000 AXNT20 KNHC 170552 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 08N21W 09N38W 07N41W 07N59W. A SURFACE TROUGH LOCATES OFFSHORE OF W AFRICA ANALYZED FROM 09N20W TO 18N17W. LOW-LEVEL CYCLONIC FLOW IS FOCUSED IN THE VICINITY OF THE TROUGH AXIS AND SUPPORTS SCATTERED MODERATE CONVECTION FROM 03N-12N BETWEEN 18W-24W AND WITHIN 120 NM EITHER SIDE OF THE TROUGH AXIS N OF 12N. ANOTHER SURFACE TROUGH IS ANALYZED OVER THE CENTRAL TROPICAL ATLC FROM 07N40W TO 14N38W AND IS EMBEDDED WITHIN A MONSOONAL GYRE BETWEEN 35W-43W. TOTAL PRECIPITABLE WATER IMAGERY INDICATES A BROAD AREA OF LOW-LEVEL MOISTURE POOLING IN THE VICINITY OF THE SURFACE TROUGH GENERATING ISOLATED MODERATE CONVECTION FROM 06N-13N BETWEEN 33W-40W. ELSEWHERE SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 01N-08N BETWEEN 24W-35W. ...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 1021 MB HIGH CENTERED OVER THE NW GULF NEAR 29N92W THAT IS PROVIDING THE BASIN WITH MOSTLY NE WINDS UP TO 15 KT AND OVERALL CLEAR SKIES FOR THE OVERNIGHT PERIOD. THE FAIR WEATHER CONDITIONS ARE FORECAST TO CONTINUE OVER THE NEXT FEW DAYS AS THE SURFACE RIDGE TRANSLATES EASTWARD 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 HISPANIOLA NEAR 19N72W 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 14N77W TO A 1012 MB LOW CENTERED NEAR 09N81W. SCATTERED SHOWERS AND ISOLATED TSTMS REMAIN DISORGANIZED BUT ARE OCCURRING OVER THE AREA S OF 17N W OF 75W. GIVEN THE CURRENT ANALYSIS...AND INDICATION FROM MANY OF THE GLOBAL MODELS...THIS AREA OF LOW PRESSURE OVER THE SW CARIBBEAN WILL PERSIST AND CONTINUE 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 16N60W 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. ATLANTIC OCEAN... AN UPPER LEVEL LOW CENTERED OVER NOVA SCOTIA CANADA EXTENDS AN UPPER LEVEL TROUGH AXIS ALONG 62W TO 30N60W. THIS SLIGHTLY NEGATIVELY TILTED TROUGH SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N55W EXTENDING SW TO 25N65W THEN INTO THE REMNANT CIRCULATION OF PAULA...A 1012 MB LOW...CENTERED NEAR 23N77W. WHILE NO SIGNIFICANT DEEP CONVECTION IS ASSOCIATED WITH THE FRONT OR REMNANT LOW...SCATTERED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE FRONT AND FROM 21N-23N BETWEEN 75W-77W IN ASSOCIATION WITH THE REMNANT LOW. STRONG WESTERLY UPPER LEVEL FLOW IS NOTED BEHIND THE FRONT FEEDING INTO THE BASE OF THE 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 TO 10N. THIS TROUGH SUPPORTS A BROAD AREA OF SURFACE LOW PRESSURE N OF 25N BETWEEN 25W-40W ANCHORED BY A 1010 MB LOW CENTERED NEAR 33N30W. A SURFACE TROUGH MEANDERS FROM THE LOW ALONG 31N27W 25N35W 22N44W THEN INTO A WEAK 1013 MB LOW CENTERED NEAR 24N50W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 60 NM EITHER SIDE OF THE SURFACE TROUGH BETWEEN 28W-34W...WHILE POSSIBLE ISOLATED SHOWERS LINGER WITHIN 90 NM EITHER SIDE OF THE BOUNDARY BETWEEN 42W-50W. ELSEWHERE OVER THE REMAINDER OF THE EASTERN ATLC...WEAK SURFACE RIDGING ASSOCIATED WITH A 1015 MB HIGH CENTERED NEAR 26N22W COVERS THE FAR E ATLC AND SUPPORTS OVERALL STABLE CONDITIONS N OF 18N SE OF A LINE FROM 32N20W TO 18N40W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN