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Area forecast discussion 
National Weather Service Twin Cities/Chanhassen Minnesota
533 PM CST Tuesday Feb 9 2016

issued at 534 PM CST Tuesday Feb 9 2016

Updated to include 00z aviation discussion below.


Short term...(this evening through wednesday)
issued at 350 PM CST Tuesday Feb 9 2016

Strong northwesterly flow will persist at upper levels over our a 100-150 knots upper level jet stretches from Saskatchewan
through western Minnesota southeastward to the Gulf Coast region and
remains nearly stationary through Wednesday. An Arctic airmass will
continue to funnel into Minnesota and WI under this northwesterly flow
pattern...resulting in colder than normal temperatures and generally
dry air in most locations. The exception will likely be in parts of
western/SW Minnesota...where a weak clipper system is projected to produce
light snow on Wednesday.

A middle-level shortwave will move southeastward through the Dakotas
and western Minnesota from Wednesday morning through the early
evening...with a surface low moving through the central Dakotas at
this time. To the northeast of the low...a band of light snow will
develop along a sharp baroclinic zone from eastern North Dakota
through Iowa. During Wednesday morning and afternoon...the snow is
most likely to fall near and west of a line from Alexandria through
Redwood Falls. Despite high snowfall ratios with much of the lower
troposphere in the dendritic growth zone...light precipitation rates
should limit accumulation near the Minnesota/South Dakota border to 1-2
inches...tapering off quickly to the east.

Temperatures will become quite cold over eastern Minnesota and western WI
tonight as winds decrease and mostly clear skies are
lows in the single digits below zero are likely. Lows should be at
least several degrees milder in western Minnesota...where low clouds will
likely prevent much radiational cooling. Highs in the upper single
digits and teens are expected on Wednesday.

Long term...(wednesday night through tuesday)
issued at 350 PM CST Tuesday Feb 9 2016

Main theme for the extended are the below normal temperatures this
week...followed by a return of mild air and above normal
temperatures next week. As we make that transition from cold to warm
on will find our best chance at widespread light snow.

The main story for Wednesday through Saturday is the cold. A deep
long wave trough will remain anchored across eastern North
America...keeping US firmly entrenched in northwest flow. This will open US
up to a couple of Arctic highs. The first will be around a 1030 mb
high coming through on Thursday...with the big one coming down
Friday night...when a 1045mb high looks to be centered over Minnesota by
Sat morning. The coldest period will be Friday into Saturday...when
highs will be in the single digits above with lows Saturday morning
in the teens/20s below zero. Between the highs...we will see a weak
surface trough work across the area...with another quick hit of moisture
starved Arctic fluff possible Thursday night into Friday. The
NAM/Canadian are most bullish with another inch or two of snow
falling from west central into south central Minnesota...while the
European model (ecmwf)/GFS show this wave coming through mainly dry. At this
time...kept previous forecast more or less unchanged with 20 probability of precipitation
sliding down for locations along/south of the upper Minnesota river.

This weekend we will see a pattern shift begin as the eastern through
begins to shift off to the east and a more El Nino esque weather
pattern returns. As this does so...the medium range models are
starting to come into better agreement on a burst of warm air advection snow moving
across the upper MS valley Sat night/Sunday. From the amounts
perspective...there does look to be potential for advisory type
snows...with 3-6 inch amounts not out of the question for western
Minnesota...though warning type amounts are looking less likely. 20-30 miles per hour
south winds may also accompany this there will be a
blowing snow component to keep an eye on as well.

This system Sunday will usher in a more zonal flow across much of
the Continental U.S. Next week...which will signal the return of above normal
temperatures next week. However...there is quite a bit of
disagreement on timing of any weak systems within this flow so all
we really can say with much confidence is temperatures next week
will be returning to the above side of normal...likely with fairly
cloudy skies. Any precipitation we do see next week will likely have
the threat of mixed p-types as well.


Aviation...(for the 00z tafs through 00z Wednesday evening)
issued at 534 PM CST Tuesday Feb 9 2016

A quiet period is expected across the area... with VFR conditions
and winds decreasing tonight. High pressure currently over the
area will drift east as an area of low pressure drops southeast
from western Canada into the Southern Plains. This feature and its
associated upper level shortwave will work to increase middle/high
clouds over most of the area late tonight and during the day on
Wednesday. The southwest portion of the area will see the greatest
increase in clouds... and could get into MVFR Wednesday
afternoon with some light snow possible there. However... kept
things dry and just into the VFR category at this point.

Kmsp...confidence in VFR conditions prevailing through the period
is high. Only real item of uncertainty is exactly how low ceilings
could get Wednesday afternoon. For now kept them well into the VFR
category... but if the upstream feature is a bit farther east then
it/S possible some ceilings of around 5k feet above ground level could occur for a
period of time Wednesday afternoon and evening.

/Outlook for kmsp/
Wednesday overnight...VFR. North wind 5 knots or less.
Thursday...VFR. Northwest wind less than 10 knots becoming west.
Thursday night...VFR. West wind less than 10 knots becoming northwest
around 10 knots.
Friday...VFR. Northwest wind 10 to 15 knots.
Friday night...VFR. North wind 5 to 15 knots.
Saturday...VFR. North wind 5 knots or less becoming east.


Mpx watches/warnings/advisories...


short term...additional
long term...mpg

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