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Area Forecast Discussion (AFD)

Issued by Kansas City/Pleasant Hill, MO (EAX)

                            
000
FXUS63 KEAX 222044
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
344 PM CDT Wed May 22 2019

.Discussion...
Issued at 344 PM CDT WED MAY 22 2019

Message of the day: Dangerous storms are expected to develop in a 
somewhat narrow band from about Tulsa, OK northeast to Quincy, MO 
(roughly between KC and Springfield and KC and St. Louis). 
Tornadoes, quarter to tennis ball sized hail, and wind gusts up to 
65 mph are all possible. Storms should start developing after 4 PM 
with the severe threat continuing through about 11 PM. A tornado
watch has been issued for Linn County, KS up to Macon County, MO
and only includes one KC metro county (Cass County, MO) through 11
PM



We have been able to have a nice break from the showers and storms 
today, thanks to the low pressure system moving out early this 
morning. This will be short lived though due to a shortwave trough 
moving overhead and a southwest to northeast oriented convergent 
boundary working its way north into parts of our area. This 
feature will be the focus for storm development this afternoon and
evening. Current thinking is the boundary will generally set up 
along a line from Blue Mound, KS up to Kirksville, MO. Both a CAPE
and effective bulk shear gradient also looks to be setting up 
along this line. CAPE should be about 1500 J/kg with deep layer 
shear around 55 kts. When looking at hodographs and soundings, the
shear is more speed shear than directional, however, the 
intensity of the speed shear is likely to compensate for the lack 
of directional shear, therefore, storms with broad rotation is 
expected. In addition, low level lapse rates look to be near 9-10
C/km with SRH around 200 m2/s2. With all this said, discrete, 
supercellular like storms are expected initially and then they 
should merge into a multi cell line within a few hours after 
initiation. A few tornadoes, hail quarter to tennis ball sized, 
and damaging winds up to 65 mph are all on the table today. The 
greatest severe risk, especially for tornadoes and the largest 
hail, is going to be right along and east of the convergent 
boundary from about Butler, MO to Boonville, MO. As of 3 PM, radar
is starting to pick up weak returns. We expected storms to 
develop within the next hour or so with the severe weather risk 
moving east as the evening goes on, lasting through about 11 PM in
central MO. Storm chances though will likely continue through 
much of the night, mainly for our far southern counties. Those 
north of KC and west of I-35 should stay dry tonight and tomorrow 
morning.

As for rainfall and flooding concerns, there is a lot of moisture in 
the atmosphere with PWAT values up to 1.5 inches. Therefore, an 
additional 1-2 inches of rain is expected to fall from Miami 
County, KS to Howard County, MO. With the expected rainfall and 
rain that has fallen over the past few days, a flash flood watch 
has been issued for tonight, starting at 7 PM through 10 AM 
tomorrow. As for about Johnson County, MO up to Adair County, MO 
up to about 1 inch of rain is possible.

Overnight, a cold front like feature will move through, eventually 
stalling, orienting itself west to east, across southern MO. This
and additional shortwave troughs will keep rain chances going 
tomorrow morning. On and off showers and storms are then expected 
to continue tomorrow night through the holiday weekend thanks to 
persistent southerly surface flow and low pressure systems on the 
west coast continuously ejecting shortwave troughs into the 
Midwest. Severe weather is going to be possible both Thursday and 
Friday and possibly Saturday with our storm chances. With that in 
mind and it being a holiday weekend with many outdoor activities 
planned, stay updated on the forecast and remain weather aware. 
With the ground as saturated as it is and with additional rainfall
expected, flooding will continue to be a big concern.


&&

.Aviation...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1259 PM CDT WED MAY 22 2019

VFR conditions are expected across the area, though, a brief
period of lower ceilings and visibility are possible with storms 
that move through. Storms are expected to develop after 21Z and 
move northeast mainly along and east of a line from Kansas City to
Kirksville. Storms are expected to stick around through much of 
the night, especially in the southern half of MO and KS. A cold 
front like boundary will move through as well overnight, shifting 
winds to the northwest and eventually to the east. Late tomorrow 
morning, another round of showers could move through the area, 
though it is not clear where exactly it will set up. Current 
thinking is areas south of I-70 have the greatest chance. 


&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...Flash Flood Watch from 7 PM CDT this evening through Thursday 
     morning for KSZ057-060.

MO...Flash Flood Watch from 7 PM CDT this evening through Thursday 
     morning for MOZ040-043>046-053-054.

&&

$$

Discussion...Grana
Aviation...Grana