000 AXPZ20 KNHC 190914 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON OCT 19 2015 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0730 UTC. ...SPECIAL FEATURES... HURRICANE OLAF WAS CENTERED NEAR 9.9N 136.4W AT 0900 UTC MOVING WEST OR 280 DEGREES AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE WAS 978 MB. THE MAXIMUM SUSTAINED WIND SPEED WAS 85 KT WITH GUSTS TO 105 KT. NUMEROUS STRONG CONVECTION WAS WITHIN 90 NM OF CENTER...WITH SCATTERED MODERATE TO STRONG CONVECTION WITHIN FROM 06N-12N BETWEEN 133W-138W. OLAF IS FORECAST TO CONTINUE TO INTENSIFY THROUGH TUE AS IT MOVES W-NW. OLAF IS EXPECTED TO REACH MAJOR HURRICANE INTENSITY TONIGHT. PLEASE SEE LATEST FORECAST ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS ON OLAF. GULF OF TEHUANTEPEC...LOW PRESSURE HAS FORMED AS A RESULT OF THE INTERACTION OF THE MONSOON TROUGH AND THE GAP WINDS EXTENDING S- SW FROM THE GULF OF TEHUANTEPEC. THIS LOW PRESSURE AREA IS EMBEDDED IN A LARGE-SCALE CENTRAL AMERICAN GYRE. ABUNDANT TROPICAL MOISTURE ACROSS THE NORTHERN HALF OF CENTRAL AMERICA AND SOUTHERN MEXICO ASSOCIATED WITH THE GYRE WILL INCREASE THE POTENTIAL FOR ACTIVE WEATHER OVER THIS AREA FOR THE NEXT COUPLE OF DAYS. THE GLOBAL MODELS CONTINUE TO SUGGEST THE LOW COULD DEVELOP INTO A TROPICAL CYCLONE AROUND MID-WEEK. THERE IS CURRENTLY A MEDIUM CHANCE FOR TROPICAL CYCLOGENESIS WITHIN THE NEXT 48 HOURS. REGARDLESS OF TROPICAL CYCLONE FORMATION...THIS SYNOPTIC SETUP HAS INCREASED THE POTENTIAL FOR LOCALLY HEAVY RAINFALL WHICH MAY LEAD TO FLASH FLOODING AND DANGEROUS MUDSLIDES OVER PORTIONS OF CENTRAL AMERICA AND SOUTHEASTERN MEXICO OVER THE NEXT COUPLE OF DAYS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 14N92W TO LOW PRES NEAR 12.5N95.5W 1008 MB TO 07N121W. SCATTERED MODERATE TO STRONG CONVECTION WAS OVER FORECAST WATERS FROM 11N-15N BETWEEN 87W-94W AS WELL AS N OF 13N BETWEEN 96W-102W. ...DISCUSSION... A 1026 MB SUBTROPICAL HIGH PRESSURE CENTER NEAR 34N139W EXTENDS A RIDGE SE TO THE ISLAS REVILLAGIGEDO. RECENT SCATTEROMETER PASSES SHOW MODERATE TO FRESH N-NW WINDS ALONG THE PACIFIC COAST OF THE BAJA CALIFORNIA PENINSULA N OF 26N...TO THE N OF THE RIDGE. THE TIGHTEST PRESSURE GRADIENT IS FORECAST TO SHIFT N THROUGH EARLY WED AS TROUGHING BUILDS OVER THE INTERIOR WESTERN UNITED STATES. INCREASING WINDS N OF THE AREA WILL SEND NW SWELL INTO THE NE PORTION OF THE FORECAST AREA WHERE IT WILL MEET UP WITH THE LONGER PERIOD NW SWELL ALREADY IN PLACE. 7-9 FT SEAS IN THIS LONGER PERIOD SWELL CURRENTLY SPAN THE AREA N OF 25N W OF 118W. THE AREA WILL SHRINK TO E OF 127W BY TUE AND REMAIN RELATIVELY UNCHANGED THROUGH EARLY WED. THE BUILDING SUBTROPICAL HIGH HAS HELPED EXPAND THE 20-33 KT WINDS OVER THE NORTHERN PART OF OLAF TO WITHIN 420 NM N QUADRANT. THE RIDGE WILL SHIFT SLIGHTLY TO THE W OVER THE NEXT TWO DAYS IN TANDEM WITH HURRICANE OLAF...MAINTAINING THIS PRESSURE GRADIENT. OUTSIDE OF THE CIRCULATION ASSOCIATED WITH OLAF... MODERATE TO FRESH TRADE WINDS PREVAIL OVER MUCH OF THE DISCUSSION AREA N OF 15N W OF 115W. THIS AREA WILL SHIFT SLIGHTLY WESTWARD AS THE RIDGE AXIS SHIFTS WESTWARD THROUGH EARLY WED. THE 18-20 SECOND PERIOD SW SWELL THAT IS CURRENTLY AFFECTING THE PACIFIC COAST OVER THE ENTIRE FORECAST AREA WILL SUBSIDE TODAY. THIS LONG-PERIOD SWELL COULD MAKE FOR DANGEROUS CONDITIONS ENTERING AND EXITING PORTS AND WILL INCREASE THE THREAT OF RIP CURRENTS TODAY...BUT CONDITIONS SHOULD IMPROVE BY TUE. $$ SCHAUER