Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/26/20

Area Forecast Discussion

National Weather Service Grand Forks ND

 917 PM CST Fri Dec 25 2020

.UPDATE...
Issued at 916 PM CST Fri Dec 25 2020

Seeing some patchy ground fog forming around Fargo to Thief River
Falls. Conditions over the region highly variable. Some spots are
calm and temps have dropped to around 10 degrees. Other locations
mainly west of the RRV have a light west wind and not as cold.
Then Warroad to Bemidji area in clouds and likely stay in them as
upstream cloud cover extends well north. Updated to expand patchy
fog mention to most areas, except far east, into Sun AM.

UPDATE Issued at 604 PM CST Fri Dec 25 2020

A mild day west of the Red River and this evening continued mild
with a light NW wind and some high clouds. Band of stratocu that
dropped out of E Manitoba and Ontario is moving south mainly
affecting Baudette but finger of low clods moving thru Bemidji to
near Detroit Lakes. This band is moving southeast pretty quickly
with clearing behind it. But upstream stratocu in E Manitoba
likely will keep immediate Lake of the Woods area cloudy tonight.

Rest of the area, the degree of cloud cover and especially what
type is uncertain. Many of the short term models develop low
clouds in an area of high pressure which will be Minot to
Jamestown region late tonight. Some fog in this zone as well is
possible. Uncertain as to extent of this in our fcst area, though
higher chances in DVL region to Valley City and this is where prev
shift has some patchy fog overnight. Low temperatures as well are
a bit tricky as dew pts at 00z in the 15-25 degree range E ND but
with high moving in and winds going light radiational cooling
enough to lower temp and dew pt...though HRRR sfc temps have more
teens vs single digits in E ND.

&&

.SHORT TERM...(This afternoon through Sunday)
Issued at 330 PM CST Fri Dec 25 2020

Main short term focus is on the clipper this weekend that could
bring light accumulations and slick travel conditions to our region.

This afternoon-Tonight: Quiet and relative mild conditions are in
place with above freezing temperatures across much of eastern ND
this afternoon and mostly sunny skies. There will be an increasing
trend in cloud cover (high from the west and low from the east) this
evening. Overnight temperatures should be near seasonal averages in
the single digits above zero. As low level moisture increases low
clouds and even some patchy fog may develop by Saturday morning.

Saturday-Sunday: The clipper moves across our region Saturday night
into Sunday followed by a stronger cold front Sunday night. There is
good consensus that light snow will progress across most of our
forecast area west to east, with around 1" or less likely based on
model consensus. Good synoptic forcing is advertised, but mesoscale
forcing will tend to be more disorganized, with progressive pockets
of elevated frontogenesis shown by NAM/GFS. So, while localized
higher amounts are possible as indicated by HREF/and some outliers
confidence isn`t as high in where 2" or greater amounts may actually
set up. Winds during the event should generally remain 5-15 mph,
but as the cold front moves in, northerly gusts 20-30 mph may
lead to patchy drifting/blowing of any snow that has fallen Sunday
afternoon. Most likely impacts will be slick travel conditions
with some visibility restrictions mainly due to the snowfall
itself.

.LONG TERM...(Sunday night through Friday)
Issued at 330 PM CST Fri Dec 25 2020

Overview...

A potentially impactful winter weather system will be possible
Tuesday into Wednesday, but exact details are still variable at this
time. Otherwise, the majority of the long term period is expected
to remain quiet with generally below normal, but still
seasonable, temperatures.

Northwesterly flow aloft looks to continue to dominate the upper
level pattern. While this pattern is typically conducive to
periodic, transient shortwaves, ridging over the Pacific Northwest
will keep the majority of these waves to the north of the
international border. The Tuesday/Wednesday system, however, will be
driven by an upper level trough progressing through the Plains.

Sunday night and Monday...

Some lingering light snow may be possible across west central
Minnesota but should taper off moving into the overnight hours. A
brisk northerly wind will aid in dropping low temperature by Monday
morning into the negative single digits to negative teens across the
forecast area. Below normal temperatures are expected to persist
into Monday with highs in the single digits to mid teens.

Tuesday through Thursday...

The quiet weather pattern may potentially be disrupted by the
aforementioned upper level trough. Ensemble guidance is in
relatively good agreement on the timing of the incoming system, but
there are still significant discrepancies from member to member with
respect to the location of this potential system. GEFS and ECMWF
ensembles are depicting a negatively tilted system that would
increase snow potential over our forecast area as a result of the
placement of the deformation zone. In contrast, CMC ensemble
members are showing indications of a relatively vertically stacked
system which would keep the system further to the south of our
forecast area. This variance between models and ensemble members
alike adds to the uncertainty of the location and intensity of this
system which in turn factors heavily into the potential impacts from
this system. All of that being said, current consensus is leaning
toward the best chance for measurable snow for areas south of
highway 2. Confidence is still low however and this system will
continue to be monitored moving forward into next week.

Prior to this system, high temperatures on Tuesday are expected to
remain near normal for much of the forecast area. Following the
passage of this system, high pressure looks to settle in and
slightly below normal temperatures return to the area and
should persist through the midweek period.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 604 PM CST Fri Dec 25 2020

Uncertainity is present in regards to develop of lower ceilings
(MVFR and psbl IFR) late tonight/Sat AM. DVL seems most likely vs
GFK/FAR/TVF. High pressure will be in the Minot-Jamestown area by
12z and with it light winds and potential for some fog/low cloud
formation. Bemidji area too could be affected by lower
ceilings...one band moving thru at 00z but upstream clouds in
eastern Manitoba may affect BJI area overnight/Sat AM.


&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
$$

UPDATE...Riddle
SHORT TERM...DJR
LONG TERM...Rick
AVIATION...Riddle