000 AXNT20 KNHC 091017 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE OCT 09 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...SPECIAL FEATURE... AN AREA OF LOW PRESSURE CENTERED OVER THE NW CARIBBEAN ANALYZED AS A 1004 MB LOW OFF THE COAST OF BELIZE NEAR 17N86W MOVING ERRATICALLY. BROAD ILL-DEFINED UPPER RIDGE COVERS THE W CARIBBEAN WITH SCATTERED SHOWERS/THUNDERSTORMS FROM THE COAST OF HONDURAS THROUGH THE YUCATAN CHANNEL W OF 84W TO ALONG THE COAST OF THE YUCATAN PENINSULA. CONDITIONS REMAIN APPEAR FAVORABLE FOR DEVELOPMENT AND THIS SYSTEM COULD BECOME A TROPICAL DEPRESSION BEFORE REACHING THE EAST COAST OF THE YUCATAN PENINSULA. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 45W S OF 14N MOVING W NEAR 15 KT. WEAK SATELLITE SIGNATURE WITH ASSOCIATED CONVECTION EMBEDDED WITHIN THE ITCZ. TROPICAL WAVE IS ALONG 60W S OF 20N MOVING W NEAR 10 KT. WEAK SATELLITE SIGNATURE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 11N TO JUST INLAND OVER GUYANA SOUTH AMERICA BETWEEN 57W-60W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N10W 5N29W 10N43W 9N53W 10N63W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 90/120 NM OF LINE FROM 7N38W TO 11N48W. LARGE CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE WITHIN 180/225 NM OF THE ITCZ AXIS FROM 11W-38W AND FROM 6N-15N BETWEEN 48W-57W. DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE ANCHORED IN THE E PACIFIC REGION COVERS MEXICO INTO THE W GULF W OF 95W WITH A SHORTWAVE UPPER TROUGH EXTENDING FROM OVER LOUISIANA TO NEAR 25N93W. A BROAD UPPER TROUGH IN THE W ATLC EXTENDS W OVER THE E GULF E OF 85W WITH AN INDUCED UPPER RIDGE BETWEEN. UPPER DIFFLUENCE IS GENERATING SCATTERED SHOWERS/ THUNDERSTORMS ACROSS THE GULF WITHIN 120/150 NM OF LINE FROM THE LOUISIANA COAST NEAR ATCHAFALAYA BAY ALONG 25N93W INTO THE BAY OF CAMPECHE TO NEAR 19N95W. BROAD UPPER RIDGE IN THE NW CARIBBEAN COVERS THE S GULF ENHANCING THE SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS OVER THE S GULF S OF 24N E OF 90W THROUGH THE FLORIDA STRAITS. THE E GULF N OF 24N E OF 90W IS UNDER DRY STABLE AIR THUS CLEAR SKIES THIS MORNING. CARIBBEAN SEA... THE MAIN FOCUS THIS MORNING REMAINS THE 1004 MB LOW IN THE NW CARIBBEAN ADDRESSED IN THE SPECIAL FEATURES ABOVE. OTHERWISE...A BROAD UPPER HIGH ANCHORED OVER THE YUCATAN NEAR BELIZE COVERS THE CARIBBEAN TO THE LESSER ANTILLES. UPPER DIFFLUENCE AND AN ABUNDANCE OF TROPICAL MOISTURE ARE GENERATING SCATTERED SHOWERS/THUNDERSTORMS OVER MOST OF THE CARIBBEAN W OF 71W WITH THE HEAVIEST ACTIVITY ACROSS THE HISPANIOLA AND E CUBA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 16N FROM THE VIRGIN ISLANDS TO 70W. ATLANTIC OCEAN... AN UPPER TROUGH IN THE W ATLC EXTENDS FROM AN UPPER LOW NEAR 28N67W W INTO THE E GULF OF MEXICO N OF 24N. A SURFACE TROUGH EXTENDS FROM 28N61W THROUGH A 1010 MB SURFACE LOW NEAR 24N70W TO JUST NE OF THE TURKS AND CAICOS NEAR 22N72W. SCATTERED SHOWERS/THUNDERSTORMS ARE FROM 18N-26N BETWEEN 63W-70W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 24N FROM 73W THROUGH THE FLORIDA STRAITS. A DEEP LAYERED TROUGH IS OVER THE N/CENTRAL ATLC N OF 30N DRAPING A COLD FRONT THROUGH 32N52W TO 31N68W AND A SURFACE TROUGH DEEPER INTO THE REGION THROUGH 32N40W TO 23N53W WITH SCATTERED SHOWERS/THUNDERSTORMS WITHIN 250 NM E OF THE SURFACE TROUGH N OF 28N AND WITHIN 180 NM EITHER SIDE OF THE REMAINDER OF THE SURFACE TROUGH. NO SHOWERS ARE ASSOCIATED WITH THE COLD FRONT. BROAD UPPER HIGH IS OVER THE W TROPICAL ATLC NEAR 14N44W COVERING THE AREA S OF 26N FROM 36W-55W. BETWEEN THE UPPER RIDGE IN THE CARIBBEAN AND THE UPPER HIGH IN THE CENTRAL ATLC IS AN INDUCED UPPER TROUGH EXTENDING BETWEEN 55W-60W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 14N-19N BETWEEN 55W-60W. A NARROW RIDGE AXIS EXTENDS NE FROM 23N45W TO BEYOND 32N33W ENHANCING THE ACTIVITY ASSOCIATED WITH THE SURFACE TROUGH. AN UPPER TROUGH COVERS THE E ATLC EXTENDING FROM AN UPPER LOW OFF THE COAST OF MOROCCO ACROSS THE CANARY ISLANDS INTO THE E TROPICAL ATLC OVER THE CAPE VERDE ISLANDS AND COVERS THE REMAINDER OF THE ATLC. A SURFACE RIDGE COVERS THE E ATLC EXTENDING FROM A 1028 MB HIGH NEAR 36N20W THROUGH 32N25W S TO NEAR 19N40W COVERING THE AREA E OF THE SURFACE TROUGH. $$ WALLACE