000 AXNT20 KNHC 041118 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST TUE NOV 04 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...SPECIAL FEATURE... IN THE W CARIBBEAN...A SURFACE TROUGH EXTENDS FROM A 1008 MB SURFACE LOW IN THE SW CARIBBEAN NEAR 13N81W TO 15N79W TO 18N78W. LOW LEVEL CONVERGENCE NEAR THE LOW AND TROUGH...COMBINED WITH DEEP MOISTURE AND UPPER LEVEL DIVERGENCE OVER THE W CARIBBEAN... IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS FROM 13N-19N BETWEEN 77W-82W...WITH ISOLATED SHOWERS AND THUNDERSTORMS S OF 11N W OF 80W. THIS ACTIVITY IS BECOMING SLIGHTLY BETTER ORGANIZED...AND ADDITIONAL SLOW DEVELOPMENT OF THIS SYSTEM IS POSSIBLE OVER THE NEXT COUPLE OF DAYS. ...THE ITCZ... ITCZ AXIS IS ANALYZED ALONG 10N13W 7N22W 4N35W 3N43W 3N53W. ISOLATED MODERATE CONVECTION IS FROM 1N-6N BETWEEN 11W-23W... WHICH IS BEING ENHANCED BY WEAK UPPER LEVEL DIFFLUENCE. SCATTERED MODERATE CONVECTION IS S OF 14N BETWEEN 25W-39W... WHICH IS BEING ENHANCED BY STRONG UPPER LEVEL DIFFLUENCE. ...DISCUSSION... GULF OF MEXICO... WEST-SOUTHWESTERLY FLOW ALOFT COVERS MUCH OF THE GULF...WHERE DEEP LAYER DRY AIR AND SUBSIDENCE ARE GENERALLY IN PLACE. A SURFACE RIDGE OF HIGH PRESSURE OVER THE SE CONUS EXTENDS INTO THE GULF...FURTHER ENHANCING THE SUBSIDENCE. AS A RESULT...STABLE ATMOSPHERIC CONDITIONS AND GENERALLY FAIR WEATHER CONDITIONS ARE PRESENT ACROSS THE GULF REGION. CARIBBEAN SEA... AN UPPER LEVEL HIGH IS OVER THE E CARIBBEAN NEAR 15N68W...WITH THE ANTICYCLONIC FLOW AROUND THE HIGH COVERING MUCH OF THE CARIBBEAN. DEEP MOISTURE AND UPPER LEVEL DIVERGENCE W OF THE HIGH...AS WELL AS LOW LEVEL CONVERGENCE AROUND A SURFACE LOW AND SURFACE TROUGH IN THE W CARIBBEAN...ARE SUPPORTING SHOWERS AND THUNDERSTORMS OVER THE W CARIBBEAN. PLEASE SEE THE SPECIAL FEATURE SECTION ABOVE FOR MORE INFORMATION ON THIS SYSTEM. FARTHER TO THE E...UPPER LEVEL DIVERGENCE SW OF THE UPPER HIGH IS SUPPORTING ISOLATED MODERATE CONVECTION FROM 12N-14N BETWEEN 72W-75W. DEEP LAYER DRY AIR E OF THE UPPER HIGH IS RESULTING IN MAINLY FAIR WEATHER CONDITIONS ACROSS THE E CARIBBEAN. ALSO... DEEP LAYER DRY AIR OVER THE GULF OF MEXICO IS MOVING INTO THE FAR NW CARIBBEAN. ATLANTIC OCEAN... STRONG SOUTHWESTERLY FLOW ALOFT E OF AN UPPER TROUGH AXIS OVER THE E CONUS IS ENHANCING UPPER LEVEL DIVERGENCE AND DEEP ATMOSPHERIC LIFT OVER PORTIONS OF THE W ATLC. ALSO...A 1013 MB SURFACE LOW IS CENTERED E OF THE BAHAMAS NEAR 27N76W. AN OCCLUDED FRONT EXTENDS FROM THE LOW TO 25N74W...WHERE THE OCCLUDED FRONT INTERSECTS BOTH A STATIONARY FRONT AND A COLD FRONT. THE STATIONARY FRONT EXTENDS FROM 25N74W TO 23N66W TO 19N60W. THE COLD FRONT EXTENDS FROM 25N74W TO 20N75W. ADDITIONALLY...TO THE NW OF THE LOW...A SURFACE TROUGH EXTENDS FROM 27N76W TO 32N78W AND EXTENDS NE OF THE DISCUSSION AREA. TO THE S OF THE LOW...A SURFACE TROUGH EXTENDS FROM 27N76W TO 21N77W. LOW LEVEL CONVERGENCE IS FURTHER ENHANCING THE DEEP ATMOSPHERIC LIFT NEAR THE SURFACE FRONTS...TROUGHS...AND LOW... WHERE DEEP MOISTURE IS MOVING NORTHEASTWARD FROM THE W CARIBBEAN. AS A RESULT...SCATTERED MODERATE CONVECTION IS ALONG AND N OF THE STATIONARY FRONT BETWEEN 61W-73W...WITH ISOLATED MODERATE CONVECTION FROM 21N-30N BETWEEN 72W-77W. FARTHER TO THE E...AN UPPER LEVEL TROUGH IS PRESENT WITH AN AXIS THAT EXTENDS FROM 4N47W TO 16N42W TO 32N43W. THIS UPPER TROUGH IS ACCOMPANIED BY A SURFACE TROUGH THAT EXTENDS FROM 21N46W TO 17N47W TO 14N47W. THIS SURFACE TROUGH IS ENHANCING ISOLATED MODERATE CONVECTION FROM 14N-17N BETWEEN 41W-47W. THE UPPER TROUGH IS ACCOMPANIED BY ANOTHER SURFACE TROUGH EXTENDING FROM 27N47W TO 31N44W...WITH A COLD FRONT EXTENDING FROM 31N44W TO NE OF THE DISCUSSION AREA...WITH ISOLATED SHOWERS N OF 23N BETWEEN 35W-44W. ALSO...AN UPPER RIDGE AXIS EXTENDS FROM 15N16W TO 20N23W TO 30N23W...WITH ASSOCIATED UPPER LEVEL DIFFLUENCE S OF THE RIDGE AXIS ENHANCING THE CONVECTION IN THE VICINITY OF THE ITCZ AXIS. $$ COHEN