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

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000
FXUS63 KEAX 120721
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
221 AM CDT Tue Mar 12 2024

.KEY MESSAGES...

- 20 to 40% chance for thunderstorms tonight. Marginal (5 to
  10%) Risk of a severe storm tonight. Quarter size hail and 60
  mph winds are the greatest concern if a robust updraft can get
  going.

- 60 to 80% chance for thunderstorms late Wednesday afternoon
  and Evening. There is a Slight (10 to 15%) Risk of a few
  severe storms with the initial activity. Hail up to half
  dollar size, 60 mph wind gusts, and locally heavy rainfall are
  the greatest concerns.

&&

.DISCUSSION...
Issued at 219 AM CDT Tue Mar 12 2024

Shallow mid-level ridging is slowly shifting east this morning, with
water vapor revealing the eastward surge of the short wave trough
across the central Plains. Southwest winds persist, and will
increase through the day ahead of the advancing surface trough. With
generally unimpeded return flow from the Gulf, expect a steady
stream of boundary layer moisture to pool ahead. The NAM and it`s
derivative the NAMnest are the most bullish of guidance, with the
NAMnest suggesting a ribbon of 60 F dew points developing by the
afternoon. In response, it`s convecting more aggressive compared to
the HRRR and other CAMs and conventional guidance, which all have
dew points in the lower to mid 50s by the afternoon. Overall,
consistency between guidance is good with respect to the low/short
wave placement, with a compact H500 short wave lifting east-
northeast across the KC Metro around 00Z (7 PM). With a decent shot
of vorticity advection, support aloft will exist with ample forcing
for ascent from the surface front. Forecast soundings suggest a
decent capping inversion, with erosion toward 23Z (6 PM), and
rather elevated LCLs and skinny CAPE profiles. The latest HRRR runs
have very little convection, the answer is somewhere in the middle
of the CAMs. With that said, any initiation looks to be around 00Z
(7 PM) and given placement of the surface boundary, initial focus
will be on the eastern side of the KC Metro, perhaps as far north as
US 36, near Chillicothe and generally south-southwest toward the
southeast Kansas/southwest Missouri border. Storms that do develop,
will likely be in a broken line. With modest deep layer shear
profiles, 30 to 40 kts, if any robust updrafts can get going and
sustain before loss of peak heating, perhaps a few elevated hailers
may develop. Therefore, the Marginal Risk (5 to 10%) remains
warranted from SPC. Remaining storms will quickly push east and
southeast through 06 to 07Z (1 to 2 AM).

Shallow mid-level ridging will follow the exiting short wave through
daybreak Wednesday. To the west, a large H500 trough will continue
to emerge across the Inter-Mountain West, with a defined surface
trough developing over the western High Plains of CO/KS. Through
midday and into the afternoon, the region will be firmly within the
warm sector, with a warm front along and near the IA/MO border.
Surface dew points in the mid to upper 50s, pushing 60 will pool
across western Missouri and far eastern Kansas ahead of a dry line
that will advance as far as US 77 by 22 to 00Z (5 to 7 PM). Initial
convection will be delayed until the late afternoon and early
evening as the stout EML finally begins to breakdown. Elevated
instability on the order of 1000 to 2000 J/Kg will be present, with
initial convection developing along the warm front across
northwestern Missouri into northeastern Kansas through the late
afternoon and evening. Most guidance continues to hint at additional
warm sector convection through sunset across central and eastern
Kansas as well. A few updrafts early in the event may take advantage
of the elevated instability, ample forcing for ascent along the warm
front, and modest deep layer shear to result in severe hail and
wind. Hail to the size of half dollars and 60 mph wind gusts are the
greatest concern. The tornado risk is low, but with backed winds at
the surface and veering with height, there`s an outside chance any
initial updraft anchored on the warm front could have some
potential, but it`s not the greatest severe concern at the moment.
Through the late evening and overnight, expect continued development
of showers and thunderstorms across the region. Although much of the
area has remained in D0 to D1 Drought, will need to keep an eye on
any slow moving updrafts that may result in some minor flash
flooding concerns overnight. Widespread rainfall amounts will range
from 0.50 to 1.00 inches, with locally higher amounts in
thunderstorms.

Thursday morning, the region will remain well within the warm
sector, with the surface low continuing to lift northeast across
eastern Nebraska, with the surface cold front trailing to the
southwest. The LLJ will continue to stream northeastward which will
provide some support for continued scattered convection across the
region through the morning. Towards afternoon, with little eastward
progression of the surface low, expect some recovery with dew points
back in the 50s and MLCAPE values in the 1000 to 1500 J/Kg range.
Looking at forecast soundings, a noticeable EML will hold on for much
of the afternoon and into the evening. There may be an opening for
some convection once the front pushes east through 5 to 7 PM, but by
then the better axis of instability will be across eastern Missouri.

Into Friday, high pressure will build in from the west-northwest, as
negatively tilted ridge axis develops ahead of a strong H500 trough
nearly cutoff over the southwestern CONUS. Cooler, highs in the 50s
and 60s, and dry conditions will persist before a dry cold front
settles southward across the region bringing cooler temps to kick
off next work week.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1250 AM CDT Tue Mar 12 2024

VFR conditions are forecast to prevail through the period.
Increasing southwest winds by late morning will continue
through the afternoon. Wind gusts to 25 kts can be expected.
Mid-level ceilings will increase in coverage as a frontal
boundary approaches area terminals from the west this evening.
VCTS and -TSRA chances are low at this time given current
expectations are for development east of the terminals. However,
it is best to watch for adjustments, if needed, in later TAF
issuances.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...None.
KS...None.

&&

$$

DISCUSSION...Kurtz
AVIATION...Kurtz


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