Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 112156

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
356 PM CST Wed Jan 11 2017

.SHORT TERM...(This evening through Thursday)
Issued at 315 PM CST Wed Jan 11 2017

Light snow has come to an end across the CWA this afternoon as
the jetstreak overhead and fairly strong divergence aloft
continues off to the east. Tonight, a weak shortwave will make
its way through Iowa with enough mid-level ascent to possibly
squeeze out some light snow across far southern MN. Drying this
afternoon has kept things quite dry below 700 mb however so only
expecting a few tenths of an inch of light snow where ascent will
be strong enough to moisten the entire column. Across the
northwestern CWA, clearing tonight and diminishing winds will
allow for prime radiational cooling to occur with the fresh
snowpack on the ground. Lows look to bottom out from -10 to -15
across the NW CWA Thursday morning. Winds will be just strong
enough to create wind chills of -25 to -30 so a Wind Chill
Advisory has been issued for this area.

A clipper system will pass along southern Canada to the
north, dragging with it an Arctic front across Minnesota and
Wisconsin Thursday morning. Behind the front, winds will be gusty
Thursday afternoon with potent pressure rises ahead of the
incoming 1046+ mb high. Strong cold air advection will only aid
in mixing out the shallow boundary layer, mixing down gusts of 20
kts across E MN & WWI, and 25-30 kts to the NW. As a result,
despite temperatures in the upper single digits & lower teens
Thursday will feel like a below-zero day... before the real
freeze comes Friday morning.

.LONG TERM...(Thursday night through Wednesday)
Issued at 315 PM CST Wed Jan 11 2017

The main forecast issues in the longer term remain winds diminishing
Thursday night with arctic high moving over the area and resultant
wind chill threat. Then overall model trends for the weather system
possibly affecting the area later Sunday night into next Tuesday.

Models continue to trend the placement of the arctic high over
western/central cwa by Friday morning. There is some increase
in high clouds possible during the overnight...bu we still have
temperatures dropping in the upper 20s below zero over the far
northern the teens below in the south.  We do expect
winds to decouple for the boundary layer overnight under the most of the area should see little threat to wind

The models then trend the warming ahead of another weakening short
wave as it moves into southwest MN Friday/Friday night. We will hold
onto the small pops for now across the south. It appears to weaken
as it moves into confluent flow aloft over the Great Lakes and the
dry high pressure retreating to the east.

Further temperature modification is expected into the weekend with
above normal readings developing. The models continue to indicate
the southwest cut off trough will advance east into early next week
as the next powerful storm plows into the pacific northwest by
Tuesday.  This helps eject the low and lift it northeast over the
western Great Lakes in the Monday/Tuesday time period. At the
moment...if it does occur...will be a mixed p-type event once again.
Still have plenty of time to monitor overall trends to see how this
system will affect the area. We did mention the mixed precipitation
threat in the outlook for now.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1214 PM CST Wed Jan 11 2017

Light snow is tapering off across the area with precip expected to
end at MSP & RNH by 19Z, & EAU by 20Z. Ceilings have begun to lift
and will continue throughout the day with VFR conditions
prevailing at all terminals by mid-afternoon and through the TAF
period. The NAM wants to develop some light snow tonight at RWF,
MSP, & EAU, but upstream soundings & hi-res models are much drier
at low levels so it looks unlikely any will reach the ground at
these terminals. NW winds will diminish through the night and
become westerly into the morning. Clear skies and westerly gusts
of 20-25 kts are likely by late morning as an arctic front moves
through the area.

KMSP...Lingering light snow expected through 19z, with VFR
visibilities and ceilings prevailing through the period.
Diminishing NW winds becoming W overnight, with gusts of 20-25 kts
picking up by 17Z.

Thu...VFR. Wind NW 5-10 kt.
Fri...VFR. Wind variable 5 kt or less.
Sat...VFR. Wind S 5-10 kt.


MN...Wind Chill Advisory from midnight tonight to 9 AM CST Thursday
     for MNZ041>045-047>050-054>057.



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