000 AXNT20 KNHC 241800 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON JUL 24 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 1630 UTC. ...SPECIAL FEATURES... A SURFACE LOW PRESSURE AREA CENTERED JUST EAST OF LA PESCA MEXICO IS MOVING NORTH AT 5 TO 10 KT. SHOWER AND THUNDERSTORM ACTIVITY OVER MUCH OF THE WESTERN GULF OF MEXICO AND BAY OF CAMPECHE HAS INCREASED AND BECOME A LITTLE BETTER ORGANIZED... AND NOAA BUOYS IN THE SOUTHWESTERN GULF OF MEXICO HAVE RECORDED WIND GUSTS OF 40 TO 50 MPH THIS MORNING. UPPER-LEVEL WINDS ARE EXPECTED TO BECOME A LITTLE MORE FAVORABLE...AND A TROPICAL DEPRESSION COULD DEVELOP DURING THE NEXT DAY OR SO...IF THE LOW PRESSURE CENTER REMAINS OFFSHORE. LATEST SATELLITE PICTURES AND SURFACE DATA SHOW THAT A SURFACE LOW IS FORMING NEAR TAMPICO IN MEXICO. ...TROPICAL WAVES... HIGH AMPLITUDE TROPICAL WAVE WITH PRONOUNCED INVERTED V PATTERN IS ALONG 43/44W S OF 24N MOVING WEST NEAR 15 KT. A 1011 MB LOW IS ON THE WAVE AXIS NEAR 14N. THIS WAVE AND LOW REMAIN WELL-DEFINED IN AFTERNOON VISIBLE IMAGERY. HOWEVER...THIS FEATURE CONTINUES TO BE VOID OF ANY SIGNIFICANT CONVECTION. A FEW SHOWERS ARE SPIRALING ON THE NORTHERN AND WESTERN SEMICIRCLE OF THE SFC LOW AND AT THE BASE OF THE WAVE WITHIN 300 NM EITHER SIDE OF THE AXIS S OF 10N. THIS CENTRAL ATLC WAVE WILL LIKELY INCREASE IN FORWARD SPEED OVER THE NEXT COUPLE OF DAYS AS IT TRACKS UNDER A STRONG LOW-LEVEL RIDGE...BRINGING IT INTO THE TROPICAL ATLC WATERS TUE NIGHT AND THROUGH THE E CARIBBEAN THU AND FRI. TROPICAL WAVE IS ALONG 66/67W S OF 19N MOVING WEST NEAR 15 KT. THIS WAVE REMAINS WEAK AND LOW AMPLITUDE. WAVE EMBEDDED WITHIN AN AREA OF DENSE SAHARAN DUST LIMITING ANY ORGANIZED SHOWER ACTIVITY. TROPICAL WAVE IS ALONG 78/79W S OF 21N MOVING WEST 15-20 KT. THIS WAVE IS ALSO WEAK WITH LITTLE ASSOCIATED CONVECTION. ONLY A HINT OF SOME EVIDENCE OF A WAVE-LIKE STRUCTURE IS EVIDENT ON SATELLITE IMAGERY. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 9N9W 14N40W 12N45W TO INLAND OVER SOUTH AMERICA NEAR 8N65W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION EXISTS ALONG THE ITCZ NEAR COASTAL LIBERIA AND SIERRA LEONE BETWEEN 6-11N. THE ITCZ BETWEEN 21-40W IS RELATIVELY QUIET WITH ONLY FEW SHOWERS/TSTMS EVIDENT. SCATTERED MODERATE CONVECTIONS EXISTS ALONG TH ITCZ BETWEEN 50W/64W. ...DISCUSSION... GULF OF MEXICO... QUASI STATIONARY UPPER TROF STILL LIES IN THE SE GOMEX THIS AFTERNOON NEAR 25N85W. A WEAK UPPER RIDGE EXTENDS EAST OF THIS REGION THROUGH THE FLORIDA PENINSULA AND INTO THE ADJACENT ATLANTIC/BAHAMA WATERS. IN THE WESTERN GULF...UPPER RIDGE CONTINUES TO EXTEND EAST FROM INLAND S MEXICO AND INTO THE BAY OF CAMPECHE. NORTH OF THIS REGION UPPER SW FLOW FOLLOWS THE SOUTHERN PERIPHERY OF THE ELONGATED TROF STRETCHING FROM THE MID ATLANTIC REGION TO THE NW GULF. ASSOCIATED UPPER DIFFLUENCE AND MOISTURE BETWEEN THESE FEATURES IS YIELDING NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IN THE SW GULF BETWEEN 18N-26N AND 91W-97W. AT THE SURFACE...ANTICYCLONIC FLOW AROUND THE SW PORTION OF THE BERMUDA HIGH IS CONVERGING WITH FLOW AROUND A WEAK HIGH OVER THE APPALACHIANS TO PRODUCE A QUASI-STATIONARY SURFACE FRONTAL BOUNDARY JUST NORTH OF THE GULF COASTAL REGION. SCATTERED WEAK CONVECTION/ISOLATED MODERATE LIES IN THE MOIST AIR JUST SOUTH OF THIS BOUNDARY WITHIN 3 DEGREES FROM A LINE BETWEEN CORPUS CHRISTI TX AND LAKE CITY FL. RADAR MOSAIC IMAGERY CONFIRMS NUMEROUS CELLS IN THIS REGION. SFC WINDS REMAIN LIGHT IN THE E/SE GULF UNDER WEAK GRADIENT FROM THE ATLANTIC HIGH INFLUENCE. CENTRAL AND WESTERN GULF SFC FLOW GENERALLY S/SE 10-20 KT EXCEPT HIGHER UNDERNEATH THE NUMEROUS SHOWERS AND THUNDERSTORMS PRESENT...AND CONTAIN MORE OF A WESTERLY COMPONENT NORTH PORTIONS SOUTH OF FRONTAL BOUNDARY. SIMILAR CONDITIONS EXPECTED THRU 48HRS WITH STRONGEST S/SE FLOW WESTERN PORTION AS ATLANTIC RIDGE CONTINUES TO INTERACT WITH LOWER PRESSURE TO THE WEST. SEE SPECIAL FEATURES FOR MORE INFO ON CONVECTIVE ACTIVITY IN THE SW GULF. CARIBBEAN SEA... TWO WEAK LOW AMPLITUDE TROPICAL WAVES EXIST IN THE CARIBBEAN SEA. BOTH REMAIN BENIGN/DRY FEATURES. FOR MORE DETAILS SEE THE TROPICAL WAVES SECTION ABOVE. WATER VAPOR SHOWS MOSTLY DRY MID/UPPER LEVEL AIR IN THE CARIBBEAN FROM 11-19N BETWEEN THE WINDWARD ISLANDS AND 81W. THIS REGION IS DOMINATED BY AN UPPER RIDGE TO THE EAST AND TROF TO THE WEST...EXTENDING SOUTH FROM E CUBA THROUGH HAITI. WEST OF THIS REGION IN THE NW CARIBBEAN LIES PATCHES OF SCATTERED MODERATE CONVECTION ON THE EAST SIDE OF THE UPPER RIDGE CENTERED NEAR ACAPULCO MEXICO. MODERATE TO STRONG TRADE WINDS ARE OCCURRING ACROSS THE CARIBBEAN ON THE SOUTH SIDE OF THE SUBTROPICAL ATLANTIC RIDGE. A GALE WARNING IS IN EFFECT BETWEEN 12N-15N AND 73N-77W UNTIL TUESDAY. ATLANTIC OCEAN... UPPER RIDGE LIES JUST OFF THE SPACE COAST OF FLORIDA THIS AFTERNOON...SOUTH OF AN UPPER TROF OVER THE MID ATLANTIC COAST. MOISTURE ASSOCIATED WITH THESE FEATURES (IN TAFB AREA OF RESPONSIBILITY) LIES MOSTLY N OF 25N AND W OF 65W. LARGE SCALE UPPER RIDGING AND LOTS OF DRY AIR CONTINUES TO DOMINATE MUCH OF THE WEST/CENTRAL ATLANTIC IN THE REGION BETWEEN 40 AND 65W. A PATCH OF MODERATE CONVECTION LIES ON THE WEST PORTION OF THIS RIDGING BETWEEN 22N-25N AND 62W-64W. A LARGE UPPER RIDGE EXTENDS FROM W AFRICA OUT TO 35W. A SMALL UPPER TROF LIES JUST WEST OF THIS RIDGE...CENTERED NEAR 27N46W. AT THE SURFACE...A 1028MB HIGH PRESSURE CENTER LIES NEAR 34N53W. MOSTLY FAIR WEATHER...SCATTERED PATCHES OF LOW TO MID CLOUDS...AND LIMITED SHOWER ACTIVITY LIE SOUTH OF THIS RIDGE EAST OF 61W. 24/15Z UW-CIMSS SAHARAN AIR LAYER TRACKING PRODUCT DEPICTS WESTERN EXTENT OF DENSE DUST OUT TO 42W. THE DUST IS MUCH LESS PRONOUNCED IN THE VICINITY OF THE STRONG TROPICAL WAVE ALONG 43W-44W...WITH THE CONCENTRATION OF THE DUST INCREASING WEST OF THIS WAVE THROUGH THE CENTRAL CARIBBEAN NEAR 81W. $$ WILLIS