NWS Wichita, KS wrote its last area forecast discussion before the first event at Feb 15, 5:58 PM CST, 6 hours 32 minutes earlier.
Area forecast discussion, Feb 15, 5:58 PM CST, 6 hours 32 minutes before
Area Forecast Discussion
National Weather Service Wichita KS
558 PM CST Tue Feb 15 2022
.SHORT TERM...(This evening through Thursday night)
Issued at 306 PM CST Tue Feb 15 2022
NEAR TERM (through tonight)
Unseasonably mild temperatures and strong/gusty south
winds will continue overnight, as low pressure continues to
strengthen over the High Plains, and a cold front begins to
approach from the northwest. The boundary layer remains fairly
mixed overnight, and with a 50-60+ kt nocturnal low-level jet
around 1500-2000 ft AGL cranking up, thinking the strongest winds
may actually occur this evening and overnight, with a rogue 60 mph
gust not out of the question. Consequently, will continue the
wind advisory through the night for most areas except portions of
central and north-central KS. Additionally, this mixy boundary
layer combined with low-level warm/moist advection will support
unseasonably mild overnight lows in the 40s-50s for many.
Kleinsasser
SHORT TERM (Wednesday-Thursday night)
A potent upper level shortwave is steadily digging south along the
CA coastline this afternoon and shows up very nicely on water vapor
imagery. This system will continue to dig S/SE into the Four Corners
region, then take on a negative tilt as it lifts out across the
Central/Southern Plains WED/THU. There are a lot of factors with
this system, so let's break down what we know and what we don't.
WHAT WE KNOW
There is really good ensemble and deterministic model guidance
agreement with the ejecting wave (strength, amplitude, track). There
is also good agreement with a northward shift of the track of the
upper low and, consequently, the track and strength of the SFC low.
Model trends have generally "stabilized", so to speak, suggesting we
may not see much more in the way of significant changes with the
track and strength of the SFC and upper level features.
While models differ on precip type (see WHAT WE DON'T KNOW section),
there is good agreement on warmer temps aloft at the onset of the
heaviest precip, which has increased our confidence in mixed phase
precip, and potentially for a longer duration, as it may take
several hours for temps aloft to cool.
Regardless of precip type, the combination of a coupled jet
structure, elevated instability, strong low-level moisture
convergence, strong WAA, and a deep layer of moisture will favor
moderate to heavy precip rates with this event (both liquid and
frozen/freezing). Initially, the instability and strong forcing
should favor a round of showers and elevated strong thunderstorms
developing, eventually transitioning to a large area of stratiform
precip, possibly with some embedded thunderstorms. In fact, it's
entirely plausible we'll see some lightning even where wintry
precip occurs, especially in the transition zone, which would
favor enhanced winter precip rates. Because of this, confidence is
moderate to high that we will see 1"/hr+ snowfall rates where the
transition to all snow occurs. Where mixed phase occurs, moderate
to heavy freezing rain and sleet will occur. Fortunately, where
moderate to heavy freezing rain occurs, icing may not be as
significant due to the heavier rates favoring more runoff, giving
less time for accretion.
Given good agreement on the strength and track of the SFC low,
confidence has increased regarding the strong wind potential on the
cold side of the system. Like today, it's expected that 40-50+ mph
gusts will occur with the precip. Where this overlaps with snow,
areas of blowing/drifting snow will be possible.
WHAT WE DON'T KNOW
The main differences with model guidance is the temps aloft, which
has a huge impact on precip type and snow/ice amounts. Even with the
varied guidance on temps aloft, there are generally 2 camps. One
favors a swath of heavy winter precip along and northwest of the KS
Turnpike/I-35 corridor. The other favors along and southeast of that
same corridor. Additionally, models differ some on the depth of
moistening within the SGZ as well as in the low-levels. A dry
conveyor belt in the low-levels may cut into snowfall rates/amounts
along the northern periphery of the precip shield, while the dryslot
aloft may favor more freezing drizzle/freezing rain on the southern
shield of the precip. The question is where those dry layers will
setup during the event. The "sweet spot" for heavier precip rates
will be in between those two areas.
Because of the increased probability of mixed phase precip,
potential snowfall ranges will be larger than ideal, even this
close to the event starting. Basically, you can assume the lower-
end of the snowfall range where mixed phase is more predominant,
and the higher end of the snowfall range where a shorter duration
of mixed phase precip occurs. Where the duration of mixed phase
precip lasts the longest, accumulating ice and sleet will be
followed by accumulating snow.
WINTER HEADLINES
From a probabilistic standpoint, the Turnpike corridor and the
counties immediately on either side of it fall in the middle of both
of the above-mentioned winter accumulation camps. It is in that area
where confidence is at least 50% in seeing winter storm impacts.
With this forecast issuance, then, we will issue a Winter Storm
Watch and focus it where confidence in higher-end winter impacts is
the highest. This watch may need to be expanded on either side
depending on which camp gets more support in later model runs.
The key takeaway here is to not focus solely on the watch area for
impacts.
One additional note about the watch area. While snowfall amounts
may fall short of traditional Winter Storm Warning criteria, the
combination of snow on top of sleet/ice, as well as the strong
winds, may lead to warning-level impacts.
Precipitation will wind down from west to east on Thursday,
although some drifting snow could linger into Thursday afternoon
before the wind subsides.
Martin
.LONG TERM...(Friday through Tuesday)
Issued at 306 PM CST Tue Feb 15 2022
After the mid-week system, the flow aloft briefly flips to more of a
dry, milder, zonal flow. Again, any moderation in temps will be
offset by areas that see accumulating snow with this upcoming
system. Models continue to remain in good agreement with a broad, SW
flow regime returning next week, potentially with another risk of
convection and winter precip.
Martin
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 537 PM CST Tue Feb 15 2022
South winds will remain strong and gusty overnight across the
region. Meanwhile low clouds will develop over southeast Kansas
Wednesday morning and linger through the day. South winds will
remain strong over mainly southeast Kansas during the day on
Wednesday.
&&
.FIRE WEATHER...
Issued at 306 PM CST Tue Feb 15 2022
THROUGH THIS EVENING-TONIGHT: Will continue the red flag warning
through its expiration at 7 PM. Thereafter, cooling temperatures and
continued moisture advection will support a gradual humidity
recovery back into the 50s-70s percent by around midnight. However,
strong/gusty south winds will continue much of the night across
central, south-central, and southeast KS, with gusts of 40-50+ mph
much of the evening and night. Consequently, thinking grassfire
danger will remain elevated much of the night, although probably
mostly below critical/extreme levels.
WEDNESDAY: Despite increasing dewpoints/humidity, thinking VERY HIGH
grassland fire danger will encompass locations generally along/east
of the KS Turnpike Wednesday, due to continued warm temperatures and
stout/gusty south winds.
SUNDAY: Could be looking at a return to VERY HIGH grassland fire
danger Sunday, due to breezy south winds and above normal
temperatures. However, this fire danger threat will be contingent on
how much precipitation and snow cover we receive from the upcoming
storm system.
&&
.HYDROLOGY...
Issued at 306 PM CST Tue Feb 15 2022
A widespread 0.50"-1.50" of liquid-equivalent precipitation is
forecast with the storm system this week. The axis of heaviest
liquid-equivalent precip (1.50"+) has shifted east and is focused
over the Ozarks. The highest risk of flooding, then, appears to be
focused just to our east. However, the heavier precipitation rates
at the onset of the event, especially where thunderstorms occur,
could lead to some minor ponding/flooding concerns.
Martin
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 51 66 22 30 / 0 10 90 80
Hutchinson 48 62 20 31 / 0 10 80 60
Newton 51 62 21 29 / 0 20 90 70
ElDorado 52 65 22 28 / 0 20 90 80
Winfield-KWLD 54 68 25 31 / 0 10 90 90
Russell 35 48 20 36 / 0 0 40 20
Great Bend 38 50 20 35 / 0 0 60 30
Salina 47 54 21 33 / 0 10 70 40
McPherson 48 60 20 31 / 0 10 80 50
Coffeyville 54 66 31 38 / 0 40 90 90
Chanute 54 65 27 33 / 0 40 100 90
Iola 54 64 27 32 / 0 40 100 90
Parsons-KPPF 54 65 29 36 / 0 40 100 90
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 7 PM CST this evening for KSZ032-033-
047>053-067>072-082-083-091>096-098>100.
Wind Advisory until 3 PM CST Wednesday for KSZ053-069>072-
093>096-098>100.
Wind Advisory until 6 AM CST Wednesday for KSZ048>052-067-068-
082-083-091-092.
Winter Storm Watch from Wednesday evening through Thursday
afternoon for KSZ051>053-067>070-082-083-091>093.
&&
SHORT TERM...ADK/RM
LONG TERM...RM
AVIATION...CDJ
FIRE WEATHER...RM
HYDROLOGY...RM