December 2021 Weather Discussion

[MVWxObserver]

Nothing going on flake-wise here in Greenville but as expected the cut off boundary was up to and south of the I-70 corridor.

Glad that others are getting in on some mood flakes!

Currently 23 here and progged for around 20 to perhaps the upper teens Wed morning.

[tpweather]

Good Morning and a nice coating of snow this morning and enough to close Kenton Country Schools. Looks like around 3/4 of an inch but will check it out more once daylight hits.

[mikeyp]

Picked up 1/2-3/4” over night. Nice to see the snow!

[Bgoney]

Car topper here, that's a win in my book.

On to Friday/Saturday. Pretty good threat for severe weather, intensifying low near Chicago, temps rising throughout Friday night into mid 60s with warm frontal passage, high shear in the lower levels. For now storms in the early morning hours on Saturday 4-8am bit that may change.

[tron777]

Good morning all! Looks like Boone Co is on a 1 hour delay. Wrecks are everywhere due to ice so be careful for those who have to commute to work. On mornings like these I am so thankful to be working from home! Looks like about a 1/4" here. CVG I believe recorded 0.20" Will have to double check that for our contest thread.

[tron777]

Car topper here, that's a win in my book.

On to Friday/Saturday. Pretty good threat for severe weather, intensifying low near Chicago, temps rising throughout Friday night into mid 60s with warm frontal passage, high shear in the lower levels. For now storms in the early morning hours on Saturday 4-8am bit that may change.

SPC has a marginal risk out for most. Slight risk to the SW of the Cincy Metro.

[tpweather]

Car topper here, that's a win in my book.

On to Friday/Saturday. Pretty good threat for severe weather, intensifying low near Chicago, temps rising throughout Friday night into mid 60s with warm frontal passage, high shear in the lower levels. For now storms in the early morning hours on Saturday 4-8am bit that may change.

100p/c agree. Strong winds look to be the key as these systems keep speeding up. Would not be surprised to have 2 rounds of storms with the first Friday afternoon and then the 4-8am period on Saturday. Rainfall will be heavy but the speed of the system should keep totals around 1 inch.

[Bgoney]

On to the extended. Here is EPS for most of week 3, 15th to 21st. Some movement going on at 500mb level with the ridging nudging into Western Alaska in response to the MJO movement (allegedly) . As long as the MJO keeps progressing through 7 , so should the ridging progress into Alaska and eventual movement of Arctic air. Crucial to fate of the last week of Dec and beyond

331087073_14-kmEPSGlobalNorthAmerica500hPaHeightAnom(2).gif.33c095ac401247a8c1db171a05cd0975.gif

765692388_14-kmEPSGlobalNorthAmerica850hPaTempAnom(1).gif.208156676cb454ef8c0610e5cbbf5e88.gif

[tron777]

Car topper here, that's a win in my book.

On to Friday/Saturday. Pretty good threat for severe weather, intensifying low near Chicago, temps rising throughout Friday night into mid 60s with warm frontal passage, high shear in the lower levels. For now storms in the early morning hours on Saturday 4-8am bit that may change.

100p/c agree. Strong winds look to be the key as these systems keep speeding up. Would not be surprised to have 2 rounds of storms with the first Friday afternoon and then the 4-8am period on Saturday. Rainfall will be heavy but the speed of the system should keep totals around 1 inch.

I forgot which model it was and what run... but I did see two bands of storms moving thru the area Tim. I have not checked any model yet for today so this was from yesterday's runs.

[tron777]

On to the extended. Here is EPS for most of week 3, 15th to 21st. Some movement going on at 500mb level with the ridging nudging into Western Alaska in response to the MJO movement (allegedly) . As long as the MJO keeps progressing through 7 , so should the ridging progress into Alaska and eventual movement of Arctic air. Crucial to fate of the last week of Dec and beyond


331087073_14-kmEPSGlobalNorthAmerica500hPaHeightAnom(2).gif.33c095ac401247a8c1db171a05cd0975.gif
765692388_14-kmEPSGlobalNorthAmerica850hPaTempAnom(1).gif.208156676cb454ef8c0610e5cbbf5e88.gif

Agreed... and the MJO wave is very slow moving so patience is required. The good news... if it can get deep into 7 and God forbid 8.. with the slow movement, a cold pattern can develop and actually last for several weeks because of the slow moving MJO wave. We just have to see if we can get there but if we can, the rewards could be plentiful.

[tron777]

CVG got 0.07" QPF from this light snow event so the Euro did awful with the lower QPF that it had. GFS and NAM did a much better job overall as a whole surprisingly.

[tron777]

Zonal wind anomalies are looking good right now showing a continued eastward progression of the current MJO wave. Keep on truckin'!

EPSMJO.png

EPS850wind.png

[tron777]

SnowTalk! https://www.wave3.com/2021/12/08/stormt ... pdate-128/

[fyrfyter]

Picked up 5/8” overnight here. Roads are fine here. Don’t understand why everywhere else is a mess. This wasn’t worth any of that. They act like it’s never snowed before.

[tpweather]

Good Morning and took my father-n-law to church this morning. Road conditions are good for the most part though Dixie Hwy near Dixie High School is very icy. Driveways and sidewalks are very slick and solid sheet of ice. Measured around 3/4 of an inch but my neighbors car had 1 1/4 inch so it depends if every flake stuck.

[cloudy72]

Prob between 1/4 and 1/2" of snow here. Main roads were fine but parking lots, side roads and sidewalks were icy in spots.

[cloudy72]

06z GFS wind gust potential Fri night-Sat morning. Def need to watch this.

gfs-deterministic-cincinnati-gust_swath_mph-9213200.png

[cloudy72]

Overnight Euro has highest gusts north of I-70.

[tron777]

Picked up 5/8” overnight here. Roads are fine here. Don’t understand why everywhere else is a mess. This wasn’t worth any of that. They act like it’s never snowed before.

The issue down here was that when the snow started it melted and the temp dropped 4-5 degrees and caused black ice to develop with a 1/4" of snow on top of it. No road treatment at all as the road crews were caught with their pants down. It was a disaster in NKY this morning.

[tron777]

06z GFS wind gust potential Fri night-Sat morning. Def need to watch this.


gfs-deterministic-cincinnati-gust_swath_mph-9213200.png

Wow... very impressive!!! If we can get elevated or SB CAPE this could be better then the last storm. Wind shear looks more impressive with this particular system.

[tpweather]

06z GFS wind gust potential Fri night-Sat morning. Def need to watch this.


gfs-deterministic-cincinnati-gust_swath_mph-9213200.png

Wow... very impressive!!! If we can get elevated or SB CAPE this could be better then the last storm. Wind shear looks more impressive with this particular system.

Interesting and the last system really was impressive and what we saw on Sunday to start with was clouds but the sun came out all day and that adds so much energy to the atmosphere. During the day on Friday will also gives us some clues to what happens later in the day and early Saturday. If we stay cloudy then it should hold back on some of the energy though the winds are going to be strong no matter what happens but getting several hours of sunshine can elevate those storms.

[cloudy72]

12z NAM with gust potential in the 45-50 mph range (local 50+) on this run for FRI night-SAT AM. Also of note, check the precipitable water prediction with this system.....in mid-December!! That's quite the moisture feed for this late in the year.

nam-218-all-ecentus-pwat-9213200.png

[tron777]

Good posts Mike and Tim. I think wind gusts in the 40-50 mph range even without severe storms looks good. Despite the high PWATS, this front looks to be more progressive so that will help to cut down on the rain totals. Still, where strong storms occur, an inch of rain is easily doable.

[tron777]

12Z NAM sounding near CVG has like 70-80 knot bulk 0-6km Shear! Not much SB CAPE only about 100 J/kg but it isn't going to take much of it with those kind of dynamics in place. Cold season severe wx events are much different then in the warmer months.

[tpweather]

Zonal wind anomalies are looking good right now showing a continued eastward progression of the current MJO wave. Keep on truckin'!


EPSMJO.png


EPS850wind.png

Les very important part of the puzzle. If this stalls or just dies out it may be several weeks before we get a long term cold pattern. Sure we can head towards normal but even in late December that is highs near 40 and lows in the low-mid 20's but that would be a warm up before a system and then cold behind that gives us the normal. I believe it will keep on truckin and models will show that over the next several days.