Flash Flooding and Flooding in Kansas, May 25, 2019

Area Forecast Discussion
National Weather Service Dodge City KS
1035 PM CDT Fri May 24 2019

...Updated Aviation...

.SHORT TERM...(This evening through Saturday)
Issued at 329 PM CDT Fri May 24 2019

The main forecast issue in the short term is chances for high-end
severe storms Saturday. A surface boundary has stalled out across
south central Kansas with rich low level moisture confined to the
southern plains. As the influence of last night's shortwave
trough wanes, with southwesterly mid level flow re-established,
surface troughing in the lee of the Rockies will lead to a rapid
moisture return. 500mb temperatures are progged to be around -13C
across western Kansas Saturday afternoon along and east of a weak
frontal boundary. A dryline is expected to meet this boundary
around Elkhart. With the cold mid level to upper level
temperatures, it is not a matter of IF storms will develop, it is
a matter of how early in the afternoon and exactly where. The
best chance of storm initiation is along the front and then
southwestward to where it meets the dryline from Scott City to
Johnson or Springfield, CO. Upper level winds are progged to be
around 90kts, which will allow for good storm ventilation. Very
large hail and tornadoes can be expected, provided that the storms
remain isolated. This is a concern given the high dewpoints and
cold mid level temperatures. If many storms develop then the
storms would be less severe or severe for a shorter period of
time. Right moving supercell storms will move to the east-
northeast or east at 25 to 30 mph. So places like Dodge City,
Ashland and Wakeeney would experience storms a little later in the
evening, assuming they are still supercells that late. Of course,
given all the rain we have had over the past few weeks, flooding
will again be a concern, especially for areas to the east of Dodge
City later at night. However, it is unclear whether the isolated
evening t-storms will evolve into a large cluster and dump
widespread heavy rain. We are monitoring for this potential.

.LONG TERM...(Saturday night through Friday)
Issued at 329 PM CDT Fri May 24 2019

On Sunday, a shortwave trough will approach western Kansas late
in the evening. Ahead of this feature, it will be extremely
unstable once again, with the possibility of very large hail and
tornadoes.The most favored location for initiation of severe is
across far western Kansas in the afternoon, then storms would move
east-northeastward once again and affect Dodge City, Ashland and
Wakeeney later in the evening. Of course, given all the rain we
have had over the past few weeks, flooding will again be a
concern.

On Monday, a large upper low pressure system will be located over
the Rockies. A dryline will be situated across western Kansas.
Mid level temperatures are progged to increase by Monday and given
that the dryline may be the sole surface lifting mechanism aside
from local terrain features, storm initiation is questionable.
There may only be one or two storms roaming the plains in the
evening dropping big hail. Therefore, chances for widespread heavy
rainfall is low.

A break in the severe storm/heavy rainfall regime is expected
Tuesday through Thursday as the upper level low passes to the
east and drier air moves into western Kansas. There is a chance of
thunderstorms again by Friday and Saturday as low level moisture
surges back north into western Kansas and another upper level low
develops near the west coast. It is uncertain how prolonged this
next wet spell may be. Heavy rain potential may be confined to
only a couple of days.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1035 PM CDT Fri May 24 2019

VFR will prevail through the majority of this TAF cycle. In a
moist boundary layer, areas of stratus of BR/fog are possible
through sunrise Saturday. Short term models do not develop much,
so kept out of the TAFs, but will monitor for amendments. Light
SE winds will pravail overnight. After 15z Sat, SE winds will
increase at all airports, gusting in the 25 kt range by afternoon.
The strongest winds are expected at LBL, the weakest at HYS.
During the 20z Sat- 03z Sun, time frame scattered to numerous
thunderstorms are expected at all airports. Have enough confidence
to include convective TEMPO groups with this TAF issuance. Some
storms will be strong to severe, with large hail and wind gusts in
excess of 50 kts.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  61  82  60  83 /  20  60  60  50
GCK  58  83  57  83 /  20  40  40  50
EHA  53  83  56  81 /  10  90  30  60
LBL  56  83  58  83 /  20  60  40  60
HYS  59  82  58  80 /  20  30  70  40
P28  65  82  62  82 /  50  50  70  40

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch from Saturday afternoon through Sunday morning
for KSZ046-064>066-078>081-087>090.

&&

SHORT TERM...Finch
LONG TERM...Finch
AVIATION...Turner

Hazardous Weather Outlook
National Weather Service Dodge City KS
306 AM CDT Fri May 24 2019

KSZ030-031-043>046-061>066-074>081-084>090-250815-
Trego-Ellis-Scott-Lane-Ness-Rush-Hamilton-Kearny-Finney-Hodgeman-
Pawnee-Stafford-Stanton-Grant-Haskell-Gray-Ford-Edwards-Kiowa-
Pratt-Morton-Stevens-Seward-Meade-Clark-Comanche-Barber-
306 AM CDT Fri May 24 2019 /206 AM MDT Fri May 24 2019/

This hazardous weather outlook is for portions of central...south
central...southwest and west central Kansas.

.DAY ONE...Today and tonight.

Day 1 Discussion
----------------

Scattered thunderstorms will be restricted to the southeast zones
Friday afternoon and evening, where the strongest storms may
produce large hail and strong winds.

Day 1 Hazards
-------------
* Flooding: Limited risk
* Lightning: Limited risk
* Thunderstorm Wind: Limited risk
* Thunderstorm Hail Risk: Limited risk

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Days 2-7 Discussion

Additional rounds of severe thunderstorms are expected both
Saturday and Sunday afternoon/evening. High end severe weather is
possible on both these days, with tornadoes and very large hail
possible. Drier more stable air is expected next week.

Days 2-7 Hazards
----------------
* Saturday
  - Flooding: Elevated risk
  - Lightning: Elevated risk
  - Severe thunderstorm: Elevated risk

* Sunday
  - Lightning: Elevated risk
  - Flooding: Elevated risk
  - Severe thunderstorm: Elevated risk

* Monday
  - Non thunderstorm wind: Limited risk

* Tuesday
  - Lightning: Elevated risk

* Wednesday
  No hazards.

* Thursday
  No hazards.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be required across the southeast zones
Friday afternoon and evening.

&&

For more details visit our webpage http://weather.gov/ddc/ehwo

Turner