Areal Flood Warning 43, NWS Wichita, KS

Area Forecast Discussion
National Weather Service Wichita KS
1145 PM CDT Wed Jul 14 2021

.SHORT TERM...(This evening through Friday night)
Issued at 305 PM CDT Wed Jul 14 2021

BOTTOM LINE UP FRONT: An increased risk of thunderstorms, some with
strong gusty winds and intense rainfall rates, is likely through the
weekend. Widespread severe weather is not expected at this time, but
scattered instances of damaging winds and flash flooding will be
possible.

DISCUSSION

As of 19z/2pm, a modestly deep SFC low was located over the Central
High Plains, just south of Goodland. A semi-stationary frontal
boundary stretched northeast from western Kansas into eastern
Nebraska. A broken band of convection was ongoing along, and just
south, of the frontal boundary (across parts of NRN KS/SRN NE).
South of the frontal boundary, the warm sector was moderately to
strongly capped across central/southern KS. Aloft, a s/w was
beginning to move out of the central Rockies.

The central Rockies' s/w will cross the High Plains tonight, then
move across the Central Plains Thursday/Thursday night. This should
encourage a gradual southward movement of the above-mentioned
frontal boundary. Meanwhile, the SFC low, currently south of
Goodland, will move east along the southward-sagging front. A modest
LLJ ahead of the SFC low should encourage steady moistening and
persistent elevated moisture transport into the frontal zone as it
sags south through Friday. This combined with the potential added
lift from the entrance region of a 40-60kt upper jet should lead to
scattered to numerous showers and thunderstorms along the frontal
zone through Friday. Instability looks weak to modest (perhaps on
the order of 500-1500 j/kg at night, and as high as 1500-2500 j/kg
during the day). Flow aloft is fairly weak, which should keep
effective shear on the lower side (maybe 15-25 kt). The weaker shear
should limit storm organization, with clustering of storms likely.
Overall, this should keep the risk of severe weather low with storms
along the front. However, the high PWat airmass (1.5-2.2") plus
modest CAPE during the daytime hours could support some wet
microburst/water-loaded downdrafts, with gusts of 50-60 mph. A few
instances of sub-severe hail cannot be ruled out if any updraft can
get tall enough, or be sustained long enough, but this risk appears
lower than the wind gust potential. Lastly, steep low-level
instability (3CAPE of 100-150 j/kg) and lower LCLs may support some
funnel clouds or "scary-looking", low-hanging clouds, but I don't
envision a true tornado threat given the lack of stronger
instability and weak shear. For additional information on the
hydro/flooding concerns, please see the "Hydrology" section.

I hit pops the hardest Thursday, but slowed the onset down as the
front probably won't get a good southward push until Thursday as the
above-mentioned s/w moves through. Additionally, there remains some
uncertainty with how far south the front will get Thursday night.
Some model guidance hint at an MCV or some low-mid level feature
moving through our area Thursday. If this occurs, this could force
the front further south into northern Oklahoma by Friday morning.
However, if that does not occur, the front could get hung up across
southern KS. For now, we decided to keep the highest pops focused
along/south of the KS/OK border for Friday, but held onto some pops
as far north as the HWY 54/400 corridor to account for the front
possibly getting hung up in that area.

By Friday night, the front should begin to lift back north as the
nocturnal LLJ increases. Convection developing across the High
Plains Friday afternoon/evening may then grow upscale into a small
MCS that moves SE along the frontal boundary, potentially
impacting portions of central/southern KS late Friday night. The
area impacted may be dependent on where that frontal boundary set
up Friday and how far north it reaches Friday night.

Temperatures should be the warmest this afternoon, then "cool" some
through Friday as the front moves through. I lowered temps some from
the previous forecast to account for more post-frontal cloudcover
and an easterly SFC flow, especially Friday. Temps may need to be
lowered even more depending on where the front hangs up on Friday.
Of note, too, some post-frontal drying and clear skies may allow
some fog to develop along the I-70 corridor tomorrow night into
early Friday morning.

Martin

.LONG TERM...(Saturday through Wednesday)
Issued at 305 PM CDT Wed Jul 14 2021

The frontal boundary from Friday will probably still be draped west
to east, or NW to SE, across KS/OK on SAT/SUN, likely affording a
continued risk of thunderstorms (maybe a couple of convective
clusters/MCS'??). With time, this boundary should shift south into
OK/TX as a more pronounced northerly flow regime develops aloft.
This would set the stage for a more stable/post-frontal regime
across Kansas, probably with below climo temps as well.

Martin

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1143 PM CDT Wed Jul 14 2021

A broken line of showers and thunderstorms will continue to move
slowly eastward across the region for tonight into Thursday.
Cigs are expected to be in the mid-levels before scattering out
from west to east later in the day. The thunderstorms could
increase in coverage during the afternoon hours with more daytime
heating.

&&

.HYDROLOGY...
Issued at 305 PM CDT Wed Jul 14 2021

An increased risk of thunderstorms is expected through the weekend
thanks to a frontal boundary moving slowly through the area. This
boundary may get hung up over parts of OK/KS SAT/SUN, adding to the
rainfall potential. 6hr Flash Flood Guidance is pretty high right
now, ranging from 3-5" across the area. Additionally, soil moisture
is relatively dry, especially across central Kansas. Initially, this
should keep the threat of flooding/flash flooding more localized,
and not as widespread. With time, the threat of flooding could
increase over the weekend depending on how much rain falls over the
next 24-36 hours. We'll continue to monitor this potential, but hold
off on issuing any flood headlines due to the limitations mentioned
above and some uncertainty with where the front will stall FRI-SUN.
Regardless, the high PWat airmass and modest instability should
support some intense rainfall rates at times. Of note, the one area
of initial concern is southeast Kansas where soil moisture is a
little higher and runoff potential may be higher than across central
KS.

Martin

&&

.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT    74  86  68  88 /  40  80  60  20
Hutchinson      73  83  66  88 /  50  80  40  10
Newton          73  83  66  87 /  50  80  50  20
ElDorado        73  85  67  84 /  40  90  70  20
Winfield-KWLD   74  88  69  87 /  20  80  70  30
Russell         68  83  64  88 /  60  60  10  10
Great Bend      69  83  64  86 /  70  70  20  10
Salina          72  83  66  90 /  50  80  30  10
McPherson       72  83  65  87 /  50  80  40  10
Coffeyville     73  89  71  87 /   0  60  90  60
Chanute         74  87  69  85 /  10  80  90  50
Iola            74  86  69  84 /  10  80  90  40
Parsons-KPPF    73  89  70  87 /   0  70  90  50

&&

.ICT WATCHES/WARNINGS/ADVISORIES...
None.
&&

SHORT TERM...RM
LONG TERM...RM
AVIATION...CDJ
HYDROLOGY...RM

Hazardous Weather Outlook
National Weather Service Wichita KS
509 PM CDT Wed Jul 14 2021

KSZ032-033-047>053-067>072-082-083-091>096-098>100-152215-
Russell-Lincoln-Barton-Ellsworth-Saline-Rice-McPherson-Marion-Chase-
Reno-Harvey-Butler-Greenwood-Woodson-Allen-Kingman-Sedgwick-Harper-
Sumner-Cowley-Elk-Wilson-Neosho-Chautauqua-Montgomery-Labette-
509 PM CDT Wed Jul 14 2021

This hazardous weather outlook is for portions of Central Kansas,
South Central Kansas and Southeast Kansas.

.DAY ONE...Tonight

Scattered thunderstorms will impact portions of central Kansas
tonight. The risk of severe weather appears low with this activity.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

An increased risk of thunderstorms is expected Thursday through
Sunday. At this time, the threat of widespread severe weather
appears low. However, the strongest thunderstorms will be capable of
strong wind gusts of 50-60 mph, small hail to penny size, and
intense rainfall rates. Additionally, flash flooding and river
flooding will be possible.

Patchy, dense fog is possible Thursday night through Friday morning
along the Interstate 70 corridor.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated tonight.

&&

For a graphical version of this information, see our webpage at:
https://weather.gov/crh/ghwo?sid=ict

Martin