Jackstraw

Nice AFD from Ryan at KIND (and one of the longest short term's I've ever seen)... .SHORT TERM /Tonight through Thursday Night/... Issued at 330 AM EST Tue Feb 25 2020 Forecast challenges quite a bit greater than 24 hours ago as the model suite has shifted the potential for accumulating snow further to the southeast than previous runs had it. The overall model mayhem has led to some drastic changes to the forecast from just a day or two ago...highlighted by an increasing threat for accumulating snow...especially over the northern half of the forecast area. Still though with such a rapid change within many of the model solutions...confidence is nowhere near where would like to see it at this stage. A headache inducer to say the least. So why such large scale changes over just the last few model runs from just a few tenths of snow to potentially needing to consider headlines? Much has to do with the model suite`s handling of the evolution of the upper level pattern as the energy diving out of the northern Rockies carves out a deep trough over the center of the country by Wednesday. Previous runs had a cleaner transition of the energy aloft from the weakening wave over the region this morning into the expanding energy aloft dropping in from the northwest. Model guidance this morning still has this transition taking place but it is quite a bit messier with strung out energy aloft described in the near term section above aiding in less phasing at the surface and subsequently a shift south to almost all of the key features involved with this storm. A developing upper low will close off over Oklahoma/Kansas this evening then deepen as the energy aloft carves out the trough as it tracks across the Mississippi and Ohio Valleys Wednesday. Just two days ago...a new surface wave was developing over northern Illinois late tonight and early Wednesday in tandem with the upper low but now due to the strung out nature of the waves aloft ahead of the approaching northern stream energy...this secondary low never develops with the current surface wave over the region drifting slowly east near the Ohio River. This results in the colder airmass pivoting into the region much faster than originally thought... perhaps as early as this evening in the northern Wabash Valley before expanding southeast across the area into Wednesday. Model soundings support a gradual transition to snow from rain overnight into Wednesday morning over the northwest half of the forecast area...with a rain to snow/rain mix over the southeast half on Wednesday. Low level thermals support snow as the primary precip type over the entire forecast area by late day Wednesday. So while there is an increased threat for snow accumulations late Tuesday night into Wednesday...especially along and north of the I- 70 corridor...several caveats remain that must be considered in determining amounts. The model suite is capturing a trailing surface trough behind the departing low pressure system with a trowal extending west in tandem Wednesday morning. The strong energy aloft mentioned above will dive around the base of the approaching upper low and into the region Wednesday morning enhancing diffluence aloft. These features combined with the potential for a mid level deformation axis to rotate across the northern half of the forecast area could support a threat for heavier bursts of snow through the day. With that being said...surface and ground temps will be a factor for a good chunk of the day with low to mid 30s common across the region before turning colder by Wednesday evening. The above factors could lead to heavier snowfall rates that would overcome these marginal temps but some melting of snow does seem likely when rates remain lighter which will knock totals down. A lot to consider here and a lot that could bust potential snowfall totals. That being said...feel strongly from a public impact standpoint that a headline needs to be introduced over northern counties where confidence is highest at the moment for impacts and accumulations. Will introduce a Winter Storm Watch...essentially north of a Crawfordsville-Anderson line...which offers the most flexibility at this point considering the constant model shuffling that has occurred over the last 24-48 hours and may continue with the 12Z runs today. Have 3-5 inches in these areas...1 to potentially as high as 3 to 4 near the I-70 corridor in the transition zone and lighter amounts further south. Fully expect that an Advisory at a minimum will be needed over parts of the northern forecast area should trends continue and the dayshift will have an additional set of runs to determine if further adjustments in location and amounts is needed. The main message at this point is that adverse winter weather and snow accumulations are becoming more likely for late Tuesday night and especially Wednesday over the northern half of the forecast area. Snow will gradually diminish Wednesday night as the upper low shifts east of the region. High pressure will build in on Thursday but cloud coverage will remain higher as a fast moving clipper system dives through the Missouri Valley. This feature will track into the lower Ohio Valley Thursday night. While the focus of the precipitation will be southwest of the forecast area...flurries or light snow may skim the lower Wabash Valley early Friday. Plan on keeping the forecast dry at this point but will be something to monitor going forward. Temps...heavily utilized ConsAll numbers for hourly temps late tonight in Wednesday to try and better capture the expansion of the colder air. Temps will drop steadily after 06Z tonight back into the lower and middle 30s with little to no recovery on Wednesday before the much colder air arrives Wednesday night. Generally undercut MOS guidance as a result for highs Wednesday. Much colder Thursday with some portions of the area remaining in the 20s. Lows will fall back into the teens over much of the area by Thursday night. &&

Like Stebo said this system is barely inside 48 hours. I think the "consistency" of the models showing substantial snow inside 120/96 and not letting up this time got everyone excited, plus the light at the end of the tunnel for this winter season is in sight. I'd love to lock in this 00Z NAM in but my ass has been on fire all this season lol. 00Z runs we'll see if the trend continues, think there's a good chance to back some NW. For posterity I'll take a sounding like this all day long...

The Carpathia is down here in N Central IN to pick up survivors

Fat Lady sings at 00Z

Just sitting back enjoying the L&O Valley show lol .

Thats flippin crazy. Storm Ciara was the strongest in like 10 years but that pressure is nuts.

-4 last night, already 6 below forecast low, down to 1. Snow pack helping the radiational cooling for sure.

-SN again, getting tickled. Got till midnight to collect another inch so I can verify lol.

One thing to note and I was surprised. Within 36-24 hours most of the models had a NW/SE nearly 50% +/- in total snowfall right over the extreme NW part of the county. I drove 2 miles S today and totals dropped off noticeably. From about my area NW into Tipton and SW Howard county the totals were higher just as the models forecast, especially the NAM the Canuk and the ARW. Euro totals were obviously overdone and had no bearing on my fantasy call. But I am surprised at how accurately the models forecast totals over my area. Some of them got the math right at least locally.

Well almost 20 tenths lol, ended up with 5 here so I busted low by an inch (like anyone believed my call including me ) We could've hit 6 but had a couple hours of freezing drizzle before it flipped back to -SN and whiffed on the front and any tickler from the lake. The bookshelf is full now for this season around here and we matched Halloween to keep them all in place. New shelf for any new books to come. At least this is gonna be around for a few days. Glad to see most everyone got something.

Back to -SN here. One of the caveats in KIWX afternoon discussion was misalignment of DGZ and Omega, seems to be coming to fruition. Sitting at 3 here. Gonna be selective banding and backside potential to keep me from busting. Sitting on 2 pair mother nature holding 3 of a kind, waiting on the river

Snow shut off 30 minutes ago. Don't know whats coming with the NWS radar data down. It's the 1800's lol.

As I posted that it just cut loose, heaviest snow of the season. 30+ dbz band overhead all Peruvian flake.

Definitely IMC conditions. Its Slicker Than a Witches Tit on the secondary roads (dont ask me something my grandpa always said). 1/4 mile visibility, flakes shrunk some but still SN/+SN. Estimate over 2 with compaction. I had a feeling that warm nose would underperform knock on wood. This is our last hurrah for the month in central IN, enjoy!

Haven't seen any pingers (fingers crossed). Good inch already, nickle sized Rockwell flakes. Everything's covered, including the dogs and more importantly the mud! I do live in the country so it doesn't take much for the roads. Sticking to my fantasy call lol.

Yeah it's gonna be a nail biter here lol, still moderate snow. Gonna go play

Roads had no problem covering up. Nice big sticky flakes the last 30 minutes. Ground temps right at 32, roof at 33. If we can keep this up for the next 6-7 hours and keep that warm nose south we're on our way.

Me lol!

Seldom does KIND go bullish. Upped their call for here early this morning to 3-5 to be more inline with IWX 4-7 (their graphic is still messed up). Also mentioned potential overperformer in their AFD while IWX had a few caveats for under performer in theirs. I've said it before but I swear these two offices have running bets on their borders lol. Dealing with some dry air here no precip yet but we're running 3-4 degrees below forecast. Snow reported to my north. I'm sticking with my dog call

Parents lived on Sullivans Island since 84, I lived in Mt. Pleasant for 12 years, left in 2012. Like anywhere else it's changed a lot but it's still a great area to live. Got 5 inches of snow down there in like '08, biggest snow in a century or something. Brought the entire area to a standstill literally for 2 days lol. I go down there at least once a year,. Get used to this winter we've been having because this is low country winter minus the snow lol.

00Z crazy Ukie, lock it in..

The models be sayin"...

I wouldn't bet on it. I wouldn't bet on my call of 6-7. I do think there's a 50/50 chance that northern Marion county could over perform the forecast. I'm just not that sold on the warm nose with this system.