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Area Forecast Discussion (AFD)

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

                            
000
FXUS63 KEAX 212030
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
330 PM CDT Sat Sep 21 2019

.Discussion...
Issued at 329 PM CDT SAT SEP 21 2019

The main concerns in the short term will continue to be the chance 
for flash flooding and river flooding tonight. There is also a 
chance for isolated severe storm this evening. This afternoon a area 
of showers will occasional embedded thunderstorms is moving through 
the area. The good news is these storms have kept clouds around 
which has kept the atmosphere from becoming too unstable. MLCAPE 
values do still range in the 1000-1500J/Kg range and there is some 
concern that upstream clearing across northeastern Kansas and 
southeastern Nebraska will help storms grow upscale as they develop 
out ahead of a cold front this evening. However, clouds are expected 
to persist through the evening over the CWA which will keep the 
severe threat isolated. The main threat would be for damaging winds. 
The bad news associated with the afternoon storms is that they have 
been fairly efficient producing rainfall amounts of half to three-
quarters of an inch of rain over an area from north central Missouri 
back through St Joseph and the extreme northern Metro. This 
additional rainfall preceding the round of heavy rain expected 
tonight will only lower flash flood thresholds across those areas. 
The main line of storms is expected to develop this evening over 
northwest Missouri and northeastern Kansas. This line will slowly 
sag into the area tonight. This line will move into a extremely 
moist airmass with low level moisture being pumped into the area 
from the Gulf and mid and upper level moisture being ushered into 
the area from the eastern Pacific. This will push PWAT values into 
the 2.00"-2.25" range which is near the max for the end of 
September. Couple that with a LLJ that will hang the front up and 
provide additional lift along the front and several rounds of heavy 
showers and thunderstorms will be likely. Widespread 2 to 4 inches 
with a potential band of 4 to 6 inches will be possible. This will 
lead to areas of flash flood as well as river flooding. As such, a 
flash flood warning is in effect from 00Z Sunday to 00Z Monday. 
Finally, on Sunday afternoon/evening the upper level trough that 
forced the cold front into the CWA will move through the region and 
force the cold front south of the CWA. This will finally bring rain 
to an end. Clearing with light winds behind the front on Sunday 
night/Monday morning will allow areas of fog to develop. Some areas 
of fog may be dense and may require a dense fog advisory be issued 
with later updates. We will also experience the coolest 
temperatures of the season thus far Monday morning with lows in the 
low to mid 50s. 

Conditions should dry out for Monday and Tuesday. with highs in the 
mid 70s to near 80. The next round of storms will be possible Tuesday 
night into Wednesday as a mid-level trough moves forces another cold 
front through the region. Another brief dry period is expected 
Wednesday night into Thursday with highs in the mid 70s on Thursday. 
By Thursday night another stronger upper level trough will approach 
the area. This will bring the chance for another round of storms to 
the area Thursday night into Friday. This system will need to be 
monitored for severe potential.


&&

.Aviation...(For the 12Z TAFS through 12Z Sunday Morning)
Issued at 620 AM CDT SAT SEP 21 2019

Scattered showers and isolated thunderstorms are currently 
bubbling up around the Kansas-Missouri state line terminals. We 
expect the activity to fade a little as the morning progresses, 
with CIGs likely clearing out for a bit by the afternoon. But, we 
are expecting more storms to develop ahead of a cold front that 
will slowly settle into northern Missouri tonight. Expect south 
winds to prevail through the day as the front will hang in far 
northern Missouri till Sunday afternoon. 


&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...Flash Flood Watch from 7 PM CDT this evening through Sunday 
     evening for KSZ025-057-060-102>105.

MO...Flash Flood Watch from 7 PM CDT this evening through Sunday 
     evening for MOZ001>008-011>017-020>025-028>033-037>040-
     043>046-053-054.

&&

$$

Discussion...73
Aviation...Cutter