000 AXNT20 KNHC 021741 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT JUL 02 2005 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE OVER THE E ATLANTIC ALONG 32W S OF 15N MOVING W NEAR 15 KT. THERE IS SOME INDICATION THAT THE WAVE IS LOCATED FURTHER E. HOWEVER...SATELLITE IMAGERY AND TIMESECTIONS FROM AFRICA ARE NOT CONCLUSIVE ENOUGH TO WARRANT A REPOSITION. FOR NOW... EXTRAPOLATION IS USED AS THE PRIMARY MEANS FOR LOCATING THIS WAVE. WIDELY SCATTERED MODERATE CONVECTION IS LOCATED WITHIN THE ITCZ. TROPICAL WAVE OVER THE CENTRAL ATLANTIC ALONG 45W MOVING W NEAR 15 KT. THE WAVE DISPLAYS AN IMPRESSIVE SIGNATURE IN SATELLITE IMAGERY WITH WELL DEFINED CYCLONIC ENVELOPE. HOWEVER...DEEP CONVECTION REMAINS LIMITED WITH ONLY A SMALL AREA OF WIDELY SCATTERED ACTIVITY FROM 11N-15N BETWEEN 41W-43W. THE WAVE IS SURROUNDED BY A LARGE SAHARAN LAYER AND ASSOCIATED DUST WITH THE LEADING EDGE ALONG 54W/55W. THIS AREA OF DUST IS SPREADING RAPIDLY WESTWARD AHEAD OF THE WAVE NEAR 20 KT. TROPICAL WAVE OVER THE W CARIBBEAN ALONG 83W S OF 23N MOVING W AROUND 15 KT. LATEST SATELLITE IMAGERY AND SURFACE OBSERVATIONS SUGGEST THAT THE WAVE HAS BECOME BETTER ORGANIZED AND UPPER LEVEL CONDITIONS APPEAR GENERALLY FAVORABLE. AS A RESULT... SCATTERED MODERATE TO STRONG CONVECTION CONTINUES ALONG AND E OF THE WAVE AXIS TO 76W MAINLY N OF 15N INCLUDING THE CAYMAN ISLANDS AND JAMAICA. HEAVY RAINS ASSOCIATED WITH THIS WAVE HAVE PERSISTED OVER JAMAICA DURING THE LAST 18 HOURS LIKELY PRODUCING LOCALIZED FLOODING. THIS ACTIVITY WILL CONTINUE TO SPREAD NW OVER W CUBA AND THE YUCATAN PENINSULA DURING THE NEXT 24 HOURS WITH LOCALLY HEAVY RAINFALL. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 12N10W 8N30W 9N43W ENTERING S AMERICA NEAR SURINAME AND CONTINUING WESTWARD OVER N PORTIONS OF VENEZUELA AND COLOMBIA. WIDELY SCATTERED TO LOCALLY SCATTERED MODERATE CONVECTION FROM 6N-10N BETWEEN 22W-38W. ...DISCUSSION... GULF OF MEXICO... MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH OVER THE SE UNITED STATES CLIPS THE N PORTION OF THE AREA OVER N FLORIDA WITH A SECOND MOVING THROUGH LOUISIANA. THESE TWO FEATURES ARE IGNITING A LARGE AREA OF WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE NE GLFMEX AND MUCH OF FLORIDA N OF 25N E OF 90W. ELSEWHERE...THE AREA IS UNDER THE INFLUENCE OF A MIDDLE TO UPPER LEVEL LOW OVER THE BAY OF CAMPECHE TRAPPED BENEATH A RIDGE EXTENDING FROM THE ATLC WNW THROUGH THE FLORIDA STRAITS TO THE CENTRAL GLFMEX NEAR 27N90W. THIS PATTERN IS CREATING CONFLUENCE AND DRY/STABLE AIR ALOFT OVER THE W GLFMEX W OF 90W AND OVER THE SE GULF S OF 25N E OF 90W. HOWEVER...THIS DRY/TRANQUIL PATTERN WILL GRADUALLY GIVE WAY TO A INCREASINGLY UNSETTLED AND STORMY PATTERN AS THE UPPER LOW MOVES SLOWLY NW AND AMPLE DEEP-LAYERED MOISTURE ASSOCIATED WITH A TROPICAL WAVE OVER THE W CARIBBEAN MOVES INTO THE SE GLFMEX SUNDAY. EXPECT INCREASING CLOUDINESS AND SHOWERS/TSTMS DURING THE DAY SUNDAY S OF 25N E OF 90W. CARIBBEAN SEA... A STRONG TROPICAL WAVE OVER THE W CARIBBEAN IS THE MAIN WEATHER MAKER WITH A LARGE AREA OF SHOWERS/THUNDERSTORMS COVERING A GOOD PORTION OF THE NW CARIBBEAN N OF 15N FROM JAMAICA WESTWARD TO 85W. THIS ACTIVITY WILL CONTINUE TO SPREAD NW AFFECTING THE REMAINDER OF THE AREA N OF 15N INCLUDING W CUBA AND THE YUCATAN PENINSULA. ELSEWHERE...VERY DRY AIR BEHIND THE AFOREMENTIONED WAVE HAS OVERSPREAD THE AREA PRODUCING NICE CONDITIONS. ONLY ISOLATED TRADE WIND SHOWERS ARE NOTED IN LATEST SATELLITE IMAGERY. THESE CONDITIONS ARE EXPECTED TO CONTINUE UNTIL THE NEXT WAVE AND ASSOCIATED MOISTURE MOVES INTO THE E CARIBBEAN MONDAY. ATLANTIC OCEAN... TWO WEAK SHORTWAVE TROUGHS MOVING OVER THE W ATLC ARE PRODUCING AN AREA OF CLOUDINESS AND WIDELY SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 26N W OF 55W. THIS ACTIVITY IS EXPECTED TO CONTINUE DURING THE NEXT DAY OR SO AS UPSTREAM SHORTWAVES MOVE INTO THE AREA. OVER THE CENTRAL ATLC...A LARGE UPPER LOW NEAR 36N50W TRAILS AN TROUGH SWD ALONG 50W WITH AN ASSOCIATED AREA OF SCATTERED SHOWERS/TSTMS N OF 28N BETWEEN 45W-50W. THIS ACTIVITY IS EXPECTED TO LIFT N OF THE AREA DURING THE NEXT 12 HOURS. OVER THE E ATLC...A LARGE SAHARAN AIR LAYER AND ASSOCIATED DUST COVERS MUCH OF THE AREA S OF 25N E OF 55W LIMITING DEEP CONVECTION TO AREAS S OF 15N. $$ RHOME