Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus63 kict 181041 
afdict

Area forecast discussion
National Weather Service Wichita Kansas
541 am CDT Wed Sep 18 2019

Short term...(today through Friday night)
issued at 314 am CDT Wed Sep 18 2019

Ridging over the Ohio Valley and the Gulf Coast states will continue
to break down today, as the shortwave along the West Coast of the
conus lifts northeast into The Rockies and eventually into the
northern plains. Current models have been trending slower with this
shortwave, which will keep most of the forecast area in south-
southwest flow again today, with similar Max temps from the previous
day, almost 10 degrees above normal. So a persistence forecast looks
like the way to go. As this shortwave lifts northeast, the surface
trough centered over western Kansas will slowly drift further east into
central Kansas for this afternoon. The weak convergence along this
boundary and increasing low level moisture along it, may lead to an
isolated shower of storm developing across north central Kansas for late
this afternoon. A warm elevated mixed layer will probably keep most
of the forecast area capped, with the best chance for convection
being along and north of I-70 where the cap will be the weakest.
Will keep a low pop in for this chance for central KS, but think
confidence in this occurring is low.

The ridge over the Ohio Valley continues to break down for Thu/Fri
with Gulf moisture beginning to stream back north into the plains.
This will lead to increasing chances of diurnally driven
showers/storms for both days. Thu is beginning to look like more of
a dryline day for western KS, in the weakly capped environment.
Think storms are possible along the north to south oriented dryline
in western KS, with some of this convection making its way into
western sections of the forecast area for Thu evening.

The better chance for widely scattered showers and thunderstorms
looks to occur on Fri, as a tropical moisture remnants from dew point
Imelda lift north through ern Texas into ern OK and The Ark Ozarks for
Fri afternoon/evening. Think areas east of the Kansas Turnpike will see
widespread showers and storms for Fri afternoon as this moisture
plume spreads north, with the weakly capped environment. Latest GFS
is coming around to the European model (ecmwf) solution on bringing a portion of this
moisture into the Flint Hills and southeast Kansas. Precipitable water values
of 190-200 percent of normal, suggests pockets of heavy rainfall may
also occur, but pinpointing where the heaviest rainfall will occur
is still uncertain, given the lack of any surface boundary to focus
the storms.

Ketcham

Long term...(saturday through tuesday)
issued at 314 am CDT Wed Sep 18 2019

Medium range models have been trending slower with a frontal
boundary expected to push into the forecast area for Fri night into
Sat. GFS and European model (ecmwf) now suggest that the frontal boundary will push
into the area for Sat/Sat afternoon. Abundant moisture will still be
located south of the slow moving boundary for increasing chances of
showers and thunderstorms for Saturday afternoon/evening. A
moderately unstable airmass will be located south of the front, with
increasing bulk shear also suggesting a strong to severe storm
chance for Sat afternoon/evening as well. Very high precipitable
water values will still be located to the south of the boundary as
well, suggesting very efficient rainfall producers. So heavy
rainfall and localized flooding will be an increasing concern going
into Sat night. GFS low level moisture transport vectors continue
to feed low level moisture into this boundary for most of Sat into
sun, which could pose a threat of several rounds of showers and
thunderstorms, especially for areas east of the Kansas Turnpike.

Latest medium range models and GFS ensemble members suggest that the
frontal boundary may stall or "wash out" over areas east of the Kansas
Turnpike for sun, before completely washing out on Mon. European model (ecmwf) shows
this more so than the GFS. But low level moisture plume looks to
continue over the eastern half of the forecast area throughout the
weekend. This may lead to a continued chance of heavy rainfall for
most of the weekend. Stay tuned.

Ketcham

&&

Aviation...(for the 12z tafs through 12z Thursday morning)
issued at 538 am CDT Wed Sep 18 2019

Primary aviation concerns: llws, gusty winds, and isolated thunderstorms and rain

Today will mostly be a repeat of yesterday, with possible low level wind shear early
this morning and again at night. That said, the low level wind shear threat
doesn't look as good over the next 24 hrs as it did over the past
24. Low level wind shear was only added where confidence is highest. Gusty winds
can be expected this afternoon, but are not expected to be quite
as high as yesterday. A surface low and associated frontal
boundary over the High Plains will shift slowly east today,
possibly nearing central Kansas by late this afternoon. Ahead of
the front, an isolated shower or thunderstorm cannot be ruled out
early this morning or again late this afternoon/early this
evening. Latest radar data already shows a few rain showers developing
across central Kansas. They are widely scattered, though, and
confidence in thunderstorms and rain impacting krsl, ksln, kgbd this morning is too
low for a mention yet. We'll closely monitor the potential,
though. Otherwise, VFR cigs look to prevail through tonight.

Martin

&&

Preliminary point temps/pops...
Wichita-kict 91 70 88 68 / 10 0 10 10
Hutchinson 92 70 89 68 / 10 0 10 10
Newton 90 70 88 68 / 10 10 10 10
Eldorado 89 70 87 69 / 10 0 10 10
Winfield-kwld 90 69 88 68 / 10 0 10 10
Russell 94 70 91 68 / 20 10 10 20
Great Bend 93 69 89 66 / 10 10 10 20
Salina 93 71 90 70 / 10 10 10 10
McPherson 91 69 87 67 / 10 10 10 10
Coffeyville 91 70 90 69 / 10 0 10 20
Chanute 91 70 89 69 / 10 0 10 10
Iola 91 70 89 69 / 10 0 10 10
Parsons-kppf 91 70 89 69 / 10 0 10 10

&&

Ict watches/warnings/advisories...
none.
&&

National Weather Service Glossary of Abbreviations