000 AXNT20 KNHC 041043 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED OCT 04 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 40W S OF 18N WITH A 1011 MB LOW ON THE WAVE NEAR 12N MOVING W 10-15 KT. LOW LEVEL ROTATION AND BROAD INVERTED-V SIGNATURE ARE NOTED ON SATELLITE IMAGERY. WAVE IS ON THE E SIDE OF AN UPPER LEVEL TROUGH RESULTING IN SOUTHWESTER SHEAR. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 10N-15N BETWEEN 34W-39W WITH SCATTERED MODERATE CONVECTION WITHIN 75 NM OF LINE FROM 16N40W-19N35W. TROPICAL WAVE IS ALONG 50W/51W S OF 17N MOVING W 5-10 KT. WEAK LOW AMPLITUDE INVERTED-V SIGNATURE. WAVE IS EMBEDDED WITH DRY AIR SO THERE ARE ONLY SCATTERED SHOWERS WITHIN THE ITCZ FROM 8N-10N BETWEEN 46W-52W. TROPICAL WAVE IS ALONG 69W S OF 21N MOVING W 10 KT. WEAK WAVE IS ON THE E SIDE OF AN UPPER TROUGH MASKING THE LOW LEVEL SIGNATURE ON SATELLITE IMAGERY. ANY SHOWER ACTIVITY IS DUE TO THE UPPER LEVEL FEATURE. TROPICAL WAVE IS ALONG 90W/91W S OF 18N MOVING W AT 10-15 KT. WAVE IS INLAND OVER CENTRAL AMERICA AND IS WEAK IN THE E PACIFIC REGION. ANY SHOWER ACTIVITY IS DUE TO UPPER LEVEL FEATURES. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N11W 4N26W 10N49W 7N60W ACROSS THE SOUTH AMERICA INTO THE E PACIFIC REGION. SCATTERED STRONG CONVECTION IS MOVING OFF AFRICA FROM 13N-18N E OF 20W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 1N-6N BETWEEN 12W-37W. ...DISCUSSION... GULF OF MEXICO... SHARP UPPER TROUGH EXTENDS FROM E/CENTRAL TEXAS AND JUST OFF THE E COAST OF MEXICO INCLUDING THE GULF W OF 93W. BROAD UPPER RIDGE EXTENDS FROM THE E BAY OF CAMPECHE/W YUCATAN OVER THE GULF OVER THE E US COVERING THE REMAINDER OF THE GULF. THIS COMBINATION IS ADVECTING AN ABUNDANCE OF TROPICAL MOISTURE ACROSS THE AREA GIVING MOST OF THE GULF SCATTERED SHOWERS/THUNDERSTORMS WITH THE EXCEPTION OF THE FAR E GULF N OF 25N E OF 86W WHERE CLEAR SKIES PREVAIL. A SURFACE RIDGE COVERS THE N GULF WITH A SURFACE TROUGH EXTENDING ALONG FROM 27N94W TO THE YUCATAN NEAR 19N89W. CARIBBEAN SEA... UPPER LEVEL TROUGH OVER THE W ATLC EXTENDS S INTO THE CARIBBEAN TO 13N FROM HISPANIOLA TO 85W WITH AN UPPER RIDGE OVER THE E CARIBBEAN ALONG 66W. THIS IS GIVING MUCH OF THE AREA SCATTERED SHOWERS/THUNDERSTORMS WITH THE EXCEPTION OF THE CENTRAL CARIBBEAN FROM 12N-16N BETWEEN 74W84W WHERE CLEAR SKIES PREVAIL. ATLANTIC OCEAN... UPPER LEVEL TROUGH EXTENDS OVER THE W ATLC INTO THE CARIBBEAN FROM 71W TO OVER THE FLORIDA PENINSULA WITH THE ASSOCIATED SURFACE TROUGH EXTENDING THROUGH 32N58W SW ALONG 27N67W TO OVER THE S BAHAMAS NEAR 22N73W. LARGE CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE S OF 29N BETWEEN 70W-80W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 200 NM NW OF THE REMAINDER OF THE SURFACE TROUGH. THE UPPER RIDGE FROM THE CARIBBEAN EXTENDS ACROSS PUERTO RICO ALONG 23N65W THEN NE BEYOND 32N56W. THIS IS GIVING THE AREA FROM 10N-23N BETWEEN 61W-67W SCATTERED SHOWERS/ISOLATED THUNDERSTORMS. A SECOND INDUCED UPPER HIGH IS CENTERED NEAR 25N50W BY A DEEP LAYERED TROUGH THAT EXTENDS FROM AN UPPER LOW NEAR 30N34W SW TO 18N43W. THE AREA FROM 15N-30N BETWEEN 42W-60W IS UNDER STRONG SUBSIDENCE AND DRY AIR...THUS NO SHOWER ACTIVITY. AT THE SURFACE...A PAIR OF 1015 MB LOWS ARE CENTERED NEAR 28N36W AND 32N33W. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE WITHIN 90 NM OF LINE 27N35W-33N32W. BROAD UPPER RIDGE HAS AGAIN SET UP ALONG THE COAST OF AFRICA TO WELL N OF THE CANARY ISLANDS. $$ WALLACE