000 AXNT20 KNHC 131056 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE JUL 13 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1000 UTC... ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 18N31W TO 6N29W MOVING W 15-20 KT. THE WAVE LIES AHEAD OF A MAXIMUM IN DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. BROAD CYCLONIC FLOW IS ALSO ABOUT THE WAVE AXIS EVIDENT IN IN THE FIRST VISIBLE SATELLITE IMAGES OF THE DAY. THESE IMAGES ALSO INDICATE AN AREA OF DUST ASSOCIATED WITH A DRY SAHARAN AIR LAYER IS ACROSS MUCH OF THE TROPICAL ATLC SUPPRESSING CONVECTION NEAR THE WAVE. HOWEVER...SCATTERED MODERATE/STRONG CONVECTION IS NEAR THE ITCZ FROM 8N-11N BETWEEN 28W-35W. TROPICAL WAVE IS ALONG 51W/52W S OF 16N MOVING W 15-20 KT. WAVE IS SUPPRESSED AND MASKED DUE TO A DRY SAHARAN AIR LAYER ACROSS THE TROPICAL ATLC KEEPING CONVECTION TO A MINIMUM AND RESTRICTED TO THE ITCZ. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 7N-11N BETWEEN 49W-54W. TROPICAL WAVE IS ACROSS THE YUCATAN PENINSULA INTO THE E PACIFIC EXTENDING FROM 19N88W TO 8N90W MOVING W NEAR 20 KT. MOISTURE ASSOCIATED WITH THIS WAVE HAS NOW MOVED MOSTLY OUT OF THE WRN CARIBBEAN. THE WAVE ALSO LIES AHEAD OF A DRY SAHARAN AIR LAYER AND A LARGE AREA OF DUST ACROSS THE TROPICAL ATLC AND ACROSS THE CARIBBEAN. DUE TO A DIFFLUENT ZONE ALOFT SCATTERED MODERATE/STRONG CONVECTION IS ACROSS GUATEMALA/YUCATAN PENINSULA S OF 17N BETWEEN 88W-93W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 12N15W 10N30W 7N42W 9N52W 7N61W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 7N-10N BETWEEN 13W-17W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-7N BETWEEN 36W-40W. SIMILAR ACTIVITY IS FROM 9N-11N BETWEEN 41W-46W. ...DISCUSSION... GULF OF MEXICO... A DRY AND STABLE AIRMASS LIES ACROSS MUCH OF THE GULF OF MEXICO AROUND AN UPPER LEVEL RIDGE CENTERED OVER LOUISIANA NEAR 31N91W MAINTAINING FAIR CONDITIONS ACROSS THE BASIN. SCATTERED SHOWERS/THUNDERSTORMS HAVE FLARED UP IN THE SW GULF S OF 21N BETWEEN 94W-97W AROUND AN UPPER LEVEL TROUGH IN THE BAY OF CAMPECHE ALONG 96W. SOME OF THIS ACTIVITY MAY BE INFLUENCED BY A TROPICAL WAVE ALONG 95W IN THE E PACIFIC. AT THE SURFACE...RIDGING DOMINATES ANCHORED BY A 1017 MB HIGH CENTERED W OF FLORIDA NEAR 26N83W. LIGHT ANTI-CYCLONIC FLOW IS AROUND THE SURFACE RIDGE WITH STRONGER SLY WINDS REACHING UP TO 20 KT ALONG THE TEXAS COASTLINE. EXPECT SURFACE RIDGING TO REMAIN ACROSS THE BASIN ALONG WITH DRY AIR AND MOSTLY FAIR CONDITIONS. CARIBBEAN SEA... MOST OF THE MOISTURE ASSOCIATED WITH A TROPICAL WAVE...NOW OVER THE YUCATAN PENINSULA...HAS MOVED OUT OF THE CARIBBEAN. A FEW ISOLATED SHOWERS/THUNDERSTORMS REMAIN S OF 18N W OF 84W. ISOLATED SHOWERS/THUNDERSTORMS ARE ALSO IN THE SW CARIBBEAN S OF 14N DUE TO SURFACE CONVERGENCE NEAR AN EXTENSION OF THE E PACIFIC ITCZ FROM COSTA RICA TO NRN COLOMBIA. A FEW ISOLATED SHOWERS/THUNDERSTORMS ARE ALSO NOTED S OF HISPANIOLA. ELSEWHERE...A DRY SAHARAN AIR LAYER IS KEEPING CONDITIONS FAIR. SEVERAL STATIONS CONTINUE TO REPORT THE PRESENCE OF DUST. ALOFT...MAINLY ELY FLOW IS ACROSS THE NW CARIBBEAN AROUND A BROAD UPPER LEVEL TROUGH IN THE SW CARIBBEAN. EXPECT FAIR CONDITIONS TO REMAIN ACROSS MUCH OF THE BASIN UNDER THE PRESENCE OF DRY AIR. ATLANTIC OCEAN... A SHORTWAVE UPPER LEVEL TROUGH OFF THE ERN SEABOARD SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS N OF 30N BETWEEN 77W-80W. A SECOND SHORTWAVE UPPER LEVEL TROUGH EXTENDS OVER THE SE BAHAMAS SUPPORTING A SURFACE TROUGH FROM 25N76W TO 21N78W. SCATTERED SHOWERS/THUNDERSTORMS ARE FROM 23N-26N BETWEEN 74W-76W. A FEW ISOLATED SHOWERS ARE ALSO NOTED OFF THE SE COAST OF FLORIDA DUE TO WIND CONVERGENCE ALONG THE COAST. FARTHER E...RIDGING DOMINATES THE ENTIRE BASIN ANCHORED BY A 1033 MB HIGH CENTERED NEAR 41N44W. A DRY SAHARAN AIR LAYER ACCOMPANIED BY DUST COVERS MUCH OF THE TROPICAL ATLC KEEPING CONDITIONS FAIR. ALOFT...AN UPPER LEVEL TROUGH IS BETWEEN 59W-67W...WITH UPPER RIDGING BETWEEN 50W-59W...FOLLOWED BY ANOTHER UPPER LEVEL TROUGH BETWEEN 36W-50W. AN UPPER LEVEL RIDGE COVERS THE ERN ATLC CENTERED W OF THE CANARY ISLANDS NEAR 27N26W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON