HAWAII EXTENDED FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD 755 AM EDT TUE OCT 09 2012 VALID 00Z WED OCT 10 2012 - 00Z WED OCT 17 2012 9/00Z MODEL PACKAGES INCLUDING THE OPERATIONAL GFS/ECMWF AND THEIR RESPECTIVE ENSEMBLES ARE SOLID PIECES OF GUIDANCE THROUGH DAY 7. ALTHOUGH THE RECENT GUIDANCE HAS SHIFTED THE BROAD LONGWAVE BY 20 DEGREES...ALONG 170W (9/00Z RUNS) VS ALONG 170E (8/00Z)...THEY CONTINUE TO HOLD FIRM WITH THE FAST-ZONAL FLOW BETWEEN 40N-50N. THIS REGION OF LONGITUDE IN THE WEST CENTRAL PACIFIC WILL REMAIN IN FLUX FOR ANOTHER 2-4 DAYS...SINCE THE TROPICAL THAT WILL EVENTUALLY BECOME ENTRAINED INTO THE FLOW...HAS BEEN IDENTIFIED BUT INCORRECTLY INTRODUCED INTO THE SOLUTION. STILL BELIEVE THE LONGWAVE WILL FORM WEST OF THE DATELINE. THE SERIES OF MODERATE TO STRONG SHORTWAVES GENERATED BY THE ZONAL FLOW ALOFT...ARE STILL ON TRACK TO CREATE A SEMI-STABLE WAVE TRAIN THROUGH NEXT WEEKEND (FRIDAY/SATURDAY/SUNDAY) AT MID LATITUDES. THIS ESTABLISHES A MID-LEVEL RIDGE AND STABLE CONDITIONS TO WORK INTO THE SUBTROPICS THROUGH THE END OF THE FORECAST PERIOD. ONSET OF A 'FRESH TRADEWIND' STILL LOOKS TO OCCUR ON WEDNESDAY...WITH MODEST ACCELERATION OF THE FLOW THROUGH NEXT WEEKEND AND INTO MONDAY. UNTIL THE TROPICAL SYSTEM BECOMES ENTRAINED INTO THE FLOW PATTERN OFF THE COAST OF SOUTH CENTRAL ASIA...EXPECT SEASONAL SENSIBLE WEATHER CONDITIONS. THE 9/00Z GFS/ECMWF OPERATIONAL RUNS WERE DECENT PIECES OF SHORT RANGE AND MEDIUM RANGE GUIDANCE FOR HAWAI'I. OVERALL...BOTH OPERATIONAL RUNS ARE SLIGHTLY SLOWER VERSIONS OF THEIR ENSEMBLE MEANS OVER THE PACIFIC. VOJTESAK