000 AXNT20 KNHC 011712 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT AUG 01 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1630 UTC. ...TROPICAL WAVES... A TROPICAL WAVE EXTENDS ALONG 23N34W 18N32W 13N29W 5N29W MOVING W NEAR 20 KT. VISIBLE SATELLITE IMAGERY AND SATELLITE DERIVED WINDS INDICATE LOW-LEVEL CYCLONIC FLOW IN THE VICINITY OF THIS WAVE AXIS. THE N PORTION OF THIS WAVE COINCIDES WITH A RELATIVE MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY...WHILE THE S PORTION OF THE WAVE LIES AHEAD OF A DEEP LAYER MOISTURE MAXIMUM EMBEDDED WITHIN THE ITCZ. A DRY SAHARAN AIR LAYER IS E OF THE WAVE AXIS INHIBITING ANY DEEP CONVECTION. HOWEVER...SCATTERED SHOWERS ARE EMBEDDED WITHIN THE ITCZ S OF 14N BETWEEN 28W-32W. A TROPICAL WAVE EXTENDS ALONG 25N51W 18N55W 6N55W MOVING W 20-25 KT. VISIBLE SATELLITE IMAGERY AND SATELLITE DERIVED WINDS INDICATE LOW-LEVEL CYCLONIC FLOW IN THE VICINITY OF THE WAVE AXIS. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THIS WAVE. HOWEVER...SCATTERED SHOWERS ARE FROM 8N-12N BETWEEN 53W-57W. A TROPICAL WAVE EXTENDS ALONG 21N79W 13N83W EQ84W MOVING W NEAR 25 KT. THIS WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. AN UPPER LEVEL LOW IS NEAR THE N PORTION OF THIS WAVE NEAR 20N82W ENHANCING SCATTERED MODERATE CONVECTION OVER ERN CUBA FROM 19N-21N BETWEEN 76W-78W...AND SCATTERED MODERATE/ISOLATED STRONG CONVECTION W OF THE WAVE AXIS FROM 12N-18N BETWEEN 82W-90W. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 12N14W 10N20W 10N40W 10N54W AND INTO NRN VENEZUELA NEAR 9N63W. SCATTERED MODERATE CONVECTION IS JUST OFF THE AFRICA COAST FROM 6N-12N BETWEEN 14W-20W. SIMILAR CONVECTION IS FROM 9N-10N BETWEEN 59W-63W. ...DISCUSSION... THE GULF OF MEXICO... A BROAD SURFACE RIDGE COVERS THE MAJORITY OF THE GULF OF MEXICO BRINGING GENERALLY FAIR WEATHER ACROSS THE AREA. A 1016 MB SURFACE HIGH IS AT THE MEXICAN COAST NEAR 22N98W. DRY AIR AND SUBSIDENCE ALOFT AROUND AN UPPER LEVEL HIGH CENTERED OVER NRN MEXICO NEAR 28N104W SUPPORTS THE SURFACE RIDGE AND ASSOCIATED FAIR WEATHER. A WEAK SURFACE TROUGH IS ANALYZED ACROSS THE SE GULF EXTENDING ACROSS S FLORIDA FROM 27N80W TO WRN CUBA NEAR 22N84W. SURFACE CONVERGENCE NEAR THIS TROUGH ALONG WITH UPPER LEVEL DIFFLUENCE BETWEEN THE UPPER LEVEL RIDGE COVERING THE GULF AND AN UPPER LEVEL LOW S OF CUBA NEAR 20N82W ARE SUPPORTING ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS ACROSS THE ERN GULF E OF 89W. ANTICYCLONIC SURFACE FLOW IS PRESENT AROUND THE SURFACE RIDGE WITH WINDS REACHING 15 KT ACROSS THE WRN GULF. EXPECT THE N PORTION OF A TROPICAL WAVE TO MOVE ACROSS THE SRN GULF LATER TONIGHT AND SUN. THE CARIBBEAN SEA... A TROPICAL WAVE EXTENDING FROM 21N79W TO 10N83W AND INTO THE E PACIFIC IS SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE NW CARIBBEAN FROM 12N-18N BETWEEN 82W-90W INCLUDING PORTIONS OF NICARAGUA AND HONDURAS. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO ACROSS PORTIONS OF CUBA N OF 20N BETWEEN 75W-84W. BOTH AREAS OF ACTIVITY ARE ENHANCED BY UPPER LEVEL DIFFLUENCE ASSOCIATED WITH AN UPPER LEVEL LOW S OF CUBA NEAR 20N82W. ISOLATED SHOWERS ARE IN THE SW CARIBBEAN S OF 11N BETWEEN 76W-79W DUE TO SURFACE CONVERGENCE NEAR A 1009 MB SURFACE LOW OVER COLUMBIA NEAR 8N76W. THE REMAINDER OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER INFLUENCED BY SUBSIDENCE ALOFT AND A DRY SAHARAN AIR LAYER E OF 76W. FRESH TO STRONG TRADE WINDS ARE PRESENT ACROSS MUCH OF THE CARIBBEAN. EXPECT A SECOND TROPICAL WAVE TO REACH THE E CARIBBEAN LATER TONIGHT. THE ATLANTIC OCEAN... SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS THE FAR NW ATLC N OF 29N W OF 77W DUE TO UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL RIDGE ACROSS THE GULF OF MEXICO AND AN UPPER LEVEL TROUGH OVER THE ERN CONUS N OF 33N. FARTHER E...ISOLATED SHOWERS ARE N OF 28N BETWEEN 56W-65W ASSOCIATED WITH AN UPPER LEVEL LOW NEAR 32N61W. ELSEWHERE ACROSS THE ATLC...A BROAD SURFACE RIDGE DOMINATES ANCHORED BY A 1031 MB SURFACE HIGH NEAR 35N54W...AND A 1029 MB SURFACE HIGH NEAR 35N43W. ACROSS THE TROPICAL ATLC...A BROAD UPPER LEVEL RIDGE COVERS THE AREA S OF 25N CENTERED NEAR 18N40W. $$ WALTON