000 AXPZ20 KNHC 301550 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC WED AUG 30 2006 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1545 UTC. ...SPECIAL FEATURES... CATEGORY FOUR HURRICANE JOHN CENTERED NEAR 16.6N 102.3W AT 30/1500 UTC 948 MB MOVING NW OR 305 DEG AT 10 KT. MAXIMUM SUSTAINED WINDS ARE 115 KT WITH GUSTS TO 140 KT. JOHN IS LOCATED ABOUT 140 NM W OF ACAPULCO MEXICO AND ABOUT 83 NM S OF LAZARO CARDENAS MEXICO. JOHN HAS A EYE CURRENTLY ESTIMATED AT 12 NM. NUMEROUS STRONG CONVECTION IS NOTED OUTSIDE THE EYE WITHIN 120 NM SE AND WITHIN 90 NM NW SEMICIRCLES OF CENTER. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED ELSEWHERE WITHIN 240 NM OF CENTER AND DANGEROUS INLAND FLOODING IS LIKELY. CONDITIONS ARE FAVORABLE FOR ADDITIONAL STRENGTHENING. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS INCLUDING SEVERAL PUBLIC WATCHES AND WARNINGS. TROPICAL STORM KRISTY CENTERED NEAR 16.7N 115.1W AT 30/1500 UTC MOVING NW OR 305 DEG AT 5 KT. MAXIMUM SUSTAINED WINDS ARE 50 KT WITH GUSTS TO 60 KT WITH AN ESTIMATED MINIMUM CENTRAL PRESSURE OF 1000 MB. KRISTY IS LOCATED ABOUT 460 NM SW OF THE SRN TIP OF BAJA CALIFORNIA. NUMEROUS STRONG CONVECTION IS WITHIN 90 NM S SEMICIRCLE AND WITHIN 60 NM N SEMICIRCLE. BANDING FEATURES ARE FORMING OVER THE E SEMICIRCLE SUGGESTING STRENGTHENING AND KRISTY WILL LIKELY BECOME A HURRICANE WITHIN 24 HOURS. A MID-LEVEL RIDGE N AND NE OF KRISTY SHOULD MOVE KRISTY INITIALLY WNW WITH AN INCREASE IN FORWARD SPEED...FOLLOWED BY A MORE W MOTION OF THE WEAKENING CYCLONE AS IT MOVES OVER COOLER WATERS AND ENCOUNTERS AN INCREASE IN SHEAR IN A COUPLE OF DAYS. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... .NONE ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N78W 8N85W 14N97W THEN BECOMES DISTORTED BY THE TROPICAL CYCLONES. THE AXIS IS NOTED AGAIN FROM 12N118W TO 10N140W. NUMEROUS MODERATE ISOLATED STRONG CONVECTION IS OBSERVED NE OF LINE 2N79W 10N91W AND FROM 10N TO 14N BETWEEN 103W AND 112W. SCATTERED MODERATE ISOLATED STRONG WITHIN 60 NM EITHER SIDE OF LINE 10N112W 10N133W. ...DISCUSSION... AN UPPER SHORTWAVE TROUGH...ORIGINATING FROM A DEEP LAYERED CYCLONE OVER WRN N AMERICA...EXTENDS SW INTO THE DISCUSSION AREA ALONG 35N124W THROUGH A WEAK UPPER CYCLONE AT 32N127W CONTINUING SW THROUGH 26N132W INTO ANOTHER WESTWARD MOVING CYCLONE AT 18N143W...AND FINALLY EXTENDING SW LOSING IDENTITY OVER THE ITCZ AT 12N146W. TO THE S OF THIS TUTT...LIES AN UPPER ANTICYCLONE AT 21N129W RIDGING SW TO A SHARP CREST AT 13N141W. THIS ANTICYCLONE ALSO RIDGES SE TO JUST NW OF TROPICAL STORM KRISTY BUT IS FORECAST TO SHIFT W WITH TIME. STRONG UPPER DRY AIR IS INDICATED WITHIN 120 NM OF THE TROUGH AXIS WITH MODERATE DRY AIR ELSEWHERE NW OF LINE 14N140W 15N120W 30N114W. SE OF THIS SAME LINE TO 4N THE UPPER LEVELS ARE QUITE MOIST DUE TO DEBRIS MOSITURE FROM THE ITCZ CONVECTION AND THE TWO CYCLONES. AN UPPER ANTICYLONE IS OVER NRN OLD MEXICO NEAR 28N110W WITH THE DEBRIS MOISTURE ADVECTED N FROM THE TROPICS TRAPPED UNDER ITS ANTICYCLONIC ENVELOPE CRESTING OVER SRN ARIZONA AND NEW MEXICO. AT THE SURFACE A WEAK RIDGE EXTENDS SE ACROSS THE NW WATERS TO NEAR 22N122W. $$ NELSON