Scientific Forecaster Discussion
fxus63 kmpx 222354
Area forecast discussion
National Weather Service Twin Cities/Chanhassen Minnesota
554 PM CST Mon Jan 22 2018
Short term...(this evening through tuesday)
issued at 310 PM CST Mon Jan 22 2018
Water vapor imagery showing upper low drifting slowly E-NE across
northeast MO this afternoon. Enhanced area of clouds now over
southeast Minnesota and is beginning to pivot. Another area of enhanced
clouds drifting into far southern Minnesota where moderate to heavy snow
has been falling much of the afternoon. Strong north/northeast
winds gusting to 35-40 kts at times continue into south Central
Area, where they have already observed 8 to 12 in the heavy snow
band. Significant blowing and drifting snow with near whiteout
conditions expected to continue through the remainder of the
afternoon in the Blizzard Warning area. The greater rates have
worked into the southern Metro where 1 to 2 inches an hour will
likely continue through about 6-7 PM. Will likely see around a
foot of snow in Scott and Dakota co. With 6 to 10 inches likely
across the Metro.
The system is forecast to exit to the east this evening and will
continue the headlines through 06z. An addition 1 to 3 inches
likely accumulating after 6 PM over the southeast area.
Trimmed the highs for Tuesday over the expected heavy snow area
over south central Minnesota into western WI. Otherwise, we should see
more sunshine for Tuesday.
Long term...(tuesday night through monday)
issued at 310 PM CST Mon Jan 22 2018
The weather pattern will be progressive for the extended period,
however no significant hazardous weather is expected. The shortwave
that is anticipated to pass through overnight Tuesday into Wednesday
morning will keep skies mostly cloudy through Thursday. Temperatures
will become more mild as the week continues as the thermal ridge
builds-in on Thursday and continues through Friday. Temperatures
will be above-normal with highs reaching the lower to mid 40s on
This third January thaw will not last long as a cold front will
arrive late Friday into Saturday morning. Depending on the exact
timing of the front, Saturday may be one of those days where the
high temperatures of mid to upper 30s occur close to midnight in the
eastern half of our County Warning Area. There is a chance for light snowfall late
Saturday into Sunday, primarily over west central Wisconsin, with an
upper-level trough in place. Temperatures will remain near normal to
slightly below normal on Sunday and Monday.
Aviation...(for the 00z tafs through 00z Tuesday evening)
issued at 554 PM CST Mon Jan 22 2018
Deformation band continues to go strong across the Twin Cities
Metro and looking at the hrrr, this band is not going anywhere for
the next 3-5 hours, so delayed improvements toward a hrrr timing
for msp/mkt/rnh/eau. After the snow, hrrr and other hi-res models
show a clearing aggressively working south out of northern Minnesota in
the subsidence behind this system. However, the stratus behind
this system GOES clear up to the middle of Lake Winnipeg, so went
with the slower timing for cig improvements seen with the GFS
BUFKIT profiles and lav guidance. Monday afternoon we will see
another shortwave coming at US from the Dakotas. Lav shows some
MVFR cigs trying to work back in out west during the afternoon,
but that doesn't have much support from GFS soundings. Instead it
looks like an increase in mid level clouds.
Kmsp...based on continued high reflectivity in the band just west
of msp and hrrr forecasts showing this deformation band lingering
through at least 5z, delayed improvements to above 1/2sm in snow
until 4z. This may be a little long, but will watch trends.
Another 2-4 inches of snow is expected before the snow finally
/Outlook for kmsp/
Wed...MVFR/IFR cigs. Winds SW 5 kts.
Thu...chc MVFR/IFR cigs. Winds southeast 5-10 kts.
Fri...mainly VFR. Winds S-SW 5-15 kts.
WI...Winter Storm Warning until midnight CST tonight for wiz014>016-
Minnesota...Winter Storm Warning until midnight CST tonight for mnz060>063-
Winter Weather Advisory until midnight CST tonight for mnz053-
Blizzard Warning until midnight CST tonight for mnz074>077-