Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
321 AM EDT Fri Jun 05 2020
Valid Jun 05/0000 UTC thru Jun 08/1200 UTC
...See NOUS42 KWNO (ADMSDM) for the status of the upper air
ingest...
00Z Final Model Evaluation Including Preferences and Confidence
...Amplifying wave shifting east across Ontario through tonight
and northern New England Saturday night...
Preference: Blend of 00Z ECMWF/NAM/CMC with some 00Z GFS/UKMET
Confidence: Average
Good agreement among global guidance with this trough amplifying
as it shifts east across the northeastern CONUS this weekend. The
00Z GFS depicts its typical too progressive bias by Sunday/Day 3,
but that is as the mid-level trough axis is shifting off Maine.
The 00Z CMC is now much more in line with the consensus with
rather similar QPF to the 00Z NAM. Day 2 QPF from the 00Z ECMWF/
NAM are similar and are preferred along with the CMC. The GFS QPF
is a bit progressive for Day 2, but inclusion of it and the 12Z
UKMET are reasonable at lower weights.
...Initial cut-off low offshore southern California, moving
onshore tonight, into Great Basin Saturday, the Wyoming Rockies
Saturday night, and the northern Plains Sunday.
Preference: General Model Blend
Confidence: Slightly above average
A cut off upper low will onshore into southern California this
evening. The low opens up as it moves inland within confluent flow
and becomes an open wave and deamplifies as it moves north across
the Great Basin Saturday. The shortwave energy merges with the
northern stream closed low over the Pacific northwest, with the
models showing a 700-500 mb wave and sfc flow developing in MT
late Saturday, with the sfc low crossing into Canada by 12Z
Sunday. Even the sfc low developing in ID and moving into MT Sat
has good clustering among global guidance. The good clustering
supports a model blend to mitigate minor timing and location
differences.
...Closed low off British Columbia drifting south through Friday
night and then off Washington/Oregon Saturday, moving east and
onshore Saturday night-Sunday...
Preference: General Model Blend
Confidence: Above average
Excellent global deterministic clustering with the closed 500 mb
low moving south offshore from British Columbia Friday, then off
WA/OR Saturday, then moving the low onshore
Saturday night, and into the Northern Rockies Sunday. There is
better than usual clustering among these models and their
respective ensemble means.
...Cristobal...
Preference: 03Z NHC advisory
Confidence: Refer to NHC products
The official track for T.D. Cristobal is a good of compromise of
non-GFS 00Z global guidance through Day 2 since the GFS is farther
east and faster through this time. The 00Z ECMWF/NAM/UKMET/CMC
cluster well through Day 2. Most guidance shifts the track west on
Day 3 near the central Gulf coast with the NHC track right near
all global deterministics but the 00Z CMC by Sunday night.
Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml
Jackson