000 AXNT20 KNHC 281152 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI AUG 28 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 1015 UTC. ...SPECIAL FEATURES... TROPICAL STORM DANNY IS CENTERED NEAR 30.1N 75.2W AT 28/1200 UTC OR ABOUT 310 NM S OF CAPE HATTERAS NORTH CAROLINA MOVING NNW AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SCATTERED TO NUMEROUS MODERATE TO STRONG CONVECTION IS FROM 27N-31N BETWEEN 69W-74W. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT5/WTNT35 KNHC AND THE FULL FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. TROPICAL WAVE IS ALONG 32W S OF 19N MOVING W NEAR 20 KT. THIS WAVE COINCIDES WITH A BROAD AREA OF LOW-LEVEL CYCLONIC CURVATURE FOCUSED AROUND A 1010 MB SURFACE LOW CENTERED ALONG THE WAVE AXIS NEAR 10N. THE CIMSS WAVETRAK GUIDANCE DEPICTS A MAXIMUM AREA OF 850 MB VORTICITY IN THE VICINITY OF THE WAVE AXIS AS WELL. SATELLITE IMAGERY SHOWS AN AREA OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION LOCATED W OF THE WAVE AXIS FROM 6N-12N BETWEEN 34W-40W. THIS CONVECTION IS BEING ENHANCED BY UPPER LEVEL DIFFLUENCE ON THE SRN PERIPHERY OF AN ERN TROPICAL ATLC UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 19N33W. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 52W S OF 19N MOVING W NEAR 15 KT. WHILE LOCATED BENEATH A WEAK UPPER LEVEL INVERTED TROUGH AND MODERATE TO STRONG SUBSIDENCE ALOFT...ONLY A FEW SCATTERED SHOWERS ARE NOTED IN THE VICINITY OF THE WAVE AXIS N OF THE ITCZ AXIS FROM 10N-15N BETWEEN 50W-57W. TROPICAL WAVE IS ALONG 82W S OF 16N MOVING W NEAR 13 KT. THIS WAVE REMAINS WITHIN AN AREA OF MAXIMUM DEEP LAYER MOISTURE ACROSS THE WRN CARIBBEAN AS OBSERVED ON THE TOTAL PRECIPITABLE WATER IMAGERY...HOWEVER DRY...SUBSIDENT NELY FLOW ALOFT DUE TO AN UPPER LOW CENTERED NEAR 16N79W IS INHIBITING ANY SIGNIFICANT DEEP CONVECTION OR SHOWER ACTIVITY. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 14N17W 11N30W 9N34W 9N50W 10N53W 10N63W. OUTSIDE OF THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 10N-17N BETWEEN 16W-24W. ELSEWHERE...WIDELY SCATTERED MODERATE CONVECTION AND SCATTERED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 39W-46W. ...DISCUSSION... GULF OF MEXICO... AS OF 0900 UTC...A SURFACE TROUGH IS ANALYZED ACROSS THE NE AND S/CENTRAL GULF EXTENDING FROM 29N85W ALONG 25N87W TO OVER THE ERN BAY OF CAMPECHE NEAR 20N92W. MOST OF THE EARLIER CONVECTION NEAR THE SURFACE TROUGH HAS DISSIPATED WITH ONLY WIDELY SCATTERED SHOWERS REMAINING NEAR TAMPA BAY FLORIDA AND AREAS OFFSHORE TO THE SW COVERING AN AREA FROM 25N-28N BETWEEN 82W-84W. THIS SURFACE TROUGH IS SUPPORTED BY AN UPPER LEVEL SHORTWAVE LOW CENTERED OVER SE ALABAMA. A WEAK 1011 MB SURFACE LOW IS CENTERED NEAR THE NRN EXTENT OF THE SURFACE TROUGH NEAR APALACHICOLA BAY WITH SCATTERED SHOWERS AND ISOLATED TSTMS N OF 29N BETWEEN 83W-86W. AN UPPER LEVEL RIDGE COVERS THE REMAINDER OF THE GULF ANCHORED BY AN UPPER LEVEL ANTICYCLONE CENTERED OVER THE NW YUCATAN PENINSULA AND ERN BAY OF CAMPECHE. BETWEEN THESE TWO UPPER LEVEL FEATURES...A ZONAL BAND OF MID/UPPER LEVEL MOISTURE IS BEING TRANSPORTED EWD FROM E/CENTRAL MEXICO TO THE SE GULF AND FLORIDA PENINSULA. AT THE SURFACE...A WEAK RIDGE OF HIGH PRESSURE ACROSS THE N/CENTRAL GULF IS FORECAST TO REMAIN ACROSS THE NRN GULF WATERS THROUGH LATE SATURDAY INTO EARLY SUN AHEAD OF THE NEXT FRONTAL BOUNDARY THAT IS EXPECTED TO MOVE INTO THE NW GULF LATE SUN. CARIBBEAN SEA... AN UPPER-LEVEL ANTICYCLONE IS CENTERED OVER THE YUCATAN PENINSULA AND AN UPPER LEVEL LOW IS CENTERED NEAR 16N79W IN THE WRN CARIBBEAN. BETWEEN THESE TWO FEATURES...STRONG NELY UPPER LEVEL FLOW AND DRY STABLE AIR IS FEEDING SW FROM WRN CUBA TO NICARAGUA AND HONDURAS. THIS SUBSIDENT ATMOSPHERE IS INHIBITING ANY SIGNIFICANT CONVECTION OR SHOWER ACTIVITY W OF 80W. HOWEVER...SCATTERED SHOWERS ARE OCCURRING ACROSS THE FAR SW CARIBBEAN AND PANAMA S OF 11N IN THE VICINITY OF THE BASE OF THE UPPER LOW AND PROXIMITY TO THE ITCZ AXIS THAT EXTENDS ALONG 9N ACROSS NRN COLOMBIA...PANAMA AND COSTA RICA. THE ERN CARIBBEAN IS UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE THAT EXTENDS FROM A CENTRAL ATLC ANTICYCLONE CENTERED NEAR 23N63W. WATER VAPOR IMAGERY SHOWS STRONG SUBSIDENCE AND AN IMPLIED DRY AIR MASS E OF 72W. AS A RESULT...ONLY A FEW ISOLATED SHALLOW TRADE WIND SHOWERS ARE NOTED MOVING WWD OVER THE ERN CARIBBEAN WATERS AND LESSER ANTILLES. ATLANTIC OCEAN... ATTENTION REMAINS FOCUSED ON TROPICAL STORM DANNY MOVING NNW OVER PORTIONS OF THE SW NORTH ATLC. MOST OF THE DEEP CONVECTION IS OCCURRING TO THE EAST OF THE CENTER COVERING THE AREA WITH SCATTERED SHOWERS AND TSTMS FROM 27N-31N BETWEEN 69W-74W. THE REMAINDER OF THE SW NORTH ATLC REMAINS FAIRLY TRANQUIL AS AN UPPER LEVEL RIDGE AND ASSOCIATED 1015 MB SURFACE HIGH IS CENTERED NEAR ORLANDO FLORIDA. FARTHER TO THE E...AN UPPER LEVEL LOW IS SPINNING OVER THE CENTRAL ATLC NEAR 29N46W GENERATING WIDELY SCATTERED SHOWERS FROM 25N-32N BETWEEN 42W-49W. THE REMAINDER OF THE CENTRAL AND ERN ATLC ARE DOMINATED AT THE SURFACE BY A RIDGE OF HIGH PRESSURE ASSOCIATED WITH THE AZORES-BERMUDA HIGH. ONE CENTER IS LOCATED ENE OF T.S. DANNY AS A 1021 MB HIGH NEAR 32N61W AND THE OTHER A 1031 MB HIGH CENTERED NE OF THE AZORES NEAR 42N22W. $$ HUFFMAN