000 AXNT20 KNHC 261802 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN AUG 26 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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...METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1730 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS TILTED ALONG 16N33W 3N29W ESTIMATED TO BE MOVING W NEAR 10-15 KT. HOWEVER...MUCH OF THE CYCLONIC TURNING AND HIGHEST MOISTURE CONTENT WITH THIS WAVE HAVE HAD A SW MOTION OVER THE LAST DAY OR SO...AS DENOTED BY TODAYS VIS IMAGERY AND THE UW-CIMSS TPW PRODUCT. ASSOCIATED SCATTERED MODERATE CONVECTION REMAINS DISORGANIZED FROM 10N-13N BETWEEN 29W-35W. TROPICAL WAVE IS ALONG 53/54W S OF 15N MOVING W 10 KT. THIS SYSTEM HAS GENERALLY CHANGED LITTLE SINCE YESTERDAY WITH A LOW LEVEL CYCLONIC SWIRL AND A LOW LATITUDE INVERTED V-SHAPE CLEARLY APPARENT ON VIS IMAGES...THOUGH STILL PARTIALLY EMBEDDED IN THE ITCZ. WHILE THIS WAVE HAS MAINTAINED FAIR STRUCTURE...SHOWER AND TSTM ACTIVITY REMAINS MINIMAL. TROPICAL WAVE IS IN THE W CARIBBEAN AND OVER CENTRAL AMERICA ALONG 85W S OF 21N MOVING W 10-15 KT. THIS WAVE COULD BE ENHANCING SOME OF THE SHOWER/TSTM ACTIVITY IN THE SE GULF...AND THE SCATTERED TSTMS IN THE NW CARIB OFF THE COAST OF WRN CUBA N OF 20N. LOW CLOUD MOTIONS DO SHOW A LITTLE CYCLONIC TURNING JUST E OF BELIZE AND THE YUCATAN WHICH WAS CONFIRMED BY THIS MORNINGS QUIKSCAT PASS...BUT OVERALL SHOWER/TSTM ACTIVITY OVER THE CARIBBEAN PORTION OF THE WAVE ARE MINIMAL AND DISORGANIZED. THE TROPICAL WAVE PREVIOUSLY IN THE WRN BAY OF CAMPECHE APPEARS TO HAVE FRACTURED...AND AS OF 1500 UTC THE NRN PORTION IS BEING ANALYZED AS A TROUGH EXTENDING NW TO SE FROM NEAR BROWNSVILLE TO THE CENTRAL BAY OF CAMPECHE NEAR 19N94W. A 1010 MB LOW IS ALONG THE TROUGH AXIS NEAR 22N96W. FOR MORE DETAILS ON THIS SYSTEM SEE GULF SECTION BELOW. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 13N16W 12N28W 7N34W 9N51W 9N61W. BESIDES FOR THE CONVECTION DISCUSSED IN THE TROPICAL WAVES SECTION ...SCATTERED MODERATE CONVECTION IS MAINLY S OF THE AXIS FROM 5N-9N E OF 18W. ISOLATED CLUSTERS OF MODERATE CONVECTION ARE FROM 4N-8N BETWEEN 20W-41W. DISCUSSION... GULF OF MEXICO... THERE IS QUITE A BIT OF SPOTTY CONVECTION OVER THE GULF THIS AFTERNOON BUT NO REALLY STRONG SFC FEATURES AT THE MOMENT. THE MOST PRONOUNCED SFC FEATURE IS THE BROAD AREA OF LOW PRESSURE IN THE SW GULF. AS OF THE 26/1500 UTC MAP...A 1010 MB LOW WAS NEAR 22N96W THAT HAS WITH A TROUGH EXTENDING THROUGH THE LOW BETWEEN BROWNSVILLE AND THE SOUTH CENTRAL BAY OF CAMPECHE. THE ASSOCIATED SCATTERED MODERATE CONVECTION IS FROM 19N-25N BETWEEN 92W AND THE COAST OF MEXICO. THIS SYSTEM IS EXPECTED TO CONTINUE TO DRIFT WESTWARD OVER MEXICO WITH NO DEVELOPMENT. A WEAK 1015 MB HIGH IS OVER THE MIDDLE GULF NEAR 27N88W...AND APPEARS TO BE SLOWLY DISSIPATING. HOWEVER...THE FLOW AROUND THIS HIGH IS COLLIDING WITH ESE FLOW AROUND ATLC RIDGING TO PRODUCE A SFC TROUGH IN THE ERN GULF FROM NEAR CEDAR KEY FLORIDA TO 25N87W. THIS IS SPARKING SCATTERED TO NUMEROUS SHOWERS AND TSTMS OFFSHORE FLORIDA AND CUBA MAINLY E OF 86W. SCATTERED SHOWERS AND TSTMS ALSO DOT THE NRN GULF COASTAL REGION GENERALLY WITHIN 90 NM OF THE COAST E OF 95W. THE AFOREMENTIONED CONVECTION IS ALSO BEING SUPPORTED BY AN ABUNDANCE OF DIFFLUENCE ALOFT...WITH THE DRIVING UPPER FEATURES BEING THE LOW JUST S OF LOUISIANA...RIDGING OVER THE FAR NE AND SW PORTIONS...AND AN INVERTED UPPER TROUGH OVER THE FAR SE PORTION. WEAK RIDGING WILL MEANDER AROUND 30N OVER THE NEXT COUPLE OF DAYS AS BROAD LOW PRES TROUGHING DRIFTS W OVER THE SW PORTION. CARIBBEAN SEA... THE MOST SIGNIFICANT AREA OF CONVECTION IS OFF THE COAST OF COLOMBIA AND VENEZUELA...WITH SCATTERED MODERATE CONVECTION S OF 16N BETWEEN 64W-78W. ISOLATED TSTMS ARE ALSO N OF 16N BETWEEN THE SAME AREA AFFECTING PUERTO RICO...HISPANIOLA..AND ADJACENT WATERS. THE MORE CONCENTRATED ACTIVITY IN THE SRN CARIBBEAN APPEARS TO BE TIED TO THE ITCZ. ALL OF THE ACTIVITY IS ALSO BEING SUPPORTED BY DIFFLUENCE ALOFT BETWEEN THE UPPER TROUGHING BETWEEN PANAMA AND HAITI...AND ATLC RIDGING EXTENDING INTO THE ERN CARIBBEAN. THE TRADE WIND FLOW IS ON THE LIGHT TO MODERATE SIDE...AND IS ONLY EXPECTED TO INCREASE SLIGHTLY OVER THE NEXT COUPLE OF DAYS. ATLANTIC OCEAN... THE SFC PATTERN ACROSS THE ATLC DISCUSSION AREA REMAINS FAIRLY WEAK THIS AFTERNOON. THIS WEAK PATTERN IS MAINLY DUE TO AN UNUSUAL (FOR AUGUST) FRONT DEEP INTO THE SUBTROPICS ENTERING THE AREA NEAR 32N37W TO 26N55W THEN SNAKING WSW THEN NW AS A TROUGH THROUGH 23N63W 29N69W. SHOWER AND TSTM ACTIVITY IS MAINLY ISOLATED IN NATURE WITHIN 30NM OF THE BOUNDARY. THE MOST CONCENTRATED TSTM ACTIVITY NEAR THE FRONT IS SCATTERED FROM 24N-27N BETWEEN 55W-60W...WHICH ARE OCCURRING AROUND THE PERIPHERY OF THE UPPER LOW NEAR 25N58W. A WEAK 1018 MB HIGH IS OVER THE WRN ATLC NEAR 29N72W. A SFC TROUGH IS JUST E OF THE LEEWARD ISLANDS ALONG 21N58W 15N59W THAT IS GENERATING JUST A FEW SHOWERS WITHIN 60 NM EITHER SIDE OF THE AXIS. A WEAK RIDGE AXIS IS OVER THE REMAINDER OF THE CENTRAL AND E ATLC PORTION OF THE DISCUSSION AREA...WITH THE AXIS ENTERING THE AREA NEAR 32N29W THEN CONTINUING SW THROUGH 25N40W 23N55W. LOOK FOR THE FRONT TO CONTINUE BECOMING DIFFUSE OVER THE NEXT DAY OR SO...THOUGH REMNANT TROUGHING WILL BE SLOW TO FADE. WEAK RIDGING WILL PERSIST ELSEWHERE. ELSEWHERE ALOFT...AN UPPER HIGH IS JUST OFFSHORE N FLORIDA NEAR 30N79W. ANOTHER UPPER HIGH IS OVER THE CENTRAL ATLC NEAR 22N42W THAT IS SURROUNDED BY DRY/STABLE AIR. THIS UPPER HIGH...AMONG OTHER BENIGN UPPER FEATURES...IS EMBEDDED IN THE LARGER SCALE RIDGING EXTENDING E FROM THE COAST OF AFRICA. $$ WILLIS