000 AXPZ20 KNHC 300324 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC THU AUG 30 2007 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0300 UTC. ...SPECIAL FEATURES... TROPICAL STORM GIL CENTERED NEAR 19.6N 112.0W...OR 225 NM SSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA...AT 30/0300 UTC MOVING W 12 KT. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 999 MB. GIL IS A RATHER DISORGANIZED TROPICAL STORM WHICH IS SUFFERING FROM STRONG VERTICAL SHEAR. A FEW MICROWAVE PASSES INDICATED THAT THE LOW-LEVEL CENTER MAY HAVE BEEN ABOUT 0.5 DEGREE S OF THE ESTIMATED POSITION...FURTHERING THE IDEA OF A MESSY SYSTEM. GIL WILL BE MOVING TOWARDS COOLER WATERS AND A MORE STABLE AIR MASS...SO A GENERAL WEAKENING IS EXPECTED DURING THE NEXT FEW DAYS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 16N-21N BETWEEN 111W-114W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. A 1008 MB LOW CENTERED NEAR 12N97W...OR ABOUT 330 NM SSE OF ACAPULCO MEXICO...IS MOVING W AT 10 KT. THE LOW/MID-LEVEL CIRCULATION ASSOCIATED WITH THE LOW APPEARS TO BE WRAPPING UP A LITTLE TIGHTER AS CONVECTIVE BANDING DEVELOPS AROUND THE EASTERN PERIPHERY. HOWEVER...THE BAND CURRENTLY HAS A RATHER LINEAR ORIENTATION AND WILL HAVE TO BECOME MORE CURVED BEFORE THE SYSTEM CAN DEVELOP. THE STRONG E/NE SHEAR OVER THE AREA APPEARS TO BE RELAXING...AND IF THIS CONTINUES THEN THE SYSTEM COULD BECOME A TROPICAL CYCLONE WITHIN THE NEXT 48 HRS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 10N-15N BETWEEN 94W-103W. ...TROPICAL WAVE... TROPICAL WAVE ALONG 91W 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. SCATTERED MODERATE TO STRONG CONVECTION LIES FROM GUATEMALA WWD TO THE MEXICAN STATE OF CHIAPAS. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N77W 12N88W 14N100W 11N110W 12N130W 12N140W. ASIDE FROM CONVECTION NOTED ABOVE...SCATTERED MODERATE WITHIN 90 NM OF AXIS BETWEEN 106W AND 122W. SCATTERED SHOWERS/TSTMS FROM 10N-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 WHICH DEVELOPED OVER THE SIERRA MADRE OCCIDENTALS LATE THIS AFTERNOON HAVE DRIFTED WWD TOWARDS THE COAST DURING THE EVENING HRS...AND NOW EXTEND FROM NEAR PUERTO VALLARTA NWD TO GUAYMAS. 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 10N-16N BETWEEN 132W-138W. $$ BERG