December 2021 General Discussion

[Cary67]

1 hour ago, Baum said:

^

a relative bonanza. Really irks me when true weather watchers miss these type of events in their own back yard while trying to horn in on my futility records. 

Technically imby may have broken it Sat. morning with a dusting

[Jonger]

15 hours ago, A-L-E-K said:

xmas torch incoming folks

Doesn't look like it. There's a snow Potential on Xmas Eve. 

[Jonger]

2 hours ago, Baum said:

and there it is:

 "A REMINDER THAT THE 20TH (MONDAY) IS THE RECORD IN THE   
CITY OF CHICAGO FOR THE LATEST FIRST MEASURABLE SNOWFALL OF THE   
SEASON, SOMETHING WE HAVE YET TO SEE.  "
  
DOOM  

That's amazing. We have had measurable snow like 6 to 10 days at least. 

[roardog]

I like the text from the high wind warning out of North Platte. It says holiday decorations will be damaged or blown away. lol

[McHenrySnow]

5 hours ago, Cary67 said:

Mainstream media will start its usual white Xmas concern for a few days next week.

I had about a tenth back in November during the only remotely wintry weather we've had. I don't expect snow before January anymore. 

[Brian D]

Mid 40's tomorrow with a quick shot of rn/sn tomorrow night. Very windy conditions after, up to 45mph. 

Keeps looking like those of us that put up X-mas eve/day forecasts in the Holiday thread are going to see something moving through.

[Hoosier]

A little odd that LOT left the Indiana counties out of the wind advisory.  I have to assume it will be coming eventually because everything I'm looking at supports it.

[Frog Town]

The fly in the ointment...

Nice analysis from GRR:

Impact of Tropical Storm Rai (west Pacific) on our weather for
  next week

As it turns out, Tropical Storm Rai, in the western Pacific is
heading due west toward the Philippine Islands. It should become
a typhoon by this evening. Why to we care about this in Michigan?
As it turns out, it will have a major impact our weather for the
next week. What this does is it stalls the MJO on the edge of
phase 6 to phase 7 since in phase 7. In phase 7 the area near the
Philippines should be dry. That changes the entire northern
hemispheric wave train. It will delay the arrives of the really
cold air till after Christmas (we need a solid phase 7 for that
cold air to get here).

This means largely zonal flow for our area for the next week.
That will prevent any strong pushes of cold air and also not allow
the much phasing with the next two storm systems that follow the
Thursday event.

[Stebo]

17 minutes ago, Frog Town said:

The fly in the ointment...

Nice analysis from GRR:

Impact of Tropical Storm Rai (west Pacific) on our weather for
  next week

As it turns out, Tropical Storm Rai, in the western Pacific is
heading due west toward the Philippine Islands. It should become
a typhoon by this evening. Why to we care about this in Michigan?
As it turns out, it will have a major impact our weather for the
next week. What this does is it stalls the MJO on the edge of
phase 6 to phase 7 since in phase 7. In phase 7 the area near the
Philippines should be dry. That changes the entire northern
hemispheric wave train. It will delay the arrives of the really
cold air till after Christmas (we need a solid phase 7 for that
cold air to get here).

This means largely zonal flow for our area for the next week.
That will prevent any strong pushes of cold air and also not allow
the much phasing with the next two storm systems that follow the
Thursday event.

That is a WDM outlook if I ever read one. Great met at GRR, always looking long range at stuff in this manner too.

[Hoosier]

Exciting stuff from DVN

 

Discussion for Wed and Wed night...A greatly deepening cyclone
tracking from the west central plains at noon, to the west basin of
Lake Superior by Thu morning, becoming negatively tilted and
deepening to under 975 MB along the way, to drive high winds acrs
the region Wed afternoon and night. Plume of 50-75+ KT H925 to H85
MB southwesterly wind layer still on track to surge acrs the CWA
from late afternoon and especially the evening thru 07z or so, with
ongoing challenge of how much will translate to the sfc with ongoing
warm layers aloft and stratus clouds. If these strong LLVL jet winds
verify, even marginal mixing should produce high end advisory to
around wind warning criteria 57-63 MPH. A more enhanced mix by a
band of thunderstorms or even a fine line of showers may tap into
the higher wind stream aloft and produce isolated swaths of 70 to
near 80 MPH winds. If this scenario looks to unfold, convective
severe T-storm warnings may still need to be issued embedded in the
High Wind Warning. LLVL CAPE values of only 200 to 600 at best may
limit stronger updrafts or the intense LLVL shear(0-1km 40-50 KTs)
may shred them apart limiting discrete storm development. While the
more discrete low topped supercells(if they form) with tornado
potential and intense down-drafts will hopefully arch northeastward
at tremendous speeds over 60 MPH just off to the northwest of the
CWA Wed evening, it appears a fine line of showers with/or even
isolated embedded thunder will still sweep eastward acrs the western
CWA after 00z Thu, SREF timing crossing the MS RVR around 03z, and
out of the CWA off to the east by 06z or 07z. These may mix down the
warning criteria winds or enhanced higher gusts.

Then there are signs of a sfc wind veer more southwest and deeper
adiabatic mix with arrival of a dry slot from west to east after 04z,
which may produce more widespread gusts of 55 to 65 MPH. Both of
these processes are taken into account for with the warning upgrade
from the watch and timing tweaks. There will be higher end Advisory
winds taking place either side of the warning criteria wind surges,
lasting well into the overnight. The western sector may need to be
cancelled early, but for simplicity sake all wind warnings and
advisories to end at 12z Thu morning. Foresee trouble with high
profile vehicles Wed evening, tree damage on powerlines for outages,
and will have to watch for downed power line sparking wildfires in
cured grassy areas, especially when the dry slot arrives later Wed
night.

[Hoosier]

I believe we are going to see a large power outage event from these winds.  A wide area is under the gun with several big metro areas included.  And in some of these areas, it's not just borderline/questionable high wind warning criteria... it will be met easily.  Big difference between having 55 mph winds vs. 70 or 75 mph.

[cyclone77]

Pretty cool to see 5% tor probs in the area where over a foot of snow fell a few days ago.  Still solid snow cover on the ground there too.

[cyclone77]

18z GFS very ominous tomorrow evening into early overnight for the parts of DVN/MKX/LOT regions.  Shows 70-76mph gusts from eastern Iowa through parts of northern IL into far southeast WI.  Fully expecting power to be going out tomorrow night here.

[OrdIowPitMsp]

34 minutes ago, cyclone77 said:

Pretty cool to see 5% tor probs in the area where over a foot of snow fell a few days ago.  Still solid snow cover on the ground there too.

We’ve still got 8” otg here. Will be very interesting see how much survives tomorrow. 
 

I recall a tornado in either Kenosha or Racine County WI in January back around 2005-2008 that occurred with snow on the ground. 

[CheeselandSkies]

3 minutes ago, OrdIowPitMsp said:

We’ve still got 8” otg here. Will be very interesting see how much survives tomorrow. 
 

I recall a tornado in either Kenosha or Racine County WI in January back around 2005-2008 that occurred with snow on the ground. 

 

You're probably thinking of January 2008, same event that had the famous train vs. tornado video from near Harvard, IL.

[Baum]

3 hours ago, Hoosier said:

Exciting stuff from DVN

 

Discussion for Wed and Wed night...A greatly deepening cyclone
tracking from the west central plains at noon, to the west basin of
Lake Superior by Thu morning, becoming negatively tilted and
deepening to under 975 MB along the way, to drive high winds acrs
the region Wed afternoon and night. Plume of 50-75+ KT H925 to H85
MB southwesterly wind layer still on track to surge acrs the CWA
from late afternoon and especially the evening thru 07z or so, with
ongoing challenge of how much will translate to the sfc with ongoing
warm layers aloft and stratus clouds. If these strong LLVL jet winds
verify, even marginal mixing should produce high end advisory to
around wind warning criteria 57-63 MPH. A more enhanced mix by a
band of thunderstorms or even a fine line of showers may tap into
the higher wind stream aloft and produce isolated swaths of 70 to
near 80 MPH winds. If this scenario looks to unfold, convective
severe T-storm warnings may still need to be issued embedded in the
High Wind Warning. LLVL CAPE values of only 200 to 600 at best may
limit stronger updrafts or the intense LLVL shear(0-1km 40-50 KTs)
may shred them apart limiting discrete storm development. While the
more discrete low topped supercells(if they form) with tornado
potential and intense down-drafts will hopefully arch northeastward
at tremendous speeds over 60 MPH just off to the northwest of the
CWA Wed evening, it appears a fine line of showers with/or even
isolated embedded thunder will still sweep eastward acrs the western
CWA after 00z Thu, SREF timing crossing the MS RVR around 03z, and
out of the CWA off to the east by 06z or 07z. These may mix down the
warning criteria winds or enhanced higher gusts.

Then there are signs of a sfc wind veer more southwest and deeper
adiabatic mix with arrival of a dry slot from west to east after 04z,
which may produce more widespread gusts of 55 to 65 MPH. Both of
these processes are taken into account for with the warning upgrade
from the watch and timing tweaks. There will be higher end Advisory
winds taking place either side of the warning criteria wind surges,
lasting well into the overnight. The western sector may need to be
cancelled early, but for simplicity sake all wind warnings and
advisories to end at 12z Thu morning. Foresee trouble with high
profile vehicles Wed evening, tree damage on powerlines for outages,
and will have to watch for downed power line sparking wildfires in
cured grassy areas, especially when the dry slot arrives later Wed
night.

not excited. I hate wind. don't understand the fascination.

[Hoosier]

Gino makes a good point.  The wind direction for this is a bit unusual.  Typically it is more southwest or west when you're talking about these kinds of gusts.  But it will be S or maybe SSW before veering later. 

 

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
845 PM CST Tue Dec 14 2021

.UPDATE...
Issued at 845 PM CST Tue Dec 14 2021

Forecast looks to be on track and no big changes planned to going
forecast this evening.

An highly anomalous weather pattern looks poised to break both the
record warm low and record high tomorrow and potentially break
Thursday`s record high at midnight tomorrow evening. While the
record warm temperatures will be noteworthy, the potential exists
for a rare synoptic damaging southerly wind event tomorrow
evening. The 00z NAM looks very similar to other guidance and
previous runs with 988mb low over the central High Plains early
tomorrow afternoon and quickly deepening it to 975mb as it moves
rapidly northeast to around Duluth by midnight. The fast movement
and rapid deepening will result in very strong pressure falls to
our north while very strong low level jet of 50-60kt. It seems
likely that as temperatures remain stead or even inch up a degree
or two Wednesday evening and in response to the very strong
pressure falls to our north that some of the very high momentum
air just off the surface will likely be transported down in gusts
that could exceed 50kt at times. While the threat of 50kt+ gusts
exists over most of the CWA, the greater chances certainly look to
lie north of I-80, where the high wind watch is in effect. Wind
headlines will be coordinated with neighboring office to the east
and issued for northwest Indiana overnight tonight.

In addition to the synoptic high winds, a narrow, strongly forced
line of shallow convection should accompany the cold front in our
area late in the evening. Whether or not this line has any
lightning, it will likely be capable of transporting 50kt+ gusts
to the surface as well.

- Izzi

[cyclone77]

Record high for the day at MLI already broken.  Old record was 59, and it's already 62 there.  All-time record already only 9 degrees away from tying.  

[michsnowfreak]

23 hours ago, Jonger said:

That's amazing. We have had measurable snow like 6 to 10 days at least. 

Detroit officially has had 8 days this season with measurable snow (6 in Nov, 2 in Dec).

[weatherbo]

Up to 40 degrees.  Pretty rapid thaw underway and what a shame too, had a very nice, dense base otg.  It won't melt off totally but what a bummer.

Waiting for the winds later tonight and tomorrow morning.  Usually high winds like this are from the west or northwest/north.  I don't recall having winds of 60+ from the south before... lot's of trees, makes me anxious.

 

[hlcater]

Our first 0.0" December likely on the table.

[luckyweather]

The low humidity cold airmass we had 12/5-12/7 was some fantastic snow making weather with 10-15 degree wet bulbs. I failed to take a pic at peak base but you get the idea with this pic from when I was laying it down. The past 18 hours have zapped it all away.

[A-L-E-K]

41 minutes ago, hlcater said:

Our first 0.0" December likely on the table.

exciting really

[cyclone77]

New all-time December record at MLI of 75 which shatters the old 71 record from Dec 4 1998.  Hit 73 here.  Incredible out there today.

[A-L-E-K]

Feels increasingly weird as sun sets and temps hang up

[OrdIowPitMsp]

Grass is showing up. We’ve melted nearly 8” of snow in 18 hours. Will be left with patches and piles by morning. 

[Up_north_MI]

4 hours ago, weatherbo said:

Up to 40 degrees.  Pretty rapid thaw underway and what a shame too, had a very nice, dense base otg.  It won't melt off totally but what a bummer.

Waiting for the winds later tonight and tomorrow morning.  Usually high winds like this are from the west or northwest/north.  I don't recall having winds of 60+ from the south before... lot's of trees, makes me anxious.

 

What’s the least amount of snow you’ve had on the ground for Christmas since you’ve lived there Bo? Looks like you “should” start rebuilding the snow pack slowly starting this weekend going into Christmas Day. 

[weatherbo]

2 hours ago, Up_north_MI said:

What’s the least amount of snow you’ve had on the ground for Christmas since you’ve lived there Bo? Looks like you “should” start rebuilding the snow pack slowly starting this weekend going into Christmas Day. 

2015 was a pretty slow start with just a few inches on the ground Christmas day.  Honestly tho, the snowpack doesn't really start gaining traction until January most years and usually peaks around 45" ish in early to mid March.  The deepest was Late-February 2019 with 60 + inches after over 100" in February alone.

Cabin up on the Peshekee Grade that year.

 

[Stebo]

That is too much snow

[Frog Town]

39 minutes ago, Stebo said:

That is too much snow

No such thing!