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

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762
FXUS63 KEAX 232012
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
312 PM CDT Fri Sep 23 2016

.Discussion...
Issued at 304 PM CDT FRI SEP 23 2016

The main concern over the next few days is with the potential for
strong thunderstorms and heavy rainfall.

A stationary front is currently situated across Nebraska and Iowa.
This was resting at the northern periphery of an unseasonably strong
upper ridge and south of the front conditions remain capped. However,
a large upper trough that has been slowly progressing eastward is
currently moving through the Great Basis area. As this trough
continues to push east, low level flow will strengthen and aid in
pushing the stationary front northward. This will also establish a
large warm sector with abundant moisture for the overall system to
tap into. For Saturday, Another unseasonably warm and humid day is
expected. With low level moisture streaming north, cloud cover should
be on the increase, which may keep temperatures a bit cooler than
they are today with full sun. But dewpoints should again be in the
lower 70s, offsetting the slightly cooler temperatures.

The increased low level moisture will also aid in the development of
modest instability. Although there is fair amount of uncertainty
with how unstable the area does get, it looks like we`ll see CAPE
values ranging from about 1500 to 2000 J/kg. Shear will be
relatively low though, perhaps in the 10 to 20 kt range. This is
mainly a result of the main vorticity center of the upper trough
lifting well north of the area , taking with it the strongest mid and
upper level flow. This will also allow the lower level flow to be
roughly parallel the front, resulting in a slower progression than
would otherwise occur. Thus, with ample moisture, modest instability,
flow nearly parallel to the front and slow progression of the front,
there is a good chance for areas of heavy rain which may lead to a
localized flash flood threat. 1 hour flash flood guidance is around
2" across the area. This is more than the total so the threat should
remain isolated. The heaviest rain will likely fall late Saturday
night/Sunday morning. Overall across the area, it still looks like a
general 1 to 1.5 inches of rain. The actual cold front will move
through the area late in the day Sunday or Sunday night. As it does,
rain chances will rapidly decrease and the air mass will become
cooler and drier.

For the rest of next week, cooler than normal temperatures will
trend to more seasonal temperatures by Thursday and Friday. Normal
for this time of year in the middle 70s. The next chance for
precipitation will come late in the week.


&&

.Aviation...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 1223 PM CDT FRI SEP 23 2016

VFR conditions are expected through the forecast. Although clouds
will be on the increase overnight and ceilings should lower to 4 to 5
thousand feet as moisture builds in from the west. Winds will
generally be from the south at 10 kts or less.


&&

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

$$

Discussion...CDB
Aviation...CDB



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