000 AXPZ20 KNHC 310946 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC FRI AUG 31 2007 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...SPECIAL FEATURES... TROPICAL STORM GIL CENTERED NEAR 19.0N 116.5W...OR 430 NM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA...AT 31/0900 UTC MOVING W 9 KT. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 40 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MODERATE TO STRONG ELY SHEAR CONTINUES ACROSS THE CENTER OF THIS STORM. CONVECTION HAS BEEN SUBSIDING OVER THE PAST SEVERAL HOURS AND IS DISPLACED WELL DOWNSHEAR OF THE CENTER OF GIL...AS INDICATED BY POLAR ORBITING SATELLITE IMAGERY. GIL IS NOTABLY WEAKER...WITH ONLY ISOLATED MODERATE CONVECTION EVIDENT CURRENTLY WITHIN 60 NM IN THE S QUADRANT. HOWEVER...SATELLITE ANALYSIS SHOWS GIL IS STILL MAINTAINING MINIMAL TROPICAL STORM STRENGTH. WHILE THE ELY SHEAR IS INHIBITING DEVELOPMENT...IT IS NOT ENOUGH TO KILL THE STORM. IN ADDITION...SEA SURFACE TEMPERATURES REMAIN HIGH ENOUGH TO PROVIDE ENERGY TO GIL OVER THE NEXT COUPLE OF DAYS. THE MAIN LIMITING FACTOR BESIDE THE SHEAR WILL BE DRIER AIR MIXING INTO THE STORM AS IT MOVES FURTHER W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. TROPICAL DEPRESSION ELEVEN-E CENTERED NEAR 15.3N 99.3W...OR 115 NM SSE OF ACAPULCO MEXICO...AT 31/0900 UTC MOVING WNW AT 9 KT. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. CONVECTION IS NOTED WITHIN 60 NM OF THE CENTER...MAINLY ON THE NW SEMICIRCLE. SATELLITE IMAGERY SHOWED THIS CONVECTION WRAPPING AROUND THE CENTER OF THIS SYSTEM OVER THE PAST COUPLE HOURS. AS WITH LAST NIGHT...A LARGER AREA OF CONVECTION IS EVIDENT ALONG THE MEXICAN COAST EXTENDING OUT 30 NM...BETWEEN 99W AND 102W. THIS IS LIKELY DUE TO CONVERGENCE OF SLY FLOW ON THE E SIDE OF THE DEPRESSION'S CENTER...AND DRAINAGE FLOW OFF THE MOUNTAINOUS MEXICAN TERRAIN. EVEN IF THE DEPRESSION DOES NOT DEVELOP SIGNIFICANTLY...IT IS EXPECTED TO MOVE ALONG THE COAST PAST ACAPULCO AND MANZANILLO AND WILL PRESENT THE POSSIBILITY OF HEAVY RAINFALL ACROSS WEST CENTRAL MEXICO OVER THE NEXT COUPLE OF DAYS...ESPECIALLY IN HIGHER TERRAIN NEAR THE COAST. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N82W 15N96W 14N107W 16N120W 10N127W 11N140W. SCATTERED MODERATE CONVECTION WITHIN 60 NM OF THE AXIS BETWEEN 85W-88W. ...DISCUSSION... E OF 120W... THE MAIN ISSUE WILL BE THE DEVELOPMENT AND TRACK OF TROPICAL DEPRESSION ELEVEN-E ALONG THE MEXICAN COAST. ANALYSIS FROM UW-CIMMS SHOWS THE DEPRESSION MOVING INTO AND AREA OF SLIGHTLY WEAKER SHEAR OVER THE NEXT COUPLE OF DAYS WHICH COULD AID ITS DEVELOPMENT. AT ANY RATE...HEAVY RAINFALL IS POSSIBLE FOR THE MEXICAN COAST FROM WESTERN OAXACA TO JALISCO OVER THE NEXT 2-3 DAYS. THE OTHER ISSUE WILL BE TROPICAL STORM GIL AS DESCRIBED ABOVE. THE MODERATE TO STRONG SHEAR IS DUE TO NE TO E FLOW ALOFT BETWEEN AN UPPER LOW OVER THE SW CARIBBEAN...AND BROAD UPPER RIDGING OVER NRN MEXICO. ASIDE FROM HIGH WINDS AND ROUGH SEAS NEAR THE STORM...FRESH SWLY WINDS DIRECTLY S OF GIL AS FAR AS 7N ARE NOTED ON QUIKSCAT IMAGERY. ELSEWHERE S OF THE ITCZ...S TO SW CROSS-EQUATORIAL FLOW REMAINS LIGHT TO MODERATE. THIS CONTINUES TO BE ACCOMPANIED BY MODERATE SWELL OF UP TO 8 FT OUT OF THE SRN HEMISPHERE...MAINLY W OF 95W. W OF 110W... UPPER RIDGE AXIS EXTENDS FROM NRN BAJA THROUGH 16N140W. NE TO E FLOW ON THE SRN EDGE OF THE UPPER RIDGE CONTINUES TO BRING DRY SUBSIDENT AIR OVER PACIFIC WATERS IN THIS AREA...SUPPRESSING CONVECTIVE DEVELOPMENT MOST EVERYWHERE. THIS IS THE DRIER ENVIRONMENT AWAITING GIL AS IT TRAVELS WEST. QUIKSCAT DATA SHOWS WINDS ARE FAIRLY LIGHT AT THE SURFACE AS WELL. HOWEVER...GIL OR ITS REMNANTS MAY INCREASE NELY SURFACE FLOW SLIGHTLY AHEAD OF THE SYSTEM AS IT MOVES W OVER THE NEXT COUPLE OF DAYS. MODERATE TO LARGE CROSS EQUATORIAL SWELL AND SLIGHTLY INCREASED SLY FLOW IS POSSIBLE S OF THE ITCZ AS WELL. $$ CHRISTENSEN