Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO

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087
FXUS63 KEAX 291146
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
646 AM CDT Thu Jun 29 2017

.Discussion...
Issued at 415 CDT THU JUN 29 2017

Last night`s activity is still making its way through the
northeastern part of the forecast area. These training storms
dropped an excessive amount of water across northern MO. Areas from
Burlington Junction, MO to Bethany, MO have received anywhere from 9-
11 inches of rain with surrounding areas in the 6-9 inch range. As a
result, flooding is an issue, so an Areal Flood warning is in
effect across this area until about 3:30 PM this afternoon. The
activity in the northeastern part of the forecast area should
continue to weaken and move southeast, exiting the area within the
next few hours. To our west, another cluster of storms has taken
shape. This is in response to another upper level shortwave moving
through in conjunction with the low level jet. This activity has
already begin moving into northeastern KS and northwestern MO and
is expected to move east through about dawn and then dissipate.
Another MCS is projected to move through northern KS and northern
MO later this morning as another shortwave, currently over
western KS, moves through. This will be in conjunction with a
developing surface low in southeastern KS and its associated warm
front. The storm system should move along the warm front, making
it near the KS/MO border around 9 AM. It should continue moving
east, north of the MO River, through late morning. Don`t
anticipate much in the way of severe weather, but can`t rule out
the potential for isolated hail and damaging winds. The bigger
concern will be the additional rainfall in an area that is already
experiencing flash and river flooding.

This afternoon, it looks like we may have similar set up to
yesterday afternoon/evening. It will, however, be contingent on
this morning`s systems. A boundary with warm front characteristics
seems to be the main focus for severe storm development this
afternoon and is likely to set up somewhere across northeastern KS
and northern MO, likely a little further south than yesterday`s
activity. At the same time another shortwave is projected to move
overhead. All of the ingredients for severe weather will be
available again today. SB CAPE will range from 2000-4000 J/kg, 0-6
km shear around 40 kts, with dewpoints in the low 70s again.
General model consensus depicts storms starting to develop this
afternoon (roughly 1-3 pm time frame) in northwest MO/northeast KS
and then moving southeast, potentially reaching the northern side
of the KC metro in the 4-6 PM time frame. All hazards, hail,
damaging winds, and a few tornadoes are possible, especially in
the SPC Enhanced Risk area. Further into the evening, as storms
move southeast, they will eventually form a line as the main upper
trough and surface cold front moves in, and low level jet ramps
up again. Widespread flash flooding and river flooding may be the
biggest concern, not only in northern MO, but also the KC Metro
and areas closer to the MO River because these storms will likely
not be moving very fast and PWAT values will be approaching 2
inches. Therefore, with what has already fallen and what is
projected to fall, a Flash Flood Watch has been issued until 7 AM
Friday morning, for most of our counties north of the MO River and
the KC Metro.

The storms and cold front should exit the area by Friday night and
a surface high will work its way south over the area. This will
leave Saturday cooler and dry. Friday`s cold front, which will
stall near the MO/AR border, will retreat north as a warm front
Sunday, returning on and off storm chances starting Sunday evening
through Wednesday.

&&

.Aviation...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 645 AM CDT THU JUN 29 2017

Main concern for this forecast period is the on and off storm
chances across the forecast area. The storms this morning should
stick around through late morning/early afternoon, but northwest
MO may not get too much of a break in between the morning
convection and the afternoon convection. Otherwise, most skies
should clear some, allowing for daytime heating and priming the
atmosphere for more development this afternoon. Scattered storms
will likely develop along a boundary in northeast KS/northwest MO
and start off as discrete, before moving southeast in more of a
line. The line of storms looks to cover the entire length of the
forecast area and will take its time moving through. The line
won`t completely exit the forecast area until Friday morning. It
is important to note though that IF this morning`s activity takes
longer than expected to clear out, the afternoon convection
development could be delayed. Heavy rain is expected with these
storms, so visibilities may drop some when storms move through.
Also, it won`t be quite as windy (synoptically) today as it was
yesterday, but most areas will exceed the 12 kt wind threshold
during the afternoon. Finally, a cold front will be moving through
near the end of the period, so winds will start to veer to the
northwest, and ceilings will likely drop to at least MVFR behind
the front for a few hours.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...Flash Flood Watch through Friday morning for KSZ025-102>105.

MO...Flash Flood Watch through Friday morning for MOZ001>006-011>017-
     020>025-028>033-037.

&&

$$

Discussion...Grana
Aviation...Grana



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