HillsdaleMIWeather Posted January 19 Share Posted January 19 Might as well get a thread started for this, both the GFS and GEM have been slowly increasing the amount of ice and how long it takes to change to rain, with a swath from Central Illinois to Central Lower Michigan Link to comment Share on other sites More sharing options...
WestMichigan Posted January 19 Share Posted January 19 6z GFS doesn't look too bad. There is some ice, but nothing gets out of control. Link to comment Share on other sites More sharing options...
King James Posted January 19 Share Posted January 19 Central IL is the hub of icy/foggy bullshit 2 Link to comment Share on other sites More sharing options...
SolidIcewx Posted January 19 Share Posted January 19 2 Link to comment Share on other sites More sharing options...
madwx Posted January 19 Share Posted January 19 this system is really conflicting with my mental model of what a snow or ice storm would look like for this region. Not to say it won't happen but it just seems strange to have a 1018 mb low with nothing impressive upstairs dump so much precip 1 Link to comment Share on other sites More sharing options...
sbnwx85 Posted January 21 Share Posted January 21 Seems like this will be more of a nuisance event, but will cause issues on the roads. A tenth of an inch seems like a good bet across areas that see ice. It will be interesting to see how long freezing temps hang on around the snowpack and could lead to a little more icing. I’m not posting the GDPS because it’s an outlier but it shows a much more significant icing event across Central Indiana and Illinois, sleet across I-80 and snow north of that. Link to comment Share on other sites More sharing options...
sbnwx85 Posted January 21 Share Posted January 21 For those interested in the snow aspect of the storm. NAM is probably showing its warm bias? Link to comment Share on other sites More sharing options...
sbnwx85 Posted January 21 Share Posted January 21 IWX increased ice forecast a bit. Concerns about how quickly we get above freezing. LONG TERM...(Monday through Saturday) Issued at 337 AM EST Sun Jan 21 2024 Ahead of milder weather later this week, a wintry mix is still expected to develop Monday and persist until temperatures rise above freezing some time early Tuesday. Given the very cold conditions at the onset of the precipitation, surface/ground temperatures are likely to lag warming air temperatures for a few to several hours and allow extra time for ice to accumulate. Widespread model agreement prevails with temperatures rising above freezing over the entire area by noon. Thermal soundings are very limited with any snow (too warm aloft) and sleet (virtually no cold layer at the surface). Given the above, have increased ice accumulations from around 0.05" in the southeast (Lima) to around 0.20" west of Highway 31. Temperatures will stay much above normal through the rest of the week given a very strong positive anomaly (per CPC) over more of North America. CIPS analogs also show a 95% chance for temperatures to be above normal early next week. Link to comment Share on other sites More sharing options...
Harry Perry Posted January 21 Share Posted January 21 Yeah, this isn’t a BIG system but I feel like it’s creeping up to be something from run to run. The problem up here is with the sub-arctic snow-pack, ground temps in the teens, combined with a warm nose aloft AND all of this happening in the overnight hours - I could see some impacts for a lot of the area. 1 Link to comment Share on other sites More sharing options...
mimillman Posted January 22 Share Posted January 22 It’s always challenging to accumulate ice in the metro but given how cold it’s been and with the immediate lakeshore freezing, I could see 0.1-0.3” accumulating. Tuesday morning commute could be rough Link to comment Share on other sites More sharing options...
cyclone77 Posted January 22 Share Posted January 22 Looks like a mixed-bag for the QCA. May see all forms of precip at one point or another. Link to comment Share on other sites More sharing options...
Natester Posted January 22 Share Posted January 22 HRRR says major ice storm for central Illinois. Link to comment Share on other sites More sharing options...
IMADreamer Posted January 22 Share Posted January 22 Nothing making it to the ground here yet. A lot of Missouri schools are calling off tomorrow. Forecast is for 0.1 to 0.3 in of ice which I imagine will keep a lot of things closed tomorrow but it shouldn't be too bad in terms of power outages and tree damage. Link to comment Share on other sites More sharing options...
Chicago Storm Posted January 22 Share Posted January 22 Will be interesting to see how the mixed p-types work out for this one. These events on the heels of a solid period of cold usually have some surprises. We'll see if this one does... Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted January 22 Author Share Posted January 22 IWX upped amounts, calling for a potential Ice Storm Warning upgrade in the AFD 1 Link to comment Share on other sites More sharing options...
King James Posted January 22 Share Posted January 22 1 hour ago, HillsdaleMIWeather said: IWX upped amounts, calling for a potential Ice Storm Warning upgrade in the AFD Same with LOT for IKK Link to comment Share on other sites More sharing options...
A-L-E-K Posted January 22 Share Posted January 22 ready 2 ping Link to comment Share on other sites More sharing options...
Mogget Posted January 22 Share Posted January 22 We have a little glaze on the snow and on exposed pavement here in southern WI. Link to comment Share on other sites More sharing options...
cyclone77 Posted January 22 Share Posted January 22 52 minutes ago, Mogget said: We have a little glaze on the snow and on exposed pavement here in southern WI. Same here. Link to comment Share on other sites More sharing options...
mimillman Posted January 22 Share Posted January 22 Had moderate snow when I left Wicker this morning that was beginning to accumulate on untreated surfaces. At the office appears to be light freezing drizzle and sleet Link to comment Share on other sites More sharing options...
King James Posted January 22 Share Posted January 22 Snowing a bit currently. Feels like this one is going to be no fun, already slick looking out there Link to comment Share on other sites More sharing options...
CheeselandSkies Posted January 22 Share Posted January 22 On 1/19/2024 at 9:53 AM, madwx said: this system is really conflicting with my mental model of what a snow or ice storm would look like for this region. Not to say it won't happen but it just seems strange to have a 1018 mb low with nothing impressive upstairs dump so much precip From yesterday's afternoon AFD, MKX didn't seem to concerned about ZR in our neck of the woods. Just wet snow turning to rain. Link to comment Share on other sites More sharing options...
sbnwx85 Posted January 22 Share Posted January 22 LOT and IWX current forecasts are definitely Ice Storm Warning criteria. As long as mode trends hold I expect they pull the trigger around Noon on areas forecast to get more than 1/4” of ice. Link to comment Share on other sites More sharing options...
Stebo Posted January 22 Share Posted January 22 2 minutes ago, sbnwx85 said: LOT and IWX current forecasts are definitely Ice Storm Warning criteria. As long as mode trends hold I expect they pull the trigger around Noon on areas forecast to get more than 1/4” of ice. I feel like GRR/DTX are low balling this one too much. The only thing I could see that would lower the ice totals for along 94 for both would be a prolonged snow/sleet mixture before changing to ice. 2 Link to comment Share on other sites More sharing options...
DAFF Posted January 22 Share Posted January 22 I bet the frost level is at least 5 inches. More on asphalt and cement. To think that the transition ti just rain will happen quickly at 34 degrees. On elevated surfaces yes. But cement and shaded areas will be so icy for a long time. Link to comment Share on other sites More sharing options...
RCNYILWX Posted January 22 Share Posted January 22 LOT and IWX current forecasts are definitely Ice Storm Warning criteria. As long as mode trends hold I expect they pull the trigger around Noon on areas forecast to get more than 1/4” of ice.Re. ISW discussion, while the officially listed criteria is still 0.25"+ of flat ice accretion, that's no longer the sole consideration. We have some research based guidance that places more emphasis on the importance of wind in attaining higher end impacts. Wind results in more evaporative cooling, which translates to higher radial ice accretion that more strongly corresponds to true ice storm type impacts. Winds also bring down trees and powerlines. This case is less straightforward because of the lack of wind tonight. I can't speak to the decision process today yet, but if we don't upgrade, the lack of stronger wind will probably be a contributing factor. 1 3 Link to comment Share on other sites More sharing options...
King James Posted January 22 Share Posted January 22 2 minutes ago, RCNYILWX said: Re. ISW discussion, while the officially listed criteria is still 0.25"+ of flat ice accretion, that's no longer the sole consideration. We have some research based guidance that places more emphasis on the importance of wind in attaining higher end impacts. Wind results in more evaporative cooling, which translates to higher radial ice accretion that more strongly corresponds to true ice storm type impacts. Winds also bring down trees and powerlines. This case is less straightforward because of the lack of wind tonight. I can't speak to the decision process today yet, but if we don't upgrade, the lack of stronger wind will probably be a contributing factor. To the public, slippery is slippery though, no? Or is the main thing with the warning the possibility of a power outage? Link to comment Share on other sites More sharing options...
Stebo Posted January 22 Share Posted January 22 2 minutes ago, RCNYILWX said: Re. ISW discussion, while the officially listed criteria is still 0.25"+ of flat ice accretion, that's no longer the sole consideration. We have some research based guidance that places more emphasis on the importance of wind in attaining higher end impacts. Wind results in more evaporative cooling, which translates to higher radial ice accretion that more strongly corresponds to true ice storm type impacts. Winds also bring down trees and powerlines. This case is less straightforward because of the lack of wind tonight. I can't speak to the decision process today yet, but if we don't upgrade, the lack of stronger wind will probably be a contributing factor. I have heard this elsewhere as well about ISW vs WSW for places down south. While I agree with the accretion rate, I feel like with having been so cold the accretion on the roads will be pretty efficient and that's one variable that I don't think was considered as much down south initially. Link to comment Share on other sites More sharing options...
RCNYILWX Posted January 22 Share Posted January 22 To the public, slippery is slippery though, no? Or is the main thing with the warning the possibility of a power outage? Yep you got it, the main consideration is infrastructure impacts such as power outages. If dangerous travel conditions were the main emphasis, we'd have freezing drizzle events with a glaze to a few hundredths that would be warning worthy. 1 Link to comment Share on other sites More sharing options...
RCNYILWX Posted January 22 Share Posted January 22 I have heard this elsewhere as well about ISW vs WSW for places down south. While I agree with the accretion rate, I feel like with having been so cold the accretion on the roads will be pretty efficient and that's one variable that I don't think was considered as much down south initially.Here's the ice accumulation forecasting reference I was alluding to in my post. 3 3 Link to comment Share on other sites More sharing options...
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