beavis1729

06z FV3 is not backing down at all. 

It shows -42C H85 temps in west-central MN at 0z tonight; I think this is the coldest modeled output that I've seen so far.  Also, -38C H85 temps in N IL at 9z Wed.

LOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
604 AM CST Tue Jan 29 2019

.SHORT TERM...
323 AM CST

Through Thursday...

The long-advertised bitter and likely record cold is inbound this
morning, with the first cold front having advanced over the area
last night while the second much more substantial cold surge is
coming this evening. In terms of the cold, very little has changed
with the character of the forecast, with tonight through Thursday
morning the most dangerous time of cold. A couple all-time
records remain forecast as noted below. Wind chill headlines
continue as is. Forecast winds today have been increased some and
am concerned for areas of blowing snow, even potential ground
blizzard conditions in some rural areas this afternoon into
tonight. Will highlight this in messaging. Finally, the pattern
for nearly the past two weeks has been "every day it snows" (and
has 12 straight at Chicago), and feel that scattered snow showers
and/or flurries are a good bet from late morning on.

Satellite imagery this morning depicts the lobe of polar air
marching southward from Canada into the Upper Midwest. Observed
last evening in central Canada with this were a dynamic tropopause
below 700 mb, sub 500dm 500 mb heights, and 850 mb temperatures
near -40C. This will advance southeastward toward the area today
with little to no moderation. As this supports deepening of the
surface low over the central Great Lakes, cold advection will
persist and on a unidirectional westerly wind profile. Given
steep low-level lapse rates in this regime, even with some clouds,
see nothing to prevent winds gusting to 30 mph regularly this
afternoon and evening, possibly even 35+ mph sporadically. Given
yesterday`s blowing and drifting snow, at times producing very low
visibility especially in north central Illinois, would envision
similar problems today and maybe even to a higher degree
especially in and near any snow showers that may develop. If just
a tad higher winds, would strongly consider a Winter Weather
Advisory, but feel the WSW for the wind chills and an SPS for the
blowing snow will convey the message just fine.

As for the potential for falling snow, there are multiple small
scale impulses upstream seen on satellite. In just the broad
scale DPVA and low-level CAA pattern, there should be some daytime
enhancement with isolated to scattered snow showers and flurries
in this especially given the readily ability to saturate with
respect to ice. The cloud depths are shallow so not expecting
heavy snow showers, but with the gusty winds could temporarily
push down visibility sharply in some places.

Temperatures will hold steady on these winds with little if any
rebound today. These support the Wind Chill Advisory for today.
For duration below zero interests, it is possible some places dip
below this morning then briefly top zero before heading into the
deep cold this evening. The 925mb temperatures will drop to near
record low levels of -34C tonight using ILX sounding climatology.
While do think there will be some clouds including into the
overnight over far northern Illinois, advection will mainly drive
temperatures. Clouds could still impact a few degrees so
naturally there is uncertainty in specifics. Have only made
subtle tweaks and have Rockford right at their all time record low
of -27, while Chicago metro -18 to -24. It really is amazing to
have the wind speeds we will have with those temperatures, and as
such wind chills still fall out -45 to -55 by Wednesday morning.
This is dangerous, extremely rare cold and continues to be the
center of our safety message for this event.

While less wind on Wednesday, cold advection continues, and highs
still look to be negative double digits for most of the area. Have
both Rockford and Chicago at their all time record cold high
temperature, and again for the calendar day there will be heavy
dependence on what midnight temperature is namely at Chicago, and
that`s going to be close to -11.

The signature of the high pressure moving over northern Illinois
Wednesday night continues to be consistent and sets the stage for
ideal radiational cooling with a near to record low starting
point into the night. So all time record lows continue to show
potential with widespread -20s and some -30s in favorable places.
The -30 forecast for Rockford still looks good, with 75 percent of
available 00Z guidance forecasting a record low at Rockford. For
Chicago, about 15 percent of models forecast an all time record
low at ORD. Favorable locations in north central Illinois, could
easily push -35 to -39 for lows with all the ingredients lining
up.

In terms of impacts, the wind chills will be lessening by Thursday
morning due to the light or even calm winds in some spots.
Nonetheless, record cold is obviously impacting enough, so the
Wind Chill Warning duration looks really good. Clouds should start
moving in Thursday and many locations are likely to remain below
zero through the day. Light snow will be possible by afternoon as
the elevated baroclinic zone starts to move overhead, with better
chances after dark.

MTF

DVN

.LONG TERM...(Wednesday through Monday)
ISSUED AT 203 AM CST Tue Jan 29 2019

...Near record cold to record cold, with extreme wind chills remains
on track...

The strongest push of Arctic air will come through our area early
Wednesday morning, with the high gradually centering itself over
the CWA by Thursday morning. This entire period will be noted by
wind chills below -30. The coldest wind chills, with the combined
effect of -20s temperatures and sustained 10 to 18 mph winds will
be early Wednesday morning where wind chills in the north half
fall to the extreme range of -50 to -60. That extreme should last
through late morning, before being dominated by -35 to -45. The
south half should be -40 to -50 through Noon, then -30 to -35 in
the afternoon.

Wednesday night into Thursday morning, with high overhead and
radiation finally able to drop temperatures beyond the advection, we
will continue to face wind chill values of -25 to -45, but with
increasing variability after midnight, as winds become light.
Thursday morning, lows of -30 to -33 are likely along and north of I-
80, and over the Rock River valley in Illinois. This is possible all
time record levels!!  Just south, -15 to -25 are likely. I
specifically am not forecasting an all time low at Moline, for two
reasons. One, the urban heat island impact in light west winds, and
the second, also dealing in winds, the MLI airport really only sees
cold air drainage at the ASOS there when there is an extremely light
east to northeast wind, which taps drainage air. This is what
happened a few days ago, when we hit -22.  No matter the case, we
are within a couple degrees of all time cold!

Somewhat problematic for headlines, is that Thursday morning, wind
chills may or may not be extreme, as winds will be light. However,
ANY WIND, will bring extreme wind chills given the air temperatures
below -25 in much of the CWA. No changes expected in the wind chill
warning.

The sustained extreme cold with wind, followed by extreme cold with
lesser wind should continue to bring the advertised impacts which
include: vehicle problems(battery/tires/engine performance), 5-15
minute frostbite on exposed skin, water main breaks, burst pipes
inside homes/business, enhanced risk of fires from improper use of
home heating, pet/livestock impacts, and carbon monoxide poisoning
risk increase.  In general, we just are not routinely prepared for
dealing with this, and the widespread cancellations already declared
seem to give hope that the message is out.

13 minutes ago, Baum said:

Beavis going to be sunbathing soon....

DLH

.CLIMATE...
Issued at 251 PM CST Mon Jan 28 2019

Record lows are possible this week. Below are records and current
forecasts for select sites with a long history.

Record Lows for Tuesday January 29...

Duluth................-35 in 1951...Forecast...-21
International Falls...-41 in 1951...Forecast...-28
Brainerd..............-38 in 1965...Forecast...-25
Hibbing...............-34 in 1951...Forecast...-24
Ashland...............-35 in 1951...Forecast...-10

Record Lows for Wednesday January 30...

Duluth................-25 in 1994...Forecast...-29
International Falls...-40 in 1950...Forecast...-36
Brainerd..............-40 in 1996...Forecast...-37
Hibbing...............-33 in 1951...Forecast...-33
Ashland...............-35 in 1950...Forecast...-19

Record Lows for Wednesday January 31...

Duluth................-33 in 1982...Forecast...-32
International Falls...-35 in 1996...Forecast...-43
Brainerd..............-46 in 1996...Forecast...-40
Hibbing...............-41 in 1996...Forecast...-38
Ashland...............-33 in 1996...Forecast...-23

I know this is overdone...but 

Look at the -34 at Grand Forks, ND at 12 noon central time tomorrow on the 18z FV3.

DLH 

Area Forecast Discussion
National Weather Service Duluth MN
251 PM CST Mon Jan 28 2019

.SHORT TERM...(This evening through Tuesday)
Issued at 251 PM CST Mon Jan 28 2019

The focus remains on the extremely cold and historic air that will
soon be moving into the Northland. This latest forecast has even
colder wind chills than earlier forecast. Confidence is high for
widespread dangerous wind chills. Wind Chill Warnings and
Advisories have now been issued.

An Arctic cold front will continue moving east through the
Northland this afternoon through this evening, bringing an influx
of extremely cold air out of Canada into the Northland into
tomorrow. This will be a rare situation in which a deep upper
level polar low will dive south into the Minnesota and Wisconsin
region by tomorrow morning. This airmass will feature 850 hpa
temperatures at least as cold as -40 degrees Celsius, with the
coldest air across western into southern Minnesota. Gusty winds
late tonight and Tuesday will cause widespread dangerous wind
chills of 30 to 55 below zero across the Northland, with the
coldest wind chills across central and northern Minnesota. Expect
northwest winds of 10 to 20 mph gusting 20 to 30 mph. There will
be little improvement of the winds and wind chills for the
afternoon.

The worst conditions will come Tuesday night through Wednesday
morning. Air temperatures will plummet to 20 to 40 below zero.
Northwest winds of 5 to 15 mph, and up to 20 mph along the
Minnesota North Shore, will cause jaw dropping wind chills of 45
to 65 below zero which will continue well into Wednesday morning.
These wind chills are on the order of an event that the Northland
typically only sees at least once every 5 to 10 years. The latest
comparable situations occurred in January 2014 and February 1996.
Frostbite can occur within 5 minutes under these conditions!

This overall forecast was by no means on the extreme side of model
guidance. The temperature and wind forecasts were close to a
consensus of available model guidance, especially the
temperatures. That means there were other models that were
significantly colder. It is possible we may need to forecast even
colder temperatures with subsequent forecasts. If this were the
case, the wind chills could be substantially, and incredibly,
colder.

Point forecast at Rockford down to -30 for Thursday morning 

This Afternoon: Snow likely, mainly before 4pm. Patchy blowing snow. Cloudy, with a steady temperature around 17. Wind chill values as low as zero. North northwest wind around 15 mph, with gusts as high as 30 mph. Chance of precipitation is 60%. Total daytime snow accumulation of less than a half inch possible. 

Tonight: A slight chance of snow before 8pm, then a chance of flurries between 8pm and 11pm. Patchy blowing snow before 8pm. Cloudy, with a low around -6. Wind chill values as low as -22. West wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 20%.

Tuesday: Light snow likely with intermittent snow showers after noon. Partly sunny and cold, with a temperature rising to near -3 by noon, then falling to around -7 during the remainder of the day. Wind chill values as low as -30. Blustery, with a west wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 60%. Little or no snow accumulation expected. 

Tuesday Night: A chance of flurries before midnight. Mostly cloudy, with a low around -26. Wind chill values as low as -50. West northwest wind around 15 mph, with gusts as high as 30 mph. 

Wednesday: Mostly sunny and cold, with a high near -15. West wind around 15 mph, with gusts as high as 25 mph. 

Wednesday Night: Mostly clear, with a low around -30.

Thursday: Mostly sunny and cold, with a high near -4.

Thursday Night: A chance of snow. Cloudy, with a low around -9.

FWIW, the 18z HRRR shows H85 temps of -36C over northern IL around 4z Wed, or 10 PM central time on Tuesday.

Here are the 18z HRRR temps, as far out as they go (6z Wed).  If this is anywhere close to correct, it's good news, as ORD and RFD won't have the dreaded midnight high when Tuesday turns to Wednesday.

DVN

.CLIMATE...
ISSUED AT 251 AM CST Mon Jan 28 2019

Record lows for January 29th...

Burlington........ -19 in 1966
Cedar Rapids...... -24 in 1966
Dubuque........... -26 in 1951
Moline............ -19 in 1966

Record lows for January 30th...

Burlington........ -20 in 1899
Cedar Rapids...... -22 in 1951
Dubuque........... -25 in 1951
Moline............ -14 in 1966 and previous years

Record cool highs for January 30th...

Dubuque............ -3 in 1996
Moline............. -2 in 1951

Record lows for January 31st...

Burlington........ -20 in 1996
Cedar Rapids...... -21 in 1996 and previous years
Dubuque........... -24 in 1996
Moline............ -21 in 1996

Coldest January low temperatures...

Burlington........ -24 on  1/14/1957
Cedar Rapids...... -29* on 1/15/2009
Dubuque........... -32 on  1/07/1887
Moline............ -27 on  1/16/2009
                           1/02/1979
                           1/05/1884

Wind Chill Warning from LOT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Chicago IL
136 PM CST Mon Jan 28 2019

ILZ003>006-008-010>014-019>022-INZ001-002-290345-
/O.UPG.KLOT.WC.A.0002.190130T0000Z-190131T1800Z/
/O.NEW.KLOT.WC.W.0001.190130T0000Z-190131T1800Z/
/O.NEW.KLOT.WC.Y.0003.190129T1000Z-190130T0000Z/
/O.CON.KLOT.WW.Y.0006.000000T0000Z-190129T0000Z/
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-DeKalb-Kane-DuPage-Cook-
La Salle-Kendall-Grundy-Will-Lake IN-Porter-
Including the cities of Rockford, Belvidere, Woodstock, Waukegan,
Oregon, Dixon, DeKalb, Aurora, Elgin, Wheaton, Chicago, Ottawa,
Oswego, Morris, Joliet, Gary, and Valparaiso
136 PM CST Mon Jan 28 2019

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST THIS
EVENING...
...WIND CHILL ADVISORY IN EFFECT FROM 4 AM TO 6 PM CST TUESDAY...
...WIND CHILL WARNING IN EFFECT FROM 6 PM TUESDAY TO NOON CST
THURSDAY...

* WHAT...Light snow and areas of blowing snow this afternoon.
  Dangerously cold wind chills expected. Wind chills 20 to 30
  below Tuesday and as low as 55 below zero expected Tuesday night
  through Thursday morning.

* WHERE...Portions of northwest Indiana and north central and
  northeast Illinois.

* WHEN...For the Wind Chill Warning, from 6 PM Tuesday to noon
  CST Thursday. For the Winter Weather Advisory, until 6 PM CST
  this evening. For the Wind Chill Advisory, from 4 AM to 6 PM
  CST Tuesday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. The
  hazardous conditions could impact the morning or evening
  commute. The dangerously cold wind chills could cause
  frostbite on exposed skin in as little as 5 minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Wind Chill Warning means the combination of very cold air and
the wind will create dangerously low wind chill values. Frostbite
can occur quickly and even hypothermia or death if precautions
are not taken.

I guess this was kind of expected...but, unfortunately, the GFS appears to be backing off on the severity of the airmass a bit.  Coldest H85 temps on the 12z GFS for N IL are now around -35C, compared to -38C a couple of days ago. Even more concerning is that the duration of the extremely cold H85 temps is quite a bit shorter than it looked a few days ago...meaning that the timing of everything will need to work out even more perfectly.

Not pointing this out to raise alarm or anything, as this will still be a special event. But when going for all-time records, every degree counts.

Looks like the front just passed through De Kalb. Temp dropped from 32 to 28 over the past hour.

33 at ORD.  

15 minutes ago, cyclone77 said:

Point's been lowered down to -28 for Thu morning.  The all-time record at MLI is -28 from early feb '96.  

For here, it's -22 Wed morning, -14 for the high on Wed, then -26 Thu morning. If the models don't deviate from what is currently progged on the GFS and Euro, I could see both of our points dropping another 1-2 degrees.

Posting various AFDs for posterity.

DLH

Arctic air streams into the Northland tonight with overnight lows
generally between 10 and 30 below zero. Winds are expected to
remain elevated overnight due to cold air advection keeping the
low-levels mixed along with a tightening pressure gradient.
Resultant wind chills of 30 to 55 below zero are expected
overnight. With the prolonged period of dangerously cold
temperatures and wind chills, have decided to issue a Wind Chill
Watch from 06Z tonight through 15Z Thursday.

Dangerously cold temperatures and wind chills will continue
through the day Tuesday. Afternoon highs will struggle to reach 20
below along our western border and will climb into the middle
single digits below zero in our eastern zones. Winds will
strengthen as the pressure gradient tightens during the day with
wind chills in the 40s below zero west and to around 20 below zero
east.

.LONG TERM...(Tuesday night through Sunday)
Issued at 421 AM CST Mon Jan 28 2019

The period will start off very cold, especially Tuesday night
into Thursday.

The Northland will see very low temperatures and dangerous wind
chills Tuesday night, wind chills that are not very common even
for northern Minnesota. The area will be between high pressure
centered over the Dakotas and low pressure well off to the east
Tuesday night and this will lead to sustained wind speeds between
8 and 15 MPH for most areas. The wind combined with overnight lows
from 25 below to 35 below zero will create wind chills from 45
below to 60 below zero. The lowest wind chills will occur over the
western half of the area. High temperatures Wednesday will only
be from 5 below to around 10 below over northwest Wisconsin and
from 10 below to 18 below over northern Minnesota and wind chills
will only improve to 25 below to 40 below during the afternoon. As
the upper low moves further east, a surface ridge will move over
the area Wednesday night. The ridge will be over most of the
Northland by 12Z Thursday and winds will be lower than Tuesday
night, and may go calm in spots. Despite the coldest air aloft
moderating Wednesday/Wednesday night slightly, Wednesday nights
lows will be colder in spots than Tuesday night due to good
radiational cooling conditions. Low temperatures will drop to 25
below to around 30 below for most of northern Wisconsin and from
30 below to around 45 below over much of northern Minnesota. Wind
chills will be from 30 below to around 50 below but wind speeds
will be quite a bit lower than what occurs Tuesday night into
Wednesday. More sun is expected on Thursday, outside of the South
Shore area. Highs will rise into the single digits below zero and
wind chills will be less of a concern by Thursday afternoon.

The surface high will continue through the Northland Thursday
night with lows in the teens below zero to around 25 below and
with lighter winds, wind chill values from 20 below to 35 below
are expected.

FWIW, the 6z FV3 shows temps and wind chills significantly colder than the GFS.  For example, temps near -40 in far NW IL with wind chills in the -60s. 

I wish I could believe it, but have to admit that it's overdone.   

10 minutes ago, Roger Smith said:

Temp/dp of -53/-62 F at Geraldton ON north of Lake Superior this morning (13z obs). 

Wow. This town is located at 50N. Per Wikipedia, their all-time record low is -58F, and their normal January low is -13F.  So, this morning's low is 40 degrees below normal.

https://en.wikipedia.org/wiki/Greenstone,_Ontario

The progged -65 wind chill is SE MN is based on a temp of -35, with 16 mph winds. 

LOT

.LONG TERM...
319 AM CST

Tuesday through Sunday...

Certainly the main story continues to be the well advertised period
of dangerously and potentially historic cold temperatures from
Tuesday evening through Thursday morning.  The latest forecast still
has the Rockford area very near their all time record low of minus 27
Tuesday night and a couple degrees colder than that Wednesday
night. The forecast daytime high Wednesday around minus 15 for
RFD would beat their all time record coldest high of minus 14.
The forecast lows for Chicago presently look a few degrees above
their all time record which also is minus 27 but the forecast
daytime high Wednesday around minus 14 would beat their all time
record coldest high of minus 11. For both locations, the all time
record that looks most in jeopardy would be the all time coldest
average temperature for one day which is around minus 18 at both
sites. As an aside, the daily records for both locations look to
be crushed on Wednesday and Thursday.

Aside from all the talk about numbers, wind chill headlines also
deserve a mention.  Was not sure how best to handle wind chill
watch, advisory, and warning decisions based on the different onset
times from northwest to southeast across the forecast area.  For all
locations the key period of warning level wind chills, meaning below
minus 30 degrees, would be Tuesday evening to about noon Thursday.
This matches the watch that was issued this morning. This does not
mean to imply that the daytime Tuesday or the afternoon of Thursday
will be balmy in any way.  Wind chill advisory headlines may very
well be needed both before and after the warning period.  This is
especially true toward the northwest third of the forecast area
which likely will need an advisory starting Tuesday morning.  For
Thursday afternoon, highs look to be in the single digits both below
and above zero but winds look relatively light with a ridge moving
overhead.

Beyond the cold period...on Thursday night both the GFS and ECMWF
now want to show a quick shot of light snow associated with a weak
shortwave aloft and a bit of warm advection at lower levels.
Obviously it is too early to give this significant attention with
the bigger concerns in the near term, but anticipated QPF amounts
presently would not suggest this would warrant additional
headlines later in the week.

3 minutes ago, Baum said:

it's one model. big difference here is didn't head NE. And if it's slower that could help amounts i suspect.

Agree. Low center is right over Chicago instead of Waukegan. Makes a huge difference. Verbatim, 18z GFS shows about 0.6” of liquid at ORD, and around 0.7” at the WI/IL border. Assuming 13:1 ratios, would imply 8-10” in these areas. 

Minot ND is 40 degrees now, and should be -30 Wednesday morning. 

My point was lowered to -24 on both Wednesday morning and Thursday morning. High of -14 on Wednesday.