000 AXPZ20 KNHC 172148 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT OCT 17 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2115 UTC. ...SPECIAL FEATURE... VERY DANGEROUS AND POTENT HURRICANE RICK WAS CENTERED NEAR 14.8N 104.5W AT 2100 UTC OR ABOUT 290 NM...470 KM S OF MANZANILLO MEXICO WHICH IS ALSO ABOUT 660 NM SSE OF CABO SAN LUCAS MEXICO MOVING WNW AT 13 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 948 MB. MAXIMUM SUSTAINED WINDS HAVE INCREASED TO 130 KT WITH GUSTS TO 160 KT. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. RICK CONTINUES TO BLOSSOM WITH RESPECT TO ITS OVERALL VERY SYMMETRICAL CLOUD PATTERN WITH TIGHT WRAPPING AROUND THE NOW VERY DISCERNIBLE SMALL EYE WITH A DIAMETER OF 10 NM AS AS WAS OBSERVED IN LATEST BOTH VISIBLE AND IR SATELLITE IMAGERY. RICK IS ALSO CHARACTERIZED BY A VERY LARGE AND DENSE CORE OF CONVECTION AROUND THE EYE CONSISTING OF NUMEROUS STRONG CONVECTION WITHIN 90 NM IN THE W SEMICIRCLE AND 75 NM IN THE SE QUADRANT. OUTER RAIN BANDS FEEDING INTO THE CORE OF RICK CONSISTS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 75 NM EITHER SIDE OF 9N108W TO 11N105W TO 12N103W...AND WITHIN 45 NM EITHER SIDE OF 19N99W TO 12N101W TO 16N102W TO 17N103W. A BAND CLOSER TO THE NW QUADRANT IS MADE UP SCATTERED STRONG TO NUMEROUS CONVECTION WITHIN 30 NM EITHER SIDE OF 18N105W TO 16N107W. SATELLITE IMAGERY SHOWS VERY GOOD OUTFLOW IN QUADRANTS OF RICK. WITH SO A LARGE RADII OF TROPICAL STORM FORCE WINDS EXTENDING OUTWARD FROM RICK...20 TO 33 KT WINDS CAN BE FOUND UP TO 360 NM IN THE E AND 210 NM IN THE W SEMICIRCLES WITH SEAS 8 TO 12 FT. ATMOSPHERIC CONDITIONS ARE FAVORABLE FOR THE CYCLONE TO CONTINUE TO UNDERGO INTENSIFICATION UNDER A RATHER LOW VERTICAL WIND SHEAR ENVIRONMENT ALONG WITH VERY CONDUCIVE SEA SURFACE TEMPERATURES THROUGH AT LEAST THE NEXT 18-24 HOURS AS IT TRACKS WNW. RICK IS THEN FORECAST TO BEGIN WEAKEN AS IT ENCOUNTERS A GRADUAL COOLING OF SEA SURFACE TEMPERATURES. ...TROPICAL WAVE... A TROPICAL WAVE IS ALONG 119W FROM 6N-17N IS MOVING W AT ABOUT 13 KT. SCATTERED MODERATE CONVECTION IS MAINLY OVER AND NEAR THE SOUTHERN PORTION OF THE WAVE AXIS WELL S OF THE ITCZ FROM 6N-9N BETWEEN 114W-119W. ISOLATED SHOWERS AND TSTMS ARE WITHIN 180 NM E OF THE WAVE FROM 12N-17N. ...ITCZ... THE AXIS OF THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 8N81W TO 12N100W TO 11N110W TO 13N125W TO 11N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM S OF THE AXIS W OF 132W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM N AND 120 NM S OF THE AXIS BETWEEN 115W-127W. ...DISCUSSION... W OF 120W... A DEEP LAYER RIDGE WITH A MEAN CENTER NEAR 16N140W DOMINATES THIS PORTION OF THE AREA WITH A SURFACE 1020 MB HIGH NEAR 30N132W. A LARGE DEEP LAYER TROUGH HAS ENTERED THE FAR NW PORTION OF THE AREA WITH ITS MEAN AXIS STRETCHING FROM 32N137W TO SW OF THE AREA AT 28N140W...AND IS MOVING E ABOUT 20 KT. ITS ASSOCIATED WEAKENING SURFACE COLD FRONT HAS ALSO ENTERED THE AREA...AND EXTENDS FROM 32N134W TO 29N140W WHERE IT BECOMES STATIONARY SW 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 TONIGHT INTO SUN MORNING. AN INVERTED MID/UPPER LEVEL TROUGH IS ALONG 14N124W TO 10N125W TO 7N126W...AND MAY BE AIDING ITCZ CONVECTION BETWEEN 124W-127W. 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 OF 20-25 KT FROM 12N TO 21N W OF 132W WITH SEAS UP TO 9 FT. THE 1020 MB HIGH IS FORECAST TO MOVE SW TO NEAR 28N128W IN 24 HOURS WITH RIDGING ALONG 28N. RIDGE ALSO BUILDS ALOFT OVER THE FAR NW PART OF THE AREA OVER THE NEXT 48 HOURS. 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 28N15W 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 19N102W. 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. A MID/UPPER LEVEL INVERTED TROUGH MOVING W ABOUT 17 KT EXTENDS FROM NORTHERN HONDURAS SSW TO A MID/UPPER LEVEL CYCLONIC CIRCULATION NEAR 12N90W...BUT SINCE IT IS EMBEDDED IN MODERATE SUBSIDENCE ONLY ISOLATED SHOWERS AND WEAK TSTMS ARE NOTED N OF THE ITCZ FROM 9N TO 11N BETWEEN 89W AND 92W. GAP WINDS... THE SOUTHERN PORTION OF A LARGE DEEP LAYER TROUGH IS E OF THE AREA OVER THE NORTHERN GULF OF MEXICO...AND HAS PUSHED A RATHER STRONG AUTUMN COLD FRONT INTO THE THE BAY OF CAMPECHE. STRONG HIGH PRES IN ITS WAKE WILL USHER NORTHERLY WINDS THROUGH THE ISTHMUS OF TEHUANTEPEC BY LATE TONIGHT...WITH N TO NE WINDS INCREASING TO 25-35 KT... AND TO N-NE 35-45 KT BY SUN AFTERNOON WITHIN 45 NM EITHER SIDE OF A LINE FROM 16N95W TO 13N97W...THEN TO 40 TO 50 KT BY EARLY SAT NIGHT WITHIN 45 NM EITHER SIDE OF A LINE FROM 16N95W TO 13N97W WITH SEAS FORECAST TO BUILD INTO THE RANGE OF 10-16 FT THROUGH MON. ELSEWHERE WITHIN 90 NM EITHER SIDE OF A LINE FROM 16N95W TO 12N98W N-NE WINDS ARE FORECAST TO INCREASE TO 20-30 KT WITH SEAS BUILDING 8-11 FT BY SUN AFTERNOON AND CONTINUE INTO MON AFTERNOON PER LATEST MODEL GUIDANCE. $$ AGUIRRE