000 AXPZ20 KNHC 180926 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC FRI AUG 18 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0845 UTC. ...SPECIAL FEATURES... HURRICANE HECTOR IS CENTERED NEAR 15.8N 124.4W OR 935 MILES WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA AT 18/0900 UTC MOVING WNW OR 290 DEG AT 12 KT. MAXIMUM SUSTAINED WIND SPEED IS 90 KT WITH GUSTS TO 110 KT. IT HAS A VERY WELL DEFINED EYE WITH A DIAMETER OF 10 NM. GOOD OUTFLOW PATTERN IS STILL PRESENT OVER THE CYCLONE. A SOLID BAND OF STRONG CONVECTION WITHIN 30 NM OF THE CENTER COMPRISES THE EYEWALL. NUMEROUS MODERATE TO STRONG CONVECTION SURROUNDS THE CENTER WITHIN 60 NM. SCATTERED TO NUMEROUS CONVECTION IS IN BANDS WITHIN 180 NM OF THE E SEMICIRCLE. 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 85W N OF 4N TO ACROSS CENTRAL COSTA RICA AND PANAMA...AND CONTINUES NORTHWARD INTO THE WESTERN CARIBBEAN SEA. THIS WAVE IS MOVING W ABOUT 10-15 KT. ISOLATED MODERATE TO STRONG CONVECTION THE PAST FEW HOURS MAINLY NEAR LAND AREAS. NO ORGANIZATION TO THE CONVECTION. TROPICAL WAVE ALONG 112W FROM 4N-16N IS MOVING W 15 KT. ISOLATED MODERATE CONVECTION WITHIN 5 DEGREES EITHER SIDE OF THE WAVE AXIS. THERE IS NO ORGANIZATION TO THE CONVECTION. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N78W 9N87W 10N112W 14N123W 11N140W. SCATTERED MODERATE CONVECTION WITHIN 60 NM OF 5N79W. SCATTERED MODERATE WITHIN 60 NM EITHER SIDE OF A LINE FROM 6N90W TO 10N100W TO 8N109W. ISOLATED MODERATE WITHIN 120 NM OF 9N114W. SCATTERED MODERATE AND ISOLATED STRONG WITHIN 20 NM OF A LINE FROM 10N132W TO 12N140W. CLUSTER OF STRONG CONVECTION NEAR THE EL SALVADOR COAST WITHIN 45 NM OF 12N90W. ...DISCUSSION... A STRONG MID LEVEL RIDGE LIES OVER THE SRN US TONIGHT AND EXTENDS SW ACROSS NRN MEXICO AND BAJA TO NEAR 20N120W. A WEAKER RIDGE LIES OVER THE WRN PORTION OF THE REGION NEAR 27N140W. IN BETWEEN A SHORTWAVE TROUGH LIES BETWEEN 120W AND 130W N OF 27N. THE TROPICAL EASTERLIES ARE MOSTLY S OF 20N TONIGHT. HRCN HECTOR IS EMBEDDED IN THE EASTERLIES DUE S OF THE SHORTWAVE AND MAY BE INFLUENCED BY THE PRESENCE OF THE SHORTWAVE. ON THE SURFACE TONIGHT THE PACIFIC RIDGE AXIS LIES ALONG 30N133W TO 25N120W THEN WEAKLY SE TO NEAR 15N110W. HECTOR IS PUSHING AGAINST THE RIDGE AND ENHANCING THE NE TRADES BETWEEN 15N AND 25N W OF 125W WITH WINDS 20 TO 25 KT AND SEAS 8 TO 10 FT. WINDS ALONG THE BAJA COAST ARE NWLY 10 TO 15 KT TONIGHT ACCORDING TO QUIKSCAT AND IN GOOD AGREEMENT WITH THE GFS MODEL. GAP WINDS AROUND CENTRAL AMERICA ARE MOSTLY LIGHT ALSO. CROSS EQUATORIAL WINDS ARE MOSTLY 15 TO 20 KT ACCORDING TO QUIKSCAT AND SSMI WHERE AVAILABLE. LATER DAY 1 GFS MODEL SHOWS HECTOR CONTINUING WNW BEING NUDGED ALONG BY THE LARGE RIDGE THAT LIES OVER BAJA AND NW MEXICO. THE SHORTWAVE TO THE N OF HECTOR LOOKS LIKE IT WILL BEGIN TO LIFT OUT BUT NOTHING IS REALLY FORCING IT..SO IT WILL TAKES IT'S TIME. ON THE SURFACE LATER DAY 1 GFS MODEL SHOWS LITTLE CHANGE OVERALL WITH THE STRONGEST WINDS REMAINING IN THE NE TRADES W OF 125W. BAJA WINDS REMAIN ABOUT THE SAME 10 TO 15 KT WITH NW SWELL TO 6 FT. GAP WINDS REMAIN LIGHT AND CROSS EQUATORIAL SLY WINDS REMAIN ABOUT THE SAME STRENGTH AT 15 TO 20 KT WITH SLY SWELL TO 8 FT. FOR DAY 2 THE SHORTWAVE TROUGH BEGINS TO ACCELERATE NE AS A NEW SHORTWAVE MOVES RAPIDLY ESE. MOVEMENT OF THE NEW SHORTWAVE ALSO WEAKENS THE PRESSURE FIELD OVER THE NW CORNER OF THE AREA AND HECTOR APPEARS TO BE HEADING THAT WAY. THE SRN US MID LEVEL RIDGE REMAINS OVER THE SAME AREA DAY 2 WITH IT'S RIDGE CONTINUING SW OVER BAJA TO NEAR 20N110W. ON THE SURFACE DAY 2 COULD SEE A SLIGHT INCREASE IN NW WINDS TO 20 KT ALONG THE BAJA COAST AS THE PRESSURE GRADIENT TIGHTENS A LITTLE. NE TRADES 20 TO 25 KT BETWEEN 15N AND 25N W OF 130W WILL CONTINUE AS HECTOR PUSHES AGAINST THE PACIFIC RIDGE. CROSS EQUATORIAL SLY WINDS S OF 7N WILL REMAIN ABOUT THE SAME AT 15 TO 20 KT AND SLY SWELL TO 8 FT. $$ RRG