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Post by Chris Higgins on Feb 16, 2024 12:39:41 GMT -6
This is playing out pretty much as expected! I'm pretty happy up to this point. I still expect snow to shutdown quickly after 2pm and roads to improve very quickly thereafter.
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Post by Chris Higgins on Feb 16, 2024 12:08:04 GMT -6
Very heavy snow in Chesterfield... Vis is 1/4 mile at best in the valley.
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Post by Chris Higgins on Feb 16, 2024 11:40:07 GMT -6
Temp has dropped to 28 in Wentzville... and road temp is 31.3. This is going to pile up quickly now for the next couple of hours along I-70.
Just had a spinout in front of us on I-70 near Wright City. Roads are pretty slick out here right now because of the snowfall intensity.
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Post by Chris Higgins on Feb 16, 2024 10:32:36 GMT -6
Snow is sticking on grass here in Maryland Heights. It helps that it is kind of chunky. Slightly rimed and very well formed dendrite. Kind of lick lucky charms or captain crunch.
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Post by Chris Higgins on Feb 16, 2024 9:43:02 GMT -6
new mesoband appears to be organizing along I-44 up into STL
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Post by Chris Higgins on Feb 15, 2024 23:06:47 GMT -6
This will be fun tomorrow... and for some annoying! There will be some breaks in these bands and outside of those bands it may be hard to get snow to stick... but under the bands snowfall may be quite impressive. I also think we have a hint of what is to come tomorrow morning by looking at the snow in northwest Kansas. That is hugging the track of 850mb low.
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Post by Chris Higgins on Feb 15, 2024 19:04:12 GMT -6
I actually think this one may over achieve a little. If temperatures actually drop to near freezing before sunrise... they will likely not rebound much. This will allow ground temperatures to cool off as well... just as the precip starts to fall. Throw in some sleet at the onset, and I think this one may be a touch more efficient on the accumulation side. Time of year does matter now... but so do dynamics... and the models are showing multiple mesoscale bands that may train over the same areas for a time. In fact, radar may look a bit like a zebra for a few hours tomorrow with rows of narrow snow bands pushing east and easing south. The low/mid-level Fgen looks pretty strong with that compact 850 low developing...NWS mentioned potential CSI too. Should be some nice snow rates under those mesobands. Or it could all shift 200 miles south or north on the 00z run like Monday š¬
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Post by Chris Higgins on Feb 15, 2024 18:35:12 GMT -6
I actually think this one may over achieve a little. If temperatures actually drop to near freezing before sunrise... they will likely not rebound much. This will allow ground temperatures to cool off as well... just as the precip starts to fall. Throw in some sleet at the onset, and I think this one may be a touch more efficient on the accumulation side. Time of year does matter now... but so do dynamics... and the models are showing multiple mesoscale bands that may train over the same areas for a time. In fact, radar may look a bit like a zebra for a few hours tomorrow with rows of narrow snow bands pushing east and easing south.
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Post by Chris Higgins on Feb 15, 2024 10:47:13 GMT -6
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Post by Chris Higgins on Feb 14, 2024 23:15:19 GMT -6
The UK looks weird on Pivotal Weather. It shows 0.4 liquid precip with temps below freezing in STL, but generates almost no snowfall.
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Post by Chris Higgins on Feb 14, 2024 9:23:29 GMT -6
Very funny!
I think we are going to need to watch for sleet with this. Looking at the soundings... much of the lift is below the DGZ which may lead to more ice and less snowflakage on the southern flank of the band.
Could this be how we mess up our latest potential snow?
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Post by Chris Higgins on Feb 14, 2024 8:32:24 GMT -6
The IBM continues to look overcooked lol. I wish I could unsee it. Showing upwards of 7 inches for STL. The main reason appears to be a slower north to south translation of the banding feature...so there is what amounts to training along I-70. That would make a lot of people happy. But it is waaaaaaaaay out on its own with that kind of total. From a simple "blobology" perspective... it looks very similar to the Euro still... just over sauced. If anything, this latest run of the IBM model has shifted the focus a row of counties more south
Either way... it does look like some snow is coming our way Friday. Late AM through mid-afternoon is the prime time for most of the area. I think the NWS wording of 1-3 seems reasonable at this juncture although I'm not pinning my name or forecast to that just yet.
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Post by Chris Higgins on Feb 14, 2024 0:42:00 GMT -6
The european and the I b m model are nearly identical with plqcement. The only difference is the european is showing about half as much snow.
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Post by Chris Higgins on Feb 13, 2024 23:55:44 GMT -6
The longer range version of the IBM model in house has a nice pasting of snow sweeping across most of the area Friday afternoon and evening. It actually cranks out 4-6 inches along the Missouri River.
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Post by Chris Higgins on Feb 13, 2024 15:54:24 GMT -6
most of the models agree on a light snow on Friday. 18z ICON however would be quite nice dropping 4-6" throughout the entire area. The ICON was thr worst with yesterday's storm... by far!
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Post by Chris Higgins on Feb 12, 2024 22:06:56 GMT -6
Weāre not the only location where models have pooped the bed with this system Ouch!
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Post by Chris Higgins on Feb 12, 2024 18:34:55 GMT -6
Iām not sure if all the models show the snow of the century for a week straight I will buy into it after this winterā¦ā¦. Until I see a full radar and snow coming down will I believe again lol What makes this even more interesting, is? The energy was camped out in the southwest u s for several days period. It's not like it was not getting sampled multiple times from the upper air network. And it had several samplings out of the mountains, ao that argument doesn't hold either.
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Post by Chris Higgins on Feb 12, 2024 16:17:33 GMT -6
Chris, if there's a silver lining to the turd-polishing, it's that most people are done with winter anyway. If this was December or January, it would be a harder sell. There is truth to that for sure!
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Post by Chris Higgins on Feb 12, 2024 12:22:20 GMT -6
The first forecast may have stunk, but the recalibration is working out ok. The meso band shown on the NAM has materialized... but not in any spot along I-44 in our viewing area to overcome marginal temps.
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Post by Chris Higgins on Feb 12, 2024 12:18:41 GMT -6
Hit decent snow midway between Rolla and St James. Nothing sticking.. temps in upper 30s.
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Post by Chris Higgins on Feb 11, 2024 23:58:34 GMT -6
The euro The last 24 hours says it all. A 200 mile SOuthward shift. We have had similar shifts like this. But usually those are with 48 hours lead time. However honestly unless I'm really off. I don't recall much support for the euro solution ever??? It seemed to me even a couple days ago the consensus was South. Yesterday we had one NAM run iirc look somewhat like the euro. But that was it iirc. This is in reference to the euros robust solution. Not Mr. Higgins forecast. Which was always further South. But not far enough south...lol.
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Post by Chris Higgins on Feb 11, 2024 23:28:22 GMT -6
Excuse my crudeness but there is a term we use in the business called "shining a poop" (we use a slightly more crass word...but you get the idea). This map is my best effort to shine the poop.. put lipstick on a pig... or whatever way you chose to describe the recalibration of a forecast that is clearing going to bust. In my 32 years of forecasting, this is one of the biggest disappearing acts I can remember so close to an event. But here's the problem... while there is no denying the forecast has gone off the rails, the NAM and some of the mescale/CAMS still hint at the presence of a mesoscale band attempting to pull together near I-44 from Rolla up to Union. The NAM is by far the most robust now with this feature in this area. It does have some support based on existing weather in OK and southwest Missouri... which is why I cannot completely toss it aside. The only thing worse than a busted forecast... is having the replacement forecast bust too by pulling the snow out entirely... and then all the sudden "surprise" the band develops afterall. To be clear... I'm not talking about a sudden reappearance of the band as it was forecast earlier. That is not in the cards. However, there is enough evidence still in the modeling that something could come together along I-44. And Iām not comfortable completely pulling all snow from the forecast in that area at this time. So, Iām going to massage in that thumb of āDusting to 1 Possibleā from Franklin County, southwest into Phelps County. I readily admit, that is a super low confidence forecastā¦ but it is my effort to recognize the remaining signals from some of the guidance. It's also possible that region sees nothing or nearly nothing at all. So here you go...
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Post by Chris Higgins on Feb 11, 2024 22:47:00 GMT -6
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Post by Chris Higgins on Feb 11, 2024 22:22:44 GMT -6
This is one of the more challenging recalibrations of a forecast I can remember. I haven't had to do one like this in quite some time...which is good. But like everything in forecasting there is an art to it... but this time it is more challenging than most.
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Post by Chris Higgins on Feb 11, 2024 18:56:58 GMT -6
If the the 18z trends hold through 00z, this will go down as one of the worst model adjustments this close to an event that I can remember. Are the Russian's messing with our initialization data again?
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Post by Chris Higgins on Feb 11, 2024 15:10:52 GMT -6
Iām going to go out on a limb and say the WWA for 2-4ā of snow will not verify in northern Jeffco For what it's worth... I would not have included Jeff Co in the advisory. I was thinking most of the county would be a dusting to 1"... maybe 2 in far southern part of the county.
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Post by Chris Higgins on Feb 11, 2024 15:09:39 GMT -6
Nws is way more north with there thoughts and placement of the wwa I am not sure what they are seeing. Their forecast ... and mine for that matter... are based off careful review the morning model data for the most part. There isn't time to incorporate much of the 18z data into the 4pm forecast. You don't want to make any big decisions/changes based on partial information. Issuance of advisories needs to be coordinated between offices.. and that happens around midday to around 2pm. You have to draw the cutoff line for new data somewhere or you would just keep kicking decisions down the road and never put out a product.
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Post by Chris Higgins on Feb 11, 2024 12:08:48 GMT -6
The simulated radar products I posted are from the in-house IBM model... but shifted north a few miles to better match the ensemble 850mb low tracks.
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Post by Chris Higgins on Feb 11, 2024 12:05:38 GMT -6
Models may have shifted south a bit, but the theme is the same. Mostly noise now as the output floats on either side of the mean track that has been pretty solid actually for the past couple of days. I'm holding steady for the most part.
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Post by Chris Higgins on Feb 11, 2024 11:11:28 GMT -6
I have looked at the new observational and forecast data and I just donāt see anything that makes me want to deviate significantly from the placement of the heavier snow band Iāve had forecast for the past several days. The only tweak Iāve made, geographically, was to expand the more significant accumulations a little more to the southeastā¦ taking in Perry and all of Madison County in Missouri. While the placement has changed very little, I now have enough confidence in the location of that heavier band to boost numbers a little bit. Iām going with a 2-5 inch, wet sloppy snowā¦ an increase from the 1-3 inches I was showing with that band earlier. The potential limiting factors have been well documented over the past few daysā¦ marginal air and ground temps and time of day. Originally, this looked like a pre-dawn event, but over the past several days the system has slowed and the vast majority of it will fall during the day. It will take some pretty exceptionally heavy snow to get it to accumulate.. which is possible over the eastern Ozarks given the very favorable dynamics that are in place for a strong, narrow band of snowfallā¦. To say nothing of the potential for upright convection as well! Yes, thunder snow is a very real possibility between Salem MO and Farmington tomorrow. Itās possible some could see more than 5 inchesā¦but given the strong mitigating factors, I think it is wise to not get too aggressive with forecast totals. The other factor that may help with snowfall efficiency is the elevation of the eastern Ozarks. Now, with a 2-5 inch bandā¦ I need a buffer zone and the one I have painted on there is likely too generous in some places. The actual drop from 2 inches to nothing is probably going to be over single milesā¦ not tens of miles. But I wanted to leave some wiggle room thereā¦especially up into metro St. Louis. That being said. I think the UHI is likely to curtail and snow accumulation of consequence in metro STLā¦ assuming we are able to get any snow up that way at all. Obviously the metro is on the northern fringe of the precipitation field. As for the Illinois side of the riverā¦ the drop in elevation, time of day and model trends to weaken the mesoscale banding in Illinois for a time have me keeping much of southern Illinois in the trace to 2 inch range.
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