404
FXUS63 KSGF 271135
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
535 AM CST Mon Jan 27 2020

...12Z AVIATION UPDATE...

.DISCUSSION...
Issued at 250 AM CST Mon Jan 27 2020

Several moving pieces and parts to the forecast over the next 48
hours. Will start off with the fog currently over the area. Two
distinct areas of fog are ongoing, one area mainly along and north
of the US Highway 54 corridor, this is the most widespread and
persistently dense. Areas further south across the rest of the
Missouri Ozarks are seeing more shallow, radiation fog from clear
skies, wet ground and a sfc pressure axis. This fog tends to be
more transient however it has brought the visibility down to a
quarter mile at times, therefore a Dense Fog Advisory is in
effect for a large part of the area until 10am. Temps are at or
below freezing in several areas therefore freezing fog could
produce a small/thin glaze on exposed surfaces and perhaps
bridges.

Current water vapor imagery shows two distinct pieces of
shortwave energy. One shortwave was located across eastern
Nebraska. This energy will dive southeast today, tracking mainly
across central Missouri. Some mid level clouds and perhaps even
some sprinkles will be possible across central Missouri.
Elsewhere, winds will become more northerly by afternoon and
evening however most locations will see high temps similar to
yesterday.

Tonight, models are suggesting the potential for more fog
development, especially in central Missouri again. Visibilities
may drop below a mile again with even some dense fog possible.

The other shortwave trough was seen stretching from Idaho through
western Utah and New Mexico. The pieces of energy in this large
trough will be key players to the forecast for Tuesday through
Wednesday and models tend to struggle with this type of pattern.
This trough will move east and by early Tuesday morning a
500/700mb low will attempt to become cut off across the panhandle
of Texas with additional pieces of energy across the northern
Plains. Surface low pressure will be developing along the Red
River Valley during the day however High pressure across Minnesota
and Iowa will keep a north to northeast surface wind across our
area, therefore temps Tuesday will likely stay in the 30s.

As the energy moves closer during the day, expect clouds and
precip to begin to spread into the area from the southwest.
Depending on exact surface temps/freezing line, some mixed precip
may start off across the area as a warm nose will be present
however it does appear that for most areas it will stay liquid
during the daytime, exception being near and north of US Highway
54.

The bulk of the precip looks to arrive during the evening and
overnight hours Tuesday night into Wednesday. Temps at the sfc and
aloft look to cool enough (or be very close) for any liquid
precip to change over to snow during the overnight hours. The
overall trend in the models the past 24 hours has been an increase
in overall QPF with this system, generally closer to the
consistently wetter Canadian model. Therefore leading to a
increasing potential for light snow amounts across the area.

That being said, current operational models are in disagreement
in regards to the exact track of the upper level low pressure
areas, as well as the resultant qpf and thermal profile, therefore
confidence in the exact details of this system (snow amounts),
are uncertain. Operational GFS runs continue to be by far the
warmest with this system with a large spread in its GEFS
ensembles.

Following a blended model and mean ensemble approach, we
currently are forecasting between 1 and 2 inches of snow across a
large part of the area Tuesday night into Wednesday morning. One
positive for snowfall with this system is that most of the snow
would occur at night, which typically accumulates more efficiently
than daytime. One key item of note however is that most models
still have the 700mb low track (a good indicator/path for heavier
accumulating snowfall), tracking south of the area, therefore the
lighter amounts seem to fit with this idea. For heavier amounts
the track would likely need to be further north.

Snow looks to wind down during the morning Wednesday. To re
emphasize this is still a low confidence forecast and these snow
amounts will likely change over the next 24 hours as models
hopefully converge more.

The rest of the week will see temps gradually moderate with quick
moving systems sliding through with very little moisture to work
with. Temps look to warm well above average for the weekend into
early next week, and likely staying dry.

&&

.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 531 AM CST Mon Jan 27 2020

Areas of fog will be possible early this morning at the taf sites
with SGF likely seeing the most fog however vis will be bouncing
between LIFR and MVFR at times. Fog should erode by mid morning
with VFR conditions then likely for the rest of the day and
evening along with light and variable winds. Fog and low ceilings
will again be possible overnight into early Tuesday morning,
especially at SGF.

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
MO...Dense Fog Advisory until 10 AM CST this morning for MOZ055>058-
066>071-077>083-088>098-101>106.

KS...NONE.
&&

$$

DISCUSSION...Burchfield
AVIATION...Burchfield