RCNYILWX

What's become clear is that the outdoor mask mandates were never needed, and likely relied on faulty guidance to justify them. At this point, most adults who wanted to be vaccinated have gotten at least their first dose and a majority of those who haven't probably are hesitant or are straight up anti-vaxxers. The CDC's new guidance finally recognized that we should no longer be tailoring society to protect people who largely don't want to be, or the hypercautious. Particularly outdoors, the vaccinated have essentially zero risk and the unvaccinated have extremely low risk, especially in the warmer months. I doubt many are going to continue to heed outdoor mask mandates and they're not usually enforceable anyway. Indoors will probably be a different story. There may be increased instances of people refusing to wear masks in stores, but I suspect for a while longer that most people will see it as a minor inconvenience not worth causing a fuss over. The indoor mask ordinances do need to be rolled back sooner rather than later though.

You never know with these intense f-gen bands. I think if it snows heavy enough for long enough, a couple sloppy inches on colder surfaces certainly possible. The most likely outcome probably still is mostly white rain aside from a sloppy coating here and there (similar to what 3km NAM has been showing), but will be interesting to see what we wake up to. Sent from my SM-G998U using Tapatalk

Revisiting this, for some reason we weren't included on the SPC collaboration call even though a few of our counties were in the MD. We probably would've been fine adding those few counties into the watch had we been included on the collab call. Sent from my SM-G998U using Tapatalk

The good news for this month vs what happened in 2012 is it'll be cool for the next week and pattern overall is forecast to be on the active side into the medium-long range. If this month doesn't come in at or above normal and the ridge starts to build in June, that would become more problematic. The rain we've gotten here in the southwest suburbs over the past week, while not a lot, has helped keep things pretty green. Sent from my SM-G998U using Tapatalk

June has historically been the most active month locally. Hopefully May picks up after next week and June is rocking. If you can go into June having already had an active season, that's a bonus. Sent from my SM-G998U using Tapatalk

I'll always regret not issuing an advisory on the day shift the afternoon before 4/14/19. Was strongly considering it, but with no buy in from the neighboring offices, opted against it. That was definitely a special case, as it turned out basically every box checked for heavy snow rates and overcoming the warm ground and high sun angle. I see it as a good mental check now when there's a possible solid late season snow event, knowing what went into that event helps the forecast at a challenging time of year to forecast snowfall. Sent from my SM-G998U using Tapatalk

Maybe for the southeast part of the CWA? The other aspect that's part of the headline decision in marginal situations is time of day. It's now after midnight down there, which means much less vehicles on the roads. With no impacts to this evening's commute and snow ending well before the morning commute, can't really justify putting an advisory out for that long. The potential for slick spots can certainly be messaged by various means, such as a Special Weather Statement, graphics, social media posts, retweeting INDOT, etc, without putting an advisory out.

If there were noteworthy road impacts, the case would be more defensible. Any snow higher than a trace today would technically be historic, no? The record for the date was T so if it merely set the new record at 0.1", that warrants an advisory? From the IND Evening Update AFD: "Road impacts appear to be minimal at this time, with the majority of the accumulations occurring on grassy areas." There's really no need for further debate on it, with no real travel impacts, advisories are typically not issued. Certainly some gray area and the product has been more commonly issued for sub-advisory criteria impact-based reasons in recent years, but this event doesn't hit that bar in the Indy area, regardless of the historic nature of the snowfall.

Liking the upstream satellite and radar trends across South Dakota w.r.t. tomorrow locally. Several CG strikes and GLM flashes, and Aberdeen, SD was reporting 1/4SM +SN a couple hours ago.

Really solid f-gen band, snowed hard enough here at LOT that we've been down around 1/2sm visibility and gotten a few tenths on the grass and car tops. Just wet roads and parking lot, though part of the sidewalk outside has a minor dusting. The meso models (aside from the RGEM) and the Euro certainly did best with band placement. Main issue will be that the band is too transient to support any legit accums and impacts. Sent from my SM-G998U using Tapatalk

We definitely got NAMmed by this event, and also the ECMWF being more bullish for several runs didn't help. I was never too excited about the heart of the metro and points west and northwest. But I was overly optimistic for the southeast 1/3 or so of the CWA while the NAM still had global guidance support from the Euro. I suppose some surprises are possible if rates end up heavier along the lines of some of the meso models. Failing that though, Wednesday now appears to have a higher chance of interesting weather. Sent from my SM-G998U using Tapatalk

Agree, shades of April 2, 2016. The NAMnest is modeling 45-50 dBZ cores on Wednesday, owing to those near dry adiabatic 0-3km lapse rates. One lacking aspect on Wednesday is the weaker wind fields, whereas April 2, 2016 had 45-60 mph wind gusts. Could envision 30-40 mph gusts on Wednesday in squalls. Sent from my SM-G998U using Tapatalk

I'm skeptical of how much falls during the day Tuesday if rates aren't heavy. And a majority of the guidance has the heavier snow toward and after sunset Tuesday evening mostly east of the CWA. I was thinking back to Feb 24 2016 when the northwest fringe just outside the heavy snow band that nailed the south burbs into northwest Indiana was essentially white rain despite coming down at a good clip at times. And that was in late February.

Completely agree, I think that it's gonna rip in that rapidly intensifying defo zone Tuesday evening, 1"+/hour type stuff. I currently like south burbs and south in LOT CWA into NW/N IN and lower MI for this event. Sent from my SM-G998U using Tapatalk

NAM fits my general idea for this system so I'll ride it lol. 850 mb front much quicker this run than 18z, so baroclinic zone sets up farther southeast and the top down and bottom up intensification of the synoptic system takes place just too late for most of the IL metro, on Tuesday evening. Looks like non efficient accums, mostly on colder surfaces, during the day on Tuesday over northern IL. Sent from my SM-G998U using Tapatalk

The ECMWF ensemble suite shifted a bit southeast vs 12z, but still a good hit of QPF across much of the Chicago metro. Agree on treating the UKMET as the outlier that it is for now. The Euro, GEM, and NAM all have initial f-gen driven banding starting Monday night over northern IL, that would probably be a narrower area of appreciable accums. Big question mark is when and where does the synoptic system really take off as mid-level wave goes neutral to near negative tilt, and allow a strong deformation axis to develop. The 12z operational ECMWF more or less is the middle ground between the farthest northwest NAM and farther southeast 12z GFS and GEM. At this point, seems more likely than not 1-3" amounts from the initial banding into the metro, with Tuesday PM the wild card. If the intense defo banding sets up just southeast, subsidence northwest of it would probably quickly shut off meaningful snow. Weighing probabilities at this still pretty early juncture, within LOT CWA, southeast of I-55 and particularly northwest Indiana probably have the best chance of a higher impact headline worthy event. Sent from my SM-G998U using Tapatalk

Here's the reasonably realistic looking Kuchera output from Pivotal.

Was thinking about this, https://www.npr.org/sections/health-shots/2021/02/06/964527835/why-the-pandemic-is-10-times-worse-than-you-think, this article says that as of February we were catching about 1/4 of actual new infections. What sort of estimate was given for the current percent surveillance for India? Sad to say, going to be some unimaginable suffering there, especially in the desperately impoverished areas. And Brazil is scary bad right now.

The dreaded white rain lol. Speaking of ratios, looks like the WeatherBell Kuchera output is back on the juice. Sent from my SM-G998U using Tapatalk

This would be an interesting case for ratios. BL temps look like they'd be 32-34 during the heaviest rates. 18z GFS Cobb output for actually showed raw snow ratios peaking at 11-16:1 due to the factors you mentioned, but little/no snow accumulation because surface temps never get below 34F. So I think something in the 8:1 range might be reasonable because you could end up with decent dendrites but the marginal surface temps knock down the effective ratio. For the LOT CWA, the most recent operational solutions look less impressive than 4/14/19 from a large scale lift perspective. There could be decent low-mid f-gen but it might be more transient. Mid-upper lapse rates look good (7+C/km). PWATs are decent for a snow system peaking at ~0.6". This looks like a setup that could produce pockets of 2 to 4 inches of snow based off strongest banding placement and these areas could see some road impacts. Downtown Chicago could see issues with accums for the same reason the recent November events didn't perform there, lake water temps are well into the 40s (52F today at Chicago shore), with a north-northeast wind direction forecast. Sent from my SM-G998U using Tapatalk

April 2019 showed well that very heavy rates overcome the August equivalent sun angle, so that's what we'll need to see continued support for to get noteworthy accumulations. Looking back to those events, April 14th got going early before the peak sun angles to put down a good base of snow and keep the ground colder for continued accums under heavy rates. April 27th didn't fully change over to snow until the afternoon and the rates were not as uniformly heavy, so overall road accums and impacts were less widespread than on April 14th. For Tuesday it looks like the snow will have started by the morning, so that could point toward a more 4/14/19 like outcome *if* the heavy snow materializes. I'm out of winter mode, so the only way this would be more tolerable is if ORD gets the amount needed to get to 50+" on the season. Sent from my SM-G998U using Tapatalk

The problem is that we initialize with NBM data 36 hours out and onward and the NBM has a bunch of models, ensembles, and MOS in it, so it'll always be too warm in this sort of scenario. I'm here on the evening shift and was briefed that the MaxT needs to be much lower but surrounding offices didn't want to make a big change, so there's that unrealistic diurnal precip type trend. Hopefully the overnight shifts populate with raw model data for the Tuesday MaxT if the 00z guidance holds serve.

Do you think they could have disclosed the information about the possible rare blood clot risk and studied it while allowing people to keep their appointments? Sent from my SM-G998U using Tapatalk

Just like America writ large, there's a divide in here between people who think Fauci is a clown and those who think he's beyond reproach. A clown he is not, but his mixed messaging lately plain and simple is not helpful in our country's efforts to convince vaccine holdouts to get the shots. That's how this has to be seen. There's not nearly enough focus on how remarkable the vaccines are. All people who have had the ability to get the vaccine but have chosen not to thus far are hearing from health experts and politicians is that fully vaccinated people have to be just as cautious as unvaccinated people. They need to do a better job incentivizing. Sent from my SM-G998U using Tapatalk

We haven't publicly released the data yet, but I'm sure it'll get a lot of attention when it comes out in May. The normal annual mean went from 49.9 to 51.4. Here's the full 1981-2010 to 1991-2020 breakdown for annual normals at ORD: 1981-2010/1991-2020 Max: 59.1/59.6 Min: 40.8/43.1 Mean: 49.9/51.4 Days Tmax >=90: 14/13 Days Tmax Days Tmin Days Tmax Precip: 36.89/37.86 Snow: 36.3"/38.4" Days >=0.01" precip: 124/126 Days >=0.10" precip: 69/72 Days >=0.50" precip: 23/24 Days >=1.00" precip: 8/8 If anyone wants me to post the full RFD data too, let me know. The normal mean there went from 49.2 in 1981-2010 to 49.5 in 1991-2020. Again in comparing ORD to RFD, this shows the huge UHI contribution at ORD. Edit: Please don't share this data beyond the forum. Technically wasn't supposed to post it while in the QC phase of the new normals release.