000 AXPZ20 KNHC 212132 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC TUE SEP 21 2010 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... TROPICAL STORM GEORGETTE CENTERED NEAR 23.3N 109.9W OR ABOUT 30 MILES...45 KM N OF CABO SAN LUCAS MEXICO AT 21/2100 UTC MOVING NNW AT 8 KT. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ42 KNHC FOR MORE DETAILS. VERY DEEP CONVECTION EARLIER NOTED WITH GEORGETTE HAS SIGNIFICANTLY DIMINISHED OVER THE PAST FEW HOURS AS THE CENTER PASSES ACROSS SOUTHERN BAJA CALIFORNIA. LATEST NHC FORECAST TRACKS GEORGETTE AS A WEAKENING TROPICAL DEPRESSION OVER THE GULF OF CALIFORNIA JUST E OF BAJA CALIFORNIA NEAR 25N11W BY LATE TONIGHT...THEN TO NEAR 28N112W BY WED AFTERNOON...AND INLAND MAINLAND MEXICO NEAR 30N112W BY LATE WED NIGHT BEFORE DISSIPATING. LITTLE IN THE WAY OF A CYCLONIC CIRCULATION AND CONVECTION IS EXPECTED TO REMAIN ONCE GEORGETTE REACHES THE GULF OF CALIFORNIA LATE TONIGHT INTO WED MORNING. MAIN HAZARD ASSOCIATED WITH GEORGETTE WITH BE TOTAL RAINFALL ACCUMULATIONS OF 4 TO 6 INCHES THAT ARE EXPECTED OVER THE SOUTHERN BAJA PENINSULA AND THE MEXICAN STATES OF SINALOA AND WESTERN SONORA...WITH ISOLATED MAXIMUM AMOUNTS OF 10 INCHES POSSIBLE. THESE RAINFALL AMOUNTS MAY PRODUCE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM JUST SW OF GEORGETTE SW TO A 1007 MB LOW NEAR 14N121W...TO 11N131W TO 11N140W. NO SIGNIFICANT CONVECTION WAS NOTED. ...DISCUSSION... ALOFT... AN ANTICYCLONIC CIRCULATION IDENTIFIED OVER N CENTRAL MEXICO EXTENDS A RIDGE SW TO 25N124W...AND TO SW OF THE REGION NEAR 19N144W. ANOTHER RIDGE EXTENDS SE FROM THE ANTICYCLONE ACROSS MUCH OF CENTRAL AND SE MEXICO. SATELLITE WATER VAPOR IMAGERY SHOWED MODERATE SUBSIDENCE LEADING TO RATHER STABLE ENVIRONMENTAL CONDITIONS N OF 19N W OF 120W...AND BETWEEN 120W AND LINE FROM 27N114W TO 20N120W. SCATTERED TO BROKEN STRATOCUMULUS CLOUDS MOVING S AND SE ARE NOTED WITHIN THIS STABLE ENVIRONMENT. TO THE S OF THE ANTICYCLONE AND EASTERN RIDGE...ACTIVE CLUSTERS OF MOSTLY SCATTERED MODERATE/ISOLATED STRONG CONVECTION WERE NOTED WITHIN 90 NM EITHER SIDE OF LINE FROM 12N90W TO 12N100W TO 12N101W. SMALL CLUSTERS OF ISOLATED SHOWERS AND TSTMS WERE ELSEWHERE N OF 5N E OF 100W. THESE AREAS OF CONVECTION WERE OCCURRING IN THE CONFLUENT SWLY FLOW ON THE S SIDE OF THE MONSOON TROUGH...WHICH WAS ACTING TO INDUCE DIVERGENT FLOW ALOFT PROVIDING A FAVORABLE ENVIRONMENT TO SUSTAIN THE ACTIVITY. SURFACE... ASIDE FROM TROPICAL STORM GEORGETTE AND THE MONSOON TROUGH AXIS DESCRIBED ABOVE...A RATHER WEAK PRES GRADIENT EXISTS WITH A 1020 MB HIGH LOCATED JUST W OF THE REGION NEAR 30N142W EXTENDING A WEAK RIDGE SE TO NEAR 26N126W. THE INTERACTION BETWEEN THE RIDGE AND LOWER PRESSURES OVER NW MEXICO IS RESULTING IN NW TO N WINDS OF 20 KT WITH SEAS OF 8 FT N OF 23N AND BETWEEN 115W AND 120W. AS THE GRADIENT LESSENS THROUGH THE NEXT 48 HOURS...THE WINDS WILL DIMINISH WITH SEAS SUBSIDING TO LESS THAN 8 FT. THE LOW NEAR 14N122W MENTIONED ABOVE UNDER THE ITCZ/MONSOON SECTION IS PRODUCING 20 TO 25 KT WITHIN 120 NM OF ITS CENTER...WHILE SEAS IN THE 8 TO 10 FT RANGE PRIMARILY DUE TO A SW SWELL ARE NOTED. THE LOW AND ASSOCIATED CONDITIONS ARE FORECAST BY GLOBAL MODELS TO GRADUALLY MOVE EASTWARD OVER THE NEXT 48 HOURS TO AN AREA BOUNDED FROM 8N TO 14N AND BETWEEN 91W AND 115W. THE MODELS HINT AT ANOTHER LOW DEVELOPING ALONG THE MONSOON TROUGH OVER THE FAR WESTERN PORTION OF THE AREA ALSO DURING THE NEXT 48 HOURS... HOWEVER CURRENTLY THERE ARE NO VISIBLE INDICATIONS OF THIS MATERIALIZING. $$ AGUIRRE