000 AXNT20 KNHC 161754 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI OCT 16 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 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 73W S OF 17N MOVING W NEAR 15 KT. THE WAVE REMAINS EMBEDDED WITHIN AN AREA OF DEEP LAYERED MOISTURE AS INDICATED IN THE TOTAL PRECIPITABLE WATER IMAGERY ACROSS THE CENTRAL CARIBBEAN. VISIBLE SATELLITE IMAGERY SHOWS CYCLONIC CURVATURE IN THE LOW-LEVEL CLOUD FIELD IN THE VICINITY OF THE WAVE AXIS WITH SCATTERED SHOWERS AND ISOLATED TSTMS FROM 13N-17N BETWEEN 71W-75W. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 9N13W 7N27W 8N41W 7N45W 11N59W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ ALONG 43W FROM 5N-11N. SCATTERED TO NUMEROUS MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-11N BETWEEN 39W-47W. A SECOND SURFACE TROUGH IS ALONG 60W APPROACHING THE LESSER ANTILLES FROM 10N-16N. SCATTERED MODERATE CONVECTION IS FROM 9N-15N BETWEEN 55W-62W. ELSEWHERE...CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 4N-11N BETWEEN 20W-39W. A SIMILAR AREA OF CONVECTION IS ALONG THE W AFRICA COAST FROM 5N-9N BETWEEN 11W-16W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE IS ANCHORED OVER CENTRAL MEXICO COVERING THE SW GULF AND BAY OF CAMPECHE WHILE BROAD UPPER LEVEL TROUGHING DIPS OVER THE N/CENTRAL AND NE GULF TO 25N. THIS LONGWAVE TROUGHING SUPPORTS A COLD FRONT THAT AT 1500 UTC ENTERS THE GULF OVER THE BIG BEND REGION OF FLORIDA NEAR 30N84W AND EXTENDS SW ALONG 27N90W TO NEAR BROWNSVILLE TEXAS AND INTO NE MEXICO AS A STATIONARY BOUNDARY TO 27N104W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 90 NM EITHER SIDE OF THE FRONT W OF 90W WHILE SCATTERED SHOWERS AND TSTMS ARE WITHIN 150 NM EITHER SIDE OF THE FRONT E OF 90W TO INLAND OVER INTERIOR PORTIONS OF THE CENTRAL FLORIDA PENINSULA. BEHIND THE COLD FRONT...NLY WINDS UP TO 25 KT ARE EXPECTED TO CONTINUE SPREADING OVER THE NW AND N/CENTRAL GULF THIS AFTERNOON INTO THE EVENING. ELSEWHERE ACROSS THE REMAINDER OF THE GULF S OF THE FRONT... GENERALLY CLEAR SKIES WITH LIGHT WINDS ARE OBSERVED S OF 24N. CARIBBEAN SEA... UPPER LEVEL TROUGHING IS ANCHORED OVER PORTIONS OF CENTRAL AMERICA AND THE NW CARIBBEAN WITH MODERATE TO STRONG SUBSIDENCE AND DRY AIR NOTED ON WATER VAPOR IMAGERY W OF 80W. THIS UPPER LEVEL TROUGH EXTENDS AN AXIS FROM NICARAGUA NE ALONG 15N80W TO NEAR PUERTO RICO WITH POSSIBLE ISOLATED SHOWERS OVER JAMAICA... HISPANIOLA...PUERTO RICO AND ADJACENT COASTAL WATERS N OF 17N BETWEEN 66W-80W. THE REMAINDER OF THE CARIBBEAN BASIN E OF THE TROPICAL WAVE ALONG 73W...IS UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE S OF 17N. MOIST SWLY UPPER LEVEL FLOW E OF 70W IS DRAWING MIDDLE TO UPPER LEVEL TROPICAL MOISTURE OVER THE SE CARIBBEAN. THIS MOISTURE AND INSTABILITY COUPLED WITH A SURFACE TROUGH ALONG 60W E OF THE LESSER ANTILLES...IS GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS S OF 15N E OF 67W. ATLANTIC OCEAN... A BROAD UPPER LEVEL LONGWAVE TROUGH IS OVER THE ERN CONUS AND DIPS OVER THE FLORIDA PENINSULA AS WELL AS PORTIONS OF THE FAR W ATLC. THE ASSOCIATED SURFACE STATIONARY FRONT LIES ALONG 32N FROM 70W TO A 1005 MB LOW CENTERED OVER SE GEORGIA. LOW-LEVEL CONVERGENCE S OF THE FRONT AS WELL AS UPPER LEVEL DIFFLUENCE E OF THE UPPER TROUGH AXIS IS GENERATING SCATTERED SHOWERS AND TSTMS N OF 27N W OF 68W. FURTHER E...A BROAD UPPER LEVEL RIDGE REMAINS OVER THE CENTRAL ATLC ANCHORED NEAR 24N58W EXTENDING A RIDGE AXIS E-W ALONG 24N BETWEEN 45W TO 80W. A CENTRAL ATLC UPPER LEVEL TROUGH REMAINS LARGELY NORTH OF THE REGION...BUT EXTENDS A TROUGH AXIS ALONG 32N43W TO 30N50W. THIS UPPER LEVEL TROUGH SUPPORTS A COLD FRONT THAT ENTERS THE REGION NEAR 32N39W CONTINUING SSW ALONG 28N42W TO 26N49W. SCATTERED SHOWERS AND POSSIBLE ISOLATED TSTMS ARE WITHIN 90 NM EITHER SIDE OF THE FRONT. THE ERN ATLC IS DOMINATED BY UPPER LEVEL TROUGHING ANCHORED ON AN UPPER LOW CENTERED NEAR 26N27W. A 1014 MB LOW IS NEAR 27N30W WITH A SURFACE TROUGH ANALYZED FROM 28N26W TO 22N28W WELL E OF THE SURFACE LOW. ISOLATED SHOWERS ARE WITHIN 30 NM OF THE SURFACE TROUGH AND FROM 25N-29N BETWEEN 22W-26W. $$ HUFFMAN