Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Twin Cities/Chanhassen Minnesota
337 am CST Monday Jan 26 2015

Short term...(today and tonight)
issued at 309 am CST Monday Jan 26 2015

Patchy light snow continues to track southeast across eastern
Minnesota early this morning in advance of a north-south orientated
warm front located roughly from Staples to Hutchinson and Albert
Lea. Accumulations have been minimal. Temperatures at 3 am range
from the upper teens to middle 20s east of the boundary to 30s west of
it...and even approaching 40 at Sisseton South Dakota and Madison Minnesota.

A larger and steadier batch of snow over northeast Minnesota
will slide southeast into western Wisconsin this morning...with some
light accumulations expected. No freezing drizzle has been reported
yet...but it will be possible later this morning across WI as the
steady snow tapers off and middle level dry air begins to push
overhead. The Winter Weather Advisory was issued for impact
considerations and thus will leave it in effect for portions of WI
until 18z.

The warm front will continue making steady progress east
through the morning before stalling near the Minnesota/WI border this
afternoon. A decent temperature gradient will persist across the County Warning Area
with highs ranging from the upper 40s across western Minnesota to the upper 20s
toward central WI. If a fair amount of sun materializes out
west...cannot rule out the possibility of reaching 50. Believe
guidance is way too cold over Minnesota today...and is likely the result of
an overestimation of snow depth. Many locales only have trace
amounts on the ground which will have a negligible impact on temperatures.
Furthermore...the NAM and GFS maintain considerable low clouds which
when looking at current surface observation is clearly not the case. European model (ecmwf)
appears closest to reality in this regard and is a good 5-10 degrees
warmer than the NAM and GFS.

Long term...(tuesday through sunday)
issued at 309 am CST Monday Jan 26 2015

Long term trends remain on track for the most part. Frustrating
model differences in handling possible Arctic intrusion into next

Quiet beginning to the long term with highs pressure dominating
Tuesday weather. The next short wave draws into the area later
wedensday and lingering into early Thursday. Clouds are expected
to increase Wednesday as the wave approaches. Some warmth out
ahead of the wave should still warm readings through the 30s most
areas. The European model (ecmwf) continues its trend with this wave being a bit
more amplified/stronger than the GFS. If this continues...probability of precipitation
will have to be increased in later forecasts. Should see a rain
changing to snow scenario once again as we start out with a
rather warm boundary layer.

Somewhat cooler for Thursday and Friday in the wave of the
system. Main concern remains how cold it will get into the coming
weekend. The deterministic GFS is much less amplified with the
next short wave. This leaves the upper Midwest on the edge of the
main core of the Arctic air through the period. It also leaves US
near the baroclinic zone and embedded short waves. The European model (ecmwf) has
been most consistent in driving the Arctic boundary across the County Warning Area
Friday night into Saturday morning. The trend of the cfsv2 has
been to temper the duration of cold air associated with this
Arctic intrusion. It still is there however so will follow the
more amplified solution. We did manage to drop temperatures some
from guidance...but if the European model (ecmwf) trend continues...we may not be
cold enough. The core of the coldest arrives in the Sunday
night/Monday time frame. Readings may struggle to remain above
zero for much of this period. The only parameter that will hamper
readings dropping well below zero will be the lack of snow cover
across much of the Minnesota portion of the County Warning Area.


Aviation...(for the 06z tafs through 06z Monday night)
issued at 1109 PM CST sun Jan 25 2015

Look for mainly light snow to move across many of the taf sites
early in the morning. Light freezing drizzle/rain could mix in
with the snow at times...but difficult to nail down just when and
where that will happen. We'll have to wait until it gets closer to
the radar and some of the local airports start giving US a feel of
the weather type. MVFR ceilings linger through the day today.

we removed the freezing drizzle from the taf...only because we
think that snow will be the dominate precipiation type. Drizzle
can not be completely ruled out...but if it does occur we think it
will be quite brief. In these cases...we have a hard time knowing
specifically where/when the precipitation type will change from snow to
drizzle. It can also Switch Back and forth. The ~2000ft ceilings
have been slow to make it to the Airport...but they will
eventually arrive early this morning. Middle-level clouds are
obscuring our view of the low it's tough to get a
feel for how the MVFR ceilings are evolving.

/Outlook for kmsp/
Tuesday...VFR. Wind light/variable.
Wednesday...VFR. Chance MVFR. Wind southeast 10 knots.
Thursday...chance MVFR/-sn. Wind northwest 10-20 knots.


Mpx watches/warnings/advisories...
WI...Winter Weather Advisory until noon CST today for wiz015-016-



Short term...borghoff
long term...dwe

National Weather Service Glossary of Abbreviations