Winter Storm and Winter Weather in Missouri, January 1, 2021

Area Forecast Discussion
National Weather Service Springfield MO
1149 PM CST Thu Dec 31 2020

.SHORT TERM...(This evening through Friday)
Issued at 401 PM CST Thu Dec 31 2020

Cloud cover this afternoon along with northeast surface winds has
resulted in colder high temperatures for this afternoon generally
in the low to mid 30s. This will lead to concerns for surface
temperatures with the approaching winter weather system this
evening and tonight.

Mosaic radar imagery this afternoon shows a large area of
rainfall across eastern Texas, southern Oklahoma, and Arkansas
associated with an upper level low and its attendant surface low
in southern Texas. This precipitation will begin to quickly move
north into our area late this afternoon and overspread the area
during the evening.

Surface temperatures will start falling to around freezing for
much of the area this evening as precipitation saturates the
atmosphere and wet bulbing processes occur. Thermal profiles aloft
favor a brief wintry mix of light snow, freezing rain, and rain
beginning around 6 PM this evening where temperatures fall to
around freezing (generally starting near the Highway 60 corridor).
This wintry mix will move northward into central Missouri
throughout the evening, with precipitation transitioning primarily
to freezing rain from south to north behind the mix and lingering
into tonight.

Confidence is highest in below freezing temperatures mainly north
of a Jasper to Greene to Dent County line up into west central
and central Missouri, as well as the higher terrain of Webster and
Wright Counties. Therefore, we have issued a Winter Storm Warning
for the area where the higher confidence in below freezing
temperatures this evening and tonight will reside and the highest
impacts are expected from ice. Ice accretions across the warning
area are expected to range from 0.25-0.4", with most of these
accretions on elevated surfaces. Some power outages and tree
damage is possible due to the ice accretions and northeast winds
gusting up to 20-30 mph. Travel may become very difficult on
overpasses, bridges and untreated roadways. The Winter Storm
Warning is in effect from 9 PM this evening through 3 PM on
Friday.

Meanwhile, there is less confidence in freezing rain amounts
around the Highway 60 corridor given surface temperatures hovering
closer to freezing this evening through tonight. A slight shift
in the freezing line north or south may lead to vast changes in
ice accretions over short distances along this Highway 60
corridor. As a result of the higher uncertainty, a Winter Weather
Advisory has been issued along the Highway 60 corridor for
possible ice amounts of a glaze to 0.2", which could lead to some
slicks spots on untreated roads and bridges. Only minor to no ice
accumulations area expected over far southern Missouri where
surface temperatures are more likely to remain at or just above
freezing.

As the upper level low shifts northeast through the area on Friday
morning and afternoon, some light snow will be possible. The
highest snow amounts will be primarily isolated to eastern Kansas, west-
central, and central Missouri. Mainly a dusting to an inch of
snow will be possible across most of those locations, though some
spots could see upwards of 1-2 inches north of a line from Fort
Scott, KS to Versailles, MO. Locations south of this line and down
to Interstate 44 should only see a dusting of snow at most. The
main impacts will be from this system freezing rain.

The precipitation will end by Friday evening as the upper level
low moves out of our area. In addition to the snow and freezing
rain, additional liquid rainfall of 1-1.5" is possible across the
area. This could lead to a few sensitive low water crossings
briefly flooding tonight across south-central Missouri, otherwise
no other flooding impacts are expected.

.LONG TERM...(Friday Night through Thursday)
Issued at 401 PM CST Thu Dec 31 2020

An additional upper level low will move over Missouri late
Saturday morning and afternoon, but it will only have limited
moisture to work with. As a result, a very light rain/snow mix or
flurries is possible during the day on Saturday given
temperatures in the 30s, but little to no accumulations or impacts
are expected.

Weather turns drier and more mild for Sunday into the first half
of next week, with highs rebounding back into the upper 40s and 50s
on a daily basis.

Another disturbance may move through on Wednesday and Wednesday
night, bringing additional chances for some rain for the middle
of next week.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1141 PM CST Thu Dec 31 2020

KSGF/KJLN/KBBG tafs: Sfc low pressure will move through the region
early in the period then shift east to the OH Vly late in the
period. Expect widespread rain and freezing rain/IFR conditions
through 15z-18z before diminishing. Low clouds/IFR conditions
will linger through the period. Gusty northeast winds early will
diminish and back to the north and northwest by 18z.

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
MO...Winter Weather Advisory until noon CST Friday for MOZ082-083-088-
     090-094>098-102>105.

     Winter Storm Warning until 3 PM CST Friday for MOZ055>058-
     066>071-077>081-089-091-092.

KS...Winter Weather Advisory until noon CST Friday for KSZ101.

     Winter Storm Warning until 3 PM CST Friday for KSZ073-097.

&&

SHORT TERM...Rothstein
LONG TERM...Rothstein
AVIATION...DSA

Hazardous Weather Outlook
National Weather Service Springfield MO
304 PM CST Thu Dec 31 2020

KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-012115-
Bourbon-Crawford-Cherokee-Benton-Morgan-Miller-Maries-Vernon-
St. Clair-Hickory-Camden-Pulaski-Phelps-Barton-Cedar-Polk-Dallas-
Laclede-Texas-Dent-Jasper-Dade-Greene-Webster-Wright-Newton-
Lawrence-Christian-Douglas-Howell-Shannon-McDonald-Barry-Stone-
Taney-Ozark-Oregon-
304 PM CST Thu Dec 31 2020

This Hazardous Weather Outlook is for portions of the Missouri
Ozarks and extreme southeast Kansas.

.DAY ONE...This Afternoon and Tonight.

Weather hazards expected...

  Limited flooding risk.
  Limited non thunderstorm wind risk.
  Significant ice accumulation risk.
  Limited snow and or sleet risk.

DISCUSSION...

A large storm system will approach the region late this afternoon
into tonight. A brief wintry mix will be possible during the early
evening before quickly changing over to freezing rain for the
remainder of this evening and tonight.

Freezing rain accumulations will range from a glaze to two tenths
of an inch mainly along and south of the Highway 60 corridor.
Higher amounts of one quarter to four tenths of an inch will be
possible farther north across southeast Kansas, west central and
central Missouri where temperatures will be slightly cooler.
Portions of far southern Missouri may remain ice free.

Light snow accumulations will also be possible, with a dusting to
an inch generally expected. Again, areas of southeast Kansas and
west central Missouri will have the best chances at receiving
minor snow accumulations.

Widespread rainfall amounts of an inch or greater could cause a
few sensitive low water crossings to flood and become impassable,
mainly across south-central Missouri.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

A light wintry mix of snow and rain will be possible on Saturday
morning and afternoon. No impacts are expected as this
precipitation will remain very light in nature.

.SPOTTER INFORMATION STATEMENT...

  Spotter activation will not be needed through tonight.

&&

More detailed information can be accessed at:
http://www.weather.gov/sgf/sitrep

This product in graphical format...along with other weather...
hydrological and climate information...at
http://www.weather.gov/sgf

Rothstein