000 AXPZ20 KNHC 012121 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT SEP 01 2007 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 2100 UTC. ...SPECIAL FEATURES... TROPICAL STORM HENRIETTE CENTERED NEAR 18.2N 105.4W...OR 75 NM SW OF MANZANILLO MEXICO...AT 01/2100 UTC MOVING WNW 10 KT. MAXIMUM SUSTAINED WINDS HAVE INCREASED TO 55 KT WITH GUSTS TO 65 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 994 MB. HENRIETTE IS A LARGE TROPICAL STORM WITH A CONVECTIVE ENVELOPE WHICH EXTENDS ALONG THE MEXICAN COAST BETWEEN ACAPULCO AND PUERTO VALLARTA. VISIBLE SATELLITE IMAGERY INDICATES THAT A SMALL CORE OF DEEP CONVECTION IS SLIGHTLY ISOLATED FROM SPIRAL BANDS LOCATED MAINLY OVER THE PACIFIC WATERS...AND THERE RECENTLY WAS A HINT OF THE CENTER TRYING TO PEEK OUT WITHIN THAT CONVECTION. VERY HEAVY RAINFALL HAS BEEN AFFECTING THE PACIFIC COAST OF MEXICO AND THE NEARBY MOUNTAINS DURING THE PAST FEW DAYS AND UP TO 10" OF TOTAL ACCUMULATION IS EXPECTED IN ISOLATED POCKETS. NUMEROUS MODERATE/STRONG CONVECTION FROM 14N-21N BETWEEN 101W-113W. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. TROPICAL DEPRESSION GIL IS CENTERED NEAR 19.1N 121.6W...OR 690 NM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA...AT 01/2100 UTC MOVING W 8 KT. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. GIL CONTINUES TO PRODUCE INTERMITTENT BURSTS OF CONVECTION AS IT MOVES W OVER WATERS NEAR 27C BUT IS ALSO INGESTING STABLE AIR TO ITS W AND S. ON ITS CURRENT TRACK...GIL WILL BE MOVING OVER COOLER WATERS BELOW THE NECESSARY THRESHOLD OVER THE NEXT 12 HRS OR SO AND WILL LIKELY BECOME A SKELETON AREA OF LOW PRES. SCATTERED MODERATE WITHIN 120 NM W SEMICIRCLE. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE ALONG 88W/89W N OF 5N MOVING W 10-15 KT ACROSS WRN GUATEMALA AND EL SALVADOR. THE ONLY AVAILABLE DATA OF NOTE THAT GIVES AND INDICATION OF THE WAVE'S POSITION IS UPPER AIR DATA FROM SAN JOSE COSTA RICA...WHICH SHOWED WAVE PASSAGE NEAR 1200 UTC AUG 31. SCATTERED TSTMS ARE FORMING ACROSS CENTRAL AMERICA BUT GENERALLY REMAIN OVER LAND AREAS. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 9N77W 8N83W 13N100W 8N129W 11N140W. ISOLATED MODERATE CONVECTION N OF 6N BETWEEN 78W-84W. SCATTERED MODERATE FROM 8N-14N BETWEEN 92W-102W. ...DISCUSSION... E OF 110W... AN UPPER LEVEL RIDGE AXIS RUNS E/W ACROSS CENTRAL MEXICO WITH CONTINUED UPPER LEVEL EASTERLIES EXTENDING ACROSS THE TROPICAL PACIFIC WATERS E OF 110W. CLOUD-DRIFT WINDS AND GFS GUIDANCE BOTH INDICATE A MODERATE NE/E JET EXTENDING FROM THE MEXICO/GUATEMALA BORDER SW TO 6N100W THEN TURNING W JUST N OF THE EQUATOR. T.S. HENRIETTE HAS LIFTED JUST N OF THIS AREA OF STRONGEST SHEAR AND IS NOW EMBEDDED NEAR THE RIDGE AXIS...ALLOWING FOR AN EXPANSION OF ITS UPPER LEVEL CIRRUS CANOPY. THE DEEPEST ATMOSPHERIC MOISTURE CURRENTLY RUNS NW/SE OFF THE MEXICAN/CENTRAL AMERICAN COAST AND NWD INTO THE GULF OF MEXICO...WITH SLIGHTLY DRIER AIR SPILLING ACROSS FROM NICARAGUA TO GUATEMALA. ALTHOUGH THERE ARE A FEW DAYTIME TSTMS FORMING OVER THESE COUNTRIES...THE DRY AIR IS PROLIFIC ENOUGH TO LIMIT THE COVERAGE OF CONVECTIVE ACTIVITY. FARTHER N OVER MEXICO...A SHARP UPPER TROUGH EXTENDS FROM THE TEXAS BIG BEND ONTO THE MEXICAN PLATEAU WITH MODERATE SUBSIDENCE KEEPING MOSTLY FAIR WEATHER CUMULUS OVER THE AREA N OF 24N. W OF 110W... AN UPPER RIDGE AXIS EXTENDS FROM SOUTHERN CALIFORNIA SW TO 22N140W WITH MODERATE/STRONG SUBSIDENCE COVERING VIRTUALLY THE ENTIRE AREA W OF 110W. THERE IS SOME MOISTURE ASSOCIATED WITH T.D. GIL AND THE OUTFLOW OF T.S. HENRIETTE...BUT THIS IS MOSTLY UPPER LEVEL OUTFLOW. THE LOWER LEVELS ARE PREDOMINANTLY STABLE AND DRY WITH ALMOST NO CLOUDS N OF 20N E OF 122W TO THE BAJA PENINSULA...AND BROKEN STRATOCUMULUS N OF 20N W OF 122W. THE TRADES REMAIN LIMITED TO THE AREA W OF 130W SINCE THE ACTIVE MONSOON TROUGH OFF MEXICO CONTINUES TO PULL THE FLOW EWD INTO HENRIETTE. $$ BERG