000 AXPZ20 KNHC 060337 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC WED AUG 06 2008 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 0315 UTC. ...SPECIAL FEATURE... TROPICAL WAVE IS ALONG 107W FROM 4N TO 16N MOVING W ABOUT 10 KT. A 1007 MB LOW IS ANALYZED ON THE WAVE AXIS NEAR 12N107W AS NOTED IN CYCLONIC TURNING OF DEEP LAYERED CLOUDS IN THE AREA FROM 7N-17N BETWEEN 105W-115W. SCATTERED MODERATE TO STRONG CONVECTION IS OCCURRING WITHIN 120-150 NM OF THE W SEMICIRCLE OF THE LOW PRES CENTER. THIS CONVECTION IS INCREASINGLY BANDED IN NATURE SUGGESTING SOME DEVELOPMENT OF THIS SYSTEM. OVER THE PAST 24 HOURS THE CONVECTION HAS BECOME MORE SEPARATED FROM THE ITCZ WITH TIME. GLOBAL MODEL GUIDANCE SUGGEST THAT THIS SYSTEM MAY CONSOLIDATE AND UNDERGO SOME DEVELOPMENT OVER THE NEXT FEW DAYS AS IT MOVES UNDER A MORE FAVORABLE ENVIRONMENT WITH THE POSSIBILITY OF THIS SYSTEM BECOMING A TROPICAL DEPRESSION. ...TROPICAL WAVES... TROPICAL WAVE N OF 6N ALONG 91W/92W IS MOVING W 15 KT. LITTLE ORGANIZATION HAS BEEN NOTED WITH THIS WAVE OVER THE PAST SIX HOURS. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OVER WESTERN GUATEMALA AND THE GULF OF TEHUANTEPEC. TROPICAL WAVE IS ALONG 125W FROM 4N TO 16N MOVING W 15 KT. CURRENTLY LITTLE IN THE WAY OF CONVECTION IS OCCURRING ALONG THE WAVE AXIS WITH AN AREA OF SCATTERED MODERATE CONVECTION ABOUT 300 NM W OF THE AXIS FROM 10N TO 14N. THE WAVE COULD BECOME MORE CONVECTIVELY ACTIVE OVER THE NEXT FEW DAYS AS IT MOVES THROUGH A MORE ACTIVE ITCZ AXIS W OF 120W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 10N85W 13N102W 9N115W 12N125W 11N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 150 NM N OF THE AXIS BETWEEN 129W AND 136W...AND FROM 07N TO 13N BETWEEN 93W AND 99W. SCATTERED MODERATE WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 109W AND 113W. OTHER ITCZ-RELATED CONVECTION IS DESCRIBED ABOVE UNDER TROPICAL WAVES SECTION. ...DISCUSSION... E OF 125W... AN ANTICYCLONE CENTERED OVER THE SW UNITED STATES IS THE MAIN FEATURE DRIVING THE UPPER WIND FLOW REGIME ACROSS THIS AREA AS AN ASSOCIATED RIDGE EXTENDS SSE ACROSS MUCH OF CENTRAL AND SOUTHERN MEXICO. ANOTHER RIDGE EXTENDS FROM THIS ANTICYCLONE WNW ACROSS CENTRAL AND SOUTHERN CALIFORNIA. SATELLITE DERIVED-UPPER AIR DATA SHOWS A WIDE SWATH OF EASTERLY WINDS OVER MUCH OF THIS AREA S OF 20N...WITH WIND DIRECTION MORE NORTHERLY E OF 80W. THIS WIND FLOW IS CHANNELING DEEP LAYER MOISTURE SSW ACROSS YUCATAN PENINSULA AND SE MEXICO SW AND WESTWARD TOWARDS 110W WHERE THE UPPER LEVEL FLOW THEN BECOMES RATHER DIFFLUENT. UPPER LEVEL MOISTURE CONTINUES TO BE PRESENT ALONG THE MEXICAN COAST AND GULF OF CALIFORNIA N OF 21N. A WEAK INVERTED TROUGH LIFTING N EXTENDS FROM 24N117W SW TO 17N119W. AN UPPER TROUGH JUST NW OF THE AREA IS FORECAST TO BUILD SOME TO THE SW AND GRADUALLY LIFT NE OVER THE NEXT 48-72 HOURS WITH RATHER STABLE CONDITIONS ALONG AND WITHIN 300 NM TO ITS SE AS WATER VAPOR IMAGERY PORTRAYS. AT THE SURFACE...A RELATIVELY WEAK PRES DOMINATES THIS AREA. BROKEN TO OVERCAST LAYERS OF STRATOCUMULUS CLOUDS WITH POSSIBLE ISOLATED SHOWERS ARE NW OF LINE FROM NRN BAJA CALIFORNIA TO 15N123W. THE EASTERN EDGE OF THESE CLOUDS IS ERODING WITH TIME. A 1554 UTC ASCAT PASS INDICATED THAT NE-E WINDS OF 20 KT HAVE BEGUN IN THE GULF OF PAPAGAYO. THESE WINDS SHOULD REMAIN AROUND 20 KT AND LAST THROUGH LATE THU NIGHT. W OF 125W... MID/UPPER LEVEL TROUGH EXTENDS FROM 32N131W S TO 25N131W...WHILE A MID/UPPER LEVEL RIDGE IS EVIDENT TO ITS SW TO THE W OF THE AREA ALONG 142W. UPPER LEVEL ANTICYCLONIC LOW COVERS THE AREA N OF 15N W OF 16W WITH AMPLE MODERATE TO STRONG SUBSIDENCE AND STABLE CONDITIONS NOTED N OF 15N...EXCEPT THE FAR NW CORNER WHERE UPPER LEVEL MOISTURE IS SPILLING INTO THE DISCUSSION AREA UP AND OVER THE RIDGE. AN ELONGATED MID/UPPER LEVEL CYCLONIC CIRCULATION SLOWLY MOVING W IS LOCATED NEAR 17N132W. A RELATED TROUGH EXTENDS FROM THE CIRCULATION SW TO 15N138W. IT IS FORECAST TO GRADUALLY MOVE NW OVER THE NEXT 3-4 DAYS. ABUNDANT MID/UPPER LEVEL MOISTURE IS PRESENT FROM 4N-15N...AND IS UNDER THE SE PERIPHERY OF MID/UPPER LEVEL RIDGING TO THE N AND NW. AT THE SURFACE...A RIDGE EXTENDS SE THROUGH 32N135W TO 24N125W. HIGH PRES PROVIDING STABLE CONDITIONS COVERS THE AREA N OF 15N. $$ COBB