000 AXNT20 KNHC 122352 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU AUG 12 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 18N32W TO 6N29W MOVING W 10-15 KT. THE WAVE LOCATION IS BETTER APPARENT IN THE MID LEVELS OF THE ATMOSPHERE...SUCH AS THE 700 MB STREAMLINE ANALYSIS. SATELLITE IMAGERY INDICATES WEAK LOW-LEVEL CYCLONIC FLOW IN THE VICINITY OF THE WAVE AXIS CONFIRMED BY SATELLITE DERIVED WINDS. DUE TO A LARGE AREA OF DRY SAHARAN AIR AND DUST EAST OF THE WAVE AXIS...CONVECTION IS CONSTRAINED TO THE ITCZ. TROPICAL WAVE IS NORTHEAST OF THE LEEWARD ISLANDS FROM 22N58W TO 16N60W MOVING NW 10-15 KT. SATELLITE IMAGERY INDICATES LOW/MID-LEVEL CYCLONIC TURNING AROUND THE WAVE AXIS. THE WAVE ALSO LIES EMBEDDED IN A DEEP LAYER MOISTURE MAXIMUM EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 16N TO 20N BETWEEN 57W AND 61W...AND FROM 20N TO 23N BETWEEN 54W AND 57W. TROPICAL WAVE EXTENDS ACROSS HISPANIOLA FROM 23N70W TO 17N73W MOVING WNW NEAR 10 KT. TOTAL PRECIPITABLE WATER IMAGERY INDICATES AN AREA OF ENHANCED MOISTURE ACROSS THE N CENTRAL CARIBBEAN IN WHICH THE WAVE IS EMBEDDED. WEAK TURNING IS OBSERVED IN THE VICINITY OF THE WAVE. MOST OF THE SHOWER ACTIVITY ASSOCIATED WITH THE WAVE IS OVER HISPANIOLA AND WITHIN 90 NM OFF THE SOUTHERN COAST OF THE ISLAND. DOPPLER RADAR IMAGERY FROM PUERTO RICO ALSO INDICATES SCATTERED SHOWERS ACROSS THE ISLAND WITH ISOLATED SHOWERS SURROUNDING THE ISLAND FROM 15N TO 20N WEST OF 63W. ...ITCZ... THE ITCZ AXIS IS ANALYZED FROM WEST AFRICA OVER SIERRA LEONE NEAR 8N12W...CONTINUING WESTWARD ALONG 6N25W 4N35W 5N45W TO THE COAST OF GUYANA NEAR 7N58W CONTINUING WESTWARD ACROSS NORTHERN SOUTH AMERICA. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 130 NM ON EITHER SIDE OF THE AXIS EAST OF 36W. ...DISCUSSION... GULF OF MEXICO... DOPPLER RADAR IMAGERY INDICATES THAT THE REMNANT CIRCULATION OF TROPICAL DEPRESSION FIVE IS LOCATED OVER CAT ISLAND...OFF THE COAST OF MISSISSIPPI...NEAR 30N89W...ANALYZED AS A 1008 MB LOW CENTER AT 2200 UTC. AT THIS POINT...MOST OF THE CONVECTION PRODUCED BY THIS SYSTEM HAS MOVED INLAND. YET...SCATTERED MODERATE TO ISOLATED STRONG CONVECTION REMAINS OVER THE NORTHERN GULF COAST NORTH OF 27N BETWEEN 82W AND 90W. TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE CONVECTION IS FUELED BY PLENTY OF LOW-MID LEVEL MOISTURE EMBEDDED IN THE SYSTEM ADVECTING ACROSS THE SOUTHERN STATES WEST OF 94W. WATER VAPOR IMAGERY INDICATES MODERATELY DRY AIR ACROSS THE SE GULF KEEPING WEATHER CONDITIONS FAIR WITH CLEAR SKIES. CYCLONIC FLOW ALOFT IS NOTED OVER THE WESTERN GULF...AROUND AN UPPER LEVEL LOW/TROUGH OVER NORTHEAST MEXICO. THIS UPPER LEVEL FEATURE IS DRAWING MID-UPPER LEVEL MOISTURE FROM THE EASTERN PACIFIC SUPPORTING A FEW ISOLATED SHOWERS WITHIN 100 NM OFF THE COASTAL WATERS OF MEXICO FROM 19N TO 24N. SHORT RANGE COMPUTER MODELS KEEP SCATTER CONVECTION ACROSS THE NORTHERN GULF AS THE REMNANTS OF T.D. FIVE DRIFT FARTHER INLAND...WHILE SURFACE RIDGING BUILDS ACROSS THE GULF FROM THE WEST ATLC. CARIBBEAN SEA... A MID-UPPER LEVEL TROUGHINESS COVERS THE NORTH CENTRAL CARIBBEAN SUPPORTING A WEAK SURFACE TROUGH EXTENDING FROM THE NW BAHAMAS NEAR 25N77W ACROSS CENTRAL CUBA TO NEAR 19N78W. SURFACE CONVERGENCE NEAR THE TROUGH IS SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS NORTH OF 16N BETWEEN 75W AND 80W. FARTHER EAST...A TROPICAL WAVE ACROSS CENTRAL HISPANIOLA IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS SOUTH OF THE ISLAND NORTH OF 16N EAST OF 72W...INCLUDING PUERTO RICO AND SURROUNDING WATERS. A BROAD AREA OF CYCLONIC TURNING SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS IS OVER THE SOUTHWEST CARIBBEAN SOUTH OF 14N WEST OF 73W ENHANCED BY SURFACE CONVERGENCE NEAR AN EXTENSION OF THE ITCZ ACROSS COSTA RICA...PANAMA...AND NORTHERN COLOMBIA. WATER VAPOR IMAGERY INDICATES VERY DRY AIR ALOFT ACROSS THE SOUTHEAST CARIBBEAN AND OVERALL DRY AND STABLE ATMOSPHERE ALOFT ELSEWHERE ACROSS THE CARIBBEAN MAINTAINING FAIR WEATHER CONDITIONS. EXPECT SHOWER/THUNDERSTORM ACTIVITY TO REMAIN ACROSS THE SOUTHWEST AND CENTRAL CARIBBEAN OVER THE NEXT 24 HOURS. SHOWER ACTIVITY MAY BEGIN TO IMPACT THE NORTHERN LEEWARD ISLANDS AS A TROPICAL WAVE TO EAST OF THE ISLANDS MOVES NORTHWEST. ATLANTIC OCEAN... A WEAK SURFACE TROUGH EXTENDS FROM THE NORTHWEST BAHAMAS ACROSS EASTERN CUBA ALONG 25N77W TO 19N78W SUPPORTING SCATTERED SHOWERS WITHIN 40 NM ON EITHER SIDE OF THE TROUGH. DRY/STABLE AIR ALOFT IS ELSEWHERE ACROSS THE WESTERN ATLC WEST OF 70W PROVIDING FAIR WEATHER CONDITIONS WITH A FEW HIGH CLOUDS. FARTHER EAST...AN UPPER LEVEL TROUGH/LOW NEAR 30N57W SUPPORTS A WEAK SURFACE TROUGH IN THE CENTRAL ATLC FROM 26N55W TO 25N58W...ENHANCING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF THE AXIS. FARTHER EAST...BROAD SURFACE RIDGING DOMINATES THE EASTERN ATLC ANCHORED BY AN ELONGATED HIGH PRESSURE CENTER WELL NORTH OF THE DISCUSSION AREA. LAST VISIBLE SATELLITE IMAGES OF THE DAY INDICATED A BROAD AREA OF SAHARAN DUST COVERING MOST OF THE EASTERN ATLANTIC EAST OF 35W SUPPORTING STABLE CONDITIONS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA