000 AXNT20 KNHC 191145 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI OCT 19 2012 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...TROPICAL WAVES... WEAK TROPICAL WAVE IS ANALYZED FROM 18N48W TO 12N49W MOVING W NEAR 10 KT. WAVE REMAINS DIFFICULT TO TRACK AS IT IS ALONG THE EASTERN EDGE OF AN UPPER TROUGH. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 12N-20N BETWEEN 44W-50W AND IS BEING ENHANCED BY THE UPPER TROUGH. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH IS ANALYZED ACROSS W AFRICA INTO THE E TROPICAL ATLC NEAR 12N16W ALONG 9N21W TO 5N31W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N42W TO 4N52W. SMALL CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION DOT THE AREA FROM 3N-12N BETWEEN 12W-30W AND FROM 4N-8N BETWEEN 30W-36W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER TROUGH CONTINUES TO DIG S OVER THE GULF FROM AN UPPER LOW OVER THE GREAT LAKES REGION SUPPORTING A COLD FRONT THAT AT 19/0900 EXTENDS ACROSS NE FLORIDA JUST W OF JACKSONVILLE INTO THE GULF N OF CEDAR KEY CONTINUING TO 27N86W WHERE IT PULLS UP STATIONARY ALONG 26N96W TO INLAND OVER E MEXICO NEAR 23N98W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALONG THE IMMEDIATE FRONTAL BOUNDARY E OF 90W AND WITHIN 60/75 NM ALONG THE COAST OF MEXICO N OF TAMPICO TO THE TEXAS BORDER. A SURFACE TROUGH IS N OF THE STATIONARY FRONT EXTENDING FROM 28N91W TO THE TEXAS COAST NEAR 27N95W WITH ISOLATED SHOWERS/THUNDERSTORMS WITHIN 45 NM EITHER SIDE OF THE TROUGH. A SURFACE TROUGH IS IN THE SE GULF EXTENDING FROM FORT MYERS FLORIDA TO 24N84W WITH ISOLATED SHOWERS/THUNDERSTORMS WITHIN 60 NM EITHER SIDE OF THE TROUGH. AN UPPER RIDGE REMAINS OVER THE SW GULF WITH THE AXIS EXTENDING FROM AN UPPER HIGH SW OF MEXICO CITY ACROSS THE BAY OF CAMPECHE TO THE YUCATAN PENINSULA. THIS IS LEAVING THE REMAINDER OF THE GULF UNDER CLEAR SKIES THIS MORNING. COLD FRONT WILL EXTEND FROM SW FLORIDA TO S TEXAS BY EARLY SAT THEN DISSIPATE EARLY SUN. CARIBBEAN SEA... THE BROAD UPPER TROUGH THAT COVERS THE GULF OF MEXICO DIPS S OVER THE NW CARIBBEAN N OF 16N W OF 76W TO THE YUCATAN PENINSULA SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 20N81W TO 13N80W. A BROAD UPPER RIDGE COVERS THE REMAINDER OF THE CARIBBEAN ANCHORED NEAR 16N72W AND IS PROVIDING DIFFLUENCE ALOFT TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 16N BETWEEN 73W-80W. A SECOND SURFACE TROUGH IS OVER THE E CARIBBEAN ALONG 67W/68W FROM THE COAST OF VENEZUELA TO 17N GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS E OF 73W TO THE LESSER ANTILLES AND OVER THE VIRGIN ISLANDS...PUERTO RICO...AND THE DOMINICAN REPUBLIC. E CARIBBEAN TROUGH WILL MOVE W THROUGH THE CENTRAL CARIBBEAN THROUGH SUN THEN MERGE WITH BROAD AREA OF LOWER PRESSURE IN THE SW CARIBBEAN MON AND TUE. ATLANTIC OCEAN... BROAD UPPER TROUGH COVERS THE E CONUS INTO THE E GULF OF MEXICO ACROSS THE FLORIDA PENINSULA TO 75W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALONG THE E EDGE OF UPPER TROUGH WITHIN 60 NM OF OF LINE FROM 24N81W ACROSS THE UPPER KEYS ALONG 28N78W TO 32N76W. AN UPPER RIDGE IS ANCHORED IN THE CARIBBEAN EXTENDING A RIDGE AXIS ACROSS PUERTO RICO TO BERMUDA PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 75 NM OF LINE FROM 26N73W TO 32N68W. A SHORTWAVE UPPER TROUGH IS IN THE CENTRAL ATLC SUPPORTING A SURFACE TROUGH THAT EXTENDS THROUGH 32N55W ALONG 29N57W TO 26N60W WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 90N NM E OF THE TROUGH. A LARGE ELONGATED UPPER LOW IS IN THE CENTRAL ATLC CENTERED NEAR 20N51W WITH THE UPPER TROUGH EXTENDING S TO 10N53W AND N TO 31N46W. THIS UPPER LOW IS MASKING THE TROPICAL WAVE MAKING IT DIFFICULT TO LOCATE AND IS ENHANCING THE ACTIVITY DESCRIBED IN THE TROPICAL WAVE SECTION ABOVE. A BROAD UPPER TROUGH IS CENTERED IN THE NE ATLC EXTENDING S TO 17N E OF 25W TO INLAND OVER NW AFRICA. A BROAD SURFACE RIDGE COVERS THE CENTRAL AND E ATLC ANCHORED BY A 1024 MB HIGH JUST N OF THE REGION NEAR 34N35W. A COLD FRONT WILL WILL MOVE OFF THE SE CONUS TODAY. THE FRONT WILL REACH FROM 32N73W TO E CENTRAL FLORIDA BY EARLY SAT AND FROM 32N69W TO THE NW BAHAMAS BY EARLY SUN THEN WEAKEN AS IT SHIFTS INTO THE CENTRAL ATLC MON AND TUE. HIGH PRESSURE WILL BUILD OFF THE CAROLINAS BEHIND THE FRONT MON AND TUE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW