000 AXPZ20 KNHC 171603 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SAT OCT 17 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1545 UTC. ...SPECIAL FEATURE... HURRICANE RICK WAS CENTERED NEAR 14.2N 103.0W AT 1500 UTC OR ABOUT 280 NM...450 KM SW OF ACAPULCO MEXICO WHICH IS ALSO ABOUT 345 NM SSE OF MANZANILLO MEXICO MOVING WNW AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 938 MB. MAXIMUM SUSTAINED WINDS HAVE INCREASED TO 125 KT WITH GUSTS TO 150 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 DISCERNIBLE EYE FEATURE AS OBSERVED IN LATEST VISIBLE AND IR SATELLITE IMAGERY. THE BANDS ARE COMPRISED OF NUMEROUS MODERATE CONVECTION WITHIN 60 NM EITHER SIDE OF 14N106W TO 12N105W TO 13N103W...WITHIN 30 NM EITHER SIDE OF 16N105W TO 14N106W AND FROM 13N103W TO 14N102W TO 15N103W. NUMEROUS MODERATE TO STRONG CONVECTION IS TIGHTLY WRAPPED AROUND THE CENTER WITHIN 90 NM IN THE WESTERN SEMICIRCLE. AN OTHER BAND TO THE SE OF THE CENTER IS WITHIN 30 NM EITHER SIDE OF THE LINE FROM 10N99W TO 13N100W TO 14N102W. AN AREA OF NUMEROUS STRONG CONVECTION NW OF RICK...BUT MOVING SW AS IT RESPONSES TO THE LARGE CYCLONIC CIRCULATION AROUND RICK IS WITHIN 60 NM EITHER SIDE OF THE LINE FROM 16N108W TO 18N108W WHERE IT THEN BECOMES SCATTERED STRONG WITHIN 60 NM OF THE LINE FROM 18N108W TO 20N107W. 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 240 NM IN THE W SEMICIRCLES WITH SEAS 8 TO 12 FT. ATMOSPHERIC CONDITIONS APPEAR FAVORABLE FOR RICK TO CONTINUE TO UNDERGO INTENSIFICATION UNDER A RATHER LOW SHEAR ENVIRONMENT ALONG WITH VERY CONDUCIVE SEA SURFACE TEMPERATURES THROUGH AT LEAST THE NEXT 24 HOURS AS IT TRACKS WNW. IT IS THEN FORECAST TO BEGIN WEAKEN AS IT ENCOUNTERS A GRADUAL COOLING OF SEA SURFACE TEMPERATURES. ...TROPICAL WAVE... A TROPICAL WAVE IS ALONG 118W FROM 6N-16N 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-8N BETWEEN 115W-118W. ISOLATED SHOWERS AND TSTMS ARE WITHIN 120 NM E OF THE WAVE FROM 12N-16N...AND ALSO WITHIN 60 NM W OF THE WAVE FROM 12N-14N. ...ITCZ... THE AXIS OF THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 7N83W TO 10N95W TO 12N100W TO 11N110W TO 13N124W TO 11N130W TO 11N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 75 NM N AND 120 NM S OF THE AXIS BETWEEN 82W-85W...AND ALSO WITHIN 180 NM S OF THE AXIS W OF 132W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM N AND 45 NM S OF THE AXIS BETWEEN 125W-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 31N131W. 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 29N138W WHERE IT BECOMES STATIONARY TO SW OF THE AREA AT 28N140W. 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 13N124W TO 7N126W...AND MAY HELPING TO AID ITCZ CONVECTION BETWEEN 124W-127W. PATCHES OF SCATTERED TO BROKEN STRATOCUMULUS CLOUDS MOVING WSW ARE N OF 20N. THE PRES GRADIENT BETWEEN BROAD LOW PRES S OF 15N W OF 130W AND HIGH PRES TO THE IS RESULTING IN NE-E WINDS OF 20-25 KT FROM 12N TO 18N W OF 137W WITH SEAS IN THE RANGE OF 8-10 FT. THE 1020 MB HIGH IS FORECAST TO DISSIPATE IN 24 HOURS AS ANOTHER AREA OF HIGH PRES MOVES ACROSS THE NORTHERN THROUGH THE NEXT 48 HOURS. E OF 120W... A MID/UPPER LEVEL TROUGH EXTENDS FROM S CALIFORNIA S INTO THE AREA THROUGH 32N118W TO 24N120W. MODERATE SUBSIDENCE SUPPORTING DRY AND STABLE CONDITIONS NOTED BY A LAYER OF OVERCAST STRATOCUMULUS CLOUDS IS N OF 23N. A SMALL UPPER LEVEL CYCLONIC CIRCULATION MOVING E 17 KT IS ON THE TROUGH NEAR 30N. A DEEP LAYER RIDGING WAS NOTED OVER W MEXICO N OF 17N WITH THE ASSOCIATED ELONGATED ANTICYCLONE ANCHORED NEAR 19N104W. WITH RICK ALONG THE SOUTHERN PERIPHERY OF THE RIDGE...DEEP CONVECTION IN RAIN BANDS TIED TO RICK WILL REMAIN VERY ACTIVE THROUGH THE NEXT 48 HOURS. THE 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 CYCLONIC CIRCULATION MOVING W 18 KT IS OVER S HONDURAS WITH A TROUGH EXTENDING SSW TO NEAR 8N88W...BUT IS ONLY CREATING ISOLATED SHOWERS AND TSTMS NEAR THE CENTRAL AMERICAN COAST. 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 SAT EVENING...WITH N TO NE WINDS INCREASING TO 25-35 KT BY EARLY THIS EVENING AND TO N-NE 40-50 KT BY SUN AFTERNOON WITHIN 45 NM EITHER SIDE OF A LINE FROM 16N95W TO 13N96W...THEN TO 35 TO 45 KT BY SUN AFTERNOON WITHIN 60 NM EITHER SIDE OF A LINE FROM 16N95W TO 13N96W. SEAS THERE ARE FORECAST TO BUILD INTO THE RANGE OF 10-14 FT BY SUN AFTERNOON. 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 PER LATEST MODEL GUIDANCE. $$ AGUIRRE