000 AXNT20 KNHC 171748 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE AUG 17 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS APPROACHING THE CAPE VERDE ISLANDS ALONG 22W S OF 24N MOVING W ABOUT 10-15 KT. LOW-LEVEL CYCLONIC FLOW IS ABOUT THE WAVE AXIS EVIDENT IN VISIBLE SATELLITE IMAGERY AND CONFIRMED BY AN ASCAT SCATTEROMETER PASS. THIS WAVE ALSO COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE INDICATED BY TOTAL PRECIPITABLE WATER IMAGERY. A SMALL SURGE OF AFRICAN DUST IS BEHIND THE WAVE AXIS NEAR 23N. DUE TO THIS AREA OF DRIER AIR...NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE. TROPICAL WAVE IS IN THE CENTRAL ATLC EXTENDING FROM 24N32W TO 9N40W MOVING W 15-20 KT. VISIBLE SATELLITE IMAGERY INDICATES BROAD LOW-LEVEL CYCLONIC FLOW IN THE VICINITY OF THE WAVE. A LARGE SURGE OF DEEP LAYER MOISTURE IS E OF THE WAVE AXIS...WHILE SIGNIFICANT DRY AIR IS WRAPPING AROUND THE WRN SIDE SUPPRESSING CONVECTION NEAR THE WAVE. THE ONLY CONVECTION NOTED IS EMBEDDED WITHIN THE ITCZ. TROPICAL WAVE IS MOVING ACROSS THE ERN CARIBBEAN FROM 22N66W ACROSS THE MONA PASSAGE TO NRN VENEZUELA NEAR 9N69W. VISIBLE SATELLITE IMAGERY INDICATES BROAD CYCLONIC FLOW IN THE VICINITY OF THE WAVE AXIS. THE WAVE ALSO COINCIDES WITH AN AREA OF ENHANCED MOISTURE ACROSS THE ERN CARIBBEAN EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS IMPACTING MUCH OF THE AREA FROM 13N-18N BETWEEN 64W-68W...AND FROM 15N-23N BETWEEN 66W-70W IMPACTING AREAS OF PUERTO RICO AND HISPANIOLA. SCATTERED MODERATE CONVECTION IS ALSO FROM 13N-18N BETWEEN 71W-74W. THIS LARGE AREA ACTIVITY IS ALSO ENHANCED BY DIFFLUENCE ALOFT AROUND THE ERN SIDE OF AN UPPER LEVEL TROUGH EXTENDING FROM HAITI TO NRN COLOMBIA. TROPICAL WAVE IS APPROACHING THE YUCATAN PENINSULA EXTENDING FROM S OF WRN CUBA NEAR 21N85W ACROSS HONDURAS INTO THE E PACIFIC NEAR 8N89W MOVING W 10-15 KT. THE WAVE LIES EMBEDDED WITH AN AREA OF MODERATE DEEP LAYER MOISTURE COVERING THE W ATLC WITH A STRONGER MAXIMUM IN THE E PACIFIC INDICATED BY TOTAL PRECIPITABLE WATER IMAGERY. THE WAVE IS ALSO COLLOCATED WITH AN UPPER LEVEL TROUGH PROVIDING DIFFLUENCE E OF THE WAVE AXIS WHERE SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 11N-18N BETWEEN 82W-85W. SIMILAR ACTIVITY IS ALSO NEAR THE NRN EXTENT OF THE WAVE ACROSS WRN CUBA FROM 21N-23N BETWEEN 82W-85W...AS WELL AS ACROSS THE YUCATAN PENINSULA FROM 16N-19N BETWEEN 87W-90W. ...THE ITCZ... ITCZ AXIS IS CENTERED FROM SIERRA LEONE NEAR 9N12W ALONG 12N24W 10N37W 6N51W 9N61W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 6N-13N BETWEEN 12W-22W. SIMILAR ACTIVITY IS WITHIN 150 NM S OF THE AXIS...AND 120 NM N OF THE AXIS BETWEEN 26W-45W...AND ALONG THE AXIS BETWEEN 54W-61W. ...DISCUSSION... THE GULF OF MEXICO... A 1009 MB LOW...REMNANT OF TROPICAL DEPRESSION FIVE...HAS NOW MOVED INLAND...AND IS CENTERED OVER SE LOUISIANA NEAR 31N90W. A SURFACE TROUGH EXTENDS FROM THE LOW CENTER TOWARDS THE WSW ALONG 29N90W 28N93W TO SRN TEXAS NEAR 27N98W. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 150 NM OF THE LOW CENTER IN THE NE AND SE QUADRANTS...AND WITHIN 100 NM OF THE CENTER IN THE SW AND NW QUADRANTS. NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS ARE NEAR THE TROUGH AXIS S OF WRN LOUISIANA FROM 28N-30N BETWEEN 91W-94W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 75 NM ELSEWHERE ALONG THE TROUGH. A WEAK SURFACE TROUGH IN THE SW GULF LINES THE ERN COAST OF MEXICO ALONG 24N97W TO 19N95W SUPPORTING ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS ACROSS THE WRN BAY OF CAMPECHE. THE REMAINDER OF THE BASIN IS EXPERIENCING GENERALLY FAIR WEATHER UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE COVERING THE AREA CENTERED OVER CENTRAL TEXAS. EXPECT CONTINUED SHOWER ACTIVITY ACROSS THE NRN GULF DURING THE NEXT 24 HRS. THE CARIBBEAN SEA... A TROPICAL WAVE IS IMPACTING THE WRN CARIBBEAN EXTENDING FROM WRN CUBA ACROSS HONDURAS INTO THE E PACIFIC. SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS WRN CUBA AND THE ERN YUCATAN PENINSULA ASSOCIATED WITH THE WAVE. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO ACROSS NICARAGUA/ERN HONDURAS TO THE E SIDE OF THE WAVE AXIS INFLUENCED BY DIFFLUENCE ALOFT AROUND AN UPPER LEVEL TROUGH SITTING DIRECTLY ABOVE THE WAVE AXIS. SHOWERS/THUNDERSTORMS ARE ALSO W OF NRN COLOMBIA DUE TO SURFACE CONVERGENCE NEAR A PORTION OF THE ITCZ EXTENDING ACROSS COSTA RICA ALONG 10N. A SECOND TROPICAL WAVE IS AFFECTING THE ERN CARIBBEAN EXTENDING ACROSS THE MONA PASSAGE TO NRN VENEZUELA. NUMEROUS SHOWERS/THUNDERSTORMS ARE NEAR THE WAVE AXIS ALREADY IMPACTING PUERTO RICO AND HISPANIOLA. AN UPPER LEVEL TROUGH W OF THE WAVE AXIS IS FURTHER SUPPORTING THE SHOWER ACTIVITY NEAR THE WAVE. THE REMAINDER OF THE BASIN BETWEEN THE TWO TROPICAL WAVES...AND ACROSS THE LESSER ANTILLES IS UNDER MOSTLY FAIR CONDITIONS WITH MODERATELY DRY AIR ALOFT. EXPECT CONTINUED SHOWER ACTIVITY NEAR THE TROPICAL WAVES AS THEY PROGRESS WWD. THE ATLANTIC OCEAN... A WEAK SURFACE TROUGH...REMNANTS OF A FRONTAL BOUNDARY...REMAINS IN THE W ATLC ALONG 32N65W 29N69W 30N75W 28N78W. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 60 NM EITHER SIDE OF THE TROUGH AXIS. ALOFT...AN UPPER LEVEL RIDGE BUILDS ACROSS THE AREA FROM THE W ACCOMPANIED BY DRY AIR ALOFT KEEPING CONDITIONS FAIR ACROSS THE REMAINDER OF THE W ATLC. HOWEVER...A TROPICAL WAVE MOVING ACROSS THE ERN CARIBBEAN IS SUPPORTING SHOWERS/THUNDERSTORMS N OF HISPANIOLA FROM 19N-23N BETWEEN 66W-71W. THIS ACTIVITY MAY BEGIN AFFECTING THE SE BAHAMAS OVER THE NEXT SEVERAL HOURS. FARTHER E...SURFACE RIDING DOMINATES ANCHORED BY A 1031 MB AZORES HIGH NEAR 41N27W MAINTAINING FAIR WEATHER. SATELLITE IMAGERY ALSO INDICATES AN AREA OF AFRICAN DUST ACROSS THE CENTRAL ATLC BETWEEN 50W-65W PROVIDING STABLE CONDITIONS. ALOFT...AN UPPER LEVEL CYCLONE IS CENTERED E OF LESSER ANTILLES NEAR 19N52W. AN UPPER LEVEL RIDGE IS COVERING THE FAR E ATLC CENTERED NEAR 26N28W. 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