000 AXNT20 KNHC 251814 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE JUL 25 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN 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...WEATHER OBSERVATIONS...RADAR... AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURE... A 1009 MB SURFACE LOW PRESSURE CENTER IN NORTHEASTERN MEXICO ABOUT 45 MILES SOUTHWEST OF BROWNSVILLE TEXAS IS MOVING NORTHWARD ABOUT 10 MPH. THIS SYSTEM IS GENERATING A LARGE AREA OF SHOWERS...THUNDERSTORMS AND STRONG GUSTY WINDS IN SQUALLS OVER PARTS OF THE WESTERN GULF OF MEXICO AND THE ADJACENT COASTAL AREAS. THE SYSTEM CENTER IS OVER LAND AND IS NOT CURRENTLY FORECAST TO EMERGE OVER THE WESTERN GULF OF MEXICO. TROPICAL CYCLONE DEVELOPMENT IS UNLIKELY AT THIS TIME. A TROPICAL DEPRESSION COULD FORM IF THE CENTER EMERGES OVER THE GULF WATERS. THIS SYSTEM IS LIKELY TO BRING LOCALLY HEAVY RAINFALL TO PARTS OF EXTREME NORTHEASTERN MEXICO...SOUTHERN TEXAS...AND SOUTHERN LOUISIANA DURING THE NEXT COUPLE OF DAYS REGARDLESS OF WHETHER OR NOT A TROPICAL CYCLONE FORMS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 20W/21W S OF 21N MOVING W 15-20 KT. SCATTERED MODERATE CONVECTION LIES EAST OF THIS WAVE NEAR THE ITCZ AXIS BETWEEN 7N/11N AND 20W/15W. TROPICAL WAVE IS ALONG 50W/51W S OF 26N WITH A 1010 MB LOW ALONG THE WAVE NEAR 13N MOVING W NEAR 15 KT. VISIBLE SATELLITE IMAGERY SHOWS A WELL-DEFINED INVERTED-V PATTERN IN THE LOW CLOUD FIELD. THIS WAVE REMAINS AT THE LEADING EDGE OF THE LATEST SURGE OF AFRICAN DUST. IT REMAINS VOID OF SIGNIFICANT CONVECTION WITH ISOLATED SHOWER/TSTM ACTIVITY NOTED FROM 19N TO 24N BETWEEN 48W AND 51W. ANOTHER AREA OF SHOWERS IS TO THE EAST OF THE LOW FROM 14N TO 18N BETWEEN 52W AND 55W. TROPICAL WAVE IS ALONG 71W/72W S OF 18N MOVING W 10-15 KT. THIS WAVE REMAINS WEAK WITH NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IS ALONG 84W/85W S OF 17N MOVING W 15 KT. WEAK WAVE WITH NO ASSOCIATED DEEP CONVECTION...LIKELY SUPPRESSED BY A DENSE REGION OF AFRICAN DUST. CONVECTION NEAR THE WAVE IS ASSOCIATED WITH THE ITCZ AXIS. ...ITCZ... ITCZ 13N13W 10N46W 14N55W 8N69W AND EASTWARD ACROSS NORTHERN SOUTH AMERICA AND INTO PANAMA. SCATTERED MODERATE/ISOLATED STRONG CONVECTION ASSOCIATED WITH THE AXIS LIES OFF THE COAST OF W AFRICA BETWEEN 8N/12N AND 15W/19W. PATCHES OF MODERATE CONVECTION EXISTS BETWEEN 4N-8N AND 24W-43W. SCATTERED MODERATE/ISOLATED STRONG LOCATED BETWEEN COASTAL VENEZUELA AND 14N55W. ...DISCUSSION... GULF OF MEXICO... ELONGATED UPPER RIDGE FROM THE W ATLC EXTENDS OVER FLORIDA AND WEST INTO THE EAST AND CENTRAL GULF. ANOTHER WEAK UPPER HIGH IS CENTERED OVER SOUTH CENTRAL MEXICO WHICH IS JUST SOUTH OF ELONGATED UPPER TROUGHING EXTENDING SW FROM THE EASTERN THIRD OF THE US. UPPER DIFFLUENCE BETWEEN THESE FEATURES ALONG WITH A 1009 MB SURFACE LOW PRESSURE CENTER SW OF BROWNSVILLE TX CONTINUES TO GENERATE NUMEROUS MODERATE/ISOLATED STRONG CONVECTION IN THE WESTERN GULF BETWEEN 89W/97W AND 22N/29N. ELSEWHERE AT THE SURFACE...THE WESTERN EXTENT OF THE BERMUDA HIGH CONTINUES TO LIKE OVER THE EAST AND CENTRAL GULF WITH LIGHT WINDS/LOW SEAS OBSERVED THIS AFTERNOON. STRONGER 15-20 KT S/SE FLOW PERSISTS IN THE WESTERN GULF AS THIS HIGH INTERACTS WITH THE LOWER PRESSURE TO THE WEST. SIMILAR SFC CONDITIONS EXPECTED ACROSS THE GULF THE NEXT COUPLE OF DAYS. CARIBBEAN SEA... RATHER BENIGN TROPICAL WAVE LIES ALONG 71W/72W WITH ANOTHER EXTENDING FROM COSTA RICA THROUGH EASTERN HONDURAS TO MOVE EAST OF THE AREA OVER THE NEXT COUPLE OF DAYS. BROAD UPPER LOW CONTINUES TO DOMINATE THE CENTRAL CARIBBEAN CENTERED NEAR 16N77W WHILE AND UPPER RIDGE EXTENDS ACROSS THE LESSER ANTILLES TO OVER THE E CARIBBEAN. THE CARIBBEAN IS VOID OF SIGNIFICANT CONVECTION WITH LOTS OF DRY AIR/SAHARAN DUST. THE CLUSTER OF MODERATE CONVECTION THAT MOVED NORTH OF BOCAS DEL TORO PANAMA THIS MORNING CONTINUES TO DISSIPATE. SOUTHERN PORTION OF WEST/CENTRAL ATLC HIGH CONTINUES TO PRODUCE FRESH SFC TRADE FLOW ACROSS THE EAST AND CENTRAL CARIB BUT GALE WARNING HAS BEEN ALLOWED TO EXPIRE. ATLANTIC OCEAN... UPPER RIDGE FROM THE EASTERN GULF OF MEXICO EXTENDS OVER THE FLORIDA PENINSULA AND INTO THE FAR W ATLC. LARGE UPPER HIGH IN THE CENTRAL ATLANTIC EXTENDING SOUTH FROM 37N45W MEETS AN UPPER LOW NEAR 27N53W. UPPER RIDGE CONTINUES TO DOMINATE THE E ATLC EXTENDING WEST FROM THE COAST OF AFRICA. SURFACE HIGH PRESSURE CONTINUES TO EXTEND SOUTH FROM ITS CENTER NEAR 35N49W. MODERATE TRADE FLOW CONTINUES SOUTH OF THIS HIGH WITH THE STRONGEST WINDS IN BETWEEN THIS HIGH AND THE TROPICAL WAVE/LOW ALONG 50W. THIS HIGH LOOKS TO REMAIN QUASI STATIONARY OVER THE NEXT 48HRS WITH THE STRONGEST WINDS MOVING WEST WITH THE STRONGER GRADIENT ASSOCIATED WITH THE HIGH/TROPICAL WAVE INTERACTION. AFRICAN DUST AND MINIMAL CONVECTION LIE EAST OF THIS WAVE THROUGH THE COAST OF AFRICA. $$ WILLIS