000 AXNT20 KNHC 211040 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN JUN 21 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 1030 UTC. ...TROPICAL WAVES... A TROPICAL WAVE EXTENDS FROM 10N48W TO 2N51W MOVING W AROUND 12 KT. THIS WAVE COINCIDES WITH A RELATIVELY LOW AMPLITUDE MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. SATELLITE-DERIVED WINDS INDICATE CYCLONIC CURVATURE IN THE LOW FLOW IN THE VICINITY OF THIS WAVE...WHICH IS CONFIRMED BY THE CIMSS WAVETRAK PRODUCT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-7N BETWEEN 50W-52W. SCATTERED MODERATE CONVECTION IS FROM 9N-11N BETWEEN 44W-48W. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 9N13W 4N30W 8N48W AND INTO NE BRAZIL NEAR 7N58W. SCATTERED MODERATE CONVECTION IS FROM 6N-9N BETWEEN 35W-42W. ...DISCUSSION... GULF OF MEXICO... ATMOSPHERIC INSTABILITY ASSOCIATED WITH AN UPPER LEVEL LOW CENTERED OVER THE SOUTHERN BAY OF CAMPECHE NEAR 20N93W IS SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE S GULF S OF 22N BETWEEN 87W-95W. ACROSS THE N AND CENTRAL GULF...DEEP LAYER DRY AIR IS SUPPORTING GENERALLY FAIR WEATHER...WHERE EASTERLY FLOW ALOFT IS OCCURRING BETWEEN THE AFOREMENTIONED UPPER LEVEL LOW OVER THE YUCATAN AND AN UPPER LEVEL HIGH OVER ARKANSAS. THIS UPPER LEVEL HIGH IS REFLECTED AT THE SURFACE WITH A 1014 MB HIGH CENTER OVER THE N GULF NEAR 27N89W. ANTICYCLONIC FLOW AROUND THE SURFACE HIGH IS AFFECTING MUCH OF THE GULF...WITH SE WINDS OF 15 TO LOCALLY 20 KT OCCURRING ACROSS PORTIONS OF THE W GULF IN RESPONSE TO A BROAD SURFACE TROUGH OVER MEXICO AND THE SOUTHERN PLAINS OF THE UNITED STATES. THE SURFACE HIGH IS FORECAST TO MOVE W ACROSS THE N GULF THROUGH NEXT WEEK. A WEAK COLD FRONT WILL THEN MOVE SOUTHWARD ACROSS PORTIONS OF THE E WATERS MONDAY AND DISSIPATE TUESDAY...LEAVING BROAD LOW PRESSURE IN NE GULF THROUGH MID TO LATE WEEK. CARIBBEAN SEA... AN UPPER LEVEL LOW HAS MOVED OFF THE YUCATAN PENINSULA INTO THE BAY OF CAMPECHE AND IS CENTERED NEAR 20N93W. ATMOSPHERIC INSTABILITY ASSOCIATED WITH THIS UPPER LEVEL LOW IS IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS OVER THE W CARIBBEAN FROM 16N-20N W OF 85W INCLUDING PORTIONS OF HONDURAS...BELIZE AND YUCATAN STATE. ACROSS THE CENTRAL CARIBBEAN...UPPER LEVEL MOISTURE AND HIGH LEVEL CLOUDS ARE GENERALLY STREAMING EASTWARD. THIS MOISTURE IS INTERACTING WITH ATMOSPHERIC INSTABILITY AND UPPER LEVEL DIFFLUENCE TO RESULT IN SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER CUBA...HISPANIOLA...AND THE NEARBY COASTAL WATERS. MODERATE TO FRESH EASTERLY TRADES ARE FORECAST TO OCCUR ACROSS THE SE CARIBBEAN THROUGH THURSDAY. ATLANTIC OCEAN... SUBSIDENCE IN NORTHERLY FLOW ALOFT IS SUPPORTING GENERALLY FAIR WEATHER ACROSS THE SW NORTH ATLC. HOWEVER...UPPER LEVEL DIFFLUENCE AND UPPER LEVEL MOISTURE ARE SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM 29N-32N BETWEEN 56W-62W. TO THE E...AN UPPER LEVEL TROUGH OVER THE CENTRAL ATLC IS ASSOCIATED WITH A STATIONARY FRONT SKIRTING THE FAR NORTHERN PORTION OF THE AREA ALONG 32N BETWEEN 43W AND 50W. LOW LEVEL CONVERGENCE NEAR THE FRONT IS RESULTING IN PATCHY SHOWERS N OF 30N BETWEEN 45W-50W. ACROSS MUCH OF THE CENTRAL AND E ATLC... GENERALLY FAIR WEATHER IS PRESENT WHERE SUBSIDENCE IS OCCURRING NEAR A BROAD SURFACE RIDGE. ACROSS THE TROPICAL ATLC...A BROAD UPPER LEVEL RIDGE IS S OF 16N E OF 55W. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE UPPER LEVEL RIDGE IS SUPPORTING THE CONVECTION ASSOCIATED WITH THE ITCZ AND THE TROPICAL WAVE THAT EXTENDS FROM 10N48W TO 3N51W...AS WELL AS SCATTERED SHOWERS AND THUNDERSTORMS OFF THE W AFRICA COAST FROM 4N-6N BETWEEN 11W-13W. $$ COBB