000 AXPZ20 KNHC 272125 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SUN JUL 27 2014 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2100 UTC. ...SPECIAL FEATURES... HURRICANE HERNAN IS CENTERED NEAR 18.6N 112.2W AT 27/2100 UTC OR ABOUT 285 NM SSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MOVING NW AT 13 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 992 MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH GUSTS TO 80 KT. SCATTERED TO NUMEROUS MODERATE CONVECTION IS FROM 16N TO 22N BETWEEN 109W AND 114W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC FOR MORE DETAILS. SATELLITE IMAGERY SHOWS THE CENTER OF A 1007 MB LOW IS LOCATED NEAR 14N133W MOVING W AT 10 KT. THE LOW-LEVEL CIRCULATION CENTER REMAINS EXPOSED WITH AN AREA OF SCATTERED TO NUMEROUS MODERATE CONVECTION OCCURRING TO THE EAST FROM 12N TO 16N BETWEEN 127W AND 132W. UPPER-LEVEL WINDS ARE UNFAVORABLE FOR TROPICAL CYCLONE DEVELOPMENT...WHICH IS CONTINUING TO PROVIDE OVERALL POOR ORGANIZATION CURRENTLY. AN AREA OF FRESH TO STRONG WINDS WITH SEAS TO 12 FT IS EXPECTED TO ACCOMPANY THIS SYSTEM DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 12N94W TO 22N92W MOVING E AT 15-20 KT. WIDELY SCATTERED MODERATE CONVECTION IS FROM 07N TO 14N BETWEEN 92W AND 98W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 08N78W TO 09N94W TO 07N102W TO 11N107W THEN RESUMES FROM 13N115W TO 1010 MB LOW PRES NEAR 11N121W TO 14N128W. THE INTERTROPICAL CONVERGENCE ZONE AXIS IS FROM 13N135W TO 12N140W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 04N TO 09N BETWEEN 79W AND 87W...FROM 06N TO 10N BETWEEN 104W AND 108W...AND FROM 10N TO 13N W OF 137W. ...DISCUSSION... AN UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY WITH AXIS EXTENDING FROM 32N130W TO A BASE NEAR 15N129W. MOSTLY DRY AIR ACCOMPANIES THIS TROUGHING GENERALLY N OF 17N BETWEEN 123W AND 138W. THE 1007 MB LOW CENTERED NEAR 14N133W REMAINS JUST WEST OF THE BASE OF THE TROUGH WITH MOST OF THE CONVECTION ASSOCIATED WITH THE LOW OCCURRING TO THE EAST LEAVING THE LOW-LEVEL CIRCULATION CENTER EXPOSED. FARTHER EAST...A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER NORTH TEXAS WITH A RIDGE OVER NORTHERN MEXICO. THE RIDGING NARROWS SOMEWHAT OVER NORTHERN MEXICO AND TIES IN WITH ANOTHER ANTICYCLONE CENTERED IN THE VICINITY OF HURRICANE HERNAN NEAR 22N108W. THIS UPPER LEVEL FEATURE IS PROVIDING A FAVORABLE ENVIRONMENT ALOFT FOR HERNAN AS THE CYCLONE WILL MAINTAIN HURRICANE INTENSITY DURING THE NEXT 24 HOURS. THEREAFTER...INCREASING WESTERLY SHEAR AND COOLER WATERS ARE EXPECTED TO WEAKEN HERNAN MONDAY THROUGH WEDNESDAY. EXPECT WINDS TO PULSE UP TO A RANGE OF 15 TO 20 KT WITH SEAS TO 7 FT ACROSS THE GULF OF PAPAGAYO DURING THE EARLY MORNING HOURS WITH THE AID OF NOCTURNAL DRAINAGE FLOW. IN ADDITION...BY EARLY TUE...N WINDS IN THE RANGE OF 20 TO 25 KT WILL OCCUR BRIEFLY IN THE GULF OF TEHUANTEPEC BUILDING SEAS TO 9 FT. CONDITIONS ARE EXPECTED TO IMPROVE BY LATE TUE. OTHERWISE...A SURFACE RIDGE DOMINATES THE REMAINDER OF THE AREA N OF 20N W OF 117W. THE PRESSURE GRADIENT BETWEEN THE SOUTHERN PERIPHERY OF THE RIDGE AND THE LOW PRESSURE AREA NEAR 14N133W CONTINUES TO GENERATE WINDS IN THE RANGE OF 20 TO 25 KT WITH SEAS REACHING A MAXIMUM OF 12 FT OVER THE NEXT 48 HOURS. THE LOW IS FORECAST TO MOVE WESTWARD AND NEAR THE WESTERN EDGE OF THE FORECAST AREA BY LATE TUE. SE SWELL FROM THE SOUTHERN HEMISPHERE CONTINUES TO IMPACT THE SOUTH-CENTRAL WATERS...GENERALLY S OF 02N BETWEEN 103W AND 120W. THIS SWELL EVENT WILL CONTINUE TO PROPAGATE FARTHER WEST ACROSS THE FORECAST REGION. $$ HUFFMAN