3/20/06-3/21/06 FCST: Central Plains Snowstorm

[Mark Farnik]

Well,after a long and unusually dry winter it looks like the western High Plains may finally get its first major snowstorm of the year just in time for Spring. The NWS offices in the area are getting quite excited about this one:
Goodland Forcast Discussion:

AN EARLY SPRING SNOWSTORM LOOKS TO BE IN THE MAKING SUNDAY NIGHT
THROUGH MONDAY. AN INTENSIFYING STORM SYSTEM WILL MOVE SLOWLY
FROM SOUTHEAST COLORADO ACROSS THE THE TEXAS PANHANDLE INTO
SOUTHERN KANSAS. MOISTURE AVAILABILITY WITH THIS STORM IS RATHER
HIGH...PRODUCING MODERATE TO HEAVY SNOWFALL.[/b]

Denver Forecast Discussion:

LATEST DP/DT OF THE GFS FOR MONDAY CONTINUES TO SHOW A
TIGHTER CIRCULATION ACROSS THE NRN TEXAS PANHANdLE.
HARD TO SAY AT THIS
POINT BUT WOULD LEAN ON THE HEAVIER SNOW FALLING EAST OF THE FRONT
RANGE AND SOMEWHERE ON THE FAR EASTERN PLAINS AS THE CYLONE DOESN`T
CUTOFF UNTIL IT GETS INTO THE TX PANHANDLE.[/b]

North Platte HWO:

BEFORE THE
SYSTEM EXITS LATE MONDAY NIGHT...STORM TOTAL SNOW ACCUMULATIONS OF
8 TO 15 INCHES ARE LIKELY WITH HIGHER AMOUNTS POSSIBLE. SNOWFALL
COULD BE VERY HEAVY AND WET AT TIMES AND POSSIBLY PRODUCE POWER
OUTAGES ACROSS PORTIONS OF WESTERN AND NORTH CENTRAL NEBRASKA.
THIS WINTER STORM SYSTEM HAS THE POTENTIAL TO PRODUCE THE MOST
SIGNIFICANT WIDESPREAD SNOWFALL IN RECENT YEARS. THIS IS A
POTENTIALLY DANGEROUS WINTER STORM WITH NUMEROUS ROAD CLOSURES
POSSIBLE. PERSONS PLANNING TRAVEL FOR TONIGHT THROUGH MONDAY
NIGHT...ARE URGED TO MONITOR THE LATEST FORECAST AND STATEMENTS
ASSOCIATED WITH THIS STORM.[/b]

All the forecast offices seem to be in agreement that a major blizzard will affect the western High Plains from Sunday morning through Monday night. The snow will start in Nebraska and South Dakota early tomorrow morning and move south into eastern Colorado/western Kansas by late afternoon, increasing in intensity and areal coverage as it does. With strong north/northeasterly winds of 20-30 mph with higher gusts forecast to accompany the snow, we could be looking at blizzard conditions lasting in excess of 12-36 hours over northern and western NE/southern SD/eastern CO/northern and western KS. The surface low which will cause this storm is currently getting it's act together over Cedar City, UT and should traverse across northern New Mexico tonight into tomorrow morning. If this storm develops as predicted, the areas I've highlighted could be looking at anywhere from 8 to as much as 20 inches of heavy, wet wind driven snow depending on the speed of the storm as it ejects northeast over the TX Panhandle Sunday night/ Monday. :blink: Travel will likely be at a standstill throughout the region for at least 24 hours, and I would bank on most, if not all of the major highways in the region (i.e. I-80, I-76, I-70 just to name a few) being shut down due to the extreme drifting and low visibility expected with this storm. We definitely need the moisture, and a snow day on Monday would make me most happy. We haven't had a good blizzard in a couple of years, and I'm looking forward to it.
Anyone else have thoughts or comments on the evolution of this potential blizzard?

 

[J Gontesky]

The tricky part here in NE Kansas has been trying to nail down the timing of the switchover from rain to snow. We're looking at QPF totals around 1.5" for this system - a welcome batch of moisture to help alleviate the looming drought. This could nearly become a drought-busting system for portions of the southern plains.

The NAM seems to be coming in line with a more southerly track for this system with a switchover to all snow in the northern tier of KS counties by ~18Z Monday...the question becomes how much moisture will be left in the area by then. It looks like the switchover from rain to snow for the KC area will be mid-day on Monday, starting out to the NW and progressing SE through the middle of the day. I'm thinking snowfall totals in the 3-5" range for the northern tier of counties in KS with a very tight gradient (higher totals north) running through this area...lower totals for the KC area.

The ground in this area is warm, but I'm hoping a cold rain will help pull off some of that heat before the switch to snow occurs. The question remains how long to saturate this dry air... Evaporative cooling should help us cool down Sunday night as we saturate the column.

 

[Mike Umscheid]

We haven't had a good blizzard in a couple of years, and I'm looking forward to it.
Anyone else have thoughts or comments on the evolution of this potential blizzard?
[/b]

Actually, this storm will likely not become a true "blizzard" by definition... more than likely a marginal blizzard. Remember, sustained winds or frequent wind gusts at or exceeding 35 mph for 3 hrs qualifies as a blizzard. November 27 last fall was indeed a true, widespread blizzard... where 35 mph would have been a gentle breeze. Remember, far northwest KS into southeastern SD were severely blitzed by some 8 to 20" of snow blown by north winds 40 to 60 mph with gusts to near 70. I don't see these kinds of winds this time. Any (near) blizzard criteria winds should be confined to a localized area just northwest of the sfc/850mb low, likely western Kansas during the day Monday. There was a sfc low that bombed out at around 978mb near Manhattan at the height of that Nov 27th event. What I see here on Sunday and Monday is a good old-fasioned widespread wet snowstorm for much of the central plains with a little bit of wind (averaging 25 to 30 mph or so). I see the term "blizzard" thrown out to classify snowstorms these days more often than it should. There's a significant difference between an ordinary snowstorm and a true blizzard. Regardless, I'm excited, because I just may have the opportunity to hear thundersnow for the first time since 1993 down here in Dodge City (in 1993 I was in KC)... Dodge City is a wildcard location for this storm because of the critical track of the H5/7 lows -- for there will be a sharp gradient in amounts to little snow towards the OK Panhandle border. The new 18/18z GFS shows a slightly stronger H7 low tracking just barely south of DDC, which is optimal for 2-3" snow rates early Monday morning once we change over... with some lightning and thunder hopefully

 

[Dustin Wilcox]

Deffinetly going to be the largest 24 hour snowfall totals for SE Nebraska I have ever seen if this system pans out I just hope the Low doesnt wrap dry air into my region it seems that occurrs quite often with storms of this nature.

check out the NAM forcast 25++

http://grib2.wxcaster.com/wxcaster4/CONUS1...OWFALL_84HR.gif

 

[Justin Turcotte]

Deffinetly going to be the largest 24 hour snowfall totals for SE Nebraska I have ever seen if this system pans out I just hope the Low doesnt wrap dry air into my region it seems that occurrs quite often with storms of this nature.

check out the NAM forcast 25++

http://grib2.wxcaster.com/wxcaster4/CONUS1...OWFALL_84HR.gif
[/b]

The 06z NAM is just as scary.

OAX calling for up to a foot per AFD and WSW text. More in line with GFS QPF output. I suspect there will be some convective mesoscale bands that would produce local amounts well above this.

I'll be inadvertently chasing this event. I'm heading to Lincoln later today with cameras in hand as I volunteered to present at the Tuesday Geosciences seminar at UNL. I'm almost certain the campus will be shut down on Tuesday if this thing verifies. If so, I'll still get to see some old chase pals and sip on some brewskies in the Haymarket for a couple nights before heading back up the freeway Tues afternoon. Digging out the car would not be so entertaining.

 

[Mark Farnik]

Well, everything is still coming together quite nicely for a tremendous snowstorm across the High Plains. Looks around my neck of the woods we should see in excess of a foot of snow per the latest guidance models, the NWS, Accuweather and the Weather Channel. And yes, Mike, while it won't be a TRUE blizzard by definition with the amount of snow forecast to fall and the winds just below blizzard criteria there will be significant drifting and very low visibility at times. There will be blizzard conditions with this storm, which will result in mass road closures and, happily for me, mass school closures on Monday. It's going to be quite chilly for a couple of days after this storm, so it won't be as easy to dig out from this as it usually would be.
as for what I can say about the 2 foot + predicted storm totals in southern NE/northern KS... WOW! :blink:

 

[John Farley]

Perhaps the geography on this thread should be broadened somewhat, as it now appears a significant winter storm is also likely over portions of Missouri and Illinois, affecting some of the same areas that were hit by tornadoes last weekend. LSX just issued its first (!) winter storm watch of the 2005-06 season, covering parts of northeast MO and west-central IL. Looking at the morning runs of the GFS and NAM, I would not be surprised to see this watch extended southward to include the STL area as well. Nam forecasts very heavy mixed precip, eventually trending toward snow, over the STL area overnight Monday, with 1-1.5 inch liquid precip QPF. NAM shows the dominant precip type as sleet early Monday night, though the LSX discussion questions whether enough warm air will be entrained for that to occur. The GFS is slightly slower, lighter on the QPF, and farther south, giving STL mainly snow with .4-.6 inches liquid equivalent - maybe somewhere in the ballpark of 3-6 inches depending on how quickly it can accumulate. Of course a shift in 50 miles north or south in the storms track would produce an entirely different result.

John Farley
Edwardsville, IL

 

[Jeremy Bower]

The models are just throwing out insane amounts over SE Nebraska right now. :blink: UNL has already posted a notice on their main web page about the potential for the university to be shut down for a day or more, which I've personally never seen them do. I live on East Campus in the graduate housing so I will have no problem being able to post reports and pics from this event. Even in the FDs for OAX they seem to have no doubt in their minds that this event will indeed happen. If the current projected track holds true I believe the only area that might be effected by a potential dry slot developing would be the areas in NC and NE KS.

Have never seen or heard thundersnow before...this might be my first chance!

 

[Mark Farnik]

Note: I changed the title of the thread to better reflect the areas it will be affecting.

As of 2:18 p.m. it has been snowing like mad for half an hour all ready. Last night we got 2 inches of very heavy, wet snow that melted this morning. Before the changeover to snow this afternoon a very heavy mist/rain was falling all morning, making the roadways quite wet. Once it has snowed for a few hours they should become total skating rinks and send the various DOT's scrambling for the mag chloride they thought they wouldn't need for this storm. Up to 2" or more per hour snow rates are not out of the question with this storm, given the amount of moisture available and the intensity of the low pressure system. :blink: The snow has started here about five hours ahead of when they predicted the changeover, which was supposed to occur around sunset. That should add another 3-6 bonus inches on top of the predicted 7-14 inches for the northeastern plains of CO. B) Frankly I would not be suprised to see a foot and a half or more of snow in some locales east of a Greeley/Byers line (which, BTW, I happen to live about 50 miles east of.) My mom's a teacher in the Fort Morgan School District and they've already called her to tell her school is canceled for tomorrow (YES! :lol: ), which shows that everyone realizes how serious this storm is. I'll bet you by 10 p.m. this evening the majority of the roadways from the Front Range all the way to Omaha are going to be shut down.
This storm is awesome, and if the land could talk, it would be quoting one of my favorite songs from The Cars, "You're just what I needed!".

 

[J Gontesky]

Nebraska is going to get hammered.

KC is on the edge. I've been trying to tweek a forecast for the KC area all day long, but this incredibly tight gradient is making the KC area one of the toughest to forecast for with respect to this system.

Dry air has been working in all day long from the east. Just last hour, KCI was still at 44/20! Yes, a dew point of 20! So that isn't helping matters. But the moisture heading up from the SW is finally making inroads and it appears as though the erosion on the NE side of the moisture shield has slowed.

It appears as though neither the NAM or the GFS has a good handle on the warm, dry air currently in place over the MO river valley down here in the KC area, although I'm still hopeful that some dynamic cooling (and evaporative cooling) overnight can help make the difference. I'm envious of the totals that will be measured in feet in Nebraska and North-central KS.

I'm thinking totals will still only be in the single digits close to KC though, but rapidly increase as you go N and W.

 

[Mark Farnik]

Well, as of 9:00 a.m. MST we have received 13" of snow out here on my farm 21 miles north of Fort Morgan, Colorado. It is still snowing pretty good, and with another 3-5 inches forecast by nightfall our storm total should be around 16-18", just below or at one and a half feet of B-E-A-U-T-I-F-U-L wet heavy snow. B) We got the day off school, pretty much all the roads in the area are shut down to blowing/drifting snow... and we have not lost electricity yet (keeping my fingers crossed that we don't <_< ). I think the reason we haven't is that back in October we had 6 inches of extremely wet snow when the trees still had their leaves, which caused tremendous damage to them and knocked down most of the original poles the REA put in back in the 1950's. So since pretty much every pole is a new pole, and we didn't have severe winds with this particular storm, I think that's why we haven't lost power.
Hope everyone's staying warm and cozy at home on this first day of spring which is doubling as winter's one and only encore. This storm was a Godsend, I tell you. :lol:

 

[Mark Farnik]

Something really strange is happening with this storm. Looking at the latest East Conus Water Vapor loop, it looks like the low causing the snow storm has either slowed down considerably or even temporarily stalled over Liberal, KS. :huh: Check out this loop:

http://www.goes.noaa.gov/GSSLOOPS/ecwv.html[/b]

The result is a large dry slot has been pulled in from the Desert Southwest and is now punching northward over central/eastern KS into southern NE, while back in eastern CO/western NE/southern and western SD the snow has backed in from the east and here at home there are now whiteout conditions with snow rates I would visually guesstimate to be around 1-2" per hour. The NWS in Boulder curbed our Winter Storm Warning back down to a Snow and Blowing Snow Advisory at 4 A.M. this morning, but I think they may have not forseen what looks to be the potential stalling out of this low pressure system.
If the low has indeed stalled, southern NE/northern KS may either have to wait longer to get their anticipated snow totals or if the dry slot remains over them for an extended period of time they may not get as much snow as predicted, while back here in eastern CO/western NE/southwestern SD we may get much more than anticipated. :blink: The West Coast low approaching from upstream doesn't seem to be kicking it out towards the Midwest like forecast. We'll have to wait and see, but I don't think the low is going to be moving very far in the next 6 to 12 hours. I don't know how the models are handling this; I'll have to look at them later to see if they have absorbed the slowing/possible stalling of the low into their QPF outputs.
If it does indeed stall out for 6-12 hours, maybe this will be to us in the High Plains what the Blizzard of 2003 was to the Front Range and foothills. Who knows?
Just my observations and analysis.

 

[Chris Allington]

I can sort of vouch for what Mark said. Here in Omaha snow the forecasted heavy snow is just now begining to form to our south again after some dry air has moved into the area. The low does seem to be moving much slower and this should move the snow over our area much later this afternoon and tonight. Hopefully dry air moves east and we can get some heavy accumulating snow as the short bursts of moderate snow have left us at 5 inches. I think most schools here could've had classes today because the school day ends in a couple of hours and at my house we have dry roadyways. Oh well once this thing begins to move east we should see conditions rapidly deteriorate later this evening

 

[J Gontesky]

There are some interesting convective trends now showing up through the slot that had remained dry here in Northeast KS and Western MO throughout much of the day.

We just had a short but pronounced burst of sleet, although it was some of the largest sleet pellets I've seen - around 3/16" in diameter. The burst lasted several minutes and was enough to coat the ground with a white dusting of these little bb shots.

So how much moisture return can we get in the next ~6 hours to help this storm verify for the KC area? That's the million dollar question.

 

[Jeff Lawson]

Snow has pretty much ended along the Front Range, with only 5" of accumulation (at best) here in Longmont. Kind of a disappointment, especially considering the high snowfall totals on the Plains a short distance to the east. I've gone from looking forward to snow to looking forward to the approaching warm-up.