Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 190405
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1105 PM CDT Thu Sep 18 2014
Issued at 900 PM CDT THU SEP 18 2014
Band of stratus over the western and southern CWA has unexpectedly
cleared out since sunset. All this does is increase the risk for more
widespread fog to form. Also expect to see stratus to form as it did
last night. Did lower overnight lows by a few degrees due to lack of
evening cloud cover.
Issued at 309 PM CDT THU SEP 18 2014
Tonight - Friday:
The weak stationary front that has been draped to our south is
expected to lift northward late tonight as a warm front. This will
be most noticeable as winds become more southerly with time tomorrow
morning and temperatures start to climb into the middle 80s.
Although cloud cover may be slower to erode resulting in lower than
forecast temperatures. But the change in air mass alone will result
in much warmer temperatures by Friday afternoon, especially over
eastern Kansas and western Missouri.
Regarding precipitation, the chances for showers and storms has
decreased due to a trend to push to the strongest moist isentropic
ascent north of the forecast area. There may be some showers develop
in northwestern Missouri late tonight, but for now the chances look
too low to mention at this time.
Saturday - Sunday:
An upper-level shortwave trough will track across the Northern
Plains and Upper Midwest through the day Saturday. This will push a
cold front through the area from late in the afternoon through the
overnight hours. It still appears there will be a good chance for
thunderstorms in the vicinity of the front as it`s moving through.
But the chances for severe weather still appear to be fairly low for
several reasons. First, surface and low level winds are strongly
veered ahead of the boundary, limiting helicity values. Second, the
upper-level support from the upper trough will be well removed from
the region. This will keep the deep layer shear relatively weak.
While instability may be modest to strong, perhaps as high as 2500 to
3000 J/kg, the weak low-level convergence and low shear will inhibit
a higher probability of severe storms. However, forecast soundings
do show an increasingly favorable environment for down burst winds
across northwestern Missouri and northeastern Kansas. So while
widespread severe weather doesn`t seem likely, the strongest storms
could produce strong and/or damaging winds.
That cold front will have pushed through the area by Sunday morning
with high pressure moving in behind. So we`ll see temperatures
trending cooler with dry conditions prevailing for the day Sunday.
Monday - Thursday:
That high pressure area will lead to continued dry conditions Monday
and Tuesday with highs in the 70s. As the high shifts to the east by
Wednesday, and another shortwave trough approaches from the west,
showers and storms will become possible by Wednesday. That upper-
level shortwave makes very slow eastward progression as the upper
ridge builds over it and as a result we`ll continue to see
precipitation chances through Thursday with temperatures very close
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1105 PM CDT THU SEP 18 2014
Earlier IFR/MVFR stratus deck has all but dissipated across the
northern half of MO and eastern KS this evening. However, this now sets
the stage for better fog formation during the pre-dawn hours of
Friday morning. Adding in local effects at KSTJ and dense fog now
becomes a concern for a few hours either side of sunrise. IFR/MVFR
fog and IFR/LIFR visibilities will linger for most of the morning
before winds veer to the south and warmer air mixes in and scatters
out the cloud during the afternoon.