000 AXPZ20 KNHC 120335 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI OCT 12 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 0315 UTC. ...ITCZ... INTERTROPICAL CONVERGENCE ZONE...AXIS IS CENTERED ALONG 14N92W 12N100W 12N110W 10N120W 10N130W 10N140W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 100W-104W. ...DISCUSSION... W OF 110W... A MID/UPPER LEVEL TROUGH ENTERS THE REGION THROUGH 32N127W AND EXTENDS TO 26N132W WHERE IT BECOMES A SHEAR AXIS TO 24N140W. WSW FLOW AHEAD OF THE THE TROUGH IS ADVECTING UPPER LEVEL MOISTURE TOWARDS SOUTHERN CALIFORNIA. A MID/UPPER LEVEL RIDGE AXIS EXTENDS WSW FROM SOUTHERN BAJA CALIFORNIA THROUGH 24N120W 20N130W TO 14N140W. MODERATE TO STRONG SUBSIDENCE AND ASSOCIATED SINKING AIR COVERS MOST OF THE AREA WITH THE EXCEPTION OF THE EXTREME NORTHERN BOUNDARY E OF 138W WHERE MID/UPPER LEVEL MOISTURE IS CHANNELING SOUTHEASTWARD BEHIND THE TROUGH...AND ALSO FROM 10N-20N E OF A MID/UPPER LEVEL TROUGH THAT EXTENDS ALONG 127W FROM 11N-17N AND IS MOVING W ABOUT 10-15 KT. AT THE SURFACE...A 1017 MB HIGH IS ANALYZED NEAR 28N130W WITH A RIDGE TO 25N117W. RATHER WEAK HIGH PRES COVERS THE AREA N OF 20N W OF 120W. A COLD FRONT IS JUST N OF THE REGION WITH THE ITS MOST SOUTHERN POINT TOUCHING THE NW CORNER AT 30N140W. THE COLD FRONT IS FORECAST TO BRUSH THE FAR NORTHERN BOUNDARY AS IT WEAKENS WHILE MOVING EASTWARD TOWARDS SOUTHERN CALIFORNIA AND NORTHERN BAJA CALIFORNIA THROUGH THE NEXT 48 HOURS. E OF 110W... A MID/UPPER LEVEL ANTICYCLONE IS OVER SE MEXICO NEAR 18N94W WITH A RIDGE EXTENDING WSW THROUGH 17N100W AND THEN WNW TO 19N107W. BROAD ANTICYCLONIC FLOW COVERS THE AREA N OF 7N. MODERATE TO STRONG UPPER LEVEL NE WINDS ARE PRESENT S OF THE RIDGE E OF 100W...THEN BECOMES LIGHTER W OF 100W. EXTENSIVE MID/UPPER LEVEL MOISTURE...MUCH ATTRIBUTED TO HIGH LEVEL DEBRIS CLOUDINESS...IS NOTED IN THE AREA OF THE ANTICYCLONIC FLOW. ADDITIONAL UPPER LEVEL MOISTURE IS BEING ADVECTED WESTWARD IN THE MODERATE TO STRONG NE WINDS FROM 4N-10N E OF 90W. CONFLUENT UPPER LEVEL FLOW BETWEEN THE AREA OF ANTICYCLONIC FLOW OVER THE EASTERN PORTION ...AND A BROAD UPPER LEVEL TROUGH DIGGING SOUTHEAST OVER THE GULF OF MEXICO IS CREATING DRY AND STABLE ENVIRONMENTAL CONDITIONS OVER CENTRAL AND NORTHWESTERN MEXICO. AT THE SURFACE...BROAD TROUGHING WITH AMPLE ASSOCIATED MOIST AND UNSTABLE CONDITIONS CONTINUES TO BE PRESENT OVER THE FAR EASTERN SECTION OF THE NE PACIFIC. SW TO W WINDS IN THE RANGE OF 20-25 KT ARE EVIDENT WITHIN THIS AREA OF BROAD TROUGHING FROM ABOUT 5N-17N E OF 115W. WINDS MAY POSSIBLY GUST UP TO 30 KT NEAR CONVECTION...AS DESCRIBED ABOVE...FOUND THROUGHOUT THIS AREA. NWP MODEL GUIDANCE SUGGEST THAT LOW PRES MAY EVENTUALLY EVOLVE FROM THIS AREA WITHIN ABOUT 24-30 HOURS AND TRACK WNW AS IT OVER THE NEXT FEW DAYS WITH POTENTIAL FOR SLOW DEVELOPMENT. THE 0000 UTC SURFACE ANALYSIS HAS A 1005 MB LOW NEAR 13N98W. THIS MAY BE THE BEGINNINGS OF THE MODEL FORECAST LOW. FOR THE TIME BEING...THE MOIST AND UNSTABLE SW-W ONSHORE FLOW WILL CONTINUE TO RESULT IN SCATTERED SHOWERS AND TSTMS ALONG AND NEAR THE COAST OF CENTRAL AMERICA/SRN MEXICO. BROAD LOW PRES IS OVER THE YUCATAN PENINSULA WITH AN ANALYZED LOW CENTER NEAR 18N90W 1003 MB. THIS LOW IS EXPECTED TO REMAIN QUASI-STATIONARY THROUGH AT LEAST THE NEXT 3 DAYS. THE LOW MAY PRODUCE BRIEF SURGES OF NW TO N LOW LEVEL FLOW IN THE RANGE OF 15-20 KT INTO THE GULF OF TEHUANTEPEC THROUGH POSSIBLY THE NEXT 12-24 HOURS. $$ AGUIRRE