000 AXNT20 KNHC 071757 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT JUL 07 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... A BROAD TROPICAL WAVE IS TILTED ALONG 15N30W TO 5N35W MOVING W 10-15 KT. THIS WAVE CONTINUES TO HAVE A LARGE ENVELOPE OF LOW TO MID LEVEL CYCLONIC TURNING AND IS CAUSING A LARGE POLEWARD PERTURBATION IN THE ITCZ. DESPITE ITS LARGE SIZE...SHOWER AND TSTM ACTIVITY REMAINS MINIMAL AND DISORGANIZED. A TROPICAL WAVE IS FROM 3N-16N ALONG 59-60W MOVING W NEAR 15 KT. THIS WAVE IS PRODUCING A FEW SHOWERS AND TSTMS OVER THE WINDWARD ISLANDS. UPPER-LEVEL WINDS ARE NOT FAVORABLE FOR DEVELOPMENT. A TROPICAL WAVE IN THE CARIBBEAN IS ALONG 74/75W MOVING W 10-15 KT. THIS WAVE IS DIFFICULT TO LOCATE WITH MINIMAL CONVECTION SURROUNDING THE AXIS. THE CONVECTION OVER THE FAR SW CARIBBEAN AND CENTRAL AMERICA SEEMS MORE ASSOCIATED WITH THE ITCZ. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N13W 9N20W 12N30W 11N37W 7N50W 9N57W. SCATTERED MODERATE CONVECTION IS OFF THE COAST OF AFRICA FROM 4N-11N BETWEEN 10W-15W. SCATTERED MODERATE IS WITHIN 150NM N OF THE AXIS BETWEEN 38W-46W...AND WITHIN 60NM N AND 150NM S OF THE AXIS BETWEEN 51W-57W. ...DISCUSSION... GULF OF MEXICO... THE GULF IS BY AND LARGE DOMINATED BY VERTICALLY STACKED HIGH PRESSURE. THE 1018 MB SFC CENTER IS SSE OF NEW ORLEANS NEAR 27N88W. THIS IS KEEPING WINDS MOSTLY 15 KT OR LESS AND SEAS 4' OR LESS. THE HIGH OVER THE CENTRAL GULF WILL MERGE WITH AN ATLC RIDGE AXIS INTO SUN. WEAK...REMNANT SFC TROUGHING IS LINGERING IN THE SE GULF...RESPONSIBLE FOR THE ISOLATED SHOWERS/TSTMS S OF 26N AND E OF 88W. AN UPPER LOW IS SPINNING OVER SRN MEXICO NEAR 17N98W. THIS ALONG WITH MOIST LOW LEVEL SE/S FLOW IS SUPPORTING A FEW SHOWERS/TSTMS NOTED IN THE WRN GULF/BAY OF CAMPECHE S OF 25N W OF 95W. CARIBBEAN SEA... THE MOST SIGNIFICANT WEATHER IN THE CARIBBEAN LIES IN THE FAR SW PORTION AND OVER CENTRAL AMERICA TIED TO THE EPAC EXTENSION OF THE ITCZ. THE ASSOCIATED SCATTERED SHOWERS/TSTMS ARE S OF 12N BETWEEN 77W-85W. A FEW ISOLATED TSTMS DEPICTED BY LIGHTNING DATA ARE OVER THE NW CARIBBEAN...FROM 17N-19N BETWEEN 81W-83W AND ALSO BETWEEN JAMAICA AND CENTRAL CUBA. THESE CELLS ARE TIED TO WEAK LOW LEVEL CONFLUENCE AND ALSO THE UPPER LOW BETWEEN JAMAICA AND HAITI NEAR 18N75W. ASIDE FROM THIS ACTIVITY...THE TROPICAL WAVE MOVING THROUGH THE WINDWARD ISLANDS...AND TYPICAL TRADE WIND SHOWERS...MODERATE TO STRONG SUBSIDENCE/DRY AIR ALOFT IS PRODUCING MOSTLY FAIR WEATHER ELSEWHERE. MODERATE TO STRONG TRADE WINDS ARE IN PLACE AND EXPECTED TO PERSIST INTO EARLY NEXT WEEK. ATLANTIC OCEAN... SCATTERED SHOWERS AND TSTMS ARE OVER THE FAR WRN ATLC WITHIN 60NM EITHER SIDE OF THE LINE 24N80W 32N76W. THIS ACTIVITY IS ASSOCIATED WITH REMNANT SFC TROUGHING/CONFLUENCE EXTENDING INTO THE AREA IN ADDITION TO UPPER DIFFLUENCE AROUND AN UPPER RIDGE AXIS EXTENDING E INTO THE REGION FROM THE GULF. THE REMAINDER OF THE ATLC SFC PATTERN IS DOMINATED BY A LARGE SFC RIDGE AXIS ANCHORED BY A 1029 MB HIGH JUST W OF THE AZORES. THIS IS PRODUCING MOSTLY FAIR WEATHER AND LIGHT TO MODERATE WINDS N OF 15N E OF 75W. THE SFC TROUGHING OFF OF FLORIDA AND THE SOUTHEAST U.S. COAST IS EXPECTED TO LIFT NE THROUGH SUN WHILE THE RIDGE AXIS BUILDS W THROUGH THE GULF. ELSEWHERE ALOFT...BOTH THE FAR W AND E PORTIONS OF THE DISCUSSION AREA ARE DOMINATED BY UPPER RIDGES. SEVERAL SMALLER SCALE UPPER FEATURES NOTED OVER THE CENTRAL ATLC BUT ARE NOT GENERATING MUCH WEATHER...WITH THE FLOW ON THE LARGE SCALE WIDELY CONFLUENT OVER THE AREA. $$ MW