000 AXPZ20 KNHC 240245 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE AUG 24 2010 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 0230 UTC. ...SPECIAL FEATURE... AT 24/0300 UTC...TROPICAL STORM FRANK IS CENTERED NEAR 15.2N 100.1W MOVING WNW OR 290 DEGREES AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WINDS ARE 45 KT WITH GUSTS TO 55 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS LOCATED WITHIN 45 NM IN THE E SEMICIRCLE AND WITHIN 90 NM IN THE SW AND W QUADRANTS OF THE CENTER. FRANK IS NO LONGER FORECAST TO BECOME A HURRICANE BUT IS INSTEAD EXPECTED TO REMAIN A TROPICAL STORM GRADUALLY STRENGTHENING TO A STRONG TROPICAL STORM BY 72 HOURS AS THE SHEAR DECREASES A LITTLE WITH WEAKENING COMMENCING THEREAFTER AS FRANK MOVES OVER COOLER WATER. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 08N78W TO 09N84W TO 12N90W THEN FROM 13N103W TO 13N110W TO 12N115W TO 13N119W THEN FROM 13N126W TO 10N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 90 NM S OF THE AXIS E OF 83W. ...DISCUSSION... AN UPPER ANTICYCLONE IS CENTERED NEAR 30N134W WITH AN UPPER RIDGE AXIS EXTENDING TO 19N140W. VERY DRY AIR UNDER MODERATE TO STRONG SUBSIDENCE IS NOTED ACROSS THE AREA N OF 16N AND W OF 135W. AN INVERTED TROUGH IS E OF THIS RIDGE STRETCHING FROM NEAR 18N126W TO 32N125W. MID TO UPPER LEVEL MOISTURE IS BEING ADVECTED N FROM THE ITCZ UP ALONG THE TROUGH AXIS AND INTO THE SE PERIPHERY OF THE ABOVE MENTIONED ANTICYCLONE. ANOTHER UPPER ANTICYCLONE IS OVER THE SW PORTION POSITIONED NEAR 04N138W WITH AN UPPER RIDGE AXIS EXTENDING THROUGH 08N129W TO 01N111W. VERY DRY AIR IS NOTED BY WATER VAPOR SATELLITE IMAGERY S OF 10N AND W OF 110W. A WEAK UPPER ANTICYCLONE IS CENTERED JUST W OF BAJA CALIFORNIA NEAR 28N116W WITH A RIDGE EXTENDING S TO 20N115W. A WEAK CYCLONIC CIRCULATION IS POSITIONED JUST TO THE SE NEAR 21N113W WITH AN ASSOCIATED INVERTED UPPER TROUGH STRETCHING TO NEAR THE MEXICO/NEW MEXICO BORDER. MID TO UPPER LEVEL MOISTURE IS OVER THE AREA N OF 20N E OF 120W. NE-E WIND FLOW COVERS THE MAJORITY OF THE REMAINDER OF THE TROPICAL E PACIFIC WHICH IS BEING DRIVEN AROUND THE SE TO S SIDE OF A LARGE SCALE UPPER ANTICYCLONE OVER FAR SOUTHERN TEXAS NEAR 28N98W. THE FLOW IS BEING ACCELERATED AROUND THE E SIDE OF THE ANTICYCLONE IN RESPONSE TO AN UPPER LEVEL LOW WELL TO THE NE-E NEAR FLORIDA. THIS REGIME IS ADVECTING CIRRUS BLOW OFF FROM ITCZ CONVECTION S AND SW ACROSS THE AREA S OF 10N AND E OF 110W. AT THE SURFACE...A RIDGE ENTERS THE REGION AT 32N137W STRETCHING THROUGH 25N124W TO NEAR 21N121W. HIGH PRES COVERS THE AREA N OF 20N AND W OF 120W. A 1010 MB LOW IS EMBEDDED IN THE ITCZ AXIS NEAR 13N122W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE CENTER IN THE NE SEMICIRCLE. 20 KT WINDS ARE OCCURRING WITHIN 180 NM OF THE CENTER IN THE S SEMICIRCLE WITH COMBINED SEAS OF 9 TO 11 FT PRIMARILY IN S SWELL. THE LOW IS FORECAST TO CONTINUE TO DRIFT TO THE E EVENTUALLY DISSIPATING AROUND 24 HOURS INTO A TROUGH. A TROUGH IS ANALYZED FROM 12N132W TO 15N131W. AN EARLIER 1800 UTC ASCAT PASS CAPTURED N-NE 15-20 KT WINDS WITHIN 150 NM NE OF THE TROUGH AXIS. ONLY ISOLATED SHOWERS ARE OCCURRING WITHIN 30-45 NM OF THE TROUGH. A WEAK TROUGH WHICH IS THE REMNANTS OF T.D. EIGHT-E EXTENDS FROM 19N117W TO 22N114W. NO CONVECTION IS NOTED WITH THIS FEATURE WITH ONLY 5-10 KT WINDS ON EITHER SIDE OF IT. CROSS EQUATORIAL S AND SW SWELLS WITH PEAK WAVE PERIODS OF 18-20 SECONDS CONTINUES TO AFFECT THE WATERS SE OF A LINE FROM 20N106W TO 20N130W TO 10N140W AND W OF 90W...EXCEPT JUST N OF GALAPAGOS ISLANDS...WITH COMBINED SEAS OF 8-11 FT. THIS SWELL TRAIN WILL CONTINUE TO PROPAGATE AND EXPAND TO THE NE ALL THE WAY TO THE U.S. CALIFORNIA COAST DURING THE NEXT 24 HOURS THEN WILL GRADUALLY SUBSIDE BEGINNING BETWEEN 36-48 HOURS WHILE SE SWELL BECOMES MORE DOMINANT OVER THE FAR SW PORTION OF THE AREA. $$ LEWITSKY