OVER THE BAY OF CAMPECHE S OF 20N. THIS ACTIVITY IS ASSOCIATED TO TROPICAL DEPRESSION NINE-E CURRENTLY LOCATED ABOUT 110 NM S OF THE GULF OF TEHUANTEPEC GENERATING BROAD CYCLONIC FLOW AND CONVECTION THAT REACHES AS FAR NORTH AS THE BAY OF CAMPECHE. THE REMAINDER OF THE GULF IS UNDER THE INFLUENCE OF THE EASTERN FLOW ALOFT MENTIONED ABOVE AND THIS SUPPORTS A 1016 MB SURFACE HIGH CENTERED OVER THE CENTRAL GULF NEAR 26N91W. CLEAR SKIES ARE NOTED ELSEWHERE ON NIGHT VISION SATELLITE IMAGERY UNDER LIGHT ANTICYCLONIC WINDS. CARIBBEAN SEA... CONVERGENT LOW-LEVEL SOUTHEASTERLY FLOW DOMINATES ACROSS THE WESTERN CARIBBEAN W OF 79W S OF 18N...INCLUDING PORTIONS OF CENTRAL AMERICA. THIS AREA OF CONVECTION IS MOVING AROUND AND INTO THE BROAD CYCLONIC CIRCULATION GENERATED BY TROPICAL DEPRESSION NINE-E CURRENTLY LOCATED OVER THE EASTERN PACIFIC WATERS ABOUT 110 NM S OF THE GULF OF TEHUANTEPEC. AN ELONGATED UPPER LEVEL LOW LOCATED NE OF THE BAHAMAS EXTENDS UPPER LEVEL TROUGHINESS ACROSS HISPANIOLA...THE WINDWARD PASSAGE...AND JAMAICA...CONTINUING WESTWARD TO NEAR 18N80W...GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 20 NM ON EITHER SIDE OF THE UPPER LEVEL TROUGH AXIS. THE ITCZ AXIS EXTENDS ACROSS THE FAR SW CARIBBEAN ALONG 11N AND IS ALSO PROVIDING LOW-LEVEL FOCUS FOR SCATTERED SHOWERS AND ISOLATED TSTMS OVER PORTIONS OF NICARAGUA...COSTA RICA...PANAMA...AND NORTHERN COLOMBIA. WHILE MUCH OF THE EASTERN CARIBBEAN BETWEEN 65W-76W IS UNDER RELATIVELY CLEAR SKIES...A SURFACE TROUGH IS OVER THE LESSER ANTILLES S OF 18N GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS E OF 65W. ATLANTIC OCEAN... SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OVER MOST OF THE WESTERN ATLC W OF 73W...PRODUCED BY UPPER LEVEL DIFFLUENT NE FLOW AROUND AN ANTICYCLONIC CIRCULATION CENTERED OVER THE SE CONUS AND AN ELONGATED UPPER LEVEL LOW LOCATED NE OF THE BAHAMAS NEAR 24N74W. THE UPPER LEVEL LOW IS ALSO PROVIDING LOW LEVEL MOISTURE TO A RATHER WEAK TROPICAL WAVE ALONG 69W...PRODUCING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS FROM 20N-29N BETWEEN 62W-70W. ELSEWHERE ACROSS THE REMAINDER OF THE CENTRAL AND EASTERN ATLC...SURFACE RIDGING DOMINATES THE ATLC N OF 25N ANCHORED BY A 1025 MB HIGH CENTERED NEAR 32N29W...MAINTAINING GENERALLY FAIR WEATHER CONDITIONS E OF 62W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA