000 AXPZ20 KNHC 312210 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC FRI AUG 31 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 2130 UTC. ...SPECIAL FEATURES... TROPICAL STORM GIL CENTERED NEAR 18.9N 118.4W...OR ABOUT 500 NM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA...AT 31/2100 UTC MOVING W 9 KT. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. THE CENTER OF GIL IS PARTIALLY EXPOSED WITH SCATTERED MODERATE CONVECTION MOSTLY DISPLACED WITHIN 90 MM W SEMICIRCLE. ALL INDICATIONS ARE IT WILL EITHER MAINTAIN ITS CURRENT INTENSITY OR WEAKEN SLIGHTLY OVER THE NEXT 3 DAYS...WHILE CONTINUING ON A GENERAL W THEN WNW TRACK AFTER 24 HOURS. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. TROPICAL STORM HENRIETTE CENTERED NEAR 16.2N 101.0W...OR ABOUT 75 NM WSW OF ACAPULCO MEXICO. HENRIETTA IS MOVING WNW AT 9 KT...AND ON THIS TRACK THE CORE OF THE CYCLONE WILL BE MOVING CLOSE TO THE SOUTHWEST COAST OF MEXICO...BUT ANY DEVIATION TO THE NORTH OF THE TRACK WOULD BRING STRONGER WINDS TO THE COAST. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. HENRIETTE COULD BECOME A HURRICANE DURING THE NEXT DAY OR SO. HENRIETTE IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 4 TO 8 INCHES ALONG THE SOUTH COAST OF MEXICO FROM GUERRERO TO JALISCO...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 15 INCHES. LIFE-THREATENING FLASH FLOODS AND MUDSLIDES ARE POSSIBLE. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. NUMEROUS MODERATE TO STRONG CONVECTION CURRENTLY NOTED WITHIN 210 NM W AND 150 NM E SEMICIRCLES. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 9N82W 14N98W 19N112W 11N125W 10N140W. SCATTERED MODERATE CONVECTION WITHIN 90 NM EITHER SIDE OF AXIS BETWEEN 80W-85W...WITHIN 180NM S OF THE AXIS BETWEEN 87W-97W...AND 90NM EITHER SIDE BETWEEN 97W-100W. ...DISCUSSION... E OF 120W... THE MAIN ISSUE IS THE DEVELOPMENT AND TRACK OF TROPICAL STORM HENRIETTE ALONG THE MEXICAN COAST. GRADUAL STRENGTHENING IS EXPECTED OF HENRIETTE WITH THE SHEAR EXPECTED TO RELAX AND SSTS WARM. HEAVY RAINFALL IS A BIG CONCERN FOR A PORTION OF THE MEXICAN COAST. THE OTHER ISSUE IS TROPICAL STORM GIL. SEE SPECIAL FEATURES ABOVE FOR DETAILS. THE MODERATE TO STRONG SHEAR AFFECTING BOTH OF THESE SYSTEMS IS DUE TO NE/E FLOW ALOFT BETWEEN AN UPPER LOW OVER THE SW CARIBBEAN...AND BROAD UPPER RIDGING OVER NRN BAJA AND BUILDING OVER CENTRAL MEXICO. ASIDE FROM HIGH WINDS AND ROUGH SEAS NEAR THE STORM...MODERATE TO FRESH SWLY WINDS ARE DIRECTLY S OF GIL AS FAR AS S AS 7N AS NOTED IN AN EARLIER QUIKSCAT PASS. ELSEWHERE S OF THE ITCZ...S TO SW CROSS-EQUATORIAL FLOW REMAINS LIGHT TO MODERATE. THIS CONTINUES TO BE ACCOMPANIED BY MODERATE MIXED SE AND SW SWELLS OF UP TO 9 FT OUT OF THE SRN HEMISPHERE...MAINLY W OF 95W. W OF 120W... THE UPPER FLOW ACROSS THIS AREA IS SOMEWHAT CONFLUENT BETWEEN A WELL DEFINED UPPER RIDGE CENTERED OVER NRN BAJA AND AN UPPER LOW JUST N OF THE HAWAIIAN ISLANDS. THIS STABLE ENVIRONMENT IS SUPPRESSING ANY DEEP CLOUD FORMATION ESPECIALLY W OF 130W. EVEN THE ITCZ IS DEVOID OF DEEP CONVECTION. SOME OF THIS STABLE AIR IS AFFECTING TROPICAL STORM GIL...LOCATED JUST E OF THIS ZONE. AS GIL MOVES DEEPER INTO THIS STABLE AIRMASS FURTHER INTENSIFICATION IS LESS LIKELY. HOWEVER...WINDS AND SEAS ARE EXPECTED TO PICK UP IN THIS AREA THROUGH TONIGHT AS GIL CROSSES 120W. MODERATE TO LARGE CROSS EQUATORIAL SWELL AND SLIGHTLY INCREASED SLY FLOW IS EXPECTED S OF THE ITCZ AS WELL. $$ WILLIS/CANGIALOSI