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

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FXUS63 KEAX 222028

328 PM CDT Wed Apr 22 2015

Issued at 328 PM CDT WED APR 22 2015

Weak surface ridging will build into northern/northeastern and
central Missouri tonight with light to calm winds expected. The
airmass is very dry, with dewpoints in the teens and 20s. So with
clear skies in the that portion of the forecast area and light
winds, temperatures are likely to fall into the lower 30s with some
sheltered areas likely falling into the upper 20s. The base 50
growing degree day values range from just above 100 to over 150,
indicating a good threshold for plant vulnerability. So will plan on
going with a frost advisory northeast of roughly Harrison county to
Cooper county where the best combination of cold temperatures and
vegetation vulnerability coexist. Our northwestern zones,
northwestern Missouri and extreme northeastern Kansas will likely
see similar temperatures but have a much lower base 50 growing
degree day value likely will see less of an impact from the cold

Quiet weather is expected Thursday as shortwave ridging builds east.
Moist isentropic ascent will overspread the region late Thursday
night/Friday morning ahead of a trough approaching the area out of
the Southwest. The features associated with that trough will need to
be closely monitored for its potential impact our weather later in
the day Friday. Models seem to have shifted further west and south
with the warm front and as a result the potential for severe weather in
our forecast area looks to be lower based on the latest suite of
guidance. But it still looks like widespread showers and storms will
spread over the area Friday night as the upper low and associated
surface low move east. This may bring periods of moderate to heavy
rain to the area but with limited instability overnight, the severe
storm potential again looks to be low.

That system tracks to the east Saturday into Sunday with pronounced
shortwave ridging building into the area on Sunday. This should bring
a lull in the precipitation chances but the next upper low is
expected to move into the Southern Plains during the day Monday. This
will lead to another chance for showers and storms from mainly
Monday night into Tuesday. There is quite a bit of variability with
the positioning of the upper low so confidence is fairly low. The low
itself could be further south, as depicted by the GEM and ECMWF, or
take a little more northern path, like the GFS. All this would have
an impact on where the best chances for precipitation would be. So
have kept the PoPs in the low chance range at this point until a
clearer solution emerges.


.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1202 PM CDT WED APR 22 2015

A weak high pressure over the area will keep the region under VFR
conditions with light winds. Scattered to perhaps broken mid/high
level clouds are expected to move into the area tonight but will not
have any impact on aviation.


MO...FROST ADVISORY from 4 AM to 8 AM CDT Thursday FOR MOZ005>008-



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