000 AXNT20 KNHC 152346 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT SEP 15 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURE... TROPICAL DEPRESSION INGRID IS CENTERED 16.5N 55.0W AT 15/2100 UTC OR ABOUT 380 NM E OF GUADALOUPE IN THE LESSER ANTILLES MOVING WNW AT 10 KT. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC. BROAD LOW LEVEL CENTER IS MOSTLY EXPOSED WITH THE CONVECTION TO THE E AND W. SCATTERED SHOWERS/ THUNDERSTORMS ARE FROM 15N-18N BETWEEN 51W-54W AND FROM 16N-20N BETWEEN 56W-58W. UPPER LEVEL WINDS THAT ARE NOT CONDUCIVE FOR DEVELOPMENT ARE MOVING TOWARD INGRID AND THE DEPRESSION COULD WEAKEN FURTHER OVERNIGHT. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 36W/37W S OF 17N MOVING W 15 KT. BROAD MID LEVEL CURVATURE IS PREVALENT OVER THE WAVE WITH SCATTERED THUNDERSTORMS ARE WITHIN 120 NM OF LINE FROM 17N28W TO 13N37W. TROPICAL WAVE IS ALONG 44W/45W S OF 13N MOVING W 10 KT. WAVE POSITION IS BASED ON LONG-TERM SATELLITE IMAGES BUT IS A VERY LOW AMPLITUDE WAVE. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 6N-11N BETWEEN 41W-47W. TROPICAL WAVE IS ALONG 69W S OF 18N MOVING W 10-15 KT. WAVE IS AN AREA OF MODERATE/STRONG WLY SHEAR DISPLACING SCATTERED SHOWERS/THUNDERSTORMS TO THE E FROM 13N-18N BETWEEN 63W-69W. A TROPICAL WAVE IS ALONG 94W/95W S OF 21N MOVING W NEAR 10 KT. THIS WAVE IS MOST PREVALENT IN THE E PACIFIC REGION AND MODERATE DRY AIR OVER THE GULF OF MEXICO. THEREFORE...NO ASSOCIATED SHOWERS/CONVECTION IN THE ATLC BASIN. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 12N14W 10N21W 12N33W THEN ALONG 8N48W 9N62W. IN ADDITION TO CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 6N-10N BETWEEN 30W-36W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 120 NM OF LINE FROM 7N24W TO 4N34W. DISCUSSION... GULF OF MEXICO... AN ELONGATED UPPER LOW EXTENDS FROM 25N89W TO OVER THE BAY OF CAMPECHE AND S MEXICO NEAR 17N98W ADVECTING MODERATE DRY UPPER AIR OVER THE BAY OF CAMPECHE. THE TROPICAL WAVE ALONG 94W/95W IS BENEATH THIS DRY AIR. AN UPPER RIDGE EXTENDS FROM NE MEXICO NEAR THE TEXAS BORDER E EXPANDING E OF 86W TO ACROSS CENTRAL FLORIDA PENINSULA INTO THE W ATLC AND COVERING THE ENTIRE E GULF. DIFFLUENCE BETWEEN THE UPPER RIDGE AND AND THE UPPER TROUGH OVER THE BAY OF CAMPECHE IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 22N-27N W OF 93W TO INLAND OVER SE TEXAS AND NE MEXICO. A DEEP LAYERED UPPER TROUGH IS OVER THE E US DRAPING A SURFACE TROUGH INTO THE GULF OF MEXICO FROM NEAR JACKSONVILLE FLORIDA TO NEAR 28N87W. AFTERNOON SEA BREEZE INDUCED THUNDERSTORMS THAT HAVE DEVELOPED OVER THE FLORIDA PENINSULA ARE PUSHING SW INTO THE E GULF FROM FORT MYERS TO OVER THE FLORIDA KEYS. THE REMAINDER OF THE GULF REMAINS QUITE THIS AFTERNOON WITH THE EXCEPTION OF SOME SCATTERED SHOWERS/ISOLATED THUNDERSTORMS IN THE YUCATAN CHANNEL. CARIBBEAN SEA... AN UPPER LOW DOMINATES THE N CARIBBEAN CENTERED OVER HAITI COVERING THE AREA FROM THE VIRGIN ISLANDS TO CENTRAL CUBA AND EXTENDING N INTO THE W ATLC. THE UPPER RIDGE THAT EXTENDS ACROSS THE N GULF OF MEXICO AND OVER THE E GULF OF MEXICO EXTENDS OVER THE EXTREME NW CARIBBEAN PRODUCING ENOUGH DIFFLUENCE BETWEEN THIS UPPER RIDGE AND AND THE BROAD UPPER LOW OVER HAITI TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 20N TO THE COAST OF HONDURAS BETWEEN 84W-87W. AN UPPER RIDGE DOMINATES THE S CARIBBEAN EXTENDING FROM COLOMBIA NEAR 10N75W TO OVER CENTRAL NICARAGUA PRODUCING ENOUGH DIFFLUENCE BETWEEN THIS UPPER RIDGE AND AND THE BROAD UPPER LOW OVER HAITI TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 15N W OF 80W TO INLAND OVER CENTRAL AMERICA. SCATTERED STRONG CONVECTION IS S OF 13N TO INLAND OVER NW VENEZUELA AND N COLOMBIA BETWEEN 69W-76W. AFTERNOON THUNDERSTORMS THAT DEVELOPED OVER THE GREATER ANTILLES AND JAMAICA HAVE BEGUN TO DIMINISH AND DRIFT S INTO THE COASTAL WATERS WHILE THE CENTRAL CARIBBEAN REMAINS RATHER QUITE. ATLANTIC OCEAN... THE UPPER RIDGE THAT EXTENDS ACROSS THE N AND E GULF OF MEXICO CROSS CENTRAL FLORIDA THEN EXTENDS NE TO BEYOND 32N74W COVERING THE FAR W ATLC INTO THE NW CARIBBEAN. A BROAD UPPER TROUGH COVERS THE REMAINDER OF THE W ATLC INTO CENTRAL WITH A SERIES OF UPPER LOWS...THIS FIRST CENTERED OVER HAITI TO A SECOND NEAR 26N56W TO A THIRD JUST N OF THE REGION NEAR 33N38W AND A FORTH WELL N OF THE REGION OFF THE SW COAST OF PORTUGAL. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ASSOCIATED WITH THE LOW OVER HAITI ARE FROM 18N-25N BETWEEN 63W-71W AND WITH THE LOW NEAR 26N56W FROM 24N-27N BETWEEN 52W-60W. A SURFACE TROUGH IS ASSOCIATED WITH THE UPPER LOW N OF THE REGION EXTENDING THROUGH 32N36W SW TO 26N44W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 150/180 NM E OF THE SURFACE TROUGH. BROAD ILL-DEFINED UPPER RIDGE DOMINATES THE E AND MOST OF THE TROPICAL ATLC EXTENDING ALONG 17N FROM W AFRICA TO JUST E OF INGRID NEAR 47W. THE REMAINDER OF THE ATLC IS ENJOYING RATHER DRY CONDITIONS THIS EVENING. $$ WALLACE