FXUS63 KMPX 190440

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1040 PM CST Mon Jan 18 2021

.SHORT TERM...(This evening through Tuesday night)
Issued at 252 PM CST Mon Jan 18 2021

A shortwave diving southeast across South Dakota has produced bursts
of snow there and even some flurries farther east across central
Minnesota. An arm of vorticity extending eastward from the base of
this shortwave could spread a little steadier light snow east across
Minnesota this evening. Could see maybe a half inch across west
central MN, but progressively drier air to the east will taper
amounts to nothing but a trace along the I-94 and I-35 corridors.

Breaks in the cloud cover have developed across northwestern MN, but
the stratus is stationary across the rest of the state. Believe
models are not generous enough with the cloud cover overnight which
continues to result in temperatures that are likely too cold, but
some breaks are certainly possible that may bring localized subzero

Yet another shortwave diving southeast behind the one tonight will
track across western Minnesota Tuesday. While weak, this system
continues to be well advertised in the operational guidance and has
been consistent for a few days. This system will track along an
impressive NW-SE oriented baroclinic zone, on the leading edge of a
Pacific airmass set to arrive Wednesday. Precip amounts of at least
a few hundredths are probable across western MN. Light winds and a
saturated DGZ from the surface to 7 or 8 kft should support snow
ratios of about 20:1. The snow shouldn`t last long, but many areas
may pick up a half an inch from WC to SC MN. Raised PoPs to the
likely category in those areas.

.LONG TERM...(Wednesday through Monday)
Issued at 252 PM CST Mon Jan 18 2021

This period starts with warmer temperatures, above freezing with
some temperatures near 40 possible, midweek under northwest flow
aloft. A surface low will move across the Canadian Prairies leaving
us on the warmer side of this system Wednesday into part of Thursday.
As this surface low moves to east across Canada a cold front will
pass through the Upper Midwest. This frontal passage will bring an
end to our brief warm up and send us down into below normal
temperatures for the later part of the week. There will be a chance
for some light snow showers or flurries as this front moves through,
but there does not look to be enough dynamical support for anything

As the weekend approaches upper flow begins to shift more westerly
and some larger waves begin to move across the CONUS. This should
allow some warming back up to near seasonal normals. This also favors
a period of more active weather as a large system looks increasingly
likely to move across the central CONUS. As with many large winter
systems the final track of this low will be important in determining
where the highest impacts will occur. Despite this uncertainty of
track, the size of this system in many deterministic models and the
PoP ranges in ensemble systems it looks increasingly likely that the
Upper Midwest will see some snow from this system. The variability
that remains in these model systems and with this still being 5 to 6
days out the final track still remains uncertain so it is still early
to talk about local QPF totals. However unlike our last Winter
Storm/Blizzard event this month precipitation types look much more
likely to remain snow based on NBM and deterministic forecast
soundings. Bottom line is that the next chance for a winter storm is
this weekend, but it remains too early to have confidence in many of
the details.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1040 PM CST Mon Jan 18 2021

Light snow over south central is on its way out, but if you look out
by Bismark, you already see our next light snow maker. This wave
looks a little stronger than the ones we`ve seen the last couple of
days, as evidenced by the surface low associated with it, which is
something we haven`t seen with all of the waves we`ve seen pass
through the past couple of days. Hi-res models have a pretty good
handle on the track of this snow, with IFR vis snow expected to fall
at AXN/RWF/MKT, with an inch of snow not out of the question at RWF.
STC/MSP look to be near the northern edge of this snow field, with
RNH/EAU remaining outside of it. Any sub-VFR conditions this period
look to be tied to where snow is falling. It looks likely RNH/EAU
will remain VFR this period, while STC and MSP will be living near
the edge.

KMSP...Enough CAMS bring snow into MSP late morning that we`ve
introduced a brief period of snow for MSP. Heavier snow with IFR
vsbys look to remain southwest of MSP though. Any MVFR cigs this
period look to be mostly tied to snowfall. Winds will remain light
out of the northwest Tuesday, but late Tuesday night will start
swinging over to the southwest.

Wed...VFR. Wind SW 10-15G25 kts.
Thu...VFR. Slight chance -SN/MVFR. Wind bcmg NW 15-20G30 kts.
Fri...VFR. Wind W 5-10 kts.




SHORT TERM...Borghoff

NWS MPX Office Area Forecast Discussion