000 AXNT20 KNHC 271732 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE OCT 27 2009 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1645 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 25W S OF 15N MOVING W NEAR 10 KT. VISIBLE SATELLITE IMAGERY INDICATES GOOD LOW-LEVEL CYCLONIC FLOW NEAR THE WAVE AXIS CONCENTRATED NEAR 12N. THE WAVE ALSO COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED STRONG CONVECTION IS FROM 14N-15N BETWEEN 18W-22W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 12N-17N BETWEEN 22W-28W. TROPICAL WAVE IS ALONG 44W/45W S OF 16N MOVING W NEAR 15 KT. SATELLITE IMAGERY AS WELL AS A 1304 UTC ASCAT SCATTEROMETER PASS INDICATE BROAD LOW-LEVEL CYCLONIC FLOW AROUND THE VICINITY OF THE WAVE AXIS. THE WAVE ALSO COINCIDES WITH A SURGE IN DEEP LAYER MOISTURE OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE. TROPICAL WAVE IS ALONG 60W S OF 16N MOVING W NEAR 15 KT. THE WAVE LEADS A MAXIMUM IN DEEP LAYER MOISTURE OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. ISOLATED MODERATE CONVECTION IS FROM 14N-18N BETWEEN 57W-62W. THIS ACTIVITY MAY BE MORE ASSOCIATED WITH UPPER DIFFLUENT FLOW ALOFT. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 9N13W 9N23W 8N35W 10N47W 9N53W 11N58W. ISOLATED/MODERATE CONVECTION IS ALONG THE AXIS NEAR 12W...AND BETWEEN 15W-23W. ...DISCUSSION... THE GULF OF MEXICO... A COLD FRONT EXTENDS ACROSS THE WRN GULF OF MEXICO FROM WRN LOUISIANA NEAR 29N91W ALONG 24N93W 19N96W INTO MEXICO TO 22N99W. ISOLATED SHOWERS ARE WITHIN 250 NM NW OF THE FRONT...AND WITHIN 100 NM SE OF THE FRONT. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO AHEAD OF THE FRONT IN THE BAY OF CAMPECHE FROM 19N-21N BETWEEN 92W-94W. A 1008 MB LOW IS NEAR THE LOUISIANA/MISSISSIPPI BORDER AT 30N89W. A STATIONARY FRONT EXTENDS NW FROM THE LOW CONNECTING WITH THE AFOREMENTIONED COLD FRONT. A WARM FRONT EXTENDS E FROM THE LOW ALONG 30N86W TO 31N81W. SCATTERED SHOWERS/THUNDERSTORMS ARE FROM 22N-31N BETWEEN 83W-87W. THE FRONTAL SYSTEM IS SUPPORTED BY MOIST SWLY FLOW ALOFT AROUND THE BASE OF AN UPPER LEVEL TROUGH WITH AXIS ACROSS THE MIDWEST UNITED STATES...TEXAS AND INTO MEXICO. THE FAR SE GULF IS COVERED BY A NARROW UPPER LEVEL RIDGE EXTENDING FROM THE YUCATAN PENINSULA ACROSS S FLORIDA AND INTO THE WRN ATLC. EXPECT SHOWERS/POSSIBLE THUNDERSTORMS TO CONTINUE ACROSS MUCH OF THE GULF AS THE COLD FRONT CONTINUES TO MOVE SE ACROSS THE BASIN. THE CARIBBEAN SEA... THE MAJORITY OF THE CARIBBEAN SEA IS EXPERIENCING GENERALLY FAIR WEATHER THIS AFTERNOON. A FEW ISOLATED SHOWERS ARE IN THE NW BASIN FROM 18N-22N BETWEEN 82W-84W. THE SHOWERS ARE SUPPORTED BY DIFFLUENT FLOW ALOFT BETWEEN AN UPPER LEVEL RIDGE EXTENDING FROM THE YUCATAN PENINSULA ACROSS THE SE GULF AND INTO THE WRN ATLC AND AN UPPER LEVEL TROUGH COVERING THE REMAINDER OF THE BASIN CENTERED S OF PUERTO RICO NEAR 17N68W. THE UPPER LEVEL LOW IS ALSO SUPPORTING A FEW ISOLATED SHOWERS/THUNDERSTORMS FROM 16N-18N BETWEEN 65W-71W. SCATTERED SHOWERS/THUNDERSTORMS ARE IN THE FAR SW CARIBBEAN S OF 11N BETWEEN 76W-83W DUE TO SURFACE CONVERGENCE NEAR A 1007 MB LOW OVER COLOMBIA NEAR 8N76W...AND THE CLOSE PROXIMITY OF THE E PACIFIC ITCZ. SHOWERS ASSOCIATED WITH A TROPICAL WAVE E OF THE LESSER ANTILLES ALONG 60W HAVE BEGUN TO AFFECT THE ISLANDS E OF 62W. MODERATE TO FRESH TRADEWINDS ARE ACROSS THE MAJORITY OF THE BASIN. THE ATLANTIC OCEAN... A STATIONARY FRONT ENTERS THE FAR WRN PORTION OF THE DISCUSSION AREA NEAR 32N77W TO 31N80W BECOMING WARM ACROSS NRN FLORIDA AND THE NRN GULF COAST. ISOLATED SHOWERS ARE N OF 27N W OF 75W. THE FRONT IS SUPPORTED BY AN UPPER LEVEL TROUGH OVER MUCH OF THE ERN CONUS...GULF OF MEXICO...AND INTO THE FAR WRN ATLC. AN UPPER LEVEL RIDGE IS TO THE E EXTENDING FROM THE YUCATAN PENINSULA ACROSS S FLORIDA CONTINUING TO THE NE. THE UPPER RIDGE SUPPORTS A BROAD SURFACE RIDGE COVERING THE MAJORITY OF THE BASIN ANCHORED BY A 1023 MB HIGH NEAR 30N66W. A LINE OF SHOWERS EXTEND FROM 23N57W TO 23N66W IN ASSOCIATION WITH DIFFLUENT FLOW ALOFT BETWEEN THE AFOREMENTIONED UPPER RIDGE AND AN UPPER LEVEL LOW S OF PUERTO RICO NEAR 17N68W. FARTHER E...A DYING COLD FRONT EXTENDS FROM 31N20W TO 24N26W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 150 NM AHEAD OF THE FRONT. A SHORTWAVE UPPER LEVEL TROUGH WITH AXIS ALONG 22W SUPPORTS THE FRONT. $$ WALTON