Damaging Winds in Missouri, June 1 to 2, 2018

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
437 AM CDT Fri Jun 1 2018

.Discussion...
Issued at 437 AM CDT FRI JUN 1 2018

A rather active pattern is seen across the Nation with a number of
progressive shortwave troughs noted within the the prevailing
westerlies. Of importance for us is the trough over the Pacific
Northwest, which will move into the Northern Plains later tonight
sparking convection across Nebraska this afternoon; which is then
expected to sweep southeast late tonight. All of this will make
for a bit of a roller coaster with the conditions across our
section of the Plains States over the next 48 hours.

Lee side troughing from the Pacific Northwest trough, across
Wyoming as the trough begins to ejecting into the Northern
Plains, will help pick up the speed of our south to southeast
winds, which will help warm air and moisture advection push
afternoon highs into the lower to mid 90s, with dewpoints in the
60s to low 70s; ultimately leaving the day with heat indices in
the mid to upper 90s. While this will not be pleasant, it will be
a bit short of criteria for any kind of advisory, but will help
set the stage for convection later tonight as the hot air and
moisture will induce MUCAPE values in the 4000+ J/KG range, which
will persist well through the night, providing ample fuel for
storms late tonight into Saturday. Models are rather consistent in
initiating the storms across western Nebraska later this
afternoon, with the broader activity sweeping east overnight as
the synoptic scale trough and cold front move east. As result, we
expect a 50+ knot 850mb jet will help organize an MCS which will
sweep southeast into eastern Kansas and Missouri Saturday morning,
while a broader line of storms continues east across the Northern
Plains. These storms will likely bring with them a decent damaging
wind threat, and the potential for flooding rains as precipitable
water values will likely be running as high as 2 inches in
advance of the MCS. Timing is a bit hard to pin down for the
Saturday morning activity, as it depends highly on when activity
starts in Nebraska; but thoughts are that the MCS may spread into
Northwest Missouri around midnight, but is more likely by 3 or 4
AM, with storms moving south and east across northern Missouri
through the morning hours. Additionally, how fast this convection
moves across the state Saturday morning will likely have a direct
affect on the redevelopment of convection Saturday afternoon as
the cold front is moving through. Currently, redevelopment looks
likely across central into northeast Missouri Saturday afternoon,
with the activity shifting into eastern Missouri that evening as
the associated front with the synoptic level trough moves farther
east. On the up side, this will bring cooler temperatures for
Saturday, Sunday and Monday, with afternoon highs in the 80s. 90s
will return by mid-work-week as another ridge begins to dominate
the Southern and Central Plains.

&&

.Aviation...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1139 PM CDT THU MAY 31 2018

Primarily VFR conditions are expected through the forecast period.
Skies will be mainly clear, and light and variable winds will
gradually increase out of the southeast to around 10 kts by mid-
morning. Thunderstorms are possible just beyond the end of the TAF
period.

&&

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

Discussion...Cutter
Aviation...Laflin