Scientific Forecaster Discussion
fxus63 kmpx 222059
Area forecast discussion
National Weather Service Twin Cities/Chanhassen Minnesota
259 PM CST Fri Nov 22 2019
Short term...(this evening through Saturday night)
issued at 259 PM CST Fri Nov 22 2019
Cloud cover over eastern Minnesota and WI this morning was slow to erode
and finally dissipated during the early afternoon. This resulted in
temperatures several degrees cooler than forecast with many areas in
the upper 20s to lower 30s. Conversely, temperatures over west
central Minnesota have warmed into the upper 30s to lower 40s.
Clear skies will prevail into Saturday morning with high pressure
centered over the Central Plains. This high will also keep the
southwest flow in place, with milder air arriving for the weekend.
Expecting highs into the 40s tomorrow just about area wide as 925 mb
temps warm to near 0c. Some increase in high and mid level clouds
will occur later in the day as a dry short wave approaches from the
Long term...(sunday through friday)
issued at 259 PM CST Fri Nov 22 2019
Trending drier Sunday through Monday, with still plenty of
uncertainty regarding a potential winter storm and disruptions to
travel Tuesday into Wednesday.
A few shortwaves will pass through the upper Midwest Sunday and
Monday, with the strongest of these tracking across the Canadian
border Monday. Dry low-level air Sunday looks to limit any
precipitation on Sunday, while the stronger forcing from monday's
system stays well to the north along with the bulk of the
precipitation. Could see some light snow or even a light rain/snow
mix work down into central Minnesota and west-central Wisconsin
Monday, but precipitation amounts look to remain minor.
There remains a fair amount of spread regarding the evolution of a
low pressure area forecast to develop in the Lee of The Rockies,
and track northeast through the mid-Mississippi Valley/upper
Midwest Tuesday into Wednesday. Ensemble members on the gefs/eps
still show a wide range of solutions for the cwa, with anywhere
from a major winter storm to no precipitation at all still within
the realm of possibility. With that said, operational models along
with a general consensus among ensemble members have trended
closer to a more consistent solution this morning, tracking the
low from central Missouri through northeastern Illinois Tuesday
afternoon through Wednesday morning. This low track would keep the
bulk of the precipitation south and east of the cwa, with the
northern edge of the deformation band of precipitation perhaps
reaching north into southern Minnesota and west-central Wisconsin.
Of course, this solution is nowhere near locked in and a track of
100+ miles farther to the south or north is certainly possible
this many hours out. The dominant precipitation type will be
dependent on the track and strength of this system as well, which
we just will not have a good grasp on until closer to the event.
However, confidence does appear to be increasing in the main
timeframe for potential travel impacts from any winter weather
across the Mississippi Valley/upper Midwest coming during the day
Tuesday through Wednesday morning.
Most guidance developing an organized storm system Tuesday/Wednesday
have it clear of the area by Wednesday morning, with broad high
pressure and ridging aloft building into the region behind the
departing wave. Thus, confidence is higher in Wednesday looking like
a fair day for travel across the region. High pressure is expected
to linger into Thursday, so Thanksgiving looks like it has the
chance to at least start out dry. Model spread and uncertainty
increases again regarding the precipitation potential Thanksgiving
day into Friday, but at this point any precipitation looks to remain
Aviation...(for the 18z tafs through 18z Saturday afternoon)
issued at 1211 PM CST Fri Nov 22 2019
VFR conditions through the period. West winds will back more
southerly tonight, then veer northwest Saturday morning.
/Outlook for kmsp/
sun...VFR. Wind west 5 kts.
Mon...MVFR ceilings possible. Wind west 10-15 kts.
Tue...MVFR ceilings and -sn possible. Wind northwest 5 kts.