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Post by Chris Higgins on Dec 31, 2020 12:28:55 GMT -6
The current temps are running about 2 degrees cooler than the 12z GFS/NAM while right in step with the RAP. The HRRR is a couple of degrees too cold.
The thin overcast is allowing enough sun through for now to keep a slow warm-up going. However, if the clouds thicken at the wrong time and trap the daytime heating... that means warmer tonight. If they stay thin through sunset... then temps dip a bit more.
The set-up remains very borderline. If this were a daytime situation... it would be a pretty easy call to go light on icing. But time of day matters and this is the middle of the night...and it has sleet at the onset...both factors favor a period of tough travel for a few hours. But after the initial surge of precip and the change to rain... I would expect some improvement..especially on the more traveled roads.
This is a solid advisory level event.
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Post by Frivolousz21 on Dec 31, 2020 12:29:41 GMT -6
I'm not trying to "RAIN" on anyone's parade.
And I admittedly haven't looked at the models at all for any ice storm.
But historically these ice events in this forum are way overhyped.
Very rarely do we get any decent icing unless temps are below 29F and dews below 27F and that's with a strong cold air source.
Maybe we can get some sleet like Chris Higgins talked about.
But that HRRR sounding from yesterday is way to warm for sleet and even tho it's 29/30F at the surface it has THOUSANDS OF FEET ABOVE THE SURFACE IN THE UPPER 30S.
That's a lot different than water that's only exposed to 33/34F air in a thin layer
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Post by ndolan387 on Dec 31, 2020 12:40:18 GMT -6
So more ice accumulation than 00z for the metro? When do surface temps get above freezing on that run?  Thanks! That looks pretty realistic to me for the metro having glazing of 0.1-2" potentially with spots of 0.25-3" on elevated surfaces. |
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Post by demerson- Fletcher MO on Dec 31, 2020 12:41:51 GMT -6
I predict the summer of 2030 will be brutal. Lock it in I have a pool now lol idc |
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Post by Frivolousz21 on Dec 31, 2020 12:49:16 GMT -6
This looks amazing. It would be very hard to not see some snow out of that.   |
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Post by Snowstorm920 on Dec 31, 2020 12:51:45 GMT -6
This looks amazing. It would be very hard to not see some snow out of that. Euro goes full negative tilt with the system and generates some respectable QPF. That’s one to keep an eye on for sure |
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Post by Frivolousz21 on Dec 31, 2020 12:53:44 GMT -6
This looks amazing. It would be very hard to not see some snow out of that. Euro goes full negative tilt with the system and generates some respectable QPF. That’s one to keep an eye on for sure What's the euro depicting qpf wise? The lift is pretty high up but quite respectable as well. Sits on top of the dgz. But would easily support true cotton ball dry flakes. |
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iceman
Wishcaster
Arnold, MO
Posts: 104 
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Post by iceman on Dec 31, 2020 12:56:07 GMT -6
I don't see it warming up to 39 today. Sitting at 30 right now.
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Post by Frivolousz21 on Dec 31, 2020 12:56:16 GMT -6
The nam also has some decent low level fronto lift early Sunday AM below 700mb.
Could result in some decent bands of snow between 3-7AM along the river.
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Post by Snowman99 on Dec 31, 2020 13:01:43 GMT -6
too bad this system tonight takes all the moisture with it, or we'd really be in business saturday. #itcantsnowinstlouis
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Post by ndolan387 on Dec 31, 2020 13:02:13 GMT -6
The current temps at 18z (12pm) were 31* about 2-3* warmer than what the HRRR said for 18z today: 28-29*. The latest 17z HRRR has temps around 28-29* around the western immediate metro by 10z (4am) tomorrow so really it should be around 31* by 4am tomorrow if the trend continues. It looks like by 5-6am we will be near 32*, but no solar insolation yet. So possible slight ice accretion until 5-6am like Chris mentioned. The sun rises ~7:20am and I think by then any ice accumulation will stop. So were looking at around 4 hours of good ice accretion and about 6-7 hrs total of icing including light accretion IMO.
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Post by Frivolousz21 on Dec 31, 2020 13:02:16 GMT -6
This is on the hires nam between Farmington and St. Louis Saturday evening. That lift is in the process of organizing and strengthening as the upper level system SLOWLY passes by.  That is definitely a quick but heavy high ratio dry cotton ball snow |
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Post by bellevillewxguy on Dec 31, 2020 13:05:15 GMT -6
Sun should hold out another 2 hours or so according to visible satellite.
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iceman
Wishcaster
Arnold, MO
Posts: 104
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Post by iceman on Dec 31, 2020 13:09:17 GMT -6
RAP and HRRR appears to hold I-44 and north at or below freezing throughout the duration of the 18Z run.
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Post by Frivolousz21 on Dec 31, 2020 13:25:13 GMT -6
I recall last year the rap/hrrr being way to cold in these setups.
It looks like the first push of precip will be sleet/freezing rain.
But that is looking like 0.2" of qpf at most.
The second much stronger slug of precip will come with temps well above freezing.
Saturday afternoon-night is what looks much more interesting.
That set up won't take much at all to turn into a low end advisory snow.
On top of that. Even tho we may only see 1-2".
Snow will be in the air from late Saturday afternoon into early Sunday morning.
Even if only bursts of flurries to light snow.
While as of now it looks like a couple bands of more concentrated snow may occur.
Will someone please post the European model qpf for Saturday afternoon through Sunday morning only???
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Post by Snowstorm920 on Dec 31, 2020 13:33:01 GMT -6
I recall last year the rap/hrrr being way to cold in these setups. It looks like the first push of precip will be sleet/freezing rain. But that is looking like 0.2" of qpf at most. The second much stronger slug of precip will come with temps well above freezing. Saturday afternoon-night is what looks much more interesting. That set up won't take much at all to turn into a low end advisory snow. On top of that. Even tho we may only see 1-2". Snow will be in the air from late Saturday afternoon into early Sunday morning. Even if only bursts of flurries to light snow. While as of now it looks like a couple bands of more concentrated snow may occur. Will someone please post the European model qpf for Saturday afternoon through Sunday morning only??? Well i just found the new t-shirt logo
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iceman
Wishcaster
Arnold, MO
Posts: 104
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Post by iceman on Dec 31, 2020 13:38:17 GMT -6
For what its worth UKMET still looks fun. Showing widespread 2-4" for the metro area through sunday.
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Post by Snowstorm920 on Dec 31, 2020 13:42:54 GMT -6
RAP and HRRR appears to hold I-44 and north at or below freezing throughout the duration of the 18Z run. Their not backing down on the higher end scenario. They really hold onto the cold layer at and just above the surface for a majority of the event. |
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Post by thechaser on Dec 31, 2020 13:48:18 GMT -6
LSX added Montgomery, Gasconade, Lincoln and Warren County to the Winter Storm Warning.
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Post by Snowman99 on Dec 31, 2020 13:48:44 GMT -6
For what its worth UKMET still looks fun. Showing widespread 2-4" for the metro area through sunday. I see maybe an inch for the metro on the ukmet, just go according to the 24 hors or so from noon sunday back to neen sat..not the stuff that falls before that. |
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Post by jmg378s on Dec 31, 2020 13:50:47 GMT -6
For what its worth UKMET still looks fun. Showing widespread 2-4" for the metro area through sunday. Most of that I think is freezing rain (or sleet) with surface temps at (or below) 32F being treated as snow...at least on the Pivotal Weather site. |
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Post by Snowstorm920 on Dec 31, 2020 13:51:25 GMT -6
For what its worth UKMET still looks fun. Showing widespread 2-4" for the metro area through sunday. I see maybe an inch for the metro on the ukmet I’ve made that mistake with the ukmet snow maps to. On Pivotal anything that falls with temps below freezing gets counted as snow even if it’s frz/ip |
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Post by Snowstorm920 on Dec 31, 2020 13:52:17 GMT -6
Now I know how 99 feels
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Post by jmg378s on Dec 31, 2020 13:53:27 GMT -6
Gotta be quicker
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Post by Snowman99 on Dec 31, 2020 13:56:06 GMT -6
interesting how they added another tier of counties to the warning.I border two of them, lol.
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Post by Snowstorm920 on Dec 31, 2020 13:57:41 GMT -6
Springfield office really expanded their advisory’s and warnings south as well
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Post by Snowman99 on Dec 31, 2020 13:58:27 GMT -6
I guess I'll spent the evening making Broccoli and chicken in the instapot, and crab rangoon in the air fryer. Have a few drinks and wait for the ice. My dog went to daycare today, and they're having a doggy slumber party tonight he's staying for. So you all gotta keep me company.
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Post by guyatacomputer - NE St. Peters on Dec 31, 2020 14:00:53 GMT -6
LSX added Montgomery, Gasconade, Lincoln and Warren County to the Winter Storm Warning. Was just about to post this. Up to .4“ of ice. That starts to get pretty significant. |
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Post by cardsnweather on Dec 31, 2020 14:07:44 GMT -6
Hi res nam looks like it tries to squeeze in some showers around 8-9 through the metro. Like it’s been said many times, WAA always comes in full speed ahead.
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Post by Frivolousz21 on Dec 31, 2020 14:16:59 GMT -6
Is Tommy back?
The Euro is further NW Saturday than the other models.
It would not be favorable for an immediate metro hit.
It also looks to have some decent frontal forcing over West Central Missouri which weakens/dissipates before it reaches our local weather nursery.
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