Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wichita Kansas
1240 PM CDT Wednesday Jul 30 2014
..updated for 18z aviation discussion...
Short term...(today through thursday)
issued at 258 am CDT Wednesday Jul 30 2014
Compact but vigorous shortwave continues to drop southeast along the Front
Range of The Rockies at this time ... upslope flow and moisture
transport leading to a large area of showers and embedded
thunderstorms across most of western Kansas. Actually seeing low level
moisture transport increasing over the OK Panhandle with a band of
showers just to the SW of the forecast area beginning to develop.
Short term models suggest the 850-700h moisture transport will
continue to increase over most of SW Kansas and south central Kansas this
morning into the midday hours...with the main area of showers and
embedded thunder making its way further east as the morning
progresses. This moisture transport and Theta-E advection will be
maximized for the midday time frame...with axis of heaviest rainfall
expected to be just to the SW of the forecast area...or generally
from kddc to just north of kokc. Still think areas SW of kict will
get some healthy rainfall amounts today as this area will be on the
NE edge of the heaviest rainfall...with some areas over Harper and
Sumner counties possibly picking up 1 to 2 inches. Expecting the
heaviest rainfall axis in the forecast area to be SW of a Kingman to
Wellington to Winfield line. Think areas further to the northeast
will still see widespread showers today...but lessor amounts the
further northeast you go towards Salina and Emporia.
Not alot of elevated instability as this large area of rain moves
in...but models do show some minimal surface based instability...
which will probably be enough for some embedded thunder...but expect
predominately showers with some heavier mesoscale pockets of heavy
Flash flood guidance values across south central Kansas are 3-4
inches...with dry conditions starting out...so not expecting any
flash flooding issues...but may see some localized flooding in
low lying areas. Will cover this in the hazardous weather outlook.
The large rain shield will keep temperatures from moving much
today...especially over south central Kansas...where temperatures may only
move a couple of degrees in the morning hours...before remaining
steady due to overcast skies and widespread rain.
The main shortwave will make progress to the southeast into OK for this
evening and tonight...with rainfall diminishing from north to south
as the evening progresses. Could see some of the rainfall linger
over southern Kansas at least until around the early morning hours on
Most of the area will see a pleasant Summer day on Thursday as the northwest
flow remains on control with a weak area of high pressure building
into the plains. Both the GFS and NAM/WRF do show some lingering
instability over extreme southeast Kansas for Thursday afternoon...which may lead to
some diurnally driven showers and isolated storms...so will keep a
slight pop along the Kansas/OK border for Thursday afternoon.
Long term...(friday through tuesday)
issued at 258 am CDT Wednesday Jul 30 2014
The northwest flow pattern looks to continue for the weekend...which will
lead to temperatures staying a little below normal for late July or early
Aug. Some indications that low level moisture will slowly increase
for Sat...which could lead to a possible diurnal storm chance for
Sat afternoon. But warm air aloft will keep storms from developing.
So will keep probability of precipitation out of the forecast for the weekend for now.
Upper ridge over The Rockies begins to break down by the end of the
weekend which will lead to a gradual warming trend back towards
normal for Mon/Tue. As this ridge breaks down...the trough along
the Front Range of The Rockies will begin to move out into into the
High Plains with southerly winds ahead of it. This will lead to
shower and thunderstorm chances returning to portions of central Kansas
by Monday night into Tuesday.
Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 1238 PM CDT Wednesday Jul 30 2014
Upper system will continue to slowly move southeast...bringing slow
end to precipitation. While NAM seems to have best handle on
precipitation evolution so far...but its boundary layer moisture
seems a bit overdone relative to current ceilings/clouds. That
said...do expect continued deteriorating conditions where
precipitation persists this afternoon...with brief periods of IFR
and extended periods of MVFR. With clearing late this afternoon/
evening...could see fog develop late tonight. NAM boundary layer
moisture forecasts suggests the main threat for more extensive fog
will be along/east of I-35. -Howerton
Preliminary point temps/pops...
Wichita-kict 73 61 82 63 / 90 30 0 0
Hutchinson 75 60 85 63 / 80 20 0 0
Newton 75 60 83 63 / 60 20 0 0
Eldorado 73 60 83 62 / 70 20 0 0
Winfield-kwld 71 62 81 63 / 90 50 20 0
Russell 79 60 85 63 / 40 10 0 0
Great Bend 76 59 83 63 / 70 10 0 0
Salina 79 60 88 64 / 30 10 0 0
McPherson 76 60 85 63 / 50 10 0 0
Coffeyville 74 62 81 62 / 90 60 20 0
Chanute 73 62 82 62 / 50 30 10 0
Iola 74 62 82 62 / 40 20 0 0
Parsons-kppf 73 62 81 62 / 60 60 20 0