000 AXNT20 KNHC 040511 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 38W/39W S OF 20N WITH A 1011 MB LOW ON THE WAVE NEAR 12N MOVING W 10-15 KT. LOW LEVEL ROTATION AND INVERTED-V SIGNATURE ARE NOTED ON SATELLITE IMAGERY. WAVE IS ON THE E SIDE OF A DEEP LEVEL TROUGH RESULTING IN WESTERLY SHEAR. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION COVER THE AREA FROM 10N-22N BETWEEN 30W-40W. TROPICAL WAVE IS ALONG 49W/50W S OF 18N MOVING W 5-10 KT. WEAK LOW AMPLITUDE INVERTED-V SIGNATURE. WAVE IS EMBEDDED WITH DRY AIR SO THERE ARE ONLY SCATTERED SHOWERS FROM 9N-13N BETWEEN 46W-52W. TROPICAL WAVE IS ALONG 68W/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 89W 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 10N13W 5N25W 9N35W 9N47W 6N60W ACROSS THE SOUTH AMERICA INTO THE E PACIFIC REGION. SCATTERED STRONG CONVECTION IS MOVING OFF AFRICA FROM 14N-16N E OF 18W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM THE EQUATOR TO 9N BETWEEN 10W-37W. ...DISCUSSION... GULF OF MEXICO... SHARP UPPER TROUGH EXTENDS FROM CENTRAL TEXAS ALONG THE E COAST OF MEXICO AND INCLUDES THE GULF W OF 95W. BROAD UPPER RIDGE EXTENDS FROM SE MEXICO OVER THE CENTRAL GULF INTO THE MISSISSIPPI VALLEY 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/ ISOLATED THUNDERSTORMS WITH THE EXCEPTION OF THE FAR E GULF N OF 25N E OF 86W WHERE THERE ARE ONLY ISOLATED SHOWERS. A SURFACE RIDGE COVERS THE N GULF WITH A WEAK SURFACE TROUGH EXTENDING ALONG 94W FROM 20N-28N. CARIBBEAN SEA... DEEP LAYERED TROUGH OVER THE W ATLC EXTENDS S INTO THE CARIBBEAN TO 14N W OF HISPANIOLA TO 85W WITH AN UPPER RIDGE OVER THE E CARIBBEAN ALONG 65W. THIS IS GIVING MUCH OF THE AREA SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITH THE EXCEPTION OF THE CENTRAL PREVAIL. ATLANTIC OCEAN... DEEP LAYERED TROUGH EXTENDS OVER THE W ATLC INTO THE CARIBBEAN FROM 72W TO OVER THE FLORIDA PENINSULA WITH THE ASSOCIATED SURFACE TROUGH EXTENDING THROUGH 32N56W SW TO OVER THE S BAHAMAS NEAR 22N74W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE N OF THE BAHAMAS FROM 22N-29N BETWEEN 67W-76W. THE UPPER RIDGE FROM THE CARIBBEAN EXTENDS ACROSS PUERTO RICO TO AN UPPER HIGH NEAR 27N60W CONTINUING NE BEYOND 32N56W. THIS IS GIVING THE AREA FROM 16N-25N BETWEEN 59W-65W SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS. A SECOND INDUCED UPPER HIGH IS CENTERED NEAR 27N48W BY A DEEP LAYERED TROUGH THAT EXTENDS FROM AN UPPER LOW NEAR 30N34W SW TO 18N43W. THE AREA FROM 15N-30N BETWEEN 40-60W IS UNDER STRONG SUBSIDENCE AND DRY AIR...THUS NO SHOWERS ACTIVITY. AT THE SURFACE...A PAIR OF 1015 MB LOWS ARE CENTERED NEAR 28N35W AND 33N33W WHICH ARE ASSOCIATED WITH A RAPIDLY DISSIPATING FRONTAL SYSTEM. HOWEVER SCATTERED SHOWERS/ THUNDERSTORMS ARE WITHIN 90 NM OF LINE 27N36W-32N32W. BROAD UPPER RIDGE HAS AGAIN SET UP ALONG THE COAST OF AFRICA TO WELL N OF THE CANARY ISLANDS. $$ WALLACE