000 AXNT20 KNHC 211147 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI AUG 21 2009 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 1100 UTC. ...SPECIAL FEATURES... HURRICANE BILL IS CENTERED NEAR 26.8N 65.8W OR ABOUT 335 NM S OF BERMUDA AND ABOUT 710 NM SE OF CAPE HATTERAS NORTH CAROLINA MOVING NW AT 15 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 958 MB. MAXIMUM SUSTAINED WIND SPEED IS 100 KT WITH HIGHER GUSTS. SEE THE LATEST FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS TCMAT3/ WTNT23 KNHC FOR MORE DETAILS. HURRICANE BILL NO LONGER HAS A WELL DEFINED EYE FEATURE. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS COVERS THE AREA FROM 24N-27N BETWEEN 62W-66W WITH SCATTERED MODERATE CONVECTION COVERING THE REMAINDER OF THE AREA FROM 24N-30N BETWEEN 60W-67W. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 27W/28W S OF 16N MOVING W 10-15 KT. WAVE WAS ADVANCED TO BE WITHIN THE DEEP LAYER MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY WITH SCATTERED MODERATE TO STRONG CONVECTION FROM 11N-14W BETWEEN THE WAVE AXIS AND 32W. TROPICAL WAVE IS ALONG 55W/56W S OF 16N MOVING W 15-20 KT. WAVE HAS BECOME LESS TITLED AS HURRICANE BILL GRADUALLY PULLS N AWAY FROM THE TROPICS. WAVE REMAINS EMBEDDED WITHIN AN AREA DEEP LAYER MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 7N-12N BETWEEN 47W-58W. TROPICAL WAVE THAT WAS ALONG 94W/95W IS NO LONGER IN THE ATLC BASIN. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 15N16W 12N26W 10N37W 9N59W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN 60 NM OF 12N FROM 27W-30W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 10N-15N E OF 22W TO INLAND OVER W AFRICA...FROM 7N-10N BETWEEN 28W-34W...AND WITHIN 90 NM OF THE ITCZ AXIS FROM 44W-59W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE EXTENDS FROM OVER CENTRAL MEXICO NE ALONG THE COAST OF TEXAS ACROSS THE LOWER MISSISSIPPI VALLEY TO THE EASTERN PORTION OF NORTH CAROLINA PROVIDING UPPER DIFFLUENCE ACROSS THE N GULF TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 27N E OF 93W AND WITHIN 90 NM ALONG THE COAST OF THE FLORIDA PENINSULA N OF THE FLORIDA KEYS. THE UPPER LOW OVER THE YUCATAN COVERS THE E BAY OF CAMPECHE GENERATING SCATTERED SHOWERS/THUNDERSTORMS FROM 19N-21N BETWEEN 94W-96W. THE SURFACE RIDGE FROM THE W ATLC CONTINUES TO BUILD TO OVER THE CENTRAL GULF. THE REMAINDER OF THE GULF REMAINS TRANQUIL THIS MORNING AS CLEAR SKIES PREVAIL. CARIBBEAN SEA... AN UPPER LOW REMAINS OVER THE YUCATAN NEAR 18N90W COVERING THE NW CARIBBEAN. AN UPPER RIDGE EXTENDS FROM E PANAMA TO E CUBA ALONG 78W PROVIDING UPPER LEVEL DIFFLUENCE TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 15N-21N BETWEEN 80W-86W WITH CLUSTERS OF SIMILAR ACTIVITY WITHIN 60/75 NM OF LINE FROM 17N72W TO THE CAYMAN ISLANDS INCLUDING PORTIONS OF HAITI AND JAMAICA. THE ITCZ AXIS EXTENDS ACROSS THE N PORTION OF SOUTH AMERICA ACROSS PANAMA AND INTO THE E PACIFIC REGION GENERATING SCATTERED MODERATE/ISOLATED STRONG CONVECTION S OF 11N BETWEEN COLOMBIA AND COSTA RICA. FRESH TO STRONG EASTERLY TRADE WINDS CONTINUE ACROSS THE AREA. DRY STABLE AIR IS ACROSS THE REMAINDER OF THE AREA E OF 80W LIMITING ANY OTHER SHOWER ACTIVITY. ATLANTIC OCEAN... THE MAIN FOCUS FOR THE ATLC CONTINUES TO BE HURRICANE BILL. THE UPPER RIDGE FROM THE GULF TO THE CAROLINA COAST IS PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 45 NM OF LINE FROM 29N80W TO 33N79W. NORTHERLY UPPER FLOW COVERS THE W ATLC W OF HURRICANE BILL AS A WEAKENING UPPER LOW IS MOVING TOWARD THE CENTRAL BAHAMA ISLANDS NEAR 26N74W GENERATING ISOLATED SHOWERS S OF 26N BETWEEN 73W-77W. OTHERWISE THE ATLC BASIN IS DOMINATED BY A SURFACE RIDGE EXTENDING OVER W ATLC THROUGH 32N75W ACROSS FLORIDA TO OVER THE GULF OF MEXICO AND IN THE E ATLC BY A 1029 MB HIGH NEAR THE AZORES WITH A WEAKNESS OVER THE CENTRAL ATLC DUE TO HURRICANE BILL. $$ WALLACE