000 AXNT20 KNHC 171042 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED JUN 17 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 87W/88W S OF 19N MOVING W 15-20 KT. THE WAVE COINCIDES WITH A DEEP MOISTURE MAXIMUM BASED ON TOTAL PRECIPITABLE WATER IMAGERY. THE WAVE IS SUPPORTING ISOLATED MODERATE CONVECTION FROM 11N-15N BETWEEN 86W-88W AND FROM 16N-19N BETWEEN 82W-88W. THIS CONVECTION IS ALSO SUPPORTED BY UPPER LEVEL DIFFLUENCE ASSOCIATED WITH AN UPPER LEVEL HIGH OVER THE BAY OF CAMPECHE. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 10N12W 7N22W 6N32W 4N42W AND INTO NE BRAZIL NEAR THE EQUATOR ALONG 51W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-10N BETWEEN 12W-16W. SCATTERED MODERATE CONVECTION IS WITHIN 150/200 NM ON EITHER SIDE OF THE AXIS BETWEEN 16W-41W WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION S OF 2N BETWEEN 38W-44W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH IS AFFECTING PORTIONS OF THE S GULF EXTENDING FROM N OF THE YUCATAN PENINSULA NEAR 22N91W TO S GUATEMALA NEAR 15N91W. LOW LEVEL CONVERGENCE NEAR THIS TROUGH AND UPPER LEVEL DIFFLUENCE AROUND AN UPPER LEVEL HIGH OVER THE BAY OF CAMPECHE NEAR 21N93W ARE SUPPORTING ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS S OF 21N BETWEEN 92W-96W. STRONGER CONVECTION ASSOCIATED WITH THIS TROUGH EXTENDS INTO THE E PACIFIC.THE SURFACE TROUGH IS FORECAST TO MOVE W ACROSS THE BAY OF CAMPECHE LATER TODAY. AN UPPER LEVEL SHORTWAVE TROUGH E OF THE GEORGIA COAST IS SUPPORTING ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS OVER S FLORIDA AND THE FLORIDA KEYS FROM 24N-26N E OF 82W. ELSEWHERE...A STATIONARY 1017 MB SURFACE HIGH REMAINS NEAR 28N87W BRINGING FAIR WEATHER ACROSS THE REMAINDER OF THE GULF OF MEXICO. ANTICYCLONIC FLOW AROUND THE SURFACE HIGH IS AFFECTING MUCH OF THE GULF...WITH SE WINDS OF 15 KT OCCURRING IN THE NW GULF W OF 95W. EXPECT A TROPICAL WAVE CURRENTLY OVER THE GULF OF HONDURAS TO MOVE THROUGH THE BAY OF CAMPECHE TONIGHT AND THURSDAY. A COLD FRONT IS FORECAST TO MOVE INTO THE NE GULF OF MEXICO THURSDAY AND DISSIPATE FRIDAY. CARIBBEAN SEA... A TROPICAL WAVE IS IN THE FAR W CARIBBEAN...SEE ABOVE. THE WAVE ALONG WITH UPPER LEVEL DIFFLUENCE ASSOCIATED WITH AN UPPER LEVEL HIGH OVER THE BAY OF CAMPECHE NEAR 21N93W ARE SUPPORTING ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS ACROSS THE NW CARIBBEAN FROM 16N-19N W OF 82W AND OVER FAR W CUBA. THE CENTRAL ATLC IS EXPERIENCING GENERALLY FAIR WEATHER. NLY UPPER LEVEL FLOW BETWEEN THE UPPER LEVEL HIGH OVER THE BAY OF CAMPECHE AND AN UPPER LEVEL TROUGH EXTENDING FROM THE W/CENTRAL ATLC ACROSS THE CENTRAL CARIBBEAN TO THE COAST OF COLUMBIA NEAR 8N77W IS LIMITING THE DEEP LAYER MOISTURE. HOWEVER...UPPER LEVEL DIFFLUENCE AT THE BASE OF THE UPPER TROUGH IS SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS OVER COSTA RICA AND N COLUMBIA. ALSO...UPPER LEVEL DIFFLUENCE E OF THE UPPER TROUGH IS SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS ACROSS PORTIONS OF THE DOMINICAN REPUBLIC...PUERTO RICO AND THE ADJACENT COASTAL WATERS N OF 17N BETWEEN 65W-70W. ATLANTIC OCEAN... A SURFACE TROUGH E OF THE FLORIDA PENINSULA FROM 28N80W TO 31N88W IS SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS N OF 29N W OF 78W. THIS ACTIVITY IS ENHANCED BY A SHORTWAVE UPPER LEVEL TROUGH E OF THE GEORGIA COAST. SIMILAR ACTIVITY ASSOCIATED WITH THE UPPER LEVEL SHORTWAVE TROUGH IS ALSO OVER THE FAR NW BAHAMAS FROM 24N-27N W OF 78W. AN UPPER LEVEL TROUGH IS OVER THE W/CENTRAL ATLC EXTENDING FROM 30N63W TO 20N70W AND OVER THE CENTRAL CARIBBEAN SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS ACROSS PUERTO RICO AND THE ADJACENT COASTAL WATERS S OF 20N BETWEEN 67W-71W AND FROM 21N-23N BETWEEN 64W-67W. UPPER LEVEL DIFFLUENCE NEAR AN UPPER LEVEL LOW NEAR 31N43W IS SUPPORTING AN AREA OF SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS FROM 30N-32N BETWEEN 42W-45W. A 1012 MB SURFACE LOW IS IN THE FAR NE PORTION OF THE ATLC NEAR 30N18W. SURFACE CONVERGENCE ASSOCIATED WITH THE LOW IS SUPPORTING ISOLATED SHOWERS N OF 30N BETWEEN 16W-18W. THE REMAINDER OF THE ATLC IS DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1027 MB HIGH N OF THE DISCUSSION AREA NEAR 34N36W BRINGING FAIR WEATHER ACROSS THE BASIN. IN THE UPPER LEVELS...A BROAD UPPER LEVEL RIDGE EXTENDS FROM AN UPPER LEVEL HIGH NEAR 12N42W TO 28N34W. AN UPPER LEVEL LOW IS CENTERED DIRECTLY OVER THE SURFACE LOW NEAR 31N18W. EXPECT A WEAK COLD FRONT TO MOVE OVER THE NW WATERS LATER TODAY...STALL AND SLOWLY DISSIPATE BY THURSDAY. $$ WALTON