000 AXNT20 KNHC 091754 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI OCT 09 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 31W S OF 15N MOVING W NEAR 22 KT. LOW- LEVEL SATELLITE DERIVED WINDS AND AN EARLIER SCATTEROMETER PASS DEPICT CYCLONIC CURVATURE IN THE VICINITY OF THE WAVE AXIS. THIS LOW-LEVEL LIFTING MECHANISM COUPLED WITH AN UPPER LEVEL RIDGE ALOFT E OF 40W PROVIDING UPPER LEVEL DIFFLUENCE IS GENERATING SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 6N-12N BETWEEN 28W-37W. TROPICAL WAVE IS ALONG 63W S OF 18N MOVING W NEAR 18 KT. VISIBLE SATELLITE IMAGERY INDICATES CYCLONIC TURNING IN THE LOW-LEVEL CLOUD FIELD ACROSS THE SE CARIBBEAN NEAR THE WAVE AXIS. A MAXIMUM IN DEEP LAYER MOISTURE IS ALSO NOTED ON TOTAL PRECIPITABLE WATER IMAGERY BETWEEN 58W-66W. ISOLATED MODERATE CONVECTION AND SCATTERED SHOWERS ARE FROM 9N-14N BETWEEN 59W-65W. TROPICAL WAVE IS ALONG 83W S OF 16N MOVING W NEAR 18 KT. THE WAVE LIES IN A BROAD AREA OF DEEP LAYER MOISTURE ACROSS THE SW CARIBBEAN S OF 17N W OF 76W AS OBSERVED IN THE TOTAL PRECIPITABLE WATER IMAGERY. LOCATED BENEATH THE ERN PERIPHERY OF AN UPPER LEVEL LOW LOCATED IN THE E PACIFIC REGION...MOIST SLY DIFFLUENT FLOW ALOFT IS GENERATING SCATTERED MODERATE TO STRONG CONVECTION S OF 17N AND W OF A LINE FROM 17N82W TO THE COAST OF COLOMBIA NEAR 10N76W. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 10N14W 10N30W 9N33W 5N53W. W OF THE AREA OF CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG 63W... SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 200 NM EITHER SIDE OF THE AXIS BETWEEN 33W-46W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED IN THE W ATLC NEAR 30N74W EXTENDS AN UPPER LEVEL RIDGE ACROSS THE STATE OF FLORIDA AND ACROSS THE GULF TO 94W. STRONG SUBSIDENCE AND PLENTY OF DRY AIR IS NOTED ON WATER VAPOR IMAGERY ASSOCIATED WITH THE UPPER LEVEL HIGH. GENERALLY FAIR WEATHER AND CLEAR SKIES ARE NOTED ACROSS A MAJORITY OF THE GULF THIS AFTERNOON. FARTHER WEST...A VIGOROUS UPPER LEVEL TROUGH IS PROGRESSING EWD ACROSS NW MEXICO AND THE SRN PLAINS. THIS TROUGH SUPPORTS A COLD FRONT THAT EXTENDS FROM NERN TEXAS SW TOWARDS THE RIO GRANDE RIVER AND INTO NRN MEXICO NEAR 28N100W. E OF THE FRONTAL BOUNDARY...MOIST SLY RETURN FLOW DOMINATES ACROSS THE GULF WITH SCATTERED SHOWERS AND TSTMS BEGINNING TO ENTER THE NW GULF WATERS FROM THE TEXAS/LOUISIANA BORDER TO NORTH OF BROWNSVILLE TEXAS. THE COLD FRONT IS FORECAST TO STALL SUNDAY FROM LOUISIANA TO THE BAY OF CAMPECHE AND DRIFT NORTH BY EARLY NEXT WEEK. CARIBBEAN SEA... THE NW CARIBBEAN AND MUCH OF THE GREATER ANTILLES ARE UNDER ELY UPPER LEVEL FLOW ON THE SRN PERIPHERY OF A BROAD UPPER LEVEL RIDGE CENTERED IN THE W ATLC. DRY SUBSIDENT AIR IS SUPPORTING GENERALLY FAIR WEATHER N OF 17N W OF 73W WITH ONLY A FEW ISOLATED SHOWERS MOVING ACROSS THE YUCATAN CHANNEL. FARTHER S... AN UPPER LEVEL LOW IS CENTERED IN THE E PACIFIC REGION NEAR 12N90W AND IS PROVIDING THE SW CARIBBEAN WITH MOIST SLY FLOW ALOFT. INSTABILITY COUPLED WITH THE TROPICAL WAVE ALONG 83W ARE GENERATING SCATTERED SHOWERS AND TSTMS S OF 17N AND W OF A LINE FROM 17N82W TO THE COAST OF COLOMBIA NEAR 10N76W. ACROSS THE ERN CARIBBEAN...THE TROPICAL WAVE ALONG 63W AS WELL AS UPPER LEVEL RIDGING E OF 73W IS SUPPORTING THE SCATTERED SHOWERS AND ISOLATED TSTMS E OF 66W AND ACROSS PORTIONS OF THE LESSER ANTILLES. FRESH TO STRONG TRADE WINDS ARE ACROSS MUCH OF THE BASIN WITH THE STRONGEST WINDS LOCATED ALONG THE COAST OF COLOMBIA. ATLANTIC OCEAN... OVER THE W ATLC...AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED NEAR 30N74W AND EXTENDS UPPER LEVEL RIDGING TO 55W. MOSTLY DRY AIR AND STRONG SUBSIDENCE IS NOTED ON WATER VAPOR IMAGERY...HOWEVER THE TAIL END OF A CENTRAL ATLC COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N47W AND EXTENDS WSW ALONG 27N60W TO 26N69W. WITH DRY CONDITIONS ALOFT AND A STABLE ATMOSPHERE IN PLACE OVER THE W ATLC...ONLY ISOLATED SHOWERS REMAIN WITHIN 30 NM EITHER SIDE OF THE FRONT. SIGNIFICANT SHOWERS AND CONVECTION ASSOCIATED WITH THE FRONT ARE HOWEVER LOCATED OVER THE CENTRAL ATLC. AN UPPER LEVEL TROUGH OVER THE CENTRAL ATLC WITH AXIS ALONG 48W N OF 27N SUPPORTS THE COLD FRONT WITH SCATTERED SHOWERS AND TSTMS COVERING THE AREA FROM 24N-32N BETWEEN 43W-53W. SOUTH OF THE COLD FRONT...THE REMNANTS OF HENRI...IS ANALYZED AS A SURFACE TROUGH THAT EXTENDS FROM NERN PUERTO RICO NEAR 18N66W TO 25N60W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE SURFACE TROUGH. THE REMAINDER OF THE CENTRAL AND ERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE OF HIGH PRESSURE. ANCHORED ON A 1024 MB HIGH BETWEEN THE AZORES AND MADEIRA ISLANDS NEAR 37N17W...THE SURFACE RIDGE EXTENDS SW TO A 1018 MB HIGH NEAR 23N44W. $$ HUFFMAN