000 AXNT20 KNHC 062353 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI JUL 06 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... A VERY BROAD TROPICAL WAVE IS TITLED ALONG FROM 20N27W TO 5N30W MOVING W 10-15 KT. THIS WAVE HAS A LARGE ENVELOPE OF LOW-LEVEL TURNING AND IS CAUSING QUITE A PERTURBATION IN THE ITCZ. SCATTERED SHOWERS ARE ON THE SOUTHERN END OF THE WAVE MAINLY WITHIN THE ITCZ. A TROPICAL WAVE IS ALONG 55W MOVING W AT 10 TO 15 KT. A 1014 MB LOW REMAINS ALONG THE WAVE AXIS NEAR 11N. LATEST VISIBLE IMAGES SHOWS A SWIRL OF MAINLY LOW CLOUDS WITH SOME CONVECTIVE ACTIVITY ON THE SOUTH SIDE OF THE LOW...THAT IS FORECAST TO CONTINUE MOVING WWD AS AN OPEN WAVE REACHING THE WINDWARD ISLANDS TOMORROW. A TROPICAL IS ALONG 70W MOVING W NEAR 15 KT. THE WAVE COUPLE WITH THE AFTERNOON HEATING IS ENHANCING SOME SHOWER ACTIVITY OVER HISPANIOLA AND WESTERN VENEZUELA NEAR LAKE MARACAIBO. WAVE WILL MOVE ACROSS E CUBA AND JAMAICA SAT. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 5N10W 9N20W 11N32W 5N45W 7N52W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE MOVING OUT OF THE AFRICAN COAST ALONG 10N. SIMILAR CONVECTION IS FOUND WITHIN 60-90 NM N OF AXIS BETWEEN 36W-40W. SCATTERED SHOWERS ARE FROM 4N-7N BETWEEN 14W-17W. ...DISCUSSION... GULF OF MEXICO... WEAK SFC TROUGH REMAINS OVER CENTRAL FLORIDA AND THE E GULF EXTENDING FROM A SFC LOW LOCATED NEAR 30N79W AT 21Z. ONCE AGAIN...SHOWERS AND TSTMS HAVE FLARED UP ACROSS MOST OF CENTRAL AND SOUTH FLORIDA. THE LOW IS FORECAST TO MOVE NORTH OF AREA TONIGHT AND WILL DISSIPATE BY LATE SATURDAY. SCATTERED SHOWERS ARE ALSO SEEN ALONG THE SFC TROUGH OVER THE E GULF. A DIFFLUENT PATTERN ALOFT ASSOCIATED WITH AN UPPER HIGH LOCATED OVER THE NORTHERN GULF WATERS IS SUPPORTING THIS CONVECTIVE ACTIVITY. NUMEROUS SHOWERS AND TSTMS ARE OVER EXTREME E TEXAS...LOUISIANA AND THEIR COASTAL WATERS RELATED TO A SFC LOW/TROUGH OVER THE AREA. FURTHER S...AN UPPER LOW IS SPINNING OVER THE ISTHMUS OF TEHAUNTEPEC DRAWING TROPICAL MOISTURE FROM THE EPAC INTO THE YUCATAN PENINSULA AND THE BAY OF CAMPECHE. AS A RESULT...AN AREA OF MODERATE CONVECTION HAS DEVELOPED OVER THE NORTHERN YUCATAN PENINSULA. THE SFC FLOW IS MAINLY GOVERNED BY A 1020 MB HIGH CENTERED NEAR 27N89W. LIGHT TO MODERATE WINDS ARE BLOWING ACROSS THE GULF. WEAK RIDGING IS EXPECTED TO REMAIN IN CONTROL THIS WEEKEND. CARIBBEAN SEA... DRY AIR ALOFT...RESULTING IN MODERATE TO STRONG SUBSIDENCE DOMINATES MOST OF THE BASIN. AN UPPER LOW OVER THE WINDWARD PASSAGE IS HELPING TO DEVELOP SCATTERED SHOWERS AND ISOLATED TSTMS OVER HISPANIOLA WHERE THERE IS A TROPICAL WAVE. SEE ABOVE. SCATTERED MODERATE CONVECTION ARE ALSO SEEN OVER CENTRAL AMERICA AND THE SW CARIBBEAN DUE TO THE UPPER LOW PREVIOUSLY MENTIONED OVER THE ISTHMUS OF TEHUANTEPEC AND THE CLOSE PROXIMITY OF THE EPAC ITCZ. TYPICAL TRADE WINDS SHOWERS ARE OBSERVED ACROSS THE BASIN. SCATTERED SHOWERS AND ISOLATED TSTMS ARE AFFECTING WESTERN CUBA. THE PRES GRADIENT BETWEEN THE ATLC RIDGE AND THE COLOMBIAN LOW IS PRODUCING STRONG TRADE WINDS OF 20 TO 30 KT ACROSS THE SOUTH-CENTRAL CARIBBEAN SEA. THESE WINDS ARE EXPECTED TO PERSIST DURING THE UPCOMING WEEKEND. ATLANTIC OCEAN... AN ELONGATED AND WEAK LOW PRESSURE AREA LOCATED NEAR 30N79W IS PRODUCING DISORGANIZED SHOWERS AND THUNDERSTORMS EXTENDING FROM THE SOUTHERN FLORIDA PENINSULA NORTHEASTWARD INTO THE ATLANTIC FOR SEVERAL HUNDRED MILES. UPPER-LEVEL WINDS ARE NOT FAVORABLE FOR DEVELOPMENT. A TROUGH EXTENDS FROM THIS LOW ACROSS CENTRAL FLORIDA INTO THE GULF OF MEXICO. THE REMAINDER OF THE FORECAST AREA IS UNDER THE INFLUENCE OF THE ATLC RIDGE GIVING THE AREA MOSTLY FAIR WEATHER AND LIGHT TO MODERATE TRADE WINDS. MODERATE TO STRONG NLY WINDS ARE NEAR THE AFRICAN COAST DUE TO THE TIGHTENING PRES GRADIENT BETWEEN THE AZORES HIGH AND INVERTED TROUGHING OVER THE CONTINENT. ALOFT...DRY AIR COVERS MOST OF THE AREA. THERE IS SOME TROUGHING IN THE CENTRAL/E ATLC WITH A COUPLE OF UPPER LOWS...BUT OVERALL THESE UPPER FEATURES ARE NOT PRODUCING MUCH WEATHER. ONLY PATCHES OF LOW/MID CLOUDS ARE SEEN ACROSS THE AREA...PARTICULARLY E OF 40W. $$ GR