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Area forecast discussion 
National Weather Service Twin Cities/Chanhassen Minnesota
947 PM CST Monday Feb 8 2016

Update...
issued at 946 PM CST Monday Feb 8 2016

Updated to include 06z aviation discussion below.

&&

Short term...(this evening through tuesday)
issued at 258 PM CST Monday Feb 8 2016

Conditions have slowly improved across SC/SW/wc Minnesota
since noon...especially where blizzard conditions had occurred
between Redwood Falls...New Ulm...St. James and Fairmont. Several
highways in SW Minnesota and I-90 were closed this morning due to severe
blowing and drifting snow along with numerous car accidents. Web
cams in these area does show improvement...and with wind speeds
expected to diminish some by the evening...the Blizzard Warning will
likely be allowed to expire at 6 PM. Although "blizzard" conditions
may not be realized...areas of blowing and drifting snow will
continue due to wind speeds around 20-30 miles per hour overnight/Tuesday. I
wouldn/T be surprised if a Winter Weather Advisory is replaced with
the Blizzard Warning this evening. Elsewhere...only patchy blowing
snow is expected with skies slowly becoming clear from northwest to southeast.
Occasional snow showers will continue in far ec Minnesota/wc WI during the
evening due to the persistent deep dendritic growth zone...ample
moisture and marginal lift. Temperatures overnight will be dependent on the
amount of sky cover...especially toward morning. A few below zero
readings are likely in central Minnesota by daybreak...with single digits
above zero elsewhere. Tuesday temperatures with continued strong cold air advection will
lead to highs a few degrees cooler than today with readings only
reaching the upper single digits...to lower teens.

Long term...(tuesday night through monday)
issued at 258 PM CST Monday Feb 8 2016

The main theme in the long term is below normal temperatures. The
downward trend is already in place and will be reinforced during
the week ahead with several surges of Arctic air. After several
days late last week and this past weekend where temperatures
averaged some 10 to 15 degrees above normal...much of the long
term will feature days averaging between 10 to 15 degrees below
normal. The coldest day looks to be Saturday with morning lows
from 5 below to 15 below zero with highs in the single digits.
Moderation will begin on Sunday with temperatures then trending
above normal for early next week.

On the weather front...there are three snow events during the long
term. The first is on Wednesday...the second Thursday night and
early Friday with the third from Sunday into Monday. The first
two snow events look to be light and mainly affect west central
through south central Minnesota. We ended up adding probability of precipitation for Wednesday as
the European model (ecmwf) came further east with the wave sliding down The Spine
of Minnesota and was in very close agreement with the past two runs of
the GFS. Snow amounts are in the neighborhood of one inch from
Madison to Fairmont.

The second wave in the northwest flow passes by Thursday night and
early Friday. It is on about the same trajectory as the Wednesday
one. This time the European model (ecmwf) is a little stronger than the GFS. Parts
of the Minnesota River Valley could see up to an inch of snow accumulation.

Agreement between the GFS and European model (ecmwf) diverge for the weekend as the
flow pattern changes aloft. The GFS would switch rather quickly to
a more westerly flow with a weaker incoming wave that keeps much
of the precipitation staying more to the north and east of the
Twin Cities from Sunday into Monday. The European model (ecmwf) is slower on
backing the upper flow to the west as it brings a closed low down
across Minnesota and Iowa. This translates into snow for areas mainly west
and south of the Twin Cities. With this being days 6 and 7...we
opted to have slight chance probability of precipitation across the Minnesota County Warning Area with 25-30
probability of precipitation across much of the WI County Warning Area.

&&

Aviation...(for the 06z tafs through 06z Tuesday night)
issued at 946 PM CST Monday Feb 8 2016

Forecast thinking remains similar to earlier... with ceilings MVFR
or VFR sticking around for most locations through the night.
Improvement will occur from northwest to southeast as cyclonic
flow wanes and the ridge axis begins to work into the area.
Clearing can currently be seen over northwest Minnesota... and it
should slowly work south-southeast over time. In addition... ceilings are VFR
over a good part of north central and northeast Minnesota... so we
should see locations work into that category overnight if that
trend persists. As a result of current trends and latest forecast
soundings... did allow for somewhat faster improvement and better
overall ceiling categories. Falling snow has ended in most
areas... and will hang on over the southeast longest... although
even where snow is occurring it is generally not having much of an
impact on visibilities.

Kmsp...main areas of uncertainty are the overall timing of the
scattering out of the lower cloud deck... and how quickly it will
trend to VFR even while still broken. Current forecast reflects best
estimates... but there could certainly be timing errors of a few
hours so updates are likely to occur.

/Outlook for kmsp/
Wednesday...VFR. North wind less than 10 knots.
Wednesday night...VFR. North wind less than 10 knots.
Thursday...VFR. Variable wind less than 10 knots.
Thursday night...MVFR ceilings and visibilities possible with a
chance of snow. West wind 5 to 10 knots.
Friday...MVFR ceilings and visibilities possible early with a
chance of snow. Northwest wind 10 to 20 knots.

&&

Mpx watches/warnings/advisories...
WI...none.
Minnesota...none.
&&

$$

Update...
short term...jlt
long term...rah
aviation...

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