Baum Posted January 17, 2023 Share Posted January 17, 2023 ^ now you did it 1 Link to comment Share on other sites More sharing options...
RCNYILWX Posted January 17, 2023 Share Posted January 17, 2023 We should start a movement on the sub forums to discourage posting of the Tropical Tidbits 10:1 snow/sleet maps. While there are flaws and some minor differences site to site with all the algorithm driven snow maps, at least the other sites are relatively similar in binning in QPF as snow. I prefer Pivotal Weather's maps overall, but COD maps are decent too. A few tips:- Algorithm snow maps are not the model producing that much snow - it's the specific algorithm ratio that converts snow QPF into snow accumulation. One of the few explicit model snow outputs is snow depth and then positive snow depth change utilizes the snow depth to give an idea on explicit accumulations. There is a total snowfall output available on Pivotal Weather (for RAP and HRRR) that uses a model parameterized snow ratio and is an explicit model snowfall output. The NCEP HRRR site has explicit model output snowfall as well. - Kuchera ratio is best used in below climo (wet/dense low ratio snow) to climo normal snow ratio scenarios, but is deeply flawed in very cold air masses. The ratio doesn't have an upper limit in extreme cold.- 10:1 ratio is not bad as a first guess in climo normal snow ratio scenarios and even colder air masses because outside of banding or absent strong omega perfectly aligned with a deep DGZ, the Kuchera ratios will often be overdone. 10:1 can give a rough idea and then adjust up where you think mesoscale banding will set up. - Positive snow depth change is a useful metric in low ratio to climo average ratios but will probably be a bit underdone in general. - Tropical Tidbits is much more liberal in QPF to snow so the footprint of snow accumulations in marginal to mixed p-type scenarios will almost always be overdone. It's probably okay when p-type isn't an issue. Sent from my SM-G998U using Tapatalk 8 Link to comment Share on other sites More sharing options...
Hoosier Posted January 17, 2023 Share Posted January 17, 2023 TT is very annoying. Would never use it in mixed precip scenarios. I've seen times when people have posted a TT map showing like 18" of snow in central Mississippi or something crazy like that. Without even digging in, you can pretty well assume that it's not all snow. 2 Link to comment Share on other sites More sharing options...
Geoboy645 Posted January 17, 2023 Share Posted January 17, 2023 MKX put out their graphics for this storm. 4-6" would be a nice hit here, although I really don't like being so close to the gradient like that. This would basically be undoing the last few weeks of warmth when it comes to our totals and send us right back to being above average which would be really nice as well. 1 1 Link to comment Share on other sites More sharing options...
cyclone77 Posted January 18, 2023 Share Posted January 18, 2023 Out of all the models to me it seems that the RGEM has been the most consistent with the rain/snow line for the past few days. Other than some backside flurries Thu afternoon this is looking like 100% cold rain for the QC. Link to comment Share on other sites More sharing options...
madwx Posted January 18, 2023 Share Posted January 18, 2023 Looks like the models are honing in on 2” here. Should all fall between 9 PM and 3 AM with some drizzle afterwards Link to comment Share on other sites More sharing options...
hardypalmguy Posted January 18, 2023 Share Posted January 18, 2023 calling it -- rain for me. 1 Link to comment Share on other sites More sharing options...
OrdIowPitMsp Posted January 18, 2023 Share Posted January 18, 2023 Looks like a general 3-5” tonight across the twin cities. Closer to 6” far south and less to the north. This should replenish all we lost to the rain, and give the snowpack that nice clean look again. 1 Link to comment Share on other sites More sharing options...
Chambana Posted January 18, 2023 Share Posted January 18, 2023 27 minutes ago, OrdIowPitMsp said: Looks like a general 3-5” tonight across the twin cities. Closer to 6” far south and less to the north. This should replenish all we lost to the rain, and give the snowpack that nice clean look again. what’s a snowpack? 1 1 Link to comment Share on other sites More sharing options...
WiscoWestCoast Posted January 18, 2023 Share Posted January 18, 2023 Very little snow still holding on in the La Crosse area. Excited to get some fresh stuff with this system. 1 Link to comment Share on other sites More sharing options...
Brian D Posted January 18, 2023 Share Posted January 18, 2023 2-3" of mostly lake effect for me. Refresh the snowpack a little after the the rainy weather we just had. Then the colder weather, but still above average will turn the snowpack into ice. Link to comment Share on other sites More sharing options...
OrdIowPitMsp Posted January 18, 2023 Share Posted January 18, 2023 18 minutes ago, Brian D said: 2-3" of mostly lake effect for me. Refresh the snowpack a little after the the rainy weather we just had. Then the colder weather, but still above average will turn the snowpack into ice. We have a 55gal drum half full of water sitting on top of the snowpack this morning. I can’t believe it’s holding, must be a glacier. 1 Link to comment Share on other sites More sharing options...
mnchaserguy Posted January 18, 2023 Share Posted January 18, 2023 New zone area forecast for me has upped my total to 4-6" for this storm. Probably not quite enough for a WSW but on the upper end of a WWA. I'm a bit surprised to see that total get bumped up. Not sure what MPX is seeing in their models but from everything I've seen I look to be pretty solidly in the 3-4" range. If these updated totals are accurate then we should see another row or two of counties on the north side get added to the WWA and a row of counties get converted to a WSW on the south side of the Twin Cities. Link to comment Share on other sites More sharing options...
hlcater Posted January 18, 2023 Share Posted January 18, 2023 I’ll consider it a W if we can reach 3”. Link to comment Share on other sites More sharing options...
OrdIowPitMsp Posted January 18, 2023 Share Posted January 18, 2023 2 hours ago, mnchaserguy said: Not sure what MPX is seeing in their models Probably the 18z NAM Link to comment Share on other sites More sharing options...
mnchaserguy Posted January 18, 2023 Share Posted January 18, 2023 11 minutes ago, OrdIowPitMsp said: Probably the 18z NAM Yeah but the Nest seems an odd one to pick to make an official forecast from, especially when none of the other models (CAMs or otherwise) support WSW criteria snow for most of the metro. Idk maybe I'm missing something but I've been following weather for a long time and I don't see what they see in the models. 4-5" looks like a pretty solid bet. Link to comment Share on other sites More sharing options...
madwx Posted January 18, 2023 Share Posted January 18, 2023 HRRR really honing in on a 2-3 hour stretch between midnight and 4 AM where we get walloped with 2-3" and then the snow shuts off after that Link to comment Share on other sites More sharing options...
cyclone77 Posted January 18, 2023 Share Posted January 18, 2023 Cold rain and 35 here. Link to comment Share on other sites More sharing options...
weatherbo Posted January 18, 2023 Share Posted January 18, 2023 I feel for everyone out there hungry for snow but I'm not going to complain. Point here has 14 inches. 2 Link to comment Share on other sites More sharing options...
RogueWaves Posted January 18, 2023 Share Posted January 18, 2023 ^ 1st WWA of the season for ya then Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted January 18, 2023 Share Posted January 18, 2023 Got a little sleet before it changed to rain. Top 2 event. 3 Link to comment Share on other sites More sharing options...
RogueWaves Posted January 18, 2023 Share Posted January 18, 2023 Sucks to be a Cornhusker Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted January 18, 2023 Share Posted January 18, 2023 1 minute ago, RogueWaves said: Sucks to be a Cornhusker I feel like RC mentioned this exact scenario with the double barrel low. Brutal Link to comment Share on other sites More sharing options...
Stevo6899 Posted January 18, 2023 Share Posted January 18, 2023 8 minutes ago, RogueWaves said: Sucks to be a Cornhusker I'm confused. Parts of Nebraska are getting 12-18. Link to comment Share on other sites More sharing options...
OrdIowPitMsp Posted January 19, 2023 Share Posted January 19, 2023 P&C has been upped to 6” imby. Majority of the snow will fall overnight. I don’t think the message has gotten out, most of my coworkers didn’t know we are expecting any snowfall. Link to comment Share on other sites More sharing options...
RogueWaves Posted January 19, 2023 Share Posted January 19, 2023 1 hour ago, Stevo6899 said: I'm confused. Parts of Nebraska are getting 12-18. ++SARC Link to comment Share on other sites More sharing options...
mimillman Posted January 19, 2023 Author Share Posted January 19, 2023 Personally I’d rather live in Chicago with 4.7” of snow this season than live in Nebraska getting 12-18” this system. But that’s just me. No offense to those of you who live in Nebraska. 1 Link to comment Share on other sites More sharing options...
Chicago Storm Posted January 19, 2023 Share Posted January 19, 2023 A lot of changing precip types here at ORD this evening... Since precip began, the sequence has been... -RA, -RAPL, -RA, -RASN and then back to -RA. 1 Link to comment Share on other sites More sharing options...
wegoweather Posted January 19, 2023 Share Posted January 19, 2023 Pingers at DPA. Link to comment Share on other sites More sharing options...
RCNYILWX Posted January 19, 2023 Share Posted January 19, 2023 I feel like RC mentioned this exact scenario with the double barrel low. Brutal Yep, that was the death knell. If we got a more classic synoptic evolution where the 850 mb low was associated with the eastern surface low, parts of northern IL would've been in the game. The fact that even with the unfavorable 850 mb low placement, we're getting some mixed ptypes this evening shows it wasn't too far off from a wet snow event in parts of the CWA. 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now