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Area forecast discussion 
National Weather Service Wichita Kansas
1225 PM CDT Wednesday may 6 2015

..updated for 18z aviation discussion...

Short term...(today through friday)
issued at 341 am CDT Wednesday may 6 2015

Today-tonight: widespread showers and embedded thunderstorms will
continue to lift northeast or east of the forecast area during the
early morning hours. Could actually be seeing the back edge of the
showers over western OK at this time. Expect most of the shower
activity to end from SW to NE as the morning continues. Some
uncertainty on how this afternoon will evolve as lots of remnant
cloud cover will hamper atmospheric recovery across the area for
late afternoon thunderstorm chances.

Latest short term hi-res models suggest most of south central Kansas
will break out from the cloud cover....as dryline begins to push
east towards areas just west of the forecast area for the late
afternoon hours. With this increased heating...latest forecast
soundings show areas SW of ict becoming uncapped late this
afternoon...with MLCAPE values of 2000-2500 j/kg and bulk shear of
35-40 kts. So think a few discrete supercells will develop near the
triple point somewhere to the SW of kict late this afternoon or
early this evening. This kind of shear and directional shear (nice
curving hodograph) suggests large hail and damaging winds. But
cannot rule out a tornado or two...given this hodograph...as 0-1km
storm relative helicity increases to 200 j2/kg2...and surface winds
back just ahead of the dryline. Not expecting an outbreak of severe
weather...but think a couple of slow moving supercells may produce
some significant severe weather with possibly some very large hail.

Think the showers and thunderstorms will continue at least until
around midnight...with the supercells and possible tornado threat
continuing well after dark...as MLCAPE remains around 2000 j/kg and
the low level jet increases directional shear in the lowest layers.

Expect storms to wane after midnight as some warmer air aloft
effectively ends the storms.

Thursday-Fri: the moisture rich environment will remain across the
region for Thursday and into the start of the weekend. This will lead
to several periods of severe weather for this time frame.

Expect the dryline/surface boundary to make a little more progress
to the east into central Kansas for Thursday afternoon/evening as a low
pressure area develops over SW Kansas. This will create another triple
point across south central Kansas...as convergence is a little better on
Thursday than today. So think supercell thunderstorms may be a little
more widespread on Thursday as atmosphere destabilizes late Thursday afternoon
and convergence increases. Bulk shear of 35-40 kts and MLCAPE values
of 1500-2000 j/kg will be sufficient to produce severe weather with
large hail and damaging winds. Cannot rule out a tornado or two
..especially over south central Kansas...During the early evening
hours...as surface winds back near the triple point.

As Thursday evening progresses...low level jet will increase...which will
lead to convection filling in and becoming some sort of northeast
forward propagating convective complex (mcs). Will have to watch the
overnight hours on Thursday...for possible training storms and possible
flooding.

Forecast gets a little messier for Friday...as position of the main
surface boundary will be problematic at best. But GFS and European model (ecmwf)
suggests that the boundary will be become quasi stationary on
Friday...located somewhere across central or south central Kansas.
Copious amounts of low level moisture will still be located to the
south of this boundary...as another weak shortwave rotates northeast
across the region. This will lead to another round of showers and
thunderstorms for Friday afternoon/evening. Could see another severe
weather threat on Friday evening...with 40 kts of bulk shear and an
unstable airmass remaining in place. GFS still suggests convection
will evolve into a slow moving convective complex (mcs) of storms
across southern Kansas Friday night. Will certainly have to keep an eye on
the flooding threat...as soils will probably be saturated by this
time...and this mesoscale convective system could lead to another round of heavy rain.

Ketcham

Long term...(saturday through tuesday)
issued at 341 am CDT Wednesday may 6 2015

A more significant threat of severe storms looks to arrive on Sat
afternoon...as the main upper low that has kept most of the plains
in the SW flow begins to finally pushes east-northeast into the
plains for Sat. With the better ascent and increased bulk shear and
copious amounts of moisture still around under a weakly capped
environment...this suggests a possible high end severe storm chance
across the forecast area...with some parameters suggesting a more
widespread outbreak of severe weather and supercells for Sat
evening.

Drier air looks to push into the western half of the forecast area for
Sunday...with the main surface boundary located across the Flint
Hills and southeast Kansas. Some uncertainty on placement of the
boundary for Sunday...with a slower movement suggesting another
round of severe storms for southeast Kansas on sun.

Medium range consensus supports much quieter weather by early next
week...as the aforementioned shortwave ejects northeast of the
region...and a dryer airmass filters south into the plains. This
will allow the region to dry out at least through the middle of next
week.

Ketcham

&&

Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 1220 PM CDT Wednesday may 6 2015

Ongoing widespread IFR/MVFR ceilings across central/south central
Kansas are expected to improve with height during the afternoon hours
with some breaks likley as mixing increases.

Isolated to widely separated severe storms will develop late this
PM/eve...possibly affecting terminals along/west of Interstate
135. Will include thunderstorms in the vicinity at rsl...sln...hut...ict since coverage
is expected to be limited. Storms may affect cnu late tonight
although diminishing in intensity by then. Areas of low MVFR or
IFR ceilings are expected to develop overnight across central and
south central Kansas underneath low-level jet axis.

Jmc

&&

Hydrology...
issued at 341 am CDT Wednesday may 6 2015

Widespread rainfall moved across the forecast area
overnight..with some areas receiving over an inch of rainfall.
Additional rounds of showers and thunderstorms are expected again
today and each afternoon and evening through Sat. Additional heavy
rainfall may lead to localized flooding this evening...with the
chances of flooding and river flooding increasing for Thursday through
Sat nights.

Ketcham

&&

Preliminary point temps/pops...
Wichita-kict 76 66 79 62 / 50 40 40 70
Hutchinson 77 64 79 59 / 40 40 40 70
Newton 75 64 78 60 / 50 40 40 70
Eldorado 75 65 78 62 / 60 40 40 70
Winfield-kwld 77 66 78 63 / 50 40 30 70
Russell 77 61 80 55 / 50 40 50 50
Great Bend 77 62 79 56 / 50 30 50 60
Salina 76 65 79 58 / 50 40 50 60
McPherson 76 64 78 59 / 40 40 40 70
Coffeyville 75 66 79 64 / 70 30 40 60
Chanute 75 65 79 63 / 70 30 40 60
Iola 75 64 78 63 / 70 30 30 60
Parsons-kppf 75 66 79 64 / 70 30 40 60

&&

Ict watches/warnings/advisories...
Wind Advisory until 10 PM CDT this evening for ksz032-033-
047>051-067-068-082-083-091-092.

&&

$$

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