FCST:12/13-12/15 BLIZZARD N.Central Plains

[jshields]

I'm surprised no one has posted this yet, but it looks like a major blizzard will be affecting the northern plains this weekend followed by the season's coldest and most widespread outbreak the following week. the models are all in good agreement and have been for a long time showing a strong low pressure system moving on shore washington state today will quickly move across the northern rockies resulting in a low developing in se wyoming and ne colorado by saturday evening. the 12Z gfs had this low at 987MB at 0Z 12/14. meanwhile arctic air will begin plunging south across montana and north dakota late saturday afternoon resulting in a very strong baroclinic zone with highs on saturday afternoon near 50 across eastern nebraska to near zero in western north dakota. the low pressure will move east across nebraska and then northeast through eastern minnesota and western wisconsin. good moisture, stong isentropic lift, and waa will result in heavy snowfall especially late saturday night into sunday evening. also behind the plunging cold front will be winds that could gust to 50 mph. snowfall amounts will range from 4-10" across southwestern to northeastern south dakota to 9-16" across eastern north dakota. temps will fall rapidly to or just below zero and combined with the strong winds will result in deadly windchills of near -50 degress farenheit all day sunday and sunday night. blizzard watches have been issued across all of north dakota, most of s. dakota, western minnesota and parts of montana. the cold weather looks to last most of next week with highs staying below zero monday and tuesday all the way down into s. dakota.

 

[Bill Schintler]

A major winter storm will affect the Upper Midwest on Sunday. The Twin Cities will be along the southern fringe of the snowfall, with heavier amounts remaining to the north. Gusty winds and much colder temperatures will arrive in the storms wake.

Twin Cities area:
Light rain or showers will start at 8 AM Sunday and change over to snow between 1 and 2 PM, north to south, across the metro. During the transition from rain to snow, a brief period of freezing rain will be possible. Accumulation will range from 1 inch along the south side of the metro, to 2 inches in the north, and 4.5 inches along a St. Cloud to Cambridge line before ending early Monday morning.

Duluth:
Light to moderate Snowfall will begin at 8 PM today. Snow will become heavy at times on Sunday, and accumulate to 11 inches.

Eastern Iowa:
Most locations can expect 0.25 inches of total rainfall between Saturday night and Sunday. A cold front will then sweep through late in the day Sunday, bringing falling temperatures and gusty northwest winds. Rain will change to light freezing rain between 5 and 6 PM. Freezing rain will then change to light snow by mid-evening. Iowa City will receive once inch of snow between 9 PM Sunday and 2 AM Monday. Locations north of I-80 will see a half-inch or less of snow accumulation.

Discussion - MN:
An interesting but challenging FCST is shaping up; as minor variations in the track of the SFC/H85/H7 lows have large implications regarding snowfall totals and type, and timing of precipitation type transitions. Models differ somewhat on the track; however, they have consistently agreed on the location of the H85 low on 00Z Monday. Both the GFS and WRF are trending towards an increasingly SLY H85/SFC track between 00Z and 12Z, 12/14; with the WRF exhibiting the most amplified track. During the morning Sunday, the consensus takes the SFC and H85 low further NW; this potentially keeps the Twin Cities region in the warm sector during much of the accumulation precipitation.

Today, WAA and isentropic lift will develop over NCNTRL MN, with light S developing in NW areas and ZR S of I-94. Meanwhile, a secondary area of lift will affect SERN MN through WCNTRL WI on Saturday with isentropic lift noted along the 290K SFC, however little more then some ZL or DZ should result as soundings are dry above 800mb. The main event starts to unfold tonight as large-scale assent overspreads MN beneath the left-exit region of a 120-130kt H25 streak. Associated with is a parade of H5 VOT ribbons embedded in the SWLY flow, which will translate across MN and WI between 12Z Sunday and 00Z Monday. Between 18Z and 00Z strong UVM in excess of -10ub/s develops along and N of the I-94 corridor in MN. Synoptic trends suggest an increasingly SLY trajectory of the 700mb low across ND/SD and E into CNTRL MN. This path shifts the deformation zone S along a line extending E and W through Little Falls between 18Z and 00Z Monday. Mixing ratios AOB 5 g/kg are indicated in this area. Additionally, the Duluth area will receive lake effect enhancement. A healthy fetch off Lake Superior will exist over the duration of the event through 18Z Sunday at which time winds take on an increasingly NLY component. I will go above guidance for snowfall totals in Duluth for this reason.

CAA along with a sharp SFC/H85 gradient arrives in MN on Sunday. The low will track over the Twin Cities late Sunday, while reaching Marquette at around 06Z Monday. Ahead of the low, deep tropical moisture from the Caribbean will surge N courtesy of a 60kt LLJ. Indeed; the GFS, WFR, and the SPC SREF ensemble indicate as much as an inch of total storm QPF in CNTRL/NCNTRL MN. Behind the low, an arctic AMS surges in with H85 temperatures pushing -30C! The result is an impressive baroclinic gradient over MN Sunday.

Discussion – IA:
Strong WAA is underway, with upstream Neodesha, KS; and Conway, MO profilers each indicating SWLY 70kt flow at 3kft. 10C H85 temperatures are currently noted over ERN KS. The CF sweeps through the eastern IA area late afternoon Sunday, with increasing post-frontal precipitation and a transition to S by 4Z as frontogenetical forcing increases in response to a secondary H5/H7 wave. The H85 front lags that at the SFC, and soundings will support ZR once SFC temperatures fall below 0C.

- bill
KD0DJG
11:30 PM CST, 12/13/08

 

[Matthew K. Hartman]

To anyone that may want to follow the on-going Blizzard over the Northern Rockies and as it pushes eastward across the Northern Plains today, tonight and into Sunday, my National WeatherCam Network could suffice.

I'll be working on editing and adding new cameras throughout the day in many areas, so you may see a sporadic outage in some states, however, these should only be brief. For the most part, the entire network should remain operational.

http://webcams.mhartman-wx.com

Select the state of interest in the menu in the upper-right for additional cameras.

Enjoy!

 

[Dean Baron]

New Blizzard warnings issued for the Twin Ports area (Duluth, MN and Superior, WI) calling for 8-14 inches of snow and winds in excess of 35mph with the blizzard conditions starting around dawn tomorrow (Sunday) morning and lasting throughout the day.

 

[rdale]

Any spots where a blizzard has actually verified so far?

 

[Dean Baron]

Any spots where a blizzard has actually verified so far?

Found this on the NWS-Bismark page:
THE FOLLOWING MESSAGE IS TRANSMITTED AT THE REQUEST OF THE
NORTH DAKOTA HIGHWAY PATROL.

NO TRAVEL IS ADVISED IN THE FOLLOWING COUNTIES DUE TO WHITEOUT
CONDITIONS AND DEVELOPING DRIFTS THAT MAY BLOCK ROADS OVERNIGHT.

ADAMS...BILLINGS...SLOPE...BOWMAN...GOLDEN VALLEY...HETTINGER
...STARK...MORTON...AND DUNN.

The entire state of North Dakota now under blizzard warnings and all but i think 5 or 6 counties in South Dakota are under blizzard warnings. Central NoDak and central SoDak are getting walloped right now, the eastern Dakotas and Minnesota start seeing the same conditions tonight and in to tomorrow. The Arrowhead of MN is expecting 12-18 inches. I think its funny how well this shows the stereotype of crappy winters in ND with the entire state being under a blizzard warning. Should be interesting to hear from my sister who lives in Fargo.

 

[Zach Chappell]

Im in Pierre Strong winds and Heavy snow coming down with pretty good drifts all over the place. Here are some LSRS and i will see if its possible to get pics When the sun comes up.
1114 PM BLIZZARD PIERRE 44.37N 100.32W
12/13/2008 HUGHES SD ASOS

VISIBILITY 1/4SM S+...WIND 34030G38MPH.


&&

1052 PM BLIZZARD 5 E GROTON 45.45N 98.00W
12/13/2008 BROWN SD LAW ENFORCEMENT

ALONG HIGHWAY 12...WIND 30G37 MPH. VISIBILITY LESS THAN
100 FEET AT TIMES.

 

[Jeff Snyder]

Several interstates closed across the region (e.g. see civil emergency message from FGF) This is actually a situation that can easily lead to fatalities, unfortunately. Sure, there's quite a bit of snow falling, and there are widespread <1/4 mi visibility obs. But the real killer is going to be the cold air / wind chills. For example, these are two selected obs from SD and ND that indicate how unsafe it would be to get stuck in the middle of some country road at this time:
[FONT=lucida sans typewriter, lucida console, courier]CITY SKY/WX TMP DP RH WIND PRES REMARKS
ABERDEEN HVY SNOW -9 -14 78 N37G46 29.85R VSB 1/4 WCI -40
[/FONT]JAMESTOWN HVY SNOW -13 -18 78 N32G39 29.92R VSB<1/4 WCI -44
Sub-zero temps, 30-40+ mph winds, in heavy snow, and with -40 to -50 F windchills? And over a very large area? Eeek.

 

[Dean Baron]

Looks like most interstates and state highways have been closed in North Dakota with all the Civil Emergency Messages. I29 from the Canadian border to the South Dakota border closed and I94 from Fergus Falls, MN to Jamestown, ND per the ND DOT/ MN DOT and the ND Highway Patrol/MN Highway Patrol. This storm has effectively shut down an entire state.

 

[Matthew K. Hartman]

Hello folks,

It's pretty nasty out there, yes. Steady snow began around 8-9pm last evening and has continued pretty much all night here in Grand Forks. I-94 from Jamestown, ND to Fergus Falls, MN is closed down and I-29 from border to border is also shut down. We've certainly seen blizzard conditions all night and into this morning.

In fact, here's a 6-hour loop from the UND/RWIC WeatherCam on the west end of the city (looking west-northwest):
http://www.rwic.und.edu/webcam/archive/movie/movie.gif

Also to note, our wind chill last hour out at KGFK was recorded at -44.

 

[Joel Wright]

If this isn't a blizzard then I don't know what one is....

ABERDEEN HVY SNOW -9 -14 78 N37G45 29.86R VSB 1/4 WCI -40

 

[Dann Cianca]

If this isn't a blizzard then I don't know what one is....

ABERDEEN HVY SNOW -9 -14 78 N37G45 29.86R VSB 1/4 WCI -40

I would say ... verified!

 

[rdale]

If this isn't a blizzard then I don't know what one is....

ABERDEEN HVY SNOW -9 -14 78 N37G45 29.86R VSB 1/4 WCI -40

Can't even fathom what that would be like... That's only one hour but I assume it was enough to formally verify. I wish NWS would tweak that rule so everyone is consistent.

 

[Matthew K. Hartman]

Yeah, Rob, it's been like that all day in Grand Forks. We've had 1/8 of a mile visibilities for 5-6 hours straight at KGFK, winds easily over 30 mph, and gusts to 40-45 all morning and afternoon. With the temperatures and wind chills we've had, it's definitely Blizzard criteria.

 

[rdale]

More webcams... Any streaming ones would be good as opposed to snapshots.