479 
FXUS63 KFGF 141842
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1242 PM CST Thu Jan 14 2021

.UPDATE...
Issued at 1241 PM CST Thu Jan 14 2021

Radar returns have been increasing across portions of the CWA,
although most of the reports in the Red River Valley have been
drizzle rather than snow. Further east, more of a graupel/snow 
mix at this point although there was some drizzle/FZDZ earlier. 
Winds have increased to around 40 mph gusts in the Devils Lake 
Basin, but not much precip going on at this point. Some lower vis 
further north in Langdon, but not a whole lot of snow reported at 
this point. Will continue to monitor for changes that are needed 
for headlines. With drizzle/freezing drizzle along with snow and 
not too much in the way of whiteout conditions being reported yet,
will keep the winter weather advisory for now. Will see how 
things change later this afternoon and we get more snow and a 
better wind direction for the southern Red River Valley. 

UPDATE Issued at 940 AM CST Thu Jan 14 2021

Starting to get some snow showers and lower visibility out along
our northwestern CWA border. The heavier sustained snow is still
expected to develop further south over MN later today as the upper
system digs down and wraps up. Current CAMs runs are shifting the
heavier precip a bit further east, so still a question of if we
will get the right combination of heavier snow and strong winds in
the southern RRV. Will continue to keep an eye on things for now
and maintain the winter weather advisory. 

UPDATE Issued at 712 AM CST Thu Jan 14 2021

Lull is underway across eastern ND with light wintry mixing has
likely ending with only light snow in our far east and showing 
exiting trends to the east. Upper low is still upstream, but is 
making progress southeast. Strong winds are developing towards the
Devils Lake Basin with gusts around 40-43kt reported at Rolla and
Rugby upstream from our area. I delayed the arrival of snow 
showers this morning in our northwest to match up with upstream 
radar trends in Canada and current obs. Otherwise, forecast still 
in on track, with no change in reasoning/impacts from previous 
discussion. 

&&

.SHORT TERM...(Today through Friday)
Issued at 356 AM CST Thu Jan 14 2021

Potential for hazardous winter travel today through Friday, with a 
wintry mix this morning and snow/blowing snow potential today 
through at least Friday morning. Where moderate snow amounts of 3"
or higher occur and overlap with stronger winds there is 
potential for more significant blowing snow impacts, and at this 
point we will be monitoring the southern RRV for this potential 
(confidence is not high at this time to upgrade current Winter 
Weather Advisories). 

Large scale pattern: 

WV imagery shows circulation associated with mid/upper low 
centered on the southwest Manitoba/southeast Saskatchewan line 
north of ND. This should drop south through the day with a dry 
slot/lull this morning across our central and western CWA. As it 
moves into central and southern MN this upper low deepens and 
deformation along an inverted trough may act as a possible 
location for enhanced banding in our CWA (currently depicted in 
our MN counties). This eventually is shown to weaken as the upper 
low becomes vertically stacked/deepens and that transitions to 
more of a disorganized banding/cluster pattern within the CAA 
region of the upper low. Snow ends Friday afternoon/evening as 
shortwave ridging builds over the Northern Plains.

Regarding p-type this morning: 

A warm nose ahead of the upper low is transitioning across our 
east where showers associated with WAA continue to linger. Surface
temps are hovering near freezing, and rain continues to be 
reported in these areas. Until the colder air filters later this 
morning there continues to be potential for light icing in our 
eastern MN counties (transitioning to snow by late morning). 
Further west there are less organized areas of light radar 
returns, and there could be a pocket or two of light wintry mix 
before showers/more organized activity develops later today. By 
midday all p-types should transition to snow simplifying at least 
that part of the forecast. 

Snow amounts today-Friday: 

Highly variable totals are possible with large ensemble spread 
still present across our CWA. Consensus still keeps best chance 
for more organized banding in MN with some overlap into extreme 
southeast ND. Current consensus still favors potential 3" or 
greater totals in those areas, but with clusters of showers 
rotating through much of our CWA localized high totals may still 
occur as highlighted by ensemble outliers. Potential also still 
exists for 6"+ in parts of northwest/west central MN and the 
strongest signal will be where deformation lingers the longest 
(current WPC snow probs for this are still low). 

Blowing snow impacts today-Friday:

West-northwest flow with increasing pressure gradient and CAA as 
the upper low tracks over our CWA will result in strongest winds 
along and west of the Red River Valley escarpment with potential 
winds in excess of 50mph possible through this afternoon (maybe an
isolated 60 mph from Devils Lake to Valley City). By tonight 
models show surface and BL winds aloft decreasing some north to 
south, however the winds will be shifting to the north- northwest 
favoring possible RRV enhancement tonight into Friday. Strongest 
lingering BL winds fall in the 30-35kt range in our far south at 
that point and that may bleed over into areas where moderate 
snowfall occurs. As has been mentioned we do no have blowable snow
pack on the ground at this time, so new snowfall will be required
for blowing snow impacts. Where the stronger winds 35 mph or 
higher occur with 3" or higher snowfall Blizzard conditions can't 
be ruled out.

We are still expecting isolated whiteout/variable visibilities to
develop by this afternoon and continue into Friday, however in 
the southern RRV if higher totals do end up occurring by this 
evening/overnight we may need to consider issuance of a Blizzard 
Warning. Confidence is too low on 3" or greater amounts also 
correlating with stronger winds and I held off on upgrading. This 
will need to be monitored.

.LONG TERM...(Friday night through Wednesday)
Issued at 356 AM CST Thu Jan 14 2021

Summary... 

The deep trough that affects the area Friday clears out by Saturday 
providing dry conditions through the Northern Plains into the 
weekend. NW aloft continues to be the dominating synoptic pattern,
with the introduction of a more progressive synoptic shortwave 
troughs entering the Northern Plains. This has been indicated in 
some ensembles Sunday night through Wednesday, with two possible 
troughs moving quickly through the area. Impacts are likley to 
remain low through Sunday, with uncertain impacts for the two 
potential shortwave system Monday and Wednesday. At this time they
look to remain minimal for chances.

The weekend...

The system that brings chances for snow and windy conditions Friday 
exists by Saturday, with a NW flow aloft sticking around for the 
Northern Plains. This type of flow allows for continued 
introductions of shortwave troughs from SW Canada at times. However, 
through the weekend, we don't expect any systems to move into the 
area. Dry conditions and slightly above average temperatures stick 
around for the weekend under partly sunny skies.

Monday through Wednesday...

As mentioned before, shortwave troughs are a key feature with a good 
size NW flow over the Northern Plains. As we roll into the beginning 
of next week ensembles have picked up on two separate signals one 
for Monday and the other for Wednesday. The Monday short wave trough 
comes down from Alberta bringing chances for snow to the area. The 
exact amounts are in question as the track continues to shift 
between different runs of the models. Clusters are around minimal 
impacts to the area, with the better chances for snow further 
towards western ND and into MT. This will all be dependent on the 
track of the system. The upper level jet at 500mb is situated 
further to our west where lift potential may occur keeping snow 
amounts lighter toward our area.

The next shot of chances for snow is with a very weak signature that 
a small number of ensembles indicate. This signal is another short 
lived upper shortwave trough from the exact same location in Alberta 
that moves SE through the Northern Plains. Models have not gotten a 
great deal of grip on the system. Confidence is low at this time in 
its development, but there is a slight possibility of light snow 
chances by the middle of next week.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1137 AM CST Thu Jan 14 2021

Snow or rain snow mix has been showing up in more of the
observations across the area. Pretty light so far with visibility
2SM and above, but should see some reductions to visibility a bit
more as winds pick up and we get more of a change over to snow.
For now kept vis during the peak of snow/blowing snow this evening
to around 3/4 to 1SM, but could be briefly lower. Highest wind
gusts will be at KDVL with 40 kts or more possible but they also
have the least chances for snowfall. Ceilings are all over the
place but will gradually become more MVFR to IFR. The snow and
blowing snow will last much of the night before visibility starts
to improve late in the period as winds come down and snow tapers
off. 


&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Winter Weather Advisory until 9 AM CST Friday for NDZ006-007-014-
     015-024-026-028-029-038-049-052-054.

     Winter Weather Advisory until 3 PM CST Friday for NDZ008-016-027-
     030-039-053.

MN...Winter Weather Advisory until 3 PM CST Friday for MNZ001>009-
     013>017-022>024-027>032-040.

$$

UPDATE...JR
SHORT TERM...DJR
LONG TERM...Spender
AVIATION...JR