000 AXNT20 KNHC 162251 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN SEP 16 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 2215 UTC. ...SPECIAL FEATURE... TROPICAL DEPRESSION INGRID IS CENTERED 17.4N 58.6W AT 16/2100 UTC OR ABOUT 200 NM E OF THE LESSER ANTILLES MOVING WNW AT 9 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. INGRID IS AGAIN BECOMING LESS ORGANIZED WITH THE LOW LEVEL CENTER BECOMING MORE INDISTINCT. SMALL AREA OF SCATTERED MODERATE CONVECTION WITHIN 60/75 NM RADIUS OF 17N56W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 15N-19N BETWEEN 54W-62W INCLUDING THE LEEWARD ISLANDS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 40W/41W S OF 17N MOVING W NEAR 10 KT. WAVE WAS RELOCATED BASED ON VISIBLE SATELLITE IMAGERY AND BROAD MID LEVEL CURVATURE. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 4N-11N BETWEEN 37W-42W. TROPICAL WAVE IS ALONG 48W/49W S OF 13N MOVING W NEAR 10 KT. WAVE REMAINS A VERY LOW AMPLITUDE WAVE. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN 90/120 NM OF LINE FROM 13N43W TO 8N50W. TROPICAL WAVE IS ALONG 73W S OF 18N MOVING W 10-15 KT. WAVE IS JUST TO THE E OF AN UPPER LOW WHICH IS DRAWING UPPER LEVEL MOISTURE ACROSS THE AREA OF THE TROPICAL WAVE. SEE CARIBBEAN SECTION BELOW. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N14W 8N18W 8N32W 9N39W THEN ALONG 7N50W 6N58W. IN ADDITION TO CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...SCATTERED MODERATE CONVECTION IS WITHIN 75 NM OF LINE FROM 12N32W TO 14N36W. SCATTERED THUNDERSTORMS DOT THE AREA FROM 3N-8N E OF 32W TO JUST INLAND OVER W AFRICA. DISCUSSION... GULF OF MEXICO... AN ELONGATED UPPER LOW EXTENDS FROM 25N95W TO OVER THE W BAY OF CAMPECHE AND S MEXICO NEAR 17N98W COVERING THE AREA S OF 25N W OF 90W. AN UPPER HIGH IS IN THE SE GULF NEAR 24N85W COVERING THE AREA S OF 27N E OF 90W TO OVER S FLORIDA. A DEEP LAYERED UPPER TROUGH IS OVER THE E US INTO THE N GULF N OF 27N E OF 93W EXTENDING AN ASSOCIATED COLD FRONT INTO THE W ATLC BECOMING NEAR STATIONARY ACROSS THE FLORIDA PENINSULA NEAR 29N83W CONTINUING AS A COLD FRONT ALONG 27N89W TO THE TEXAS COAST JUST N OF CORPUS CHRISTI GENERATING SCATTERED SHOWERS/THUNDERSTORMS WITHIN 75/90 NM S OF THE FRONT FROM 92W-96W AND OVER THE FLORIDA PENINSULA S OF A LINE FROM DAYTONA BEACH TO CRYSTAL RIVER. DIFFLUENCE BETWEEN ALL OF THESE UPPER LEVEL FEATURES IS GENERATING SCATTERED SHOWERS AND WIDELY ISOLATED THUNDERSTORMS ACROSS THE GULF S OF THE FRONTAL BOUNDARY WHILE CLEAR SKIES PREVAIL ALONG THE N GULF COAST. CARIBBEAN SEA... THE UPPER HIGH IN THE SE GULF OF MEXICO COVERS THE NW CARIBBEAN N OF 19N W OF 80W. AN UPPER LOW DOMINATES MOST OF THE W CARIBBEAN CENTERED BETWEEN JAMAICA AND HAITI NEAR 18N75W EXTENDING AN UPPER TROUGH SW TO CENTRAL AMERICA NEAR THE TIP OF NICARAGUA/HONDURAS. DIFFLUENCE BETWEEN THIS UPPER HIGH AND THE BROAD UPPER LOW IN THE CARIBBEAN TO GENERATE CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS MAINLY OVER THE ISLANDS OF HISPANIOLA...CUBA...AND JAMAICA MOVING SOUTHWARD OVER THE COASTAL WATERS. AN UPPER RIDGE DOMINATES THE E CARIBBEAN EXTENDING FROM COLOMBIA NEAR 10N70W NNE TO OVER THE VIRGIN ISLANDS ADVECTING TROPICAL MOISTURE ACROSS THE S AND E CARIBBEAN PRODUCING ENOUGH DIFFLUENCE BETWEEN THIS UPPER RIDGE AND AND THE BROAD UPPER LOW MENTIONED ABOVE TO GENERATE DENSE CLOUDINESS WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS SW OF A LINE FROM NICARAGUA NEAR 14N83W TO HISPANIOLA NEAR 19N70W AND E OF 65W. THE AREA E OF 65W IS MOSTLY UNDER DRY CONDITIONS WITH THE EXCEPTION S OF THE LEEWARD ISLANDS WHERE ACTIVITY IS ROUGHLY ASSOCIATED WITH INGRID. ATLANTIC OCEAN... AN UPPER TROUGH THAT COVERS THE E US AND THE N GULF OF MEXICO EXTENDS INTO THE W ATLC N OF 27N W OF 72W WITH AN ASSOCIATED COLD FRONT ENTERING THE REGION NEAR 32N73W ACROSS THE FLORIDA PENINSULA NEAR DAYTONA BEACH AS NEAR STATIONARY WITH SCATTERED SHOWERS AND WIDELY ISOLATED THUNDERSTORMS WITHIN 120/150 NM S OF THE FRONT. JUST TO THE N OF THE REGION IS A POST-FRONTAL SURFACE TROUGH WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 30N FROM 71W-81W. A BROAD UPPER TROUGH THAT COVERS THE REMAINDER OF THE W ATLC INTO CENTRAL ATLC WITH A SERIES OF UPPER LOWS...THIS FIRST CENTERED IN THE CARIBBEAN TO A SECOND NEAR 27N60W TO A THIRD JUST NEAR 32N35W AND A FORTH WELL N OF THE REGION ALONG THE COAST OF PORTUGAL. THE TWO EASTERN UPPER LOWS ARE MOVING TOWARD THE NE WHILE THE WESTERN TWO LOWS ARE MOVING TOWARD THE SW. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ASSOCIATED WITH THE IN THE CARIBBEAN ARE S OF 26N ACROSS THE GREATER ANTILLES FROM 67W-75W AND WITH THE LOW NEAR 27N60W FROM 23N-30N BETWEEN 51W-60W. A SURFACE TROUGH IS ASSOCIATED WITH THE UPPER LOW NEAR 32N35W EXTENDING FROM A WEAK 1014 MB LOW NEAR 33N36W THROUGH 29N37W TO 25N42W WITH SCATTERED SHOWERS AND WIDELY ISOLATED THUNDERSTORMS N OF 28NB FROM 30W TO 35W. BROAD ILL-DEFINED UPPER RIDGE DOMINATES THE E AND MOST OF THE TROPICAL ATLC EXTENDING ALONG 16N FROM W AFRICA TO JUST SE OF INGRID NEAR 52W. THE REMAINDER OF THE ATLC IS ENJOYING RATHER DRY CONDITIONS THIS EVENING. $$ WALLACE