000 AXNT20 KNHC 171155 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN OCT 17 2010 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 1015 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 11N20W 07N28W 11N36W THEN RESUMES 06N47W 03N55W. A SURFACE TROUGH LOCATES OFFSHORE OF W AFRICA ANALYZED FROM 11N20W TO 23N16W. LOW-LEVEL CYCLONIC FLOW IS FOCUSED IN THE VICINITY OF THE TROUGH AXIS AND SUPPORTS SCATTERED MODERATE CONVECTION FROM 08N-18N BETWEEN 17W-21W AND WITHIN 120 NM EAST OF THE TROUGH AXIS N OF 19N. ANOTHER SURFACE TROUGH IS ANALYZED OVER THE CENTRAL TROPICAL ATLC FROM 05N46W TO A 1008 MB LOW NEAR 12N38W TO 18N35W AND IS EMBEDDED WITHIN A MONSOONAL GYRE BETWEEN 35W-45W. TOTAL PRECIPITABLE WATER IMAGERY INDICATES A BROAD AREA OF LOW-LEVEL MOISTURE POOLING IN THE VICINITY OF THE SURFACE TROUGH GENERATING SCATTERED MODERATE AND ISOLATED STRONG CONVECTION FROM 07N-13N BETWEEN 32W-41W...MAINLY E OF THE TROUGH AXIS. ELSEWHERE NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS FROM 01N-09N BETWEEN 22W-33W. SCATTERED MODERATE CONVECTION IS ALSO FROM 10N-14N BETWEEN 20W-26W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE AXIS EXTENDS FROM THE NW CARIBBEAN TO THE ARKLATEX REGION AND ALONG WITH RELATIVELY DRY SOUTHWESTERLY FLOW ALOFT ACROSS THE GULF...A STABLE ATMOSPHERIC ENVIRONMENT PERSISTS. THIS UPPER LEVEL PATTERN IS SUPPORTING A 1022 MB HIGH CENTERED OVER THE NORTH-CENTRAL GULF NEAR 28N91W THAT IS PROVIDING THE BASIN WITH MOSTLY NE WINDS UP TO 15 KT AND OVERALL CLEAR SKIES THIS MORNING...HOWEVER...SCATTERED TO BROKEN STRATOCUMULUS CLOUDS ARE NOTED ON SATELLITE IMAGERY FROM 23N-27N BETWEEN 86W-92W. THE FAIR WEATHER CONDITIONS ARE FORECAST TO CONTINUE OVER THE NEXT FEW DAYS AS THE SURFACE RIDGE TRANSLATES E-NE ALONG THE GULF COAST LOCATING OVER THE W ATLC BY EARLY MONDAY. HINTS OF SOUTHERLY RETURN FLOW WILL ONCE AGAIN APPEAR BY MONDAY OVER THE FAR WESTERN GULF WATERS SE OF LINGERING LOW PRESSURE OVER THE SOUTHERN PLAINS. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE CENTRAL CARIBBEAN NEAR 17N75W AND EXTENDS AN UPPER LEVEL RIDGE AXIS WESTWARD TO THE YUCATAN PENINSULA. WITHIN THE SOUTHWESTERN PERIPHERY OF THE UPPER HIGH...A DIFFLUENT PATTERN IN THE MIDDLE TO UPPER LEVELS OF THE ATMOSPHERE IS NOTED ON WATER VAPOR IMAGERY THAT CONTINUES TO ADVECT MOISTURE OVER PORTIONS OF THE SW CARIBBEAN AND CENTRAL AMERICA S OF 18N W OF 75W. EASTERLY TRADES AND NORTHERLY WINDS OVER THE NW CARIBBEAN ARE CONVERGING OVER THE SW CARIBBEAN WITHIN A LOW-LEVEL CYCLONIC AREA FOCUSED ALONG A SURFACE TROUGH ANALYZED FROM 15N77W TO A 1011 MB LOW CENTERED NEAR 10N81W. SCATTERED SHOWERS AND TSTMS REMAIN DISORGANIZED BUT ARE OCCURRING OVER THE AREA FROM 11N-15N BETWEEN 75W-82W. OTHER ISOLATED CONVECTION IS CONFINED S OF 17N W OF 73W. GIVEN THE CURRENT ANALYSIS...AND INDICATION FROM MANY OF THE GLOBAL MODELS...THIS AREA OF LOW PRESSURE OVER THE SW CARIBBEAN WILL PERSIST AND DRIFT W-NW OVER THE NEXT 24-48 HOURS WHILE CONTINUING TO BRING A HIGHER CHANCE OF PRECIPITATION TO WESTERN PANAMA...COSTA RICA...NICARAGUA...HONDURAS...AND THE ADJACENT COASTAL WATERS THROUGH MID-WEEK. ELSEWHERE E OF 75W...DRY NORTHERLY FLOW ALOFT IS PROVIDING FOR STABLE AND DRY CONDITIONS...HOWEVER AN UPPER LEVEL LOW IS CENTERED NEAR 16N61W THAT WILL CONTINUE TO PROVIDE A FOCUS FOR ISOLATED SHOWER ACTIVITY OVER THE NE CARIBBEAN...AND LESSER ANTILLES THROUGH MUCH OF THE UPCOMING WEEK AHEAD AS THE UPPER LOW REMAINS NEARLY STATIONARY. FINALLY...A PRE-FRONTAL TROUGH IS ANALYZED OVER SOUTHERN PORTIONS OF THE SW NORTH ATLC AND ACROSS HISPANIOLA TO NEAR 19N72W THIS MORNING. ISOLATED SHOWERS ARE OCCURRING FROM 17N-20N BETWEEN 68W-74W. ATLANTIC OCEAN... AN UPPER LEVEL LOW CENTERED OVER NOVA SCOTIA CANADA EXTENDS AN UPPER LEVEL TROUGH AXIS ALONG 40N60W TO 32N53W. THIS NEGATIVELY TILTED TROUGH SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N54W EXTENDING SW TO 24N67W BECOMING STATIONARY AND INTO THE REMNANT CIRCULATION OF PAULA...A 1015 MB LOW...CENTERED NEAR 21N76W. WHILE NO SIGNIFICANT DEEP CONVECTION IS ASSOCIATED WITH THE FRONT OR REMNANT LOW...SCATTERED SHOWERS ARE WITHIN 180 NM E OF THE COLD FRONT N OF 26N...AND WITHIN 90 NM EITHER SIDE OF THE STATIONARY FRONT. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM 23N64W SW TO HISPANIOLA WITH ISOLATED SHOWERS OCCURRING MAINLY OVER HISPANIOLA FROM 17N-20N BETWEEN 68W-74W. STRONG WESTERLY UPPER LEVEL FLOW IS NOTED BEHIND THE FRONT FEEDING INTO THE BASE OF THE WESTERN NORTH ATLC UPPER LEVEL TROUGH THAT CONTINUES TO SUPPORT STRONG SUBSIDENCE AND DRY AIR OVER MUCH OF THE SW NORTH ATLC...WHICH IN TURN SUPPORTS SURFACE RIDGING ANCHORED ON A 1021 MB HIGH CENTERED OVER THE SE CONUS. FARTHER EAST...A SHARP UPPER LEVEL TROUGH IS LOCATED ACROSS THE EASTERN ATLC WITH AXIS ALONG 30W THAT DIPS SOUTHWARD TO 10N. THIS TROUGH SUPPORTS A BROAD AREA OF SURFACE LOW PRESSURE N OF 25N BETWEEN 25W-42W ANCHORED BY A 1010 MB LOW CENTERED NEAR 33N29W. A SURFACE TROUGH MEANDERS FROM THE LOW ALONG 32N27W 25N36W 22N43W TO 23N49W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 120 NM EAST OF THE SURFACE TROUGH BETWEEN 28W-34W... WHILE POSSIBLE ISOLATED SHOWERS LINGER WITHIN 90 NM EITHER SIDE OF THE BOUNDARY BETWEEN 41W-49W. ELSEWHERE OVER THE REMAINDER OF THE EASTERN ATLC...WEAK SURFACE RIDGING ASSOCIATED WITH A 1015 MB HIGH CENTERED NEAR 28N21W COVERS THE FAR E ATLC AND SUPPORTS OVERALL STABLE CONDITIONS N OF 18N SE OF A LINE FROM 32N20W TO 18N38W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN