000 AXPZ20 KNHC 081610 CCA TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC FRI AUG 08 2008 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 1545 UTC. ...SPECIAL FEATURE... TROPICAL STORM HERNAN WAS UPGRADED TO A HURRICANE THIS MORNING...AND WAS CENTERED NEAR 14.7N 119.9W OR ABOUT 865 NM ...1390 KM SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA AT 08/1500 UTC MOVING W AT 11 KT. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH GUSTS TO 80 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 987 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. THE CYCLONE HAS CONTINUED TO BECOME BETTER DEFINED DURING THE MORNING AS OBSERVED ON SATELLITE IMAGERY. THIS IS APPARENT BY ITS WELL-DEFINED BANDING FEATURES AND WHAT APPEARS TO BE A SMALL CDO FEATURE WITH A HINT OF FORMING EYE. VERY DEEP BURSTS OF COLD TOP CONVECTION IS OVER AND WITHIN ALL QUADRANTS OF THE CENTER. THIS CONVECTION CONSISTS OF NUMEROUS STRONG WITHIN 80 NM SE AND 60 NM SW THROUGH W OF EYE FEATURE. SCATTERED STRONG CONVECTION IS ELSEWHERE WITHIN 100 NM OF THE EYE. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ELSEWHERE WITHIN 240 NM OF CENTER IN THE S QUADRANT AND 210 NM SE AND SW QUADRANTS. HERNAN IS FORECAST TO REMAIN A HURRICANE THROUGH THE NEXT 48 HOURS BEFORE ENCOUNTERING COOLER SEA SURFACE TEMPERATURES AND BEGIN TO UNDERGO WEAKENING. NEWLY FORMED LOW PRES NEAR 9N87W 1007 MB IS MOVING W 10-15 KT. BOTH CLOUDINESS AND CONVECTION CONSISTING OF THE SCATTERED MODERATE TO STRONG VARIETY HAVE BECOME MORE CONCENTRATED N OF 6.5N BETWEEN 86W-92W. FIRST VISIBLE IMAGERY FROM THIS MORNING SHOW EVIDENCE OF CYCLONIC TURNING IN THE LOW CLOUD FIELD FROM 4N-13N BETWEEN 86W-92W. NWP MODELS SUGGEST THAT THIS SYSTEM IS LIKELY TO BECOME FURTHER ORGANIZED OVER THE NEXT 48 HOURS AS IT MOVES IN WESTWARD TRACK. ...TROPICAL WAVES... THE SOUTHERN PORTION OF A TROPICAL WAVE HAS MOVED INTO THE FAR EASTERN PORTION OF THE AREA N OF 5N ALONG 82W...MOVING W 10-15 KT. SCATTERED STRONG CONVECTION IS WITHIN 45 NM OF 7N82W...AND OVER THE GULF OF PANAMA. A TROPICAL WAVE IS ALONG 106W FROM 5N TO 15N MOVING W ABOUT 13 KT. SCATTERED STRONG CONVECTION IS WITHIN 60 NM W OF THE WAVE FROM 12N-15N. SCATTERED MODERATE ISOLATED/STRONG CONVECTION IS WITHIN 300 NM E OF THE WAVE FROM 9N-15N. LITTLE CHANGE IN BOTH STRUCTURE AND ORGANIZATION OF CONVECTION HAS BEEN OBSERVED WITH THIS OVER THE PAST 24 HOURS AS IT REMAINS UNDER MODERATE ELY SHEAR...HOWEVER SOME SLOW DEVELOPMENT IS STILL POSSIBLE WITH THIS WAVE AS IT MOVES INTO A MORE FAVORABLE UPPER LEVEL ENVIRONMENT DURING THE NEXT 48 HOURS. A TROPICAL WAVE ALONG 138W/139W FROM 6N TO 15N IS MOVING W ABOUT 10-15 KT. THE WAVE IS ENHANCING ITCZ CONVECTION W OF 137W FROM 10N-13N...AND ONLY SLOW DEVELOPMENT IS POSSIBLE OVER THE NEXT COUPLES OF DAYS AS MOVES WNW. ...ITCZ... ITCZ AXIS ALONG 9N84W 8N95W 12N107W 14N118W 10N130W 10N140W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 240 NM N OF THE AXIS E OF 92W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 240 NM N OF THE AXIS BETWEEN 131W-135W ...WITHIN 180 NM N OF THE AXIS BETWEEN 100W-110W AND ALSO WITHIN 150 NM N OF THE AXIS W OF 138W. ...DISCUSSION... W OF 130W... A MIDDLE/UPPER LEVEL TROUGH EXTENDS SW INTO THE AREA FROM 32N131W TO AN ELONGATED BUT SMALL MID/UPPER LEVEL CYCLONIC CIRCULATION MOVING S 15 KT NEAR 24N140W. W OF THE AREA...THE TROUGH BECOMES A SHEAR AXIS TO JUST SE OF THE HAWAIIAN ISLANDS. THE TROUGH IS MOVING SE ABOUT 15 KT. ITS SURFACE REFLECTION IS ANALYZED AS A COLD FRONT JUST N OF THE AREA FROM 33N135W TO 33N140W WHERE IT BECOMES A STATIONARY FRONT NORTHWESTWARD FROM THERE. THE FRONT IS MOVING SSE 15-20 KT...AND IS FORECAST TO RAPIDLY WEAKEN AS IT MOVES TO JUST NE OF THE AREA IN ABOUT 18 HOURS. MODERATE SUBSIDENCE AND ASSOCIATED DRY AIR IS OBSERVED TO THE SE AND S OF THE TROUGH TO NEAR 16N WHERE ITCZ MOISTURE IS EVIDENT. UPPER LEVEL MOISTURE IS SEEN PUSHING SEWD INTO THE NORTHERN PORTION OF THE AREA BEHIND THE TROUGH N OF 20N. SLIGHT DIFFLUENCE TO THE SE OF THE TROUGH IS ENHANCING ITCZ CONVECTION NEAR 130W. THE TROUGH IS FORECAST TO LIFT NE AND DAMPEN OUT OVER THE NEXT 48 HOURS AS MID/UPPER LEVEL RIDGING BUILDS SOUTHWESTWARD FROM THE SW UNITED STATES TO N OF 20N. A NEARLY STATIONARY ELONGATED MID/UPPER LEVEL ANTICYCLONE IS LOCATED W OF THE REGION ALONG 155W N OF 22N. VERY PRONOUNCED MID/UPPER LEVEL RIDGING EXTENDS ALONG 15N...WITH MODERATE TO STRONG UPPER LEVEL E TO SE WINDS NOTED ON SATELLITE-DERIVED WIND DATA S OF 15N. AT THE SURFACE...A RIDGE EXTENDS SE FROM 30N138W TO 25N127W. HIGH PRES COVERS THE AREA N OF 21N W OF 124W. BROKEN TO SCATTERED STRATOCUMULUS CLOUDS MOVING SW TO W WITH POSSIBLE ISOLATED SHOWERS ARE PRESENT NW OF A LINE FROM 18N130W 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 MID/UPPER LEVEL CYCLONE OVER NW CUBA. A TROUGH EXTENDS FROM THE CYCLONE SW TO THE GULF OF HONDURAS...AND SW TO A MID UPPER LEVEL CYCLONIC CIRCULATION MOVING W 16 KT ALONG THE ITCZ NEAR 9N89.5W. RIDGING FROM THE ANTICYCLONE EXTENDS SW TO NW MEXICO...WHILE THE UPPER FLOW TO THE W OF THE UPPER CYCLONE AND TROUGH EXTENDS W COVERING THE YUCATAN PENINSULA...GUATEMALA AND BELIZE. UPPER LEVEL DEBRIS MOISTURE FROM ITCZ CONVECTION CONTINUES TO BE ADVECTED WESTWARD UNDER THIS UPPER LEVEL FLOW ENVIRONMENT TO BEYOND HERNAN. A MID/UPPER LEVEL RIDGE FROM THE GULF OF TEHUANTEPEC TO 10N92W O 6N91W IS MOVING W 13 KT. AT THE SURFACE...A WEAK PRES PATTERN PREVAILS...WITH THE EXCEPTION OF THE GULF OF PAPAGAYO AND THE AREA FROM 10N TO 13N E OF 90W WHERE E WINDS OF 20 KT AND SEAS TO 8 FT WILL LIKELY EXPAND W TO 95W OVER THE NEXT 48-72 HOURS AS THE 1007 MB LOW NEAR 9N87W AND TROPICAL WAVES OF THE DISCUSSION AREA PROPAGATE WESTWARD ACROSS CENTRAL AMERICA...AND INTO THE FAR EASTERN WATERS OF THE THIS AREA AS DEPICTED BY GLOBAL MODEL GUIDANCE. $$ AGUIRRE