Thought I would also pass this mini analysis around to our SOOs/DOHs, FWIW.

I've also added 6, matching color URMA 2.5km images, to get a feel for what those data contain as proxies for the MaxT for the day, which is not created in URMA, so one is left to compare to hourly URMA data:

URMA "ges" images from Dec 6th 18, 21, and 22UTC

URMA "anl" images from 22UTC, and 00UTC Dec 7

and

an URMA "err" image from 22UTC

If anyone wishes to take this analysis any further (it might be interesting to compare forecasts with longer lead times) see, and/or contribute views from other tools, feel free. 

I'm also BCCing RTMA VLab Feedback on this email, to create an entry there, as I'd be curious if one can respond there with a more direct place to read more about the ges, anl, and err fields.  I see this link, but it was not overly detailed.

RTMA-URMA - Operational Models Encyclopedia: Deterministic Models (google.com) 

Thanks to Victor for sharing the initial view of this recent anomalous event/Target.

---------- Forwarded message ---------
From: Jack Settelmaier - NOAA Federal <jack.settelmaier@noaa.gov>
Date: Mon, Dec 7, 2020 at 4:13 PM
Subject: Re: Impacts of 12"-15" of Snow in Northwest OK from last Wednesday Nite....
To: Victor Murphy - NOAA Federal <victor.murphy@noaa.gov>
Cc: _NWS SRH ERMET <srh.ermet@noaa.gov>, _NWS SRH STSD <srh.stsd@noaa.gov>, _NWS SRH OSD <srh.osd@noaa.gov>, _NWS SRH.LeadershipTeam <SRH.LeadershipTeam@noaa.gov>

For those that may be interested, I created 4 images (attached) to dig into this Target.  I've compared 3 NBM runs (07, 13, 19UTC), and one NDFD (2048UTC) forecast.  All were created on Dec 5th, all valid for the MaxT on Dec 6th (00UTC Dec 7), matching the Observed MaxT image shown here.

All images only show only areas where MaxT<50 degF (283.15K), to highlight the localized cold of the snowpack.

One can see:

1) The NBM guidance trended to cooler with each run through the day,

2) The afternoon NDFD issuance was the coolest (by about 3 degC) than even the last,19UTC NBM run, which was closest to observed.

On Mon, Dec 7, 2020 at 10:26 AM Victor Murphy - NOAA Federal <victor.murphy@noaa.gov> wrote:

....are still manifesting themselves in the observed (and forecast) max temps.  I've cut and pasted the below from today's Oklahoma Climatological Survey ticker.  What is really impressive is how the NDFD from WFO OUN captures this in the forecast max temps for today.  Great example of the 5 km resolution.

VM

http://ticker.mesonet.org/archive/20201207/yesterdays-highs.png

http://ticker.mesonet.org/archive/20201207/NW-ok-snow.png

Heavy snow in the wintertime is the gift that keeps on giving...days after it
fell. While the Restivus (NO, not Festivus) were basking in lovely 50s and 60s
(it's relative...work with me), the far NW corner downstate was stuck in the 30s
and 40s. My beloved Buffalo reached a high of 39 degrees, a full 14 degrees colder
than Slapout about 30 miles to its southeast, all under crystal clear skies. The
sun is trying, but 15 inches of snow doesn't melt that quickly. And while the rest
of the state will continue with its unseasonably warm weather this week, that
area of the state will lag behind by 5-15 degrees for awhile before finally
coming to equilibrium with the surrounding area on Thursday, just in time for
another cold front on Friday!

http://ticker.mesonet.org/archive/20201207/todays-forecast-highs.png  

--

Jack Settelmaier

Digital Techniques Meteorologist

NOAA/NWS, Southern Region HQ

Fort Worth, TX 

Work: 682 703 3685

Cell: 817 966 0386

Virtual Office (most core work hours): https://meet.google.com/ujm-ajkv-rhk

--
Jack Settelmaier RTMA/URMA Discussion Group Virtual Lab Forum http://vlab.noaa.gov/web/715073/home/-/message_boards/view_message/12846297 VLab.Notifications@noaa.gov