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000 AXNT20 KNHC 200555 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT SEP 20 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 29W S OF 18N MOVING W NEAR 10 KT. THIS WAVE IS BENEATH AN UPPER LEVEL RIDGE AND NO CONVECTION IS OBSERVED WITH THIS FEATURE. A TROPICAL WAVE IS ALONG 50W S OF 19N MOVING W NEAR 10 KT. A SMALL WEAK CYCLONIC CIRCULATION IS NOTED IN THE LOW CLOUDS ALONG THE WAVE AXIS NEAR 17N. POSSIBLE SHOWERS ARE FROM 14N-18N BETWEEN 47W-52W. A TROPICAL WAVE IS ALONG 64W S OF 19N MOVING W NEAR 5-10 KT. THIS WAVE IS EMBEDDED WITHIN A BROAD AREA OF LOW PRESSURE ACROSS THE ERN CARIBBEAN SEA AND IS GENERATING A BROAD AREA OF CLOUDINESS WITH SCATTERED SHOWERS ACROSS THE LESSER ANTILLES. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 14N-18N BETWEEN 54W-60W. A TROPICAL WAVE IS ALONG 75W S OF 19N MOVING W NEAR 10 KT. SATELLITE IMAGERY INDICATES AN INVERTED-V SIGNATURE ACROSS THE WRN CARIBBEAN WITH SCATTERED MODERATE CONVECTION FROM 13N-19N BETWEEN 75W-81W. A TROPICAL WAVE IS OVER SRN MEXICO ALONG 94W S OF 18N MOVING W AT 5-10 KT. SCATTERED MODERATE TO STRONG CONVECTION IS ACROSS SRN MEXICO S OF 19N BETWEEN 90W-96W AND INTO THE ERN PACIFIC OCEAN WITH THIS WAVE. AS THIS WAVE MOVES W IT WILL BECOME ABSORBED INTO A LARGE AREA OF DISTURBED WEATHER SSW OF THE GULF OF TEHUANTEPEC. FOR FURTHER INFORMATION SEE THE TWDEP. ...THE ITCZ... ITCZ AXIS IS ANALYZED ALONG 8N12W 6N26W 7N30W 10N47W 10N52W 10N61W. SCATTERED MODERATE CONVECTION IS ALONG THE W AFRICAN COAST FROM 10N-15N BETWEEN 15W-20W AND IS LIKELY ASSOCIATED WITH THE A NEW TROPICAL WAVE EMERGING FROM THE COAST. SCATTERED MODERATE/ ISOLATED STRONG CONVECTION IS FROM 2N-10N BETWEEN 20W-25W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH EXTENDS FROM 28N93W TO 20N94W AND COVERS THE WRN GULF WITH A BROAD AREA OF MULTILAYERED CLOUDINESS. SCATTERED SHOWERS AND ISOLATED TSTMS ARE ACROSS THE WRN AND CENTRAL GULF W OF 86W WITH UPPER LEVEL DIFFLUENCE HELPING TO SUSTAIN THE SHOWERS DURING THE OVERNIGHT PERIOD. ANOTHER AREA OF SCATTERED SHOWERS IS WITHIN 60 NM OF KEY WEST FLORIDA IN THE SE GULF. UPPER LEVEL RIDGING IS ACROSS MUCH OF THE GULF WITH WESTERLY UPPER FLOW DOMINATING FROM NRN MEXICO TO THE FLORIDA PENINSULA. A SURFACE RIDGE IS ACROSS THE SE CONUS AND THE NE GULF. AN AMPLE AMOUNT OF UPPER-LEVEL MOISTURE IS NOTED OVER THE GULF REGION WHILE SUBSIDENCE/DRY AIR IS ACROSS THE FLORIDA PENINSULA AND THE FAR NW GULF WATERS. CARIBBEAN SEA... TWO TROPICAL WAVES ARE ACROSS THE CARIBBEAN SEA...SEE THE TROPICAL WAVE SECTION FOR MORE DETAILS. WIDESPREAD CLOUDINESS AND SHOWERS ARE OVER PUERTO RICO AND THE LESSER ANTILLES WITH THE NEARBY TROPICAL WAVE ALONG 64W. CLUSTERS OF SCATTERED SHOWERS/TSTMS ARE ACROSS THE WRN CARIBBEAN IN ASSOCIATION WITH THE TROPICAL WAVE ALONG 75W...WHICH INCLUDES THE WINDWARD PASSAGE...HISPANIOLA AND JAMAICA. AN UPPER LEVEL TROUGH EXTENDS FROM THE FAR W ATLC ACROSS CENTRAL CUBA INTO THE WRN CARIBBEAN TO NORTH OF PANAMA AND IS PROVIDING UPPER LEVEL DIFFLUENCE E OF 80W TO FURTHER SUPPORT THE AFOREMENTIONED CONVECTION. UPPER LEVEL RIDGING EXTENDS FROM THE SRN GULF OF MEXICO ACROSS THE NW CARIBBEAN PROVIDING UPPER LEVEL DIFFLUENCE TO INDUCE SCATTERED SHOWERS INLAND ACROSS CENTRAL AMERICA. SIMILAR SCATTERED SHOWERS AND TSTMS ARE ACROSS THE SW CARIBBEAN S OF 11N. MODERATE TRADE WINDS ARE NOTED ACROSS THE BASIN. ATLANTIC OCEAN... A SURFACE TROUGH EXTENDS FROM A 1013 MB LOW CENTERED NEAR 31N74W TO THE NW BAHAMAS NEAR 25N78W. SCATTERED SHOWERS ARE WITHIN 90 NM EAST OF THE FRONT N OF 29N. THIS ACTIVITY IS BEING ENHANCED BY SOUTHWESTERLY FLOW AND UPPER LEVEL DIFFLUENCE EAST OF AN UPPER LEVEL TROUGH ALONG THE ERN SEABOARD OF THE US. THIS UPPER TROUGH DIGS INTO THE CARIBBEAN SEA ACROSS CENTRAL CUBA. FARTHER EAST... A BROAD UPPER-LEVEL LOW IS SPINNING OVER THE CENTRAL ATLC NEAR 25N46W. A STRONG UPPER LEVEL HIGH LOCATED INLAND OVER W AFRICA HAS A RIDGE EXTENDING W TO ABOUT 37W ENVELOPING THE CAPE VERDE ISLANDS. AT THE SURFACE...A RIDGE OF HIGH PRESSURE COVERS THE DISCUSSION AREA N OF 20N AND E OF 65W ANCHORED ON A PAIR OF SURFACE HIGHS CENTERED N OF THE REGION. $$ HUFFMAN