Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
000
FXUS63 KEAX 200020
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
620 PM CST Fri Jan 19 2018

.Discussion...
Issued at 318 PM CST FRI JAN 19 2018

Surface high pressure over the SE US and a lee-side trough over
western KS have developed a large area of SW flow and WAA over the
southern plains.  This welcomed push of warmer air has helped
today`s high temperatures climb into the upper 40s and possibly the
lower 50s in places. These above average temperatures will continue
into Saturday but will be slightly cooler than today as a low cloud
deck and reduced visibility in drizzle move into the region from the
south.

A deepening shortwave trough will enter the SW US Saturday evening
and eventually move over the southern Rockies Sunday sparking rapid
cyclogenesis over central KS. Our region will start out in the warm
sector with the surface low over expected to deepen and close off up
through 700hPa as it tracks NE over eastern Kansas.  The track of
this low will be significant to the forecast as it keeps us in the
warm sector with all liquid precipitation at first. There will be a
chance for some light freezing drizzle over NW MO Sunday morning
with low temperatures just below freezing as some lift along the
developing warm frontal boundary arrives. This chance of freezing
drizzle will be short lived as temperatures climb above freezing by
mid morning. As the cold front advects to the east it will develop a
band of showers and possible thunderstorms Sunday evening. Current
guidance indicates there will be between 100-400 J/kg of MUCAPE and
near 60kts of 0-6km shear as the front pushes through. This lack of
instability is the main limiting factor for any severe weather, but
if the CAPE can increase into the 500-750 J/kg range the possibility
of isolated low topped elevated supercells embedded into a line of
storms could be realized. Currently the forecast indicates non-
severe embedded convection along the cold front with most of the
severe weather threat south of our area into the TX/AR/LA area. A
dry slot will slide into the area on the backside of the cold front
clearing out the majority of the heavier precip overnight Sunday
into Monday changing any precip to more of a drizzle/light rain. The
wrap around deformation zone will bring cooler temperatures and a
change in precipitation type as it pushes through our area Monday
morning. There main change over will be a rain to snow transition
with no real warm layer aloft as the entire column cools with this
transition. A trace of snowfall will be possible as the deformation
zone pushes over the western and northern portion of our CWA.
Freezing rain/drizzle will again become possible over NW Missouri as
the mid level dry out and ice crystal formation dissipates. The main
region for this to occur will over NW Missouri Monday morning before
temperatures climb above freezing by mid morning. The precipitation
will finally move out of the area by Monday afternoon sending our
area into a fairly benign weather pattern over the work week.

There will not be much of a cold push behind this system as winds
stay mostly westerly keeping our temperatures above freezing
throughout the end of the work week.  Upper level ridging will help
keep us dry making for a nice week for the end of January.  The work
week will end with SW flow over the area and low 50s for high
temperatures ahead of another possible storm system next weekend.

&&

.Aviation...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 616 PM CST FRI JAN 19 2018

Upper-level clouds streaming overhead will give way to low-level
stratus advecting into the region overnight into early Saturday
morning. By midday tomorrow, enough LL saturation should have
occurred to allow for drizzle to fall from the stratus deck,
reducing visbys. SW winds will continue to prevail throughout the
TAF period.

&&

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

$$

Discussion...Barham
Aviation...lg



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.