Snowstorm on Thursday for the plains?

[chizniz16]

lol Siren I think you have to let that NGM go buddy. That GFS basicly eliminates that from happening. It is a devistating day at school today, having to tell everyone that we are now looking at 4-5 inches.

[WaitingForSiren]

No way 4-5 inches my ass...I just told my teacher 10 inches...the RUC is in line with the NGM...trust me man we cant rule the ngm or ruc out...we just cant...also the latest gfs is further north...this TREND WILL CONTINUE!! Bust? I dont think so..

[Air Force Met]

Yep the 12z GFS has went a little more northward and slower...the NAM is still crappy but has gotten a LITTLE better. My money is on the NGM right now.

Bwahahaha. NGM? The No-Good-Model?

Uhhhh....I think I would put my money on anything but the NGM...I don't even look at it anymore....unless every other model is calling for something else and I am wanting "X" to happen and the NGM is calling for it

Seriously...my daddy always said that even a blind squirrel finds an acorn every once in a while...so if the NGM proves right...it will be because it got very lucky...not because it is a better model...and the next time (and the next time...and the next time) you put your money on it...you'll lose your money.

BTW...FYI...during the winter time, the NGM has a wet bias in the upper great plains. In other words...it has a tendancy to over-forecast precip amounts. Not saying it "can't" be right...but the chances are that the other models have a better handle on it.

[plainsman]

well i stay in northwest fort worth.. for awhile last night accu had fort worth like in the low 30s and low 20s for 2-3 days with ice and snow.. now they raised the temps just slightly to the high 30s in the day and low 30s to 30 at night but they still have ice and sleet in the forecast.. most local mets are saying on and north of i 20 so from Dallas Fort worth north and west are looking at 3-7 days of possible ice and freezing rain every night and morning! this may be one of those storms where dallas especcially south and east dallas may not get as much ice as fort worth.. you know how temps are 1-3 degrees cooler in fort worth usually.. i still think all of Dallas will get ice but fort worth may get a little more ya know... the situation still looks good for an icing event ya know... its already in the 30s in amarillo and the air is coming to North Texas next waco san antonio austin will be all cold rain .. i think sherman wichita falls gainesville weatherford north and west suburbs of Dallas Fort worth will get hammered with ice and sleet and Dallas Fort worth metro will get a good dosing of ice and sleet as well

[plainsman]

gboudx and cheezy please take into account that every winter event that comes to the Dallas Fort worth metro area its always the ""north and west suberbs'' have you guys noticed that.. im so sick of the mets always saying that! ive learned to ignore that.. like 50-100 miles really makes a difference..lol.. parts of fort worth, and weatherford have a little elevation change up to 1000 ft. from 700.. it might be cooler 1-2 degrees, but nothing noticible... just like a couple months ago, the winter event on dec.7.. they said the same things.. its always the north and west suberbs.. and the city of Dallas got hit a lot harder with ice sleet and snow then the northern suburbs ya know on Dec.7!.... so please dont listen to mets when they say the north and west suberbs... id just ignore them.. it applys to city of Dallas and Fort Worth too ....

[gboudx]

plainsman, what I see developing here is a situation where they(local mets) may not really get a handle on this until it's happening. At this point, I don't think they have enough confidence to say for sure what will happen. Just look at the 0z, 6z and 12z runs of the GFS today. All of them show the 540 line barely tipping into northern Ok for this weekend. Earlier this week, that line was reaching into our area. Is that a trend, some bad data, the GFS not handling the airmass well, etc? At this point, I have no confidence to call for any wintry precip in this area.

[Air Force Met]

No way 4-5 inches my ass...I just told my teacher 10 inches...the RUC is in line with the NGM...trust me man we cant rule the ngm or ruc out...we just cant...also the latest gfs is further north...this TREND WILL CONTINUE!! Bust? I dont think so..

OK...looking a little closer at this...and let me give you some meteorological reasons why I think the NGM is hosed with the QPF.

1) Here are the rules of thumb for heavy snow forecasting...and I think you would agree that 10" is heavy...especially given a high of the teens forecasted. Heavy snow forms when the 850 temps is b/w -5 and -10C. 94% of ALL heavy snow forms when it is b/w those temps...MOST of it closer to -5C. The other 6% of cases is MOSTLY when it is b/w 0C and -5C. It is very RARE to get heavy snow when the 850 temp is below -10C. Second, the heavy snow thickness values (1000/500) are b/w 531-537...usually around 534 is good. Another is within 90-150nm to the left of the track of the 850 mb low. Along the track of the 700mb low. Within 2.5 degrees of the sfc low center. There are more...but these are the biggies.

OK...there are only minor diffs b/w the GFS and the NGM (except QPF) on most of these issues...so I'll lump them together mostly.

SFC low: You are about 4-5 degrees north of the sfc low in both models....the rule of thumb says the precip is within 150 miles of the low...you are about 250 miles.

700mb low: The 700mb low moves over extreme southern MN. So there is one rule of thumb. However, it moves from the ND/SD area to WI in a 6 hour period...hardly enough time to produce heavy snow...given the fact the 700mb shortwave passage will cut off the snow...which means it snows heavy (by this rule of thumb ONLY) for about 3 hours...but wait...theres more...

1000-500mb thickness: The GFS is in the 516-522 range and the NGM is in the 522-526 range. In other words...the air column is too cold for heavy snow

850 mb low track: Both models track it 200-250 miles to the south....which is over 100+ miles to far to the south for MN to see heavy snow.

Now for the BIGGIE BIGGIE:

850mb temps: Both models are calling for temps in the -12C to -15C range. That's TOO cold for heavy snow.

Another biggie: This system is really moving fast. The NGM moves it from W KS to E ID is 6 hours and then to southern LK MI in another 6. That's booking at about 50 knots. That's WAY to fast to give 10" of snow to anyone (well..someone MAY see 10" somewhere in the most perfect place...but NOT until the system really starts to deepen and slows down later tomorrow and into Friday.

Now...could things change? Yes. The system could not move as fast as forecasted by either model...it could move further north...it could not be as cold at 850. Lot's could change. However, by using the rules of thumb and the QPF by the other models...this is why I say the NGM is hosed on the QPF. The heavy precip being laid down is not where it should be. It's too far north and it's too cold to snow that much and it's moving too fast.

[Hurricane Cheese]

Well here in Packerland we are offically under a Winter Storm Warning with the NWS calling for 6-12 inches, and possibly even a bit more (13 inches currently forecast for just outside of GB). Could see blizzard conditions at times tomorrow here in NE WI with winds gusting upwards of 40 mph. NWS is calling for widespread blowing and drifting of snow and whiteout conditions at times. My home (Allouez, WI, just outside of GB) is currently being projected for 13 inches with widespread blowing and drifting.

So with all this said, I am offically taking a snow day from college tomorrow! Time to pop in some videos, have some late night snacks and enjoy the feeling of being a kid again, if only for one night...

It's SNOW DAY time baby!

Good luck to everyone else riding out this huge winter storm!

[PurdueWx80]

Thanks for clarifying these things, AFM!!! I didn't really have the patience today to go through what you just said. One more thing - the NGM is notorious for bringing storms and their precip shield too far north into cold air during the winter - happens all the time.

Ideas I presented earlier in the week still appear to be on the mark - so I have few changes. The NAM and GFS are now quite similar and have support from the rGEM, UKMET and WRF. WS warnings and watches have been issued from WY/CO to MI. The Milwaukee/Jefferson office is forecasting 9-15" from near Madison and points north (in their CWA). While I would normally agree with the basic rules you've presented, AFM, the baroclinicity and coupled jet here suggest those higher totals (I wouldn't be surprised to even see an 18" here or there) may come to fruition, particularly where banding and convective snows occur (NAM soundings showing close to 100 J/kg CAPE based near inversion over southern WI), so there is upright and slantwise instability capable of producing thundersnows over IA/WI/MI. The highest totals will probably occur where tonight's lighter WAA snows and tomorrow's bands overlap. There will be a sharp cutoff on the southern edge of the heavy snows, where sleet mixes in. This line will be VERY close to Madison so totals here may be greatly reduced if the shallow warm layer aloft sneaks further north. I suspect this will not be the case since max vertical motions are expected in this area, which would act to induce further cooling. It's really a matter of about 10 miles in storm track difference for the city, though.

Also, forecast soundings are showing 30-35 kt winds just above the surface - if any of these mix down during the convective snows, blizzard conditions will be met. Not a pretty day in the upper Midwest tomorrow. I would not recommend travel on I-90 or I-94 anywhere in the Lakes or Midwest tomorrow. In fact, there could be a nasty ice storm in much of SE WI and southern/central MI.

Furthermore, temps will plummet behind the system Thursday night and Friday. 2M Temps off the NAM and GFS are showing lows from -15 to -25 over the snowpack Sat morning - these are records for this time of year, and something we haven't seen in a few years.

South of the front, models are much more convective looking for Thursday. Wouldn't be surprised to see a squall line form just south of the low, moving east through the OH Valley region Thurs evening/night. Heavy rain also looks like a distinct possibility. Beware of flash freezing on roads after the front comes through - temps will drop below freezing rather quickly.

I think the TX/southern Plains (the weekend/early week storm) should have a new thread, but that's me. Looks like there could be a significant icing/snow event from TX/OK to the Carolinas - but this is early and models are varying quite a bit here.

[Air Force Met]

While I would normally agree with the basic rules you've presented, AFM, the baroclinicity and coupled jet here suggest those higher totals (I wouldn't be surprised to even see an 18" here or there) may come to fruition, particularly where banding and convective snows occur (NAM soundings showing close to 100 J/kg CAPE based near inversion over southern WI), so there is upright and slantwise instability capable of producing thundersnows over IA/WI/MI.

Oh...I think you'll see some heavy snow amounts...especially once it starts to deepen. My post was mainly directed towards MN (as far as saying no to 10"+) when I said it was moving too fast. Once it starts to slow down into E IA, Wi and MI, I think 18" is certainly possible in spots....fer sure. Just not 10" in MN...Western IA...KS/NE...etc because until it deepens and slows...the max bands will be in and out too soon.

By the time it reaches WI...it slows...they are a lot closer to the 850 low and the sfc low...in "prime" position (in southern WI)...their 850MB temps ARE in the -5 to -10C range and the thickness values are also perfect. PLus the 700mb low moves right over them...and the 850mb and 500mb wind maxes intersect. Pretty good dynamics there

So...given a slowing system and the heavy snow band...plus the big rules of thumb moving over that area...I think those heavy heavy amounts are certainly possible. My point was for MN.

[Nate-Gillson]

Not only snow for us, but also a quarter of inch of ice, yuck. There better not be an ice storm warning for us.

[AirmaN]

I hate you all. I want a snowstorm. Winter Storm warning is one county north...how lame

[JenyEliza]

I hate you all. I want a snowstorm. Winter Storm warning is one county north...how lame

Happens all the time here in the SE. Welcome to our world.

[chizniz16]

A nice little bonus of a snow line is setting up just north of the Iowa/MN boarder. I think this gives a great idea of where the heaviest snowfall will occur just by looking at this early snow line setup.

[Nate-Gillson]

Well, it looks like it is going to be a nearly all snow event (some sleet and freezing rain possible) for me. I'm under a winter storm warning.

[cheezyWXguy]

plainsman, what I see developing here is a situation where they(local mets) may not really get a handle on this until it's happening. At this point, I don't think they have enough confidence to say for sure what will happen. Just look at the 0z, 6z and 12z runs of the GFS today. All of them show the 540 line barely tipping into northern Ok for this weekend. Earlier this week, that line was reaching into our area. Is that a trend, some bad data, the GFS not handling the airmass well, etc? At this point, I have no confidence to call for any wintry precip in this area.

gboudx, I have enuf confidence to say that this storm has a good chance of happening...here...look at the TWC forecast for my area
http://www.weather.com/weather/tenday/7 ... undeclared

also, Ive noticed how the GFS has pushed the 540 line up in to N OK...I think thats not really to the extent, at least of whats possible to happen

[gboudx]

Hey cheezy, let's take this discussion to the "Cold for Deep South" thread. This thread seems more for the upper plains folks, as Purdue implied.

[cheezyWXguy]

lol...

[plainsman]

hey cheezy and gboudz lets start a new thread... the upcoming southern plains ice sleet thread for north texans and oklahomans and and people from arkansas and nw louisiana southern kansas and southern missouri. north texas is not the deep south... the deep south thread are all houstoninans and people from the southeast.....

[plainsman]

let me know if your going to start one cheezy, because im about to start a upcoming southern plains freezing rain/sleet thread now?