000 AXPZ20 KNHC 080325 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI AUG 08 2008 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 0315 UTC. ...SPECIAL FEATURE... TROPICAL STORM HERNAN IS CENTERED NEAR 14.9N 117.8W OR ABOUT 655 NM...1215 KM SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA AT 08/0300 UTC MOVING W AT 12 KT. MAXIMUM SUSTAINED WINDS REMAIN 55 KT WITH GUSTS TO 65 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 994 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. THE INTENSIFICATION TREND NOTED EARLIER HAS LEVELED OFF AS THE CYCLONE CONTINUES TO BATTLE NORTHEASTERLY SHEAR ON THE ORDER OF 15-20 KT AS DETERMINED FROM CIMSS SHEAR ANALYSES. THE MID-LEVEL CENTER IS DISPLACED TO THE SOUTHWEST OF THE LOW LEVEL CENTER DUE TO THE SHEAR. THE CONVECTION ASSOCIATED WITH HERNAN CONSISTS OF NUMEROUS STRONG WITHIN 90 NM OF THE CENTER IN THE S SEMICIRCLE. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED ELSEWHERE WITHIN 60 NM N AND 180 NM S SEMICIRCLES. DESPITE THE SHEAR HERMAN IS FORECAST TO STRENGTHEN INTO A MINIMAL HURRICANE ON FRIDAY INTO SATURDAY BEFORE MOVING ENCOUNTERING COOLER WATER AND WEAKENING. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 104W FROM 7N TO 16N MOVING W ABOUT 10 KT. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 240 NM EITHER SIDE OF THE WAVE AXIS FROM 8N-12N. SOME MID-LEVEL TURNING IS ASSOCIATED WITH THE WAVE AXIS ITSELF. THIS WAVE REMAINS UNDER A VERY FAST UPPER LEVEL ELY FLOW PREVENTING IT FROM DEVELOPING OVER THE NEXT 48 HOURS. A TROPICAL WAVE ALONG 135W FROM 5N TO 15N IS MOVING W ABOUT 10-15 KT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS NOTED W OF THE WAVE AXIS TO 140W. ...ITCZ... ITCZ AXIS ALONG 7N79W 6N88W 10N103W 15N110W 12N120W 10N130W 10N140W. SCATTERED TO NUMEROUS STRONG CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 83W-91W. SCATTERED MODERATE ISOLATED STRONG IS WITHIN 240 NM N OF THE AXIS W OF 134W...AND WITHIN 120 NM S OF THE AXIS BETWEEN 119W AND 127W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM EITHER SIDE OF THE AXIS BETWEEN 99W AND 110W. ...DISCUSSION... W OF 130W... A MIDDLE/UPPER LEVEL TROUGH EXTENDS SW INTO THE AREA FROM 32N129W SW TO NEAR 20N140W BECOMING A SHEAR AXIS W OF THE AREA. THE TROUGH IS MOVING E ABOUT 10 KT. MODERATE SUBSIDENCE AND ASSOCIATED DRY AIR IS OBSERVED WITHIN 300 NM SE OF THE TROUGH. UPPER LEVEL MOISTURE IS SEEN PUSHING SEWD INTO THE NORTHERN PORTION OF THE AREA BEHIND THE TROUGH. SLIGHT DIFFLUENCE TO THE SE OF THE TROUGH IS ENHANCING ITCZ CONVECTION W OF 134W. THE TROUGH IS FORECAST TO LIFT NE AND DAMPEN OUT OVER THE NEXT 48 HOURS AS MID/UPPER LEVEL RIDGING BUILDS SW TO NEAR 130W AND N OF 20N. A NEARLY STATIONARY ELONGATED MID/UPPER LEVEL ANTICYCLONE IS LOCATED JUST W OF THE REGION NEAR 15N144W. STRONG EASTERLY UPPER LEVEL WINDS ARE NOTED FROM 3N-15N. AT THE SURFACE...A RIDGE EXTENDS SE FROM 32N140W TO 21N110W. HIGH PRES COVERS THE AREA N OF 15N W OF 124W. BROKEN TO SCATTERED STRATOCUMULUS CLOUDS MOVING SW TO W WITH POSSIBLE ISOLATED SHOWERS ARE PRESENT NW OF A LINE FROM 21N120W TO 15N140W. E OF 130W... THE UPPER FLOW THROUGHOUT THIS AREA IS PRIMARILY BEING STEERED BY A LARGE UPPER LEVEL ANTICYCLONE CENTERED OVER THE GREAT PLAINS IN COMBINATION WITH A RATHER ELONGATED UPPER LEVEL CYCLONE OVER THE NW CARIBBEAN SEA S OF WESTERN CUBA. RIDGING FROM THE ANTICYCLONE EXTENDS SOUTHWARD TO NORTHERN MEXICO... WHILE THE UPPER FLOW TO THE W OF THE UPPER LEVEL CYCLONIC CIRCULATION EXTENDS W COVERING THE YUCATAN PENINSULA...GUATEMALA AND BELIZE AND HONDURAS. UPPER LEVEL DEBRIS MOISTURE FROM ITCZ CONVECTION IS BEING CHANNELED WESTWARD UNDER THE UPPER ELY FLOW TOWARD HERNAN. A MID/UPPER LEVEL RIDGE ALONG 88W S OF 11N IS MOVING W 10-15 KT. AT THE SURFACE A WEAK PRES PATTERN PREVAILS...WITH THE EXCEPTION OF THE GULF OF PAPAGAYO AND THE AREA FROM 10N TO 12N E OF 92W WHERE E WINDS OF 20 KT AND SEAS TO 8 FT WILL MOST LIKELY CONTINUE THROUGH THE NEXT 72 HOURS. ANOTHER TROPICAL WAVE E OF THE AREA OVER THE WESTERN CARIBBEAN SEA ALONG 79W WILL FURTHER ENHANCE THE LIFE SPAN OF THESE WINDS THROUGH THE NEXT 3 DAYS AS IT MOVES WESTWARD AT 15 KT ACROSS CENTRAL AMERICA AND INTO THE E PACIFIC WATERS. $$ COBB