878 
FXUS63 KEAX 271724
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
1124 AM CST Thu Jan 27 2022

.Discussion...
Issued at 405 AM CST THU JAN 27 2022

Key Message

* Light snow this morning south of the MO River will come to an end 
  by 9 am.

* Quiet weekend with above-normal temperatures

* Accumulating snow looking more possible middle part of next week. 

A bit of a surprise accumulating snow event ongoing this morning 
across the southern zones. Some marginal, yet seemingly adequate 
isentropic ascent best evident along the 275K Theta E surface is the 
culprit for the light snow that started around midnight. Radar 
echoes indicate mostly very light snow, or maybe better said heavy 
flurries; however, there does appear to be some higher echoes 
indicating some heavier bands. Snow has started accumulating at the 
office as of 3 am, resulting in only a dusting, but with another 
couple hours of the light snow, it's possible we could see some 
minor accumulation of a couple tenths of an inch. Forecast soundings 
across the southern zones (where radar echoes are most widespread) 
indicate a surprisingly deep saturated layer, from roughly 3 kft to 
around 10kft, the top of this layer reaching around -12C, which is 
the low end of the dendritic growth layer. So compound the meager 
lift with bare minimal ice production and you get this very light 
snow. Ultimately do not expect much (if any) impact. The isentropic 
ascent coincident with near-zero condensation pressure deficits move 
out of the area in the early to mid morning hours, so expect this 
snow to come to an end from west to east in the 7 am to 9 am 
timeframe. W/SW winds at the surface will continue through the day, 
which will usher in some warmer air and get daytime highs roughly 
into the 35 to 45 degree range. The "warm up" will be put on pause 
for Friday as a cold frontal boundary sags in this afternoon, 
switching the prevailing surface winds northwesterly. With steady 
cold air advection for Thursday night and Friday expect another 
fairly raw day on Friday with temperatures struggling to reach 30 
degrees for most of the forecast area. Areas west and south of the 
Missouri River may see some 30 to 40 degree temperatures by the end 
of the day, but overall not too great for warmth. One feature to 
watch as we go into Friday is a shortwave clipper carving into the 
NW flow aloft. Despite it's appearance it shouldn't contribute a ton 
of support of ascent, however, forecast soundings for tonight do 
indicate some signal of saturation in the dendritic growth layer, so 
it wouldn't be totally inconceivable to see a few drifting 
snowflakes on Friday morning again. Anything that does fall will 
not result in any accumulation. 

The weekend will bring a welcome change to the forecast. While there 
isn't any precipitation expected this weekend, there will be some 
more pronounced upstream surface troughing, which should contribute 
to a more wholesale warm up for Saturday. But with the mid level 
flow remaining more northwesterly, there will be a chance for an 
embedded shortwave trough, which may drag an associated surface cold 
front through the area for Sunday. Despite a bit of a cool down for 
Sunday, temperatures are expected to still be in the 30s and 40s, 
with some 50s south of the MO River. 

A wholesale change to the weather pattern is expected early next 
week, as the mid level ridge over the western CONUS will break down. 
This will push the steady NW flow aloft out of the area, and as 
broad, upstream troughing commences the mid level flow pattern will 
be come more southwesterly. This should help with more organized 
surface troughing, which is expected to be the dominant weather 
influence for the first couple days of next week. With steady warm 
air advection, uninterrupted by shots of cold air expect 
temperatures on Monday to eclipse 50 degrees area-wide and push 60 
degrees in the southern and western zones. 

While Tuesday at this point still looks to be a nice-ish day with 
temperatures generally in the 40s and 50s it will represent a 
transition day into the next big change in the pattern. While it's 
still too early to nail down any specifics there does appear to be a 
cold air intrusion into the area on Tuesday. When it moves in and 
how fast it progresses southward will dictate who gets a nice day on 
Tuesday and who get stuck in the 30s or 40s. Areas further south 
obviously have a better chance to stay in the warmer air longer on 
Tuesday than areas of far northern Missouri. 

We are still watching the prospects of what may be a significant 
winter system that has been hinted in some of the sub-seasonal 
outlooks for the last few days. Operational GFS and ECMWF seem to 
have come into at least some agreement that there will be a deep mid 
level system which should have a good moisture source and good cold 
air source,the combination of the two yielding what may be a 
significant winter storm. Now, again, where the pertinent features 
all set up, when they set up, and the magnitude of these features 
(such as low level cyclone position and track, timing of the cold 
air, location, strength, and depth of the low level warm nose 
etc...) are still elusive at this time. One thing that appears to be 
somewhat evident, although confidence is admittedly low at this 
time, is that there may be a very broad swath of light to moderate 
snow, which would increase the chances of any particular location 
seeing accumulating snow; however, significantly impactful snow may 
occur on a much narrower scale, and evades any hope for even medium 
confidence at this point. 

&&

.Aviation...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1124 AM CST THU JAN 27 2022

VFR conditions are likely for the entire forecast. Scattered to
broken mid and high level clouds will move through the area
through the period. Tomorrow, will need to watch for either low
VFR or MVFR ceilings in eastern KS that could possibly affect the
terminals. Forecast soundings and model relative humidity fields
show higher humidity values, indicating potential for the lower
clouds, in the 2000 to 4000 ft level. Confidence in this affecting
the terminal sites isn't high enough to mention at this time but
will need to be watched if it shifts east. Winds will be from the
northwest to the north through the forecast and be strongest this
afternoon before diminishing overnight into tomorrow.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

$$

Discussion...Leighton
Aviation...CDB