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335
FXUS63 KDDC 151900
AFDDDC

Area Forecast Discussion
National Weather Service Dodge City KS
200 PM CDT Tue Aug 15 2017

...Updated Long Term...

.SHORT TERM...(This afternoon through Wednesday)
Issued at 1230 PM CDT Tue Aug 15 2017

Breezy S/SE winds and seasonably warm/hot this afternoon with
scattered cirrus. Most locales will top out in the lower 90s, on
par for mid August. Dewpoints in the 60s will be maintained, and
instability (MLCAPE) axis currently seen on mesoanalysis across
W/NW Kansas will persist and strengthen. 12z NAM increases CAPE
to near 3000 J/kg across the western zones 5-7 pm.

Convective evolution this evening through tonight is a challenge,
and it will be interesting to see how it turns out. Numerous
factors lead to a high confidence in thunderstorms across western
Kansas through tonight. Primary shortwave over Utah at midday will
continue to advance into Kansas through tonight, but the eastward
timing looks slow enough that it may prevent a higher end
thunderstorm event from occurring. 12z GFS doesn`t get its
primary shortwave to the CO/KS border until late tonight/sunrise.
Still, forcing for ascent is sufficient on GFS ahead of this wave,
to generate showers and thunderstorms all night. NAM/ECMWF offer a
similar timing. It appears the NAM picks up on a leading secondary
vorticity max that ignites a strong MCS across SW KS this evening.
CAMs, typical of summer, are wildly divergent and offer little
assistance. Conceptually, have high confidence of thunderstorm
development through tonight, as forcing increases aloft over various
surface boundaries and ample instability. Some severe hail and/or
wind is likely, along with very heavy rainfall, when/where/if the
MCS decides to track/mature. High precipitable water argues that we
will need to monitor hydrology issues through tonight. Confidence
way too low on placement to issue a flash flood watch, but the
potential is certainly there. ECMWF continues to suggest a strong
MCS across northern/central KS overnight tonight, impacting the NE
zones (I-70 corridor). With the primary shortwave`s later timing,
the MCS may go well into Wednesday morning. Increased pops as far as
I felt comfortable (55-60%) and included heavy rain/gusty wind
wording in the grids.

Behind the MCS/shortwave on Wednesday, surface winds will trend
northwest to north at 10-20 mph. This process is expected to
scour instability nicely to our SE into Oklahoma, and effectively
end the risk of thunderstorms for most locations. Kept some low
pops along the eastern border Wednesday afternoon, but suspect any
thunderstorm redevelopment will occur east/SE of our CWA.
Temperatures will be a few degrees cooler, but with sufficient
sunshine in the afternoon, still expecting mid to upper 80s.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 200 PM CDT Tue Aug 15 2017

Much of Thursday will be dry along with seasonable temperatures.
Another MCS is likely to impact at least the southern zones
Thursday night into Friday morning, as the FB starting point pop
grids and 12z ECMWF solution suggest. A shortwave diving SE
through the northern plains will push an attendant frontal
boundary through Kansas Friday, with thunderstorm development
favoring the SE zones near Medicine Lodge late Friday. Medium
range models keep modest westerly flow aloft into the weekend,
with GFS maintaining convection chances late Saturday across at
least the western zones, as thunderstorm propogate eastward off
the higher terrain. After this time, Sunday through early next
week, 12z GFS shows gradually increasing 500 mb heights as high
pressure aloft over Texas attempts to expand north into the
central plains. 12z ECMWF also has rising heights across SW KS
Saturday through Tuesday, so there should be a trend to
warmer/drier weather during this time frame. Still, warming trend
in the grids undercuts 12z MEX guidance.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1136 AM CDT Tue Aug 15 2017

High confidence of convection across the area later tonight with
low confidence in regards to the specific timing and location. A
shortwave will move in from the desert southwest triggering
thunderstorm initation in eastern Colorado. Initial thought is the
round of storms will be affecting GCK and LBL roughly around 0Z and
DDC, HYS around 03Z. The storms do have the capability of strong
winds and heavy rain so brief visibility issues are possible. A
better idea on how the convection is going will be available in the
0Z TAF. From 12Z on depending on how the convection evolves a low
cloud stratus deck is expected for all airports through 18Z.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  91  68  87  61 /  20  50  30  10
GCK  91  65  85  59 /  20  50  20  10
EHA  91  63  85  61 /  30  40  10  10
LBL  94  67  88  62 /  20  30  20  10
HYS  89  68  83  61 /  30  50  40  10
P28  90  72  91  66 /  30  50  30  20

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Tatro