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

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
000
FXUS63 KEAX 170520
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
1220 AM CDT Sun Sep 17 2017

.Discussion...
Issued at 326 PM CDT SAT SEP 16 2017

A band of showers and thunderstorms has developed just west of
I-35 this afternoon where the atmosphere has acquired some
weak/moderate instability. This activity has developed near a weak
mid-level impulse moving into western Missouri, but should
gradually weaken over the next few hours as it encounters a deeper
low-level stable layer over western and central Missouri.
Meanwhile the primary surface cold front is approaching the far
northwest tip of Missouri where a rather sharp temperature
gradient is separating mid/upper 80s over KS and MO from
mid/lower 60s across Nebraska. This boundary will slowly make its
way into northwest Missouri this evening and eventually reach the
I-35 corridor around 3 AM. The band of rain and storms that has
developed out ahead of the front is stabilizing the airmass over
KS and MO somewhat, but clearing and resulting destabilization
further west could still allow for a few stronger storms across
areas from near Topeka to just north of St Joseph later this
afternoon and this evening. Shear is rather weak so brief gusts to
50-60 mph and perhaps some marginally severe hail will be the
primary threats across these areas.

Storms may increase in coverage overnight as they push into
eastern KS and western/northern MO and become aided by a stronger
midlevel wave to the north, but with instability becoming
elevated they will likely lose some of their punch. Still, it
wouldn`t be surprising to see some hail approaching an inch in a
few of the stronger storms through midnight or so, along with some
locally heavy rainfall. The front will become stalled just south
of US 50 on Sunday, and while a few storms are possible near this
boundary through the afternoon, the primary focus for additional
convection won`t arrive until after dark Sunday evening when a
secondary mid-level impulse will move in from the southwest. Some
locally heavy rainfall is again possible with this activity
especially near the slowly retreating boundary, but the lack of a
strong low-level jet should keep the overall heavy rain/flash
flood threat on the low side. A series of weak upper-level
impulses will continue to stream into the area through Monday
evening keeping rain chances around through at least early
Tuesday.

Tuesday evening appears to be the most likely time to see a dry
period before another cold front brings another potential round of
storms to the area on Wednesday and into early Thursday.

&&

.Aviation...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1220 AM CDT SUN SEP 17 2017

Multiple rounds of thunderstorms are expected to impact the TAF
locations as a cold front pushes through the area from the NW.
There is currently an area of thunderstorms just south of KMCI
over KMKC and KIXD that is expected to move out by 8Z as the
surface cold front moves to the SE. Winds are expected to shift to
the NW at all stations by 08z as well on the backside of the cold
front. The second round of storms will start to move into the area
after 08z from the NW, but there is some uncertainty as to how
long these storms will last and their exact timing so a TEMPO for
TS was added to the terminals. The threat for these storms is
generally from 8-11Z with some chance of them lasting longer in
the southern portion of the area. MVFR ceilings will develop on
the backed of the cold front just after the second round of the
thunderstorms. A period of IFR ceilings is possible just after
sunset for the southern terminals through the early afternoon. All
ceilings will start to rise with KSTJ clearing out first in the
afternoon and the southern terminals finally clearing out around
sunset with VFR expected from that point through the end of the
period. There is a chance for storms to return in the afternoon on
Sunday but there is not much consensus for when and where that
will occur at this time so it was kept out of the forecast for
now.

&&

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

$$

Discussion...Hawblitzel
Aviation...Barham



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.