Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 291137
Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
637 AM CDT FRI APR 29 2016
Issued at 348 AM CDT FRI APR 29 2016
Large trough of low pressure continues to spin across the Great Basin
and Desert Southwest this morning...with well-established southwest
flow prevailing downstream across the Plains and into the Lower
Missouri Vly. Along the surface...latest analysis places a nearly
stationary frontal boundary across the Red Rvr Vly with eastward
extension into the ARKLATEX region. Lead impulse embedded in
southwest flow aloft is combining with the 850-hPa front to result in
light rain shwrs across western portions of the fcst area...with MCI
now reporting light rain per the 08z observation. In reality...this
area of light rain will be short-lived as lead impulse shifts away
from the area.
For the remainder of today...expect increasing cloud cover as upper
trough shifts east and sfc front to our south begins to lift north
with time. As such...precip chances will again increase from south to
the north during the late afternoon hrs with activity becoming more
widespread heading into the evening and overnight hrs as main trough
ejects east and takes on a negative tilt across the central High
Plains. In terms on thunder potential...quick look at several
forecast soundings reveals little in the way of instability
today...thus have capped mention of thunder in the isolated category.
The potential looks a little better overnight as elevated
instability of a couple hundred joules develops...however no severe
weather is anticipated. With increasing cloud cover...expect daytime
highs to top out in the mid to upper 60s with values only falling
into the mid to upper 50s tonight.
On Saturday...main upper low expected to slowly meander across the
central High Plains with main surface low becoming occluded with
time. As the sfc low occludes...main frontal boundary will lift north
to the I-70 corridor by afternoon. Decent heating by afternoon south
of the boundary combined with steep lapse rates will lead to moderate
instability by afternoon...with severe concerns once again returning
to portions of the area. Main caveat going forward which could limit
the degree of storm coverage will be lack of strong mid/upper-level
forcing as main 500-hPa low remains well west and southern stream jet
remains across the the Arkansas/western Tennessee region.
Additionally...much of our area will be in subsidence through a good
portion of the day as main shortwave responsible for tonight`s
activity lifts north into the upper Miss Vly with time. In any
event...cannot rule out some isolated storms capable of large hail if
frontal convergence can initiate activity...however better threat for
severe will reside south and east of the fcst area in closer
proximity to main upper jet.
Main wave to finally start moving east trough the area on Sunday as
500 hPa circulation gets picked up be a trough moving through the
upper Midwest/western Great Lakes. This should gradually allow rain
chances to come to an end by the end of the weekend with dry weather
and warming temps then expected through much of next week. No real
weather makers of interest seen in the latest model runs through the
extended as western U.S. ridging slowly builds east with time.
.Aviation...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 637 AM CDT FRI APR 29 2016
CIGS beginning to lower into the MVFR category this morning as low-
level moisture advances south in northeast flow near the surface.
Expect MVFR cigs to be around for much of the morning before
temporarily improving near the 18z time frame. After this...initial
batch of light shwr activity will begin working into the area this
afternoon with periodic MVFR cigs possible with this activity.
Shwr activity to become more widespread during the evening and
overnight hrs with thunder chances also increasing as instability
develops aloft. After 06z...IFR conditions will be possible at all
fcst locations as cigs potentially fall below alternate mins from
time to time.