000 AXPZ20 KNHC 292156 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED AUG 29 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 2145 UTC. ...SPECIAL FEATURES... TROPICAL STORM GIL CENTERED NEAR 19.7N 110.5W...OR 190 NM S OF THE SOUTHERN TIP OF BAJA CALIFORNIA...AT 29/2100 UTC MOVING WNW 10 KT. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 999 MB. GIL LIES S OF A BROAD MID/UPPER LEVEL RIDGE CENTERED OVER NW MEXICO...AND IS UNDER THE INFLUENCE OF ABOUT 20 KT OF EASTERLY SHEAR. THIS PATTERN HAS CAUSED THE LOW-LEVEL CENTER TO BE SLIGHTLY EXPOSED ON THE ERN SIDE OF THE DEEPEST CONVECTION. THE CONVECTIVE CANOPY HAS DECREASED IN SIZE DURING THE PAST FEW HRS...BUT A CORE OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION LIES FROM 16N-20N BETWEEN 110W-113W. GIL IS EXPECTED TO STRADDLE THE THRESHOLD OF WARMEST WATERS AS IT MOVES TO THE W OVER THE NEXT FEW DAYS...BUT IT IS BEGINNING TO INGEST A MORE STABLE AIR MASS LOCATED TO ITS NW AND THIS SHOULD LIMIT ITS OVERALL DEVELOPMENT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. A 1008 MB LOW CENTERED NEAR 12N96W...OR ABOUT 370 NM SE OF ACAPULCO MEXICO...IS MOVING W AT 10 KT. THE OVERALL CONVECTIVE PATTERN OF THE LOW REMAINS RATHER DISORGANIZED...ALTHOUGH RECENTLY A MORE PRONOUNCED BAND HAS DEVELOPED ALONG THE SRN PERIPHERY OF THE CIRCULATION PRESUMABLY DUE TO STRONG LOW-LEVEL CONVERGENCE OF THE CROSS-EQUATORIAL SOUTHERLIES. ALSO...THIS BAND NOW APPEARS TO BE EXTENDING AROUND THE ERN SIDE OF THE CENTER. UW-CIMMS ANALYSES INDICATE ABOUT 40 KT OF E/NE SHEAR OVER THE SYSTEM BUT THIS SHOULD RELAX OVER THE NEXT 48 HRS. THEREFORE...THIS SYSTEM HAS THE POSSIBILITY OF BECOMING A TROPICAL CYCLONE WITHIN THAT TIME PERIOD. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 9N-16N BETWEEN 94W-103W. ...TROPICAL WAVE... TROPICAL WAVE ALONG 90W N OF 6N ACROSS GUATEMALA IS MOVING W 10-15 KT. THE WAVE HAS ITS BEST DEFINITION ACROSS THE YUCATAN PENINSULA AND S/CENTRAL GULF OF MEXICO...AND PRIMARILY LIES S OF GUATEMALA OVER THE PACIFIC WATERS BY EXTENSION. THE LOW-LEVEL FLOW IN THE REGION IS DOMINATED BY THE CIRCULATION AROUND THE AREA OF LOW PRES NEAR 12N96W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N77W 12N88W 14N100W 11N110W 12N130W 12N140W. ASIDE FROM CONVECTION NOTED ABOVE...SCATTERED MODERATE CONVECTION WITHIN 120 NM OF AXIS BETWEEN 102W-113W. SCATTERED MODERATE FROM 12N-15N BETWEEN 132W-138W. ...DISCUSSION... E OF 120W... DEEP ATMOSPHERIC MOISTURE OVER THE PACIFIC REGION IS PRIMARILY LIMITED TO THE AREA E OF 120W ACCORDING TO WATER VAPOR IMAGERY. STRONG CROSS-EQUATORIAL LOW-LEVEL FLOW HAS PUSHED THE ITCZ AXIS WELL N TOWARDS THE MEXICAN/CENTRAL AMERICAN COAST...AND SEEMS TO HAVE SPURRED THE DEVELOPMENT OF T.S. GIL AND POSSIBLY THE LOW PRES AREA SSW OF THE GULF OF TEHUANTEPEC. THE UPPER LEVEL PATTERN IS COMPLICATED OVER MEXICO AND THE W ATLC REGION...BUT THE MAIN DRIVING FORCE IS A LARGE HIGH LOCATED OVER NW MEXICO WHICH IS PRODUCING MAINLY EASTERLY FLOW OVER THE ERN PACIFIC WATERS. TSTMS ARE DEVELOPING OVER THE SIERRA MADRE OCCIDENTALS LATE THIS AFTERNOON AND WITH DEEP EASTERLY FLOW IN PLACE SOME OF THESE STORMS COULD DRIFT WWD TOWARDS THE COAST DURING THE EVENING HRS. W OF 120W... STABLE CONDITIONS PERSIST W OF 120W WITH A PANCAKE-LIKE STRUCTURE IN THE STRATOCUMULUS FIELD N OF 20N...AND MODERATE TO STRONG SUBSIDENCE N OF 14N. THE SURFACE RIDGE IS RATHER WEAK WITH QUIKSCAT SHOWING ONLY 5-10 KT W OF 120W. TO THE S...THE AREA OF LOW PRES WHICH HAD BEEN WANDERING ACROSS THE REGION OVER THE PAST FEW DAYS HAS FINALLY DEGENERATED AND IS BECOMING ABSORBED INTO THE ITCZ. THERE IS A SMALL FLARE-UP OF SCATTERED MODERATE CONVECTION FROM 11N-15N BETWEEN 135W-139W. $$ BERG