000 AXPZ20 KNHC 172207 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC THU AUG 17 2006 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 2145 UTC. ...SPECIAL FEATURES... HURRICANE HECTOR IS CENTERED NEAR 15.0N 122.1W OR 975 MILES SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA AT 17/2100 UTC MOVING WNW OR 285 DEG AT 11 KT. MAXIMUM SUSTAINED WIND SPEED IS 80 KT WITH GUSTS TO 100 KT. THE OVERALL STRUCTURE OF THE CYCLONE LOOKS QUITE IMPRESSIVE ON SATELLITE IMAGERY THIS AFTERNOON AS SEEN IN ITS VERY WELL DEFINED-BANDING FEATURES AND NOW VISIBLE EYE FEATURE. GOOD OUTFLOW CHANNEL IS EVIDENT ALL QUADRANTS EXCEPT THE SW. CONVECTION IS OBSERVED IN SPIRAL BANDS WITH SCATTERED STRONG INTENSITY WITHIN 150 NM OF CENTER OVER SE QUADRANT. SIMILAR CONVECTION IS WITHIN 120 NM OF CENTER OVER E QUADRANT...90 NM N QUADRANT AND 60 NM SW QUADRANT OF CENTER. SCATTERED MODERATE CONVECTION IS ELSEWHERE WITHIN 240 NM OF CENTER OVER S QUADRANT AND 180 NM FROM CENTER OVER E AND SE QUADRANTS. HECTOR IS FORECAST TO STRENGTHEN SLIGHTLY WITHIN THE NEXT 24 HOURS THEN BEGIN TO WEAKEN OVER OVER COOLER WATERS THEREAFTER WHILE AT THE SAME TIME UNDERGOING VERTICAL SHEAR. FOR MORE DETAILS SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... SOUTHERN PORTION OF A TROPICAL WAVE IS OVER THE EASTERN PORTION OF THE AREA ALONG 82W N OF 4N TO ACROSS BORDER OF COSTA RICA AND PANAMA...AND CONTINUES NORTHWARD INTO THE WESTERN CARIBBEAN SEA. THIS WAVE IS MOVING W ABOUT 10-15 KT. MAJORITY OF CONVECTION ASSOCIATED WITH THIS WAVE IS TIED IN WITH THE ITCZ AS DESCRIBED BELOW. THE STRONGEST CONVECTION IS OVER THE EXTREME SW CARIBBEAN SEA NEAR THE COAST OF COSTA RICA AND PANAMA. TROPICAL WAVE ALONG 110W FROM 4N-17N IS MOVING W 15 KT. THIS WAVE IS SLIGHTLY MORE DEFINED THAN THE WAVE TO THE E WITH SOME CYCLONIC CURVATURE NOTED IN THE LOW-MID LEVEL CLOUDS ABOUT THE AXIS. ISOLATED SMALL STRONG CONVECTION IN CLUSTERS IS WITHIN 150-180 NM W OF THE WAVE AXIS FROM 10N-12N. REMAINDER OF CONVECTION ASSOCIATED WITH THIS WAVE IS DESCRIBED BELOW UNDER ITCZ. TROPICAL WAVE ALONG 140W FROM 4N-19N IS MOVING W ABOUT 17 KT. THIS WAVE IS BEING DRAWN INTO A BROAD AREA OF CYCLONIC TURNING W OF THE AREA. SCATTERED STRONG CONVECTION IS OCCURRING WITHIN 60-90 E OF THE WAVE AXIS FROM 12N-14N. ISOLATED MODERATE CONVECTION IS ELSEWHERE WITHIN 60 NM OF THE WAVE AXIS. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N85W 9N85W 9N110W 11N120W 14N125W 12N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 86W-93W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 129W-132W. ISOLATED MODERATE CONVECTION IS WITHIN 240 NM S OF THE AXIS BETWEEN 99W-110W. ...DISCUSSION... A BROAD MID-UPPER LEVEL RIDGE REMAINS ESTABLISHED ACROSS THE AREA WITH THE AXIS EXTENDING FROM NRN MEXICO SWD TO A LARGE ANTICYCLONE CENTERED NEAR 17N135W. A BROAD MID-UPPER TROUGH HAS DEVELOPED A WEAKNESS IN THIS RIDGE N OF 22N BETWEEN 122W-132W. THIS TROUGH WILL REMAIN IN THIS AREA OVER THE NEXT FEW DAYS AND MAY AFFECT THE FUTURE TRACK OF HECTOR. MID LEVEL EASTERLIES LIE S OF 20N WITH HECTOR EMBEDDED IN THEM. MODERATE SUBSIDENCE AND DRY STABLE UPPER LEVEL AIR COVERS THE AREA N OF 13N W OF 125W AND ALSO NW OF A LINE FROM 17N125W TO NORTHERN BAJA CALIFORNIA. AMPLE MOSTLY UPPER LEVEL MOISTURE IS BEING ADVECTED WESTWARD SE OF THIS LINE WITH OUTFLOW FROM HECTOR BEING PART OF THE MOISTURE. A WEAK ANTICYCLONE IS CENTERED OVER GUATEMALA WITH A RIDGE EXTENDING WESTWARD TO NEAR 100W. AN UPPER LEVEL MEAN RIDGE AXIS RUNS NW TO SE FROM SE MEXICO TO NICARAGUA. ANTICYCLONIC AROUND THIS RIDGE CONTINUES TO SPREAD DEBRIS MID-HIGH LEVEL MOISTURE NORTHWARD TOWARDS SE MEXICO. S OF THE RIDGE...STRONG MID/UPPER LEVEL EASTERLIES PREVAIL ALSO SPREADING DEBRIS MID-HIGH LEVEL MOISTURE WESTWARD FROM S AMERICA TO NEAR 110W. AT THE SURFACE...RIDGE EXETNDS FROM 32N131W THROUGH 27N121W TO 25N115W. HIGH PRESSURE GENERALLY COVERS THE AREA N OF 22N. PRESSURE GRADIENT DUE TO THE RIDGE IS PRODUCING NE TRADES OF 20 KT FROM 12N-23N W OF 125W. WINDS ALONG THE BAJA COAST CONTINUE TO BE MOSTLY LIGHT UNDER A WEAK PRESSURE GRADIENT...HOWEVER MODEL GUIDANCE OF BOUNDARY LAYER WINDS INDICATES THAT THE GRADIENT MAY INCREASE JUST ENOUGH TO ALLOW FOR NW WINDS OF 20 KT TO SLIDE DOWN THE COAST OF BAJA CALIFORNIA IN 48 HOURS. $$ AGUIRRE