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Post by bdgwx on Jan 23, 2023 14:27:29 GMT -6
But isnt this more than just about the track of the 850? What about the track of the 500? Weve talked alot about both the 850 and 500 in past storms, but it doesnt seem like the 850 will produce all our snow. The 500 mb rule is discussed in Goree & Younkin 1966. There are two rules. 1. The axis of heaviest snow occurs about 150 nm (180 miles) to the left of the track of the 500mb vorticity track. and 2. The axis of heaviest snow is bisected by the 540 height and 534 thickness lines. But again, both rules are statistical. For example, 5% of the time the axis will setup along the 552 height line. |
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Post by Worldserieschampions (Chicago) on Jan 23, 2023 14:28:02 GMT -6
Did the heavy snow band shift north on the NAM Pretty similar to before. Entire metro gets a big hit with the heaviest band making it all the way to St. Charles. |
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Post by Snowstorm920 on Jan 23, 2023 14:28:39 GMT -6
It would be cool if the nam was right for once. Maybe move it north 20 miles too lol I will say, it has hardly flinched on its solution since it came in range.
Something you rarely see from the NAM
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Post by Worldserieschampions (Chicago) on Jan 23, 2023 14:29:02 GMT -6
Careful, now I know you read my posts |
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bob
Junior Forecaster
Posts: 334 
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Post by bob on Jan 23, 2023 14:30:14 GMT -6
Great I am in Ofallon mo and thought was going to miss the heavy snow
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Post by koll27–Waterloo, IL on Jan 23, 2023 14:34:40 GMT -6
The NAM is within its reliability window, correct?
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Post by Worldserieschampions (Chicago) on Jan 23, 2023 14:34:54 GMT -6
Great I am in Ofallon mo and thought was going to miss the heavy snow You might. This is just one run of one model. You are probably on the northern edge of the big totals realistically. Small differences in strength/track could move you solidly in or out of the heaviest band. |
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Post by Snowstorm920 on Jan 23, 2023 14:39:03 GMT -6
The 3km NAM jumped north a bit that run and agrees with the 12km NAM.
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Post by cardsnweather on Jan 23, 2023 14:40:10 GMT -6
The NAM is within its reliability window, correct? Inside 48 hours. But, it literally has shown almost the same solution since the storm showed up on hour 84. |
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Post by bdgwx on Jan 23, 2023 14:40:28 GMT -6
Here is the official NWS probability table.
Lo Med Hi >=0.1" >=1" >=2" >=4" >=6" >=8"
Columbia Regional Airport, MO 2 4 5 97% 92% 81% 40% 4% 0%
Jefferson City, MO 2 4 6 96% 91% 80% 41% 7% 0%
Hannibal, MO 2 3 5 98% 93% 81% 37% 7% 0%
St. Charles, MO 2 5 7 95% 90% 82% 55% 22% 4%
NWS Weldon Spring, MO 2 5 7 95% 90% 82% 57% 23% 4%
Farmington, MO 4 9 10 98% 96% 93% 84% 66% 40%
St. Louis Lambert Airport, MO 2 5 7 95% 91% 83% 59% 27% 6%
St. Louis, MO 2 6 7 95% 91% 84% 61% 30% 6%
Quincy, IL 2 4 5 98% 93% 82% 39% 7% 0%
Salem, IL 1 6 8 92% 87% 80% 60% 33% 10%
Belleville, IL 3 7 8 96% 94% 89% 71% 43% 11%
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Post by cardsnweather on Jan 23, 2023 14:41:09 GMT -6
NAM gets the WAA rolling quick tomorrow night around 8-10 PM. Will be fun to watch those temps plummet.
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Post by BRTNWXMAN on Jan 23, 2023 14:42:28 GMT -6
Mid-day NAM continues to look great for the Metro with another subtle shift N/NW. 850mb low tracks from KFAM to KMVN which is very favorable for most of the region but raises some concern for rain mixing in across the far S/E counties. It's definitely on the NW side of the model envelope though...but the trend is pretty clear.
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Post by cardsnweather on Jan 23, 2023 14:44:45 GMT -6
SREF mean still at 5" for BLV. Up to 6+ for airport. Only one dud.
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Post by BRTNWXMAN on Jan 23, 2023 14:49:35 GMT -6
NAM gets the WAA rolling quick tomorrow night around 8-10 PM. Will be fun to watch those temps plummet. Very strong isentropic lift develops tomorrow evening within the RER of the outbound jet. And the NAM continues to show favorable coupling with diffluence spreading in overnight. Also, the DAM looks to be subdued with the lack of strong ridging to the NE of the storm feeding in dry air. Basically, we should expect moderate/heavy snow to break out by tomorrow evening and continue into the early morning hours before tapering off by mid-morning. There should be a wall of snow moving NE on radar that should quickly overwhelm any lingering dry air. |
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Post by TK on Jan 23, 2023 14:50:42 GMT -6
Great I am in Ofallon mo and thought was going to miss the heavy snow You might. This is just one run of one model. You are probably on the northern edge of the big totals realistically. Small differences in strength/track could move you solidly in or out of the heaviest band. I think O'Fallon MO gets Jackpotted as usual with late slight shift North as the trends continue to show...Everyone Wang Chung tonight! |
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Post by bdgwx on Jan 23, 2023 14:50:53 GMT -6
The 19Z NBM is similar to the 13Z cycle. There's much change in amounts and locations for most of us.  |
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Post by jmg378s on Jan 23, 2023 14:52:07 GMT -6
Hmm, that's another significant increment north on the NAM at a time when you'd expect it's adjustments to be south towards the more reliable global models. Is it onto to something?
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Post by STGOutdoors on Jan 23, 2023 14:53:41 GMT -6
Let's hope not.
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Post by BRTNWXMAN on Jan 23, 2023 14:54:30 GMT -6
NAM Kuchera output looks pretty reasonable...likely a bit generous on the NW side of the heavy band but looks good otherwise.  |
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Post by Snowstorm920 on Jan 23, 2023 14:55:11 GMT -6
Hmm, that's another significant increment north on the NAM at a time when you'd expect it's adjustments to be south towards the more reliable global models. Is it onto to something? I'm starting to buy into the NAM solution.
This system is loaded to the gills with moisture.
Some of these runs from the globals have looked way too sparse on QPF in the cold sector
These negative tilt troughs also love to jump north at the last minute like this
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Post by BRTNWXMAN on Jan 23, 2023 14:57:11 GMT -6
I'd say the NWS isn't buying the low output from the NBM...
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Post by cardsnweather on Jan 23, 2023 14:58:26 GMT -6
NAM Kuchera output looks pretty reasonable...likely a bit generous on the NW side of the heavy band but looks good otherwise. I still feel like 1:7 is fairly low with low 30's during nighttime. I think 9 or 10 would be closer. |
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Post by ajd446 on Jan 23, 2023 14:58:28 GMT -6
Wow, great trends for the metro area, I was suprised to see the 5 to 10 in the warning.
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edzdad
Weather Weenie
Arnold, MO (Tenbrook Road and Jeffco Blvd.)
Posts: 5
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Post by edzdad on Jan 23, 2023 15:01:08 GMT -6
NAM gets the WAA rolling quick tomorrow night around 8-10 PM. Will be fun to watch those temps plummet. Very strong isentropic lift develops tomorrow evening within the RER of the outbound jet. And the NAM continues to show favorable coupling with diffluence spreading in overnight. Also, the DAM looks to be subdued with the lack of strong ridging to the NE of the storm feeding in dry air. Basically, we should expect moderate/heavy snow to break out by tomorrow evening and continue into the early morning hours before tapering off by mid-morning. There should be a wall of snow moving NE on radar that should quickly overwhelm any lingering dry air. BRTN, what time are you thinking this will start? |
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Post by BRTNWXMAN on Jan 23, 2023 15:04:47 GMT -6
NAM Kuchera output looks pretty reasonable...likely a bit generous on the NW side of the heavy band but looks good otherwise. I still feel like 1:7 is fairly low with low 30's during nighttime. I think 9 or 10 would be closer. I'd say ratios will end up somewhere between 8-10:1 on average...maybe as high as 12:1 with favorable dendritic growth during the stronger forcing. This will definitely be a wet, heavy snow and I'd say isolated power outages are possible with winds gusting to 20mph+ as the storm lifts out. |
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Post by BRTNWXMAN on Jan 23, 2023 15:05:35 GMT -6
Very strong isentropic lift develops tomorrow evening within the RER of the outbound jet. And the NAM continues to show favorable coupling with diffluence spreading in overnight. Also, the DAM looks to be subdued with the lack of strong ridging to the NE of the storm feeding in dry air. Basically, we should expect moderate/heavy snow to break out by tomorrow evening and continue into the early morning hours before tapering off by mid-morning. There should be a wall of snow moving NE on radar that should quickly overwhelm any lingering dry air. BRTN, what time are you thinking this will start? Looking like 8-10pm in the Metro right now. |
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Post by Snowstorm920 on Jan 23, 2023 15:15:17 GMT -6
18z ICON with a small bump north over previous runs  |
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mrbogs
Weather Weenie
Posts: 19
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Post by mrbogs on Jan 23, 2023 15:18:05 GMT -6
Hey guys...long time member and lurker, but don't post too much at all. I work in Wentzville and live in the Harvester area (right off of Dingledine...WSC knows where that is  ) I work until 11:00 PM, so guess I'll be driving home in at least the beginnings of the storm! LET IT SNOW!! |
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Post by bellevillewxguy on Jan 23, 2023 15:18:33 GMT -6
Almost 50*F high was 42*F. Amazing what light southwest winds and full sunshine can do. Enjoy it while it lasts!
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Post by STGOutdoors on Jan 23, 2023 15:22:40 GMT -6
Yea I’m a bit concerned about today’s overachieving temps. Hopefully the models aren’t underestimating the existing air mass. A couple degrees means a lot in this case.
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) I work until 11:00 PM, so guess I'll be driving home in at least the beginnings of the storm! LET IT SNOW!!