000 AXPZ20 KNHC 231542 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC MON AUG 23 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1530 UTC. ...SPECIAL FEATURES... TROPICAL STORM FRANK CENTERED NEAR 14.4N 98.2W AT 23/1500 UTC MOVING WNW AT 7 KT. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 998 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. MORNING SATELLITE IMAGERY SHOW THAT THE OVERALL CLOUD STRUCTURE DOES NOT LOOK WELL ORGANIZED AS IT APPEARS ELONGATED E TO W. AS A RESULT... CONVECTION NOTED WITHIN 180 NM W OF THE CENTER EXCEPT 240 NM IN THE W QUADRANT DOES NOT APPEAR LIKE IT IS ORGANIZING INTO BANDS. LATEST NHC FORECAST GUIDANCE TRACK HAS FRANK MOVING IN A GENERAL WNW DIRECTION PARALLEL TO THE MEXICAN COAST AS IT INTENSIFIES TO 60 KT GUSTS TO 75 KT IN 24 HOURS...AND TO MINIMAL HURRICANE FORCE IN ABOUT 48 HOURS AS VERTICAL WIND SHEAR OVER FRANK IS NOT FORECAST TO DIMINISH SIGNIFICANTLY DURING THIS PERIOD. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE AXIS IS CENTERED ALONG 11N86W 13N93W...THEN RESUMES AT 10N105W 10N114W 12N123W 10N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM N OF THE AXIS BETWEEN 90W-93W. ...DISCUSSION... A MID/UPPER RIDGE EXTENDS FROM SOUTHERN PLAINS AND TO THE SW U.S. AND SW TO AN ANTICYCLONIC CENTER NEAR 31N130W...THEN CONTINUES SW TO NEAR 21N139W. THIS IS THE SAME RIDGE THAT IS FORECAST PLAYER IN THE TRACK OF TROPICAL STORM FRANK THROUGH AT LEAST THE NEXT 48 HOURS. TO THE SE OF THE RIDGE AN INVERTED MID TO UPPER LEVEL TROUGH MOVING WNW STRETCHES FROM 31N122W TO 20N128W. A CYCLONIC CIRCULATION IS ALONG THE TROUGH NEAR 28N124W. MOISTURE ASSOCIATED WITH THE TROUGH AND LOW IS CONFINED S OF THE RIDGE TO 19N AND BETWEEN 121W-134W. SATELLITE WATER VAPOR IMAGERY SHOWS MOSTLY MODERATE SUBSIDENCE WITH RESULTANT DRY AIR PRESENT OVER A LARGE PORTION OF THE AREA OUTSIDE THE ITCZ TRADE WIND CONFLUENCE W OF 114W. AN UPPER-LEVEL LOW MOVING WNW AT 17 KT IS NEAR 22N109W. ISOLATED WEAK SHOWERS ARE WITHIN 220 NM IN THE SE QUADRANT OF THE LOW. AS THE LOW MOVES WNW...AND A SMALL ANTICYCLONE EMBEDDED IN A LARGE SCALE ANTICYCLONE OVER THE CENTRAL SECTION OF THE U.S. MOVES ESE OVER EASTERN TEXAS THE UPPER LEVEL FLOW IS ACCELERATED ACROSS THE FAR EASTERN PART OF THE AREA TO THE E AND SE OF THE UPPER LOW INCLUDING THE ENVIRONMENT OVER AND NEAR FRANK. ELSEWHERE E OF 103W...THE UPPER LEVEL WIND FLOW REGIME IS FROM THE NE AS IT IS DRIVEN AROUND THE E SIDE OF THE LARGE HIGH OVER THE CENTRAL U.S. WHILE IT IS ALSO BEING ACCELERATED IN RESPONSE TO AN UPPER LEVEL LOW WELL E OF THE AREA. THIS FLOW IS ADVECTING CIRRUS BLOW OFF FROM ITCZ CONVECTION S AND SW TO 6N AND E OF FRANK. AT THE SURFACE...A RIDGE ENTERS THE REGION THROUGH 32N136W...AND STRETCHES TO 27N128W TO NEAR 24N122W. HIGH PRES COVERS THE AREA N OF 19N AND W OF 121W. A 1009 MB LOW NEAR 21N115W...THE REMNANTS OF FORMER TROPICAL DEPRESSION EIGHT...IS DRIFTING W. ONLY FRACTURED SCATTERED TO BROKEN LOW CLOUDS ARE NOTED WITHIN 60 NM OF THE LOW. THE LOW IS WEAKENING...AND IS FORECAST TO DISSIPATE IN ABOUT 24 HOURS. A TROUGH IS ANALYZED FROM 14N127W TO 11N123W. ONLY ISOLATED WEAK CONVECTION IS OCCURRING WITHIN 30 NM OF TROUGH. ANOTHER TROUGH IS OVER THE FAR EASTERN PART OF THE AREA TO THE E OF FRANK...AND EXTENDS FROM THE NW YUCATAN PENINSULA S TO 11N90W. IT IS UNDER AN AREA WHERE THE UPPER LEVEL NE FLOW TENDS TO BECOME SOMEWHAT DIFFLUENT...ENHANCING CONVECTION ALONG AND N OF THE ITCZ AS MENTIONED ABOVE AND INITIATING A CLUSTER OF SIMILAR TYPE CONVECTION BETWEEN IT AND FRANK WITHIN 90 NM OF 14N95W. WITH RESPECT TO MARINE ISSUES...CROSS EQUATORIAL S AND SW SWELLS WITH PEAK WAVE PERIODS OF 18-20 SECONDS CONTINUES TO AFFECT THE SOUTHERN WATERS MAINLY S OF ABOUT 14N WITH COMBINED SEAS OF 8-11 FT. THIS SWELL EVENT WILL CONTINUE TO PROPAGATE AND EXPAND TO THE N-NE WITHIN THE 48 HOURS WHILE N SWELLS OF 8 FT SPREAD S TO 28N BETWEEN 120W-125W AND S TO 22N E OF 130W IN 48 HOURS. $$ AGUIRRE