000 AXPZ20 KNHC 180248 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN OCT 18 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0245 UTC. ...SPECIAL FEATURE... EXTREMELY DANGEROUS CATEGORY FIVE HURRICANE RICK WAS CENTERED NEAR 15.0N 105.9W AT 0300 UTC OR ABOUT 255 NM...475 KM SSW OF MANZANILLO MEXICO OR ABOUT 525 NM...975 KM SSE OF CABO SAN LUCAS MEXICO MOVING WNW AT 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 906 MB. MAXIMUM SUSTAINED WINDS HAVE INCREASED TO 155 KT WITH GUSTS TO 190 KT...MAKING RICK THE SECOND MOST POWERFUL HURRICANE ON RECORD IN THE EAST PACIFIC AFTER HURRICANE LINDA OF 1997. RICK CONTINUES TO UNDERGO RAPID INTENSIFICATION WITH A WELL DEFINED EYE SURROUNDED BY A 105 NM WIDE RING OF VERY COLD TOP CONVECTION. THE EYE DIAMETER IS ESTIMATED TO BE 10-15 NM. IN ADDITION OUTER RAIN BANDS FEEDING INTO THE CORE OF RICK CONSIST OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 60-75 NM EITHER SIDE OF 11N110W TO 10N105W TO 12N104W...AND WITHIN 75 NM EITHER SIDE OF 11N101W TO 13N101W TO 16N102W. RICK IS A LARGE HURRICANE WITH AN AREA OF 20 TO 33 KT WINDS FOUND UP TO 360 NM IN THE E AND 210 NM IN THE W SEMICIRCLES WITH SEAS TO 50 FT NEAR THE CORE OF THE STORM. ATMOSPHERIC CONDITIONS ARE FAVORABLE FOR THE CYCLONE TO CONTINUE TO UNDERGO ADDITIONAL INTENSIFICATION UNDER A RATHER LOW VERTICAL WIND SHEAR ENVIRONMENT ALONG WITH VERY CONDUCIVE SEA SURFACE TEMPERATURES THROUGH THE NEXT 12-24 HOURS AS IT TRACKS WNW. SEE THE LATEST NHC FORECAST ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 120W FROM 6N-17N IS MOVING W AT ABOUT 13 KT. SCATTERED MODERATE CONVECTION IS MAINLY OVER THE SOUTHERN PORTION OF THE WAVE AXIS AN ABOUT 180 NM S OF THE ITCZ FROM 7N-10N BETWEEN 115W-122W. ...ITCZ... THE AXIS OF THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 08N78W TO 13N101W TO 11N111W TO 13N125W TO 10N140W. SCATTERED MODERATE WITHIN 120 NM N OF AXIS W OF 130W....AND WITHIN 180 NM S OF AXIS BETWEEN 115W AND 122W. ...DISCUSSION... W OF 120W... A DEEP LAYER RIDGE WITH A MEAN CENTER NEAR 15N141W DOMINATES THE W PORTION OF THE AREA WITH AN ELONGATED SURFACE 1022 MB HIGH NEAR 32N140W. THE SOUTHERN EXTENT OF A BROAD DEEP LAYER TROUGH HAS ENTERED THE FAR NW PORTION OF THE AREA WITH AXIS ALONG 32N132W TO 26N140W...AND IS MOVING E 20 KT. ASSOCIATED WEAKENING SURFACE COLD FRONT HAS ENTERED THE AREA AND EXTENDS FROM 32N134W TO 29N140W WHERE IT BECOMES STATIONARY W OF THE AREA. THE TROUGH IS FORECAST TO BROADEN AND SLOWLY LIFT NE THROUGH THE NEXT 36-48 HOURS AS THE SURFACE FRONT CONTINUES TO WEAKEN...DISSIPATING BY EARLY SUN. PATCHES OF SCATTERED TO BROKEN STRATOCUMULUS CLOUDS MOVING WSW ARE N OF 20N UNDER STABLE ENVIRONMENTAL CONDITIONS. THE PRES GRADIENT BETWEEN BROAD LOW PRES S OF 15N W OF 130W AND HIGH PRES TO THE N IS RESULTING IN NE-E WINDS TRADES OF 20 KT FROM 12N TO 21N W OF 132W WITH SEAS UP TO 9 FT. E OF 120W... A MID/UPPER LEVEL TROUGH EXTENDS FROM S CALIFORNIA S INTO THE AREA TO 28N119W TO NEAR 21N121W. MODERATE SUBSIDENCE SUPPORTING DRY AND STABLE CONDITIONS NOTED BY A LAYER OF OVERCAST STRATOCUMULUS CLOUDS IS NW OF LINE FROM 28N115W TO 21N120W. A SMALL UPPER LEVEL CYCLONIC CIRCULATION MOVING E 17 KT IS ON THE TROUGH NEAR 30N. DEEP LAYER RIDGING WAS NOTED OVER W MEXICO N OF 17N WITH THE ASSOCIATED ELONGATED ANTICYCLONE ANCHORED JUST TO THE NE OF HURRICANE RICK NEAR 19N103W. WITH RICK ALONG THE SOUTHERN PERIPHERY OF THE RIDGE...INTENSE CONVECTION IN OUTER RAIN BANDS RELATED TO RICK WILL REMAIN VERY ACTIVE THROUGH THE NEXT 48 HOURS. THE RIDGE IS FORECAST TO WEAKEN AFTER SUN AS THE AFOREMENTIONED TROUGH PROGRESSES LIFTS NE WHILE WEAKENING ACROSS THE WESTERN U.S. GAP WINDS... THE SOUTHERN EXTENT OF A SHARP UPPER LEVEL TROUGH IS NE OF THE AREA OVER THE GULF OF MEXICO...AND HAS PUSHED A STRONG COLD FRONT INTO THE THE BAY OF CAMPECHE. STRONG HIGH PRES IN ITS WAKE ARE USHERING IN NORTHERLY WINDS THROUGH THE ISTHMUS OF TEHUANTEPEC WITH N TO NE WINDS OF GALE FORCE OCCURRING. WINDS ARE EXPECTED TO FURTHER INCREASE TO STORM FORCE 45-50 KT BY SUN EVENING. GALE FORCE WINDS ARE EXPECTED TO PERSIST THROUGH 48 HOURS. $$ COBB