000 AXPZ20 KNHC 270249 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC. ...SPECIAL FEATURES... TROPICAL STORM HERNAN IS CENTERED NEAR 16.2N 108.9W AT 27/0300 UTC OR ABOUT 405 NM S OF THE SOUTHERN TIP OF BAJA CALIFORNIA MOVING NW AT 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. SCATTERED TO NUMEROUS MODERATE CONVECTION IS FROM 14N TO 19N BETWEEN 106W AND 110W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC FOR MORE DETAILS. TROPICAL DEPRESSION GENEVIEVE IS CENTERED NEAR 12.5N 139.2W AT 27/0300 UTC OR ABOUT 1030 NM ESE OF SOUTH POINT HAWAII MOVING W AT 9 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. ISOLATED MODERATE CONVECTION IS FROM 09N TO 14N BETWEEN 135W AND 138W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. GOES-W SATELLITE IMAGERY SHOWS THE CENTER OF A 1007 MB LOW IS NEAR 14.5N129W. THE LOW-LEVEL CIRCULATION REMAINS EXPOSED WITH SCATTERED MODERATE CONVECTION OCCURRING TO THE EAST FROM 12N TO 15N BETWEEN 124W AND 130W. UPPER LEVEL SOUTHWESTERLY WINDS ARE TO THE NW OF THE LOW AS AN UPPER LEVEL TROUGH AXIS LIES FROM 30N129W TO 15N136W. AS THE LOW DRIFTS GENERALLY WESTWARD...IT WILL BECOME IMPACTED BY THE UPPER LEVEL DRY AIR AND WIND SHEAR THAT AWAITS IT TO THE NW. BEFORE THAT OCCURS HOWEVER...THERE IS A FAVORABLE WINDOW FOR TROPICAL CYCLONE DEVELOPMENT BEFORE SUNDAY. AN AREA OF FRESH TO STRONG WINDS WITH SEAS TO 10 FT IS FORECAST WITH THIS SYSTEM DURING THE NEXT 48 HOURS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 09N84W TO 07N96W TO 12N105W THEN RESUMES 13N111W TO 1009 MB LOW PRES NEAR 10N119W TO 1007 MB LOW PRES NEAR 14N129W TO 13N137W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 04N TO 09N BETWEEN 82W AND 89W...AND FROM 05N TO 09N BETWEEN 118W AND 124W. SCATTERED MODERATE CONVECTION IS FROM 04N TO 10N BETWEEN 96W AND 101W. ...DISCUSSION... AN UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER THE NW CORNER OF THE DISCUSSION AREA WITH AXIS EXTENDING FROM A SHORTWAVE NEAR 35N129W TO A BASE NEAR 15N136W. MOSTLY DRY AIR ACCOMPANIES THIS TROUGHING GENERALLY NW OF A LINE FROM 13N140W TO 22N125W TO 32N123W. TO THE EAST OF THIS TROUGHING...UPPER LEVEL DIFFLUENT FLOW IS ENHANCING CONVECTION ALONG THE MONSOON TROUGH MAINLY W OF 120W. A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER OKLAHOMA...NORTH TEXAS...AND THE TEXAS PANHANDLE THAT EXTENDS A RIDGE OVER NORTHERN MEXICO TO ANOTHER ANTICYCLONIC CIRCULATION CENTERED NEAR 18N106W TO THE NE OF TROPICAL STORM HERNAN. THIS RIDGING IS PROVIDING THE MIDDLE TO UPPER LEVEL DIFFLUENT ENVIRONMENT FOR GRADUAL STRENGTHENING OF HERNAN THROUGH EARLY MONDAY...WHEN THEREAFTER IT WILL GRADUALLY WEAKEN DUE TO MOVEMENT ACROSS COOLER WATERS AND A STRONGLY SHEARED ENVIRONMENT. GULF OF PAPAGAYO...NE TO E WINDS ARE EXPECTED TO PULSE EARLY SUNDAY TO A RANGE OF 20 TO 25 KT WITH SEAS OF 8 FT WEST OF THE GULF OF PAPAGAYO AREA. THE WINDS ARE FORECAST TO DIMINISH BY LATE SUNDAY WITH SEAS SUBSIDING BELOW 8 FT AS WELL. OTHERWISE...A SURFACE RIDGE DOMINATES THE REMAINDER OF THE AREA N OF 20N W OF 115W. THE PRESSURE GRADIENT BETWEEN THE SOUTHERN PERIPHERY OF THE RIDGE AND GENEVIEVE IS PRODUCING AN AREA OF FRESH TO STRONG WINDS FROM 11N TO 17N W OF 137W WITH SEAS TO 9 FT. THESE MARINE CONDITIONS ARE FORECAST TO MOVE WESTWARD IN TANDEM WITH GENEVIEVE DURING THE NEXT 12 TO 24 HOURS. $$ HUFFMAN