MODEL DIAGNOSTIC DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD 111 AM EDT SUN OCT 28 2012
VALID OCT 28/0000 UTC THRU OCT 31/1200 UTC
HURRICANE SANDY =============== PREFERENCE: 00Z GFS/12Z ECMWF COMPROMISE BY DEFAULT
THE 12Z ECMWF & 00Z GFS MODELS ARE CLOSEST TO THE NATIONAL HURRICANE CENTER (NHC) TRACK OVER THE NEXT FEW DAYS. STANDARDIZED ANOMALIES AT THE 500 HPA LEVEL WITH SANDY ARE EXTREME FROM THE GET-GO, RUNNING A RARELY-SEEN SIX SIGMAS BELOW AVERAGE NEAR THE 30TH PARALLEL AT THE INITIAL TIME STEP, STRONGLY SUGGESTING A RECORD EVENT IS UNDERWAY. A COMPROMISE OF THE TWO WILL LEAD TO A REASONABLE COMPROMISE ALOFT, WHERE THE 00Z GFS HAS MUCH LOWER 500 HPA HEIGHTS (ON THE ORDER OF 5220 METERS) THAN THE REMAINDER OF THE GUIDANCE (THOUGH ITS STANDARDIZED ANOMALIES NEAR ITS CENTER IN MARYLAND AND PENNSYLVANIA REMAIN WITHIN FOUR SIGMAS OF NORMAL FOR LATE OCTOBER SO IT CANNOT BE DISMISSED), INCLUDING THE NAM WHICH CAN BIAS IN THE DEEP DIRECTION. CONSULT LATEST NHC ADVISORIES/DISCUSSIONS FOR FURTHER INFO REGARDING SANDY.