cyclone77 Posted February 17, 2013 Share Posted February 17, 2013 Man, that ridge out ahead of this system is really crushing it. By the time the low gets to Iowa there's nothing left. The 12z GFS is down to only a few inches of snow here with that main wave of moisture. This system really looked like something special a day or two ago. It's starting to look like a loser now though. Link to comment Share on other sites More sharing options...
wisconsinwx Posted February 17, 2013 Share Posted February 17, 2013 Storm blows its load early. Really, that's been on the models for awhile...but they're now realizing the precipitation reduction for east of the Mississippi river. Which I guess, makes sense the closer we get to go time. In other words, they should get a better handle on the specifics. It's about time, I've been skeptical of all that precip making it here since Friday morning with this system occluding well before the Mississippi River. Link to comment Share on other sites More sharing options...
Chicago WX Posted February 17, 2013 Share Posted February 17, 2013 12z UK. Still occludes/weakens like the others, but 998mb into central IA at 120 hours. 12z GFS is around 1006mb at the same time. Link to comment Share on other sites More sharing options...
Chicago WX Posted February 17, 2013 Share Posted February 17, 2013 I don't think that upgrade is working out well for the GGEM. 12z run has a 999mb low on the KS/OK border at 102 hours...meanders (while weakening) east to just west of Joplin at 108 hours...and then poof at 114 hours. Link to comment Share on other sites More sharing options...
buckeye Posted February 17, 2013 Share Posted February 17, 2013 at what point will DT finally realize that YES....this IS meterologically possible? Link to comment Share on other sites More sharing options...
Gino Posted February 17, 2013 Share Posted February 17, 2013 Wanted to share some observations on this over-hyped storm. For the LOT CWA this is not looking like a big deal at all and in fact I'm thinking there's a good chance most of the area will not see even advisory level snowfall. The images I've attached nicely highlight what I think will be one of the bigger problems with the storm, the dry intrusion. The snow accumulation algorithms in the models often don't do a spectacular job and don't seem to take into account RH aloft and likely crystal type. In this case, the last few runs of the GFS and ECMWF have been remarkably similar in occluding this low over the plains with a slowly decaying frontal band of precip arcing northeast into IL Thursday night. The 12z GFS still suggests we could get a solid 3-5" snowfall over our CWA, but when you did closer into the thermodynamic and moisture profiles it becomes a lot harder to get excited about snowfall of that magnitude. I apologize the image colors and map backgrounds didn't copy over from AWIPs well, but hopefully you can still get the idea. The first image is a 4 panel layer RH prog with lowest levels in the upper left and going progressively higher as you work around counter clockwise. Notice that the massive mid/upper level dry intrusion progged to surge northeast into Illinois Thursday evening, while the first image is a 4 panel of the 12z GFS, the 00z EC is similar if not drier aloft. By the time the low levels saturate at 00z, notice that upper levels (>500mb) already has RH <60% and the drier mid level air (h7-5) has almost already overtaken northern IL. The 2nd image is of RH in the -12C to -18C level and this is just another way to show how quickly the GFS (shown) and EC (not shown, but very similar) dry out the layer that's needed for ice nuclei and subsequent snow production. The faint green numbers are QPF, notice how a large majority of the QPF in the GFS falls when it is progging very little ice to be present. The one thing to remember is that the QPF shown is total QPF ending at the time of the image while the RH is a snap shot at that time of the image, so some of the QPF shown falling over N IL between 00z-06z does occur when there will likely be some ice in the clouds, but not all of it. In fact, given the weakening UVV, drying out mid-upper levels and decaying nature of the precip band would expect the snow that does fall to be more of the smaller flake and less efficient variety, such that even a 10:1 ratio may be generous. Final image just shows a comparison between the GFS (green) and ECMWF (yellow) forecast soundings. This is just another way to illustrate the same thing noted above, the dry easterly flow will mean it starts as a virga storm Thurs afternoon as the very dry low levels eat away at the precip. Then by the time the low levels finally saturate early Thurs evening, the mid level dry intrusion is surging in robbing the clouds of necessary ice nuclei. By later Thurs night into Fri I'd suspect this will turn into a pretty significant drizzle/freezing drizzle event. Of course it's still a ways out and things can change, but my confidence in a Thurs forecast is growing and I'd say the chances of ORD getting their biggest snowfall of the season (2.5"+) aren't looking very good at all. I do hope that the forecasters out there that publicly started jumping on this storm in the day 9-10 time range, showing snowfall forecasts from the models beyond 180 hours, putting out web stories mentioning snowfall totals 7+ days out, and in general who've been publicly hyping this storm up learn that just b/c models are consistent (run to run and model to model) beyond day 7 doesn't mean that have a good handle on the exact evolution of a system. I find the medium range models beyond day 7 can sometimes be good for capturing large scale patterns, which they did well with this event, but when you start looking at the details and putting out potential forecast scenarios based on those details to the public, you're asking to get burned! Ok, done with my little rant! Link to comment Share on other sites More sharing options...
Chicago WX Posted February 17, 2013 Share Posted February 17, 2013 Even if I wouldn't have enjoyed the results here locally, we need to get this solution back. That would have been nice for quite a few. Link to comment Share on other sites More sharing options...
michsnowfreak Posted February 17, 2013 Share Posted February 17, 2013 You know the amazing thing, this at one point was snowing nearly 12" here, now I am just hoping to eek out a couple inches. I guess water eventually finds level and DTW has been pretty much one of the few jackpots this winter for the region. Its looking like yet another one of those many 1-4" type snows we have had this winter. Still plenty of time to change, especially once it gets into good sampling range. I REALLY hope for a bomb at some point anyway, but especially this season. DTW is at 33.9" on Feb 17th with an active pattern seemingly en route, 2 months of snow potential to go, and needs less than 9" of snow to receive an above normal season. I know the SE MI crew here lol and there will be some unhappy campers if the 6.2" Dec 26/27 storm is all she wrote for warning criteria events (even though climo is about or just over one 6"+ storm per winter). Actually what will probably happen is this has been a storm that has been tracked since 384 hours out, will probably be a nuisance event for most posters, and then something no ones even paying attention to will sneak up...and BAM! I have seen that before. Link to comment Share on other sites More sharing options...
Chicago WX Posted February 17, 2013 Share Posted February 17, 2013 I think we can put Mr. Izzi down as the first to call bust (for Alek's contest thread). Thanks for sharing your expertise/thoughts though. Much appreciated. Link to comment Share on other sites More sharing options...
McDude Posted February 17, 2013 Share Posted February 17, 2013 Thanks for the post gino. Hope to see you on here more often Link to comment Share on other sites More sharing options...
wisconsinwx Posted February 17, 2013 Share Posted February 17, 2013 Referring to Gino's post above, the Quad Cities and Milwaukee/Sullivan forecast offices could learn from these events for sure. Link to comment Share on other sites More sharing options...
csnavywx Posted February 17, 2013 Share Posted February 17, 2013 BOL to: STL crowd, Cyclone, Hawkeye. Might blow its load too early but I think 6"+ is almost a lock. Hopefully STL avoids p-type issues. Thanks, but I think we're going to be fighting sleet and/or freezing rain here pretty early on. Wet bulbing will help, but WAA is strong with this one. Link to comment Share on other sites More sharing options...
Snowman99 Posted February 17, 2013 Share Posted February 17, 2013 csnavy, please check your pm's. Link to comment Share on other sites More sharing options...
Chicago WX Posted February 17, 2013 Share Posted February 17, 2013 Just for fun obviously, but the 12z GFS clown map. Heck of a storm out west, if close to reality. Link to comment Share on other sites More sharing options...
Chicago WX Posted February 17, 2013 Share Posted February 17, 2013 12z Euro a tick south...and a little wetter in IL at 108 hours. Link to comment Share on other sites More sharing options...
Chicago WX Posted February 17, 2013 Share Posted February 17, 2013 Anyway, the 12z run pretty much ends up the same as the 0z run. Maybe a touch south with the track...and maybe a touch wetter for those of us east of the MS river. But really, just minor noise. Link to comment Share on other sites More sharing options...
Harry Posted February 17, 2013 Share Posted February 17, 2013 Just for fun obviously, but the 12z GFS clown map. Heck of a storm out west, if close to reality. 2:17 12z GFS clown map.gif Just wow.. Most of that here is from the Tuesday stuff. I am with midwestchaser. Unfortunately it seems to fall on deaf ears here in weenie land. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted February 17, 2013 Share Posted February 17, 2013 this thread should be moved to the C/W subforum. Link to comment Share on other sites More sharing options...
Chicago WX Posted February 17, 2013 Share Posted February 17, 2013 Just wow.. Most of that here is from the Tuesday stuff. Yeah, I should have put that qualifier in there. There's some for MN and WI as well that falls before "the storm". Road trip to Nebraska anyone? Link to comment Share on other sites More sharing options...
Snowman99 Posted February 17, 2013 Share Posted February 17, 2013 CSnavy-more PM's Link to comment Share on other sites More sharing options...
Thundersnow12 Posted February 17, 2013 Share Posted February 17, 2013 .45" liquid at ARR. I'll take a few inches at this point. Link to comment Share on other sites More sharing options...
gosaints Posted February 17, 2013 Share Posted February 17, 2013 .45" liquid at ARR. I'll take a few inches at this point. La crosse? Link to comment Share on other sites More sharing options...
Thundersnow12 Posted February 17, 2013 Share Posted February 17, 2013 La crosse? .40" Link to comment Share on other sites More sharing options...
Hoosier Posted February 17, 2013 Share Posted February 17, 2013 Gino brought up a great point about mid level dry air and how it could influence precip type. Looking at forecast soundings around here for instance, the warm layer is not all that warm but the mid level moisture gets stripped away not very long into the event, which would suggest a quicker transition to freezing rain/drizzle than what you'd ordinarily expect with those thermal profiles. Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted February 17, 2013 Share Posted February 17, 2013 Still a few days for things to change, but we are at third and long with a likely punt incoming. Link to comment Share on other sites More sharing options...
Chicago WX Posted February 17, 2013 Share Posted February 17, 2013 Gino brought up a great point about mid level dry air and how it could influence precip type. Looking at forecast soundings around here for instance, the warm layer is not all that warm but the mid level moisture gets stripped away not very long into the event, which would suggest a quicker transition to freezing rain/drizzle than what you'd ordinarily expect with those thermal profiles. Freezing drizzle/light rain would be the worst. But certainly on the table. Link to comment Share on other sites More sharing options...
Hoosier Posted February 17, 2013 Share Posted February 17, 2013 Freezing drizzle/light rain would be the worst. But certainly on the table. And the current timing would put it overnight Thursday/early Friday. Friday morning could be tricky before temps warm up. Link to comment Share on other sites More sharing options...
Chicago WX Posted February 17, 2013 Share Posted February 17, 2013 And the current timing would put it overnight Thursday/early Friday. Friday morning could be tricky before temps warm up. Yeah, no doubt. Steady light freezing liquid can be sneaky. Link to comment Share on other sites More sharing options...
BowMeHunter Posted February 17, 2013 Share Posted February 17, 2013 Referring to Gino's post above, the Quad Cities and Milwaukee/Sullivan forecast offices could learn from these events for sure. meh.. what fun is your job without a little potential hype and just a heads up to follow the forecast.. So it doesn't look to work out here and if you fell for the little bit of early hype shame on us. No harm no foul from them offices.. Its not like LOT hasn't had its shares of blunders, of under hyping especially... Look at the last snow storm... epic fail for part of their area especially waukegan. Link to comment Share on other sites More sharing options...
csnavywx Posted February 17, 2013 Share Posted February 17, 2013 Replied to ya, snowman99. Euro still pumping out 100-300 J/kg of elevated CAPE for the MCI-STL corridor during most of the event. Some dry air in place at the start, so it will be interesting to see how that battle is resolved. Link to comment Share on other sites More sharing options...
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