Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
238 AM EDT Fri Jun 14 2019

Valid Jun 14/0000 UTC thru Jun 17/1200 UTC

...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...

00Z Final Model Evaluation...with Confidence and Preferences
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...Overall CONUS Overview...
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Preference: Days 1-2: General model blend, but with limited weight
on the 00Z.14 NAM
            Day 3: Non 00Z.14 GFS
Confidence: Average

07Z Update: Non-NCEP suite has come in with little variation from
the previous cycle. Most significant discrepancy involves location
and intensity differences with the shortwave driving the
amplifying mid-level trough into the Northern Plains on Sunday
/Day 3./ The UKMET has is now on the shallow/weak side of the
envelope with the GFS remaining on the strong/fast edge. No
changes planned blend keeping a non-GFS preference due to its fast
and deep evolution of the shortwave digging out of Canada.

Previous Discussion:
Synoptic pattern across the CONUS will feature generally broad
cyclonic flow as a deep vortex across Southeast Canada gradually
lifts northeast to be replaced by renewed troughing from the
Pacific Coast of Canada by Sunday. For Friday and Saturday (D1-D2)
the global suite envelope is relatively minimal across the
northern tier, with the biggest differences occurring in the broad
cyclonic, nearly zonal, flow across the the central/southern part
of the CONUS. In this flow, small vorticity impulses shed
repeatedly from west to east, and the NAM tends to deepen each one
of these too strongly with respect to the other guidance. Although
the timing of the NAM impulses are in line with the others, the
impressive depth of each feature seems overdone and should be used
with caution. By day 3, Sunday, the GFS drops heights faster and
more robustly in the Great Lakes and Northern Plains in response
to deepening shortwave energy dropping out of British
Columbia/Alberta. The GFS far outpaces the rest of the suite and
its own ensemble mean. This has impact on both temperatures and
precipitation across the northern tier. For consistency with the
previous preferred blend and to the current global consensus, the
GFS is not preferred for the latter portion of this forecast
period.

Model trends at www.wpc.noaa.gov/html/model2.html
500 mb forecasts at www.wpc.noaa.gov/h5pref/h5pref.shtml

Weiss