419
FXUS10 KWNH 071650
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1149 AM EST THU NOV 07 2019
VALID NOV 07/1200 UTC THRU NOV 11/0000 UTC
..SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
...12Z MODEL EVALUATION WITH PRELIMINARY PREFERENCES AND
CONFIDENCE...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~
..SHORTWAVES CUTTING INTO THE PACIFIC NORTHWEST RIDGE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 07/00Z ECMWF AND EC ENSEMBLE MEAN AND 07/12Z NAM
CONFIDENCE: SLIGHTLY BELOW AVERAGE
THE 12Z SUITE OF NCEP GUIDANCE CONTINUES TO STRUGGLE WITH NUMEROUS
AND HARD-TO-TIME SHORTWAVE TROUGHS RIDING AROUND THE PERIPHERY OF
AN ANOMALOUSLY STRONG MID/UPPER LEVEL RIDGE OVER THE EASTERN NORTH
PACIFIC OCEAN. THE 07/12Z GFS HAS MORE ENERGY, AND THEREFORE A
STRONGER FRONTAL PROGRESSION, INTO THE U.S. PACIFIC NORTHWEST
WHILE THE 07/12Z NAM CLUSTERED BETTER WITH THE ECMWF. EVEN THOUGH
THE CMC/UKMET WERE MORE AGGRESSIVE THAN THE ECMWF WITH THE
PATTERN, THOSE MODELS REMAINDER CLOSER TO THE NAM/ECMWF IDEA THAN
THEY DID WITH THE GFS.
..REMAINDER OF OVERALL PATTERN ACROSS THE CONUS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND THROUGH DAY 2, THEN LESS WEIGHT TO
GFS ON SUNDAY
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
THE START OF THE SHORT RANGE PERIOD SHOWS BROAD TROUGHING ALONG
THE EASTERN 2/3 OF THE NORTHERN U.S., PRECEDED UPSTREAM BY
ANOMALOUS RIDGING OVER THE EASTERN PACIFIC INTO THE PACIFIC
NORTHWEST. BY SATURDAY/SUNDAY, THE FLOW IS EXPECTED TO FLATTEN A
BIT ALTHOUGH ANOTHER SHORTWAVE SHOULD SEND ANOTHER ARCTIC FRONT
INTO THE NORTHERN U.S..
EXCEPT FOR THE GFS BEING MARGINALLY STRONGER WITH THE DEPARTING
TROUGH OVER THE EASTERN U.S. ON SATURDAY, THE MODEL AGREEMENT WAS
GENERALLY GOOD IN TERMS OF BOTH POSITION AND INTENSITY. HOWEVER,
SHORTWAVE ENERGY DROPPING OUT OF CANADA LATE SATURDAY OR EARLY
SUNDAY WAS STRONGER IN THE GFS THAN OTHER GLOBAL MODELS WHICH
RESULTED IN IT HAVING MASS FIELDS THAT WERE DEEPER/STRONGER FROM
THE UPPER MIDWEST TO NORTHERN ROCKIES WITH CORRESPONDINGLY COLDER
THERMAL FIELDS. FOR THAT REASON, THINK A GENERAL MODEL BLEND
WORKS EARLY ON DAY 3...ALTHOUGH INCREASINGLY LESS WEIGHT OF THE
GFS SHOULD PROBABLY BE USED AS DURING DAY 3.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
BANN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page