000 AXNT20 KNHC 122350 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON JUL 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 2315 UTC... ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 27W/28W S OF 19N MOVING W 20 KT. THERE IS A MID LEVEL CYCLONIC ROTATION NW OF THE WAVE AXIS NEAR 18N30W. WAVE IS ALONG THE LEADING EDGE OF A MOISTURE MAXIMUM AS INDICATED ON THE TOTAL PRECIPITABLE WATER IMAGERY. HOWEVER...THE TROPICAL ATLC IS DOMINATED BY DRY SAHARAN AIR AND DUST N OF 10N. THEREFORE THE SATELLITE SIGNATURE IS PARTIALLY MASKED AND THERE IS NO ASSOCIATED SHOWERS/CONVECTION. TROPICAL WAVE IS ALONG 47W S OF 16N MOVING W 20 KT. WAVE IS EMBEDDED WITHIN DRY SAHARAN AIR AND DUST MASKING ANY SATELLITE SIGNATURE AND SUPPRESSING ANY SHOWER ACTIVITY/CONVECTION. TROPICAL WAVE IN THE W CARIBBEAN IS ALONG 84W/85W S OF 20N MOVING W 20 KT. WAVE IS AT THE TRAILING EDGE AN AREA OF DEEP LAYER MOISTURE THAT COVERS THE W CARIBBEAN AS INDICATED ON THE TOTAL PRECIPITABLE WATER IMAGERY AND IS ALONG THE LEADING EDGE OF THE LARGE AREA OF DRY SAHARAN AIR AND DUST THAT COVERS THE TROPICAL ATLC INTO THE CENTRAL CARIBBEAN THUS LIMITING THE SHOWER ACTIVITY/CONVECTION. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 13N16W 7N35W 9N47W 8N62W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS MOVING OFF W AFRICA WITHIN 90 NM ALONG THE COAST FROM 8N-14N. CLUSTERS OF SIMILAR CONVECTION ARE WITHIN 150 NM OF THE ITCZ BETWEEN 20W-38W AND FROM 4N-10N BETWEEN 47W-58W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE COVERS THE GULF N OF 25N EXTENDING ALONG THE N GULF COAST FROM TEXAS INTO THE W ATLC OVER NE FLORIDA. A WEAK UPPER LOW IS IN THE S GULF NEAR 22N94W. A WEAK SURFACE RIDGE EXTENDS FROM THE W ATLC ACROSS S FLORIDA OVER THE E GULF WITH A 1017 MB HIGH NEAR 26N86W. THE STATIONARY FRONT WELL N OF THE DISCUSSION CONTINUES TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND OVER GEORGIA AND NE FLORIDA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OVER THE YUCATAN PENINSULA MOVING NW INTO THE E BAY OF CAMPECHE ALONG THE IMMEDIATE COASTAL WATERS FROM 90W-92W. MODERATE SUBSIDENCE AND DRY STABLE AIR ALOFT ARE LEAVING THE GULF UNDER CLEAR SKIES THIS EVENING. CARIBBEAN SEA... THE W CARIBBEAN W OF 75W IS DOMINATED BY N TO NE FLOW ALOFT AND EASTERLY FLOW ALOFT DOMINATES THE REMAINDER OF THE CARIBBEAN WITH NO CLEAR CUT UPPER LEVEL FEATURES OVER THE CARIBBEAN BASIN. THE ITCZ EXTENDS ACROSS THE SW CARIBBEAN ALONG 10N/11N OVER COSTA RICA INTO THE E PACIFIC REGION AND COUPLED WITH THE TROPICAL WAVE ALONG 84W/85W IS GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS S OF 15N W OF 80W TO INLAND OVER PANAMA TO NICARAGUA AND HONDURAS. AFTERNOON THUNDERSTORMS THAT HAVE DEVELOPED OVER HISPANIOLA...CUBA...AND JAMAICA ARE BEING FORCED INTO THE CARIBBEAN WATERS BY THE NE FLOW ALOFT DOTTING THE AREA WITHIN 60 NM ALONG THE COASTLINES. THE CENTRAL SWATH OF THE CARIBBEAN WITHIN 120 NM OF LINE FROM THE LESSER ANTILLES NEAR MARTINIQUE ALONG 16N77W TO 18N84W IS UNDER THE INFLUENCE OF DRY SAHARAN AIR AND DUST LEAVING THE AREA UNDER MOSTLY CLEAR SKIES THIS EVENING. ATLANTIC OCEAN... AN UPPER RIDGE EXTENDS FROM THE N GULF OF MEXICO ACROSS NE FLORIDA INTO THE FAR W ATLC TO NEAR 32N76W. THE STATIONARY FRONT WELL N OF THE DISCUSSION CONTINUES TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND OVER GEORGIA/NE FLORIDA AND MOVING SE OFF THE COAST WITHIN 75 NM N OF JACKSONVILLE FLORIDA. A SEABREEZE SURFACE TROUGH EXTENDS FROM 28N79W TO OVER THE MIDDLE FLORIDA KEYS NEAR 25N81W. THE REMAINDER OF THE W ATLC IS UNDER N TO NE FLOW ALOFT GENERATING SCATTERED SHOWERS/ THUNDERSTORMS FROM OVER THE BAHAMA ISLANDS S OF 25N TO OVER CUBA BETWEEN 74W-80W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 25N BETWEEN 68W-74W INCLUDING THE TURKS AND CAICOS. A SURFACE RIDGE DOMINATES DOMINATES THE ATLC E OF 70W ANCHORED BY A 1032 MB HIGH WELL N OF THE DISCUSSION AREA THEN WEAKENS AND NARROWS OVER THE REMAINDER OF THE W ATLC AND INTO THE GULF OF MEXICO OVER S FLORIDA. THE CENTRAL ATLC AND E ATLC ARE UNDER STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT LEAVING THE AREA UNDER FAIR WEATHER THIS EVENING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW