000 AXNT20 KNHC 141042 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI AUG 14 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 0945 UTC. ...SPECIAL FEATURES... THE REMNANT LOW OF TROPICAL DEPRESSION TWO IS CENTERED NEAR 14.4N 40.2W OR ABOUT 1375 MILES E OF THE LESSER ANTILLES MOVING W AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1010 MB. SHOWERS/THUNDERSTORMS ASSOCIATED WITH THE SYSTEM HAVE INCREASED OVER THE PAST FEW HOURS AND ARE FROM 14N-16N BETWEEN 40W-43W. SLOW REGENERATION OF THIS SYSTEM IS POSSIBLE OVER THE NEXT COUPLE DAYS. THERE IS A MEDIUM CHANCE...30 TO 50 PERCENT...OF THE SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HRS. A STRONG TROPICAL WAVE IS ALONG 25W S OF 18N MOVING W NEAR 8 KT. SATELLITE IMAGERY AND A RECENT 0720 UTC QUIKSCAT PASS INDICATES A LOW-LEVEL CYCLONIC CENTER ALONG THE WAVE AXIS NEAR 12N26W. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS FROM 11N-15N BETWEEN 26W-30W. THIS SYSTEM HAS A HIGH CHANCE...GREATER THAN 50 PERCENT...OF BECOMING A TROPICAL DEPRESSION IN THE NEXT DAY OR TWO. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 74W S OF 22N MOVING W NEAR 20 KT CURRENTLY AFFECTING THE BAHAMAS AND HISPANIOLA. SATELLITE IMAGERY INDICATES LOW-LEVEL CYCLONIC FLOW IN THE VICINITY OF THE WAVE AXIS. THIS WAVE ALSO COINCIDES WITH A HIGH AMPLITUDE DEEP MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. WHILE HAS DECREASED OVER THE PAST FEW HRS...SCATTERED MODERATE CONVECTION REMAINS FROM 16N-18N BETWEEN 68W-72W. SCATTERED SHOWERS ARE FROM 18N-23N BETWEEN 66W-72W. A CLUSTER OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ALSO N OF THE BAHAMAS FROM 25N-29N BETWEEN 71W-77W. THIS ACTIVITY IS MAINLY ENHANCED BY UPPER LEVEL DIFFLUENCE. A TROPICAL WAVE IS ALONG 86W S OF 20N MOVING W 20-25 KT. THIS WAVE COINCIDES WITH A RELATIVE MAXIMUM IN DEEP LAYER MOISTURE OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. WHILE NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THIS WAVE...A FEW ISOLATED SHOWERS/THUNDERSTORMS ARE FROM 18N-23N BETWEEN 81W-85W. STRONGER CONVECTION ASSOCIATED WITH THE WAVE IS IN THE E PACIFIC BASIN. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 13N16W 12N28W 14N38W 10N50W 10N64W. ISOLATED MODERATE CONVECTION IS FROM 7N-10N BETWEEN 21W-29W. SIMILAR CONVECTION IS FROM 8N-11N BETWEEN 37W-43W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH EXTENDS ACROSS N FLORIDA AND INTO THE NE GULF FROM 29N81W TO 28N85W. SURFACE CONVERGENCE NEAR THE TROUGH AS WELL AS UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL TROUGH OVER THE ERN CONUS EXTENDING INTO THE NE GULF TO 28N86W AND AN UPPER LEVEL RIDGE OVER THE WRN ATLC ARE SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE ERN GULF N OF 22N E OF 87W. A FEW ISOLATED SHOWERS/THUNDERSTORMS ARE ALSO ACROSS THE CENTRAL GULF OF MEXICO FROM 24N-26N BETWEEN 90W-93W. THIS ACTIVITY IS SUPPORTED BY UPPER LEVEL DIFFLUENCE BETWEEN THE UPPER LEVEL TROUGH OVER THE ERN CONUS AND AN UPPER LEVEL RIDGE OVER THE WRN CONUS CENTERED OVER TEXAS NEAR 31N101W. EXPECT THE SURFACE TROUGH ACROSS FLORIDA TO DISSIPATE LATER TODAY...AND THE N PORTION OF A TROPICAL WAVE TO REACH THE STRAITS OF FLORIDA AND SE WATERS THIS EVENING. CARIBBEAN SEA... TWO TROPICAL WAVES ARE AFFECTING THE CARIBBEAN SEA AND CENTRAL AMERICA. SEE ABOVE. NUMEROUS SHOWERS/THUNDERSTORMS ARE ACROSS THE FAR SW CARIBBEAN S OF 10N BETWEEN 74W-82W. THIS ACTIVITY IS ENHANCED BY SURFACE CONVERGENCE NEAR A 1009 MB LOW OVER COLUMBIA NEAR 8N77W...AND THE PROXIMITY OF THE E PACIFIC ITCZ. FRESH TO STRONG TRADEWINDS ARE OVER THE ERN CARIBBEAN...WHILE MODERATE TO FRESH TRADEWINDS ARE ACROSS THE REMAINDER OF THE BASIN. IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS S OF E CUBA NEAR 20N77W. STRONG SUBSIDENCE IS W OF THE UPPER LEVEL LOW CENTER SUPPORTING GENERALLY FAIR WEATHER ACROSS THE CENTRAL CARIBBEAN. AN UPPER LEVEL HIGH IS OVER THE ERN CARIBBEAN NEAR 16N63W. UPPER LEVEL DIFFLUENCE BETWEEN THE UPPER LEVEL LOW AND THE UPPER LEVEL HIGH IS ENHANCING CONVECTION NEAR THE TROPICAL WAVE ALONG 74W. EXPECT SHOWERS/THUNDERSTORMS TO CONTINUE OVER THE CARIBBEAN AS THE TROPICAL WAVE TREKS WWD. ATLANTIC OCEAN... SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS THE FAR WRN ATLC NW OF A LINE FROM 28N80W TO 31N77W. THIS ACTIVITY IS ENHANCED BY SURFACE CONVERGENCE NEAR A SURFACE TROUGH EXTENDING ACROSS N FLORIDA TO NEAR 29N81W INTO THE ATLC TO NEAR 31N79W...AND UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL TROUGH OVER THE ERN CONUS AND AN UPPER LEVEL RIDGE CENTERED NEAR 36N57W. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO NE OF THE BAHAMAS FROM 26N-29N BETWEEN 70W-77W. THIS ACTIVITY IS ENHANCED BY UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL LOW OVER E CUBA NEAR 20N77W AND AN UPPER LEVEL HIGH NEAR 25N71W. THE TROPICAL WAVE ALONG 74W MAY ALSO BE ENHANCING THIS ACTIVITY AS WELL AS SCATTERED SHOWERS S OF 23N BETWEEN 66W-72W. A SURFACE TROUGH EXTENDS FROM 25N56W TO 30N53W SUPPORTING ISOLATED SHOWERS WITHIN 50 NM OF THE TROUGH AXIS. THE TROUGH AND ASSOCIATED SHOWERS ARE ALSO SUPPORTED BY UPPER LEVEL DIFFLUENCE BETWEEN THE UPPER LEVEL HIGH NEAR 36N57W AND AN UPPER LEVEL LOW NEAR 28N46W. ELSEWHERE ACROSS THE ATLC...A BROAD SURFACE RIDGE DOMINATES ANCHORED BY A 1022 MB HIGH NEAR 34N66W...AND A 1025 MB HIGH NEAR 35N33W. A BROAD UPPER LEVEL RIDGE CENTERED NEAR 22N27W DOMINATES IS OVER THE ERN ATLC ENHANCING CONVECTION ALONG THE ITCZ. $$ WALTON