000 AXNT20 KNHC 201738 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST THU NOV 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 51W SOUTH OF 16N MOVING WEST 10 TO 15 KT. THE WAVE POSITION WAS ADJUSTED AT 20/0600 UTC IN ORDER TO BE ALONG 51W ROUGHLY. ITS POSITION HAS NOT CHANGED AT THIS MAP ANALYSIS TIME...BASED ON THE VISIBLE SATELLITE IMAGERY. ISOLATED MODERATE SHOWERS AND LOCALLY STRONG THUNDERSTORMS ARE FROM 14N TO 17N BETWEEN 47W AND 51W... AND FROM 10N TO 12N BETWEEN 49W AND 51W. ...THE ITCZ... 9N12W 6N30W 9N50W 10N53W 9N61W. ISOLATED MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS ARE FROM 4N TO 10N BETWEEN 10W AND 20W. ISOLATED SHOWERS ARE ELSEWHERE FROM 3N TO 12N BETWEEN 20W AND 47W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE FROM 9N TO 11N BETWEEN 59W AND 61W. ...DISCUSSION... THE GULF OF MEXICO... BROAD UPPER LEVEL WESTERLY WIND FLOW COVERS THE AREA. THIS WESTERLY FLOW IS A COMBINATION OF RESIDUAL WESTERLY FLOW AT THE TAIL END OF THE DEEP LAYER TROUGH THAT MOVED ACROSS THE INTERIOR U.S.A. AND SUPPORTED THE COLD FRONTS THAT HAVE PASSED THROUGH THE AREA...AND BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW THAT EMANATES FROM THE EASTERN PACIFIC OCEAN AND MOVES ACROSS MEXICO INTO THE WESTERN GULF OF MEXICO. A 1023 MB HIGH PRESSURE CENTER IS NEAR 28N89W. THE CARIBBEAN SEA... THE COLD FRONT FRONT PASSES THROUGH THE DOMINICAN REPUBLIC NEAR 19N70W TO 16N78W. A STATIONARY FRONT CONTINUES FROM 16N78W TO 15N80W 12N81W TO A 1009 MB LOW PRESSURE CENTER NEAR 10N80W. THE WIND FORECAST FOR THE CARIBBEAN SEA WEST OF THE FRONTAL BOUNDARY IS NORTHERLY WINDS FROM 20 TO 30 KT AND SEA HEIGHTS RANGING FROM 8 TO 12 FT FOR THE NEXT 24 TO 48 HOURS. STRONG SHOWERS AND THUNDERSTORMS THAT ARE FROM 12N TO 14N BETWEEN 62W AND 63W IN THE SOUTHEASTERN CORNER OF THE AREA ARE CLOSE TO A SURFACE-TO-LOW LEVEL TROUGH THAT IS BETWEEN 60W AND THE EASTERN CARIBBEAN SEA ISLANDS. SCATTERED STRONG SHOWERS AND THUNDERSTORMS FROM 11N TO 13N BETWEEN 67W AND 69W AROUND THE NETHERLANDS ANTILLES ARE IN THE AREA OF A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER. SCATTERED MODERATE TO STRONG SHOWERS AND THUNDERSTORMS SURROUND THE STATIONARY FRONT AND 1009 MB LOW PRESSURE CENTER IN THE SOUTHWESTERN CORNER OF THE AREA...FROM 9N TO 12N BETWEEN 80W AND 81W...AND FROM 9N TO 14N BETWEEN 78W AND 80W. THE ATLANTIC OCEAN... THE MOST RECENT DEEP LAYER TROUGH TO EXIT THE U.S.A. HAS REACHED THE CENTRAL ATLANTIC OCEAN...IN TIME IN ORDER TO SUPPORT THE ALREADY-EXISTING TROUGH AND COLD FRONT. THE COLD FRONT PASSES THROUGH 32N53W TO 24N60W TO THE DOMINICAN REPUBLIC COAST NEAR 19N70W. ISOLATED TO WIDELY SCATTERED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 60 TO 120 NM ON EITHER SIDE OF 23N56W 28N51W BEYOND 32N48W. A 1012 MB LOW PRESSURE CENTER NEAR 28N44W REMAINS OF THE DEEP LAYER CYCLONIC ENVELOPE THAT HAS LASTED FOR NEARLY THE LAST WEEK IN THE CENTRAL ATLANTIC OCEAN. THAT CYCLONIC SYSTEM IS BEING STRETCHED ALONG A NORTHWEST-TO- SOUTHEAST LINE ON WATER VAPOR IMAGERY...FROM 25N28W TO 32N38W. SCATTERED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE FROM 25N TO 32N BETWEEN 27W AND 38W. ANOTHER UPPER LEVEL TROUGH EXTENDS FROM THE CANARY ISLANDS BEYOND 32N29W. ONE SURFACE RIDGE IS ALONG 27N80W 28N66W TO 32N61W. A SURFACE RIDGE IS TO THE EAST OF THE COLD FRONT FROM 23N33W BEYOND 32N28W. $$ MT