Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 021734
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1234 PM CDT Sat May 2 2015
Issued at 907 AM CDT SAT MAY 2 2015
Raised PoPs over most of the CWA to account for ongoing convection
over the northwest third of the forecast area as well as the
approaching activity now over central KS. The northwest MO activity
is associated with moderately strong isentropic ascent on the 300K
and 305K surfaces as well as support from a shortwave trough moving
east across NE. The KS activity is associated with a weak mid-level
vorticity trough and vorticity max. The 12z NAM picks up on the KS
vorticity max and even strengthens it as it moves into northwest MO.
Not quite buying the strengthening process nor the placement but do
expect the feature to persist as it moves east into the CWA.
The HRRR model trend maintains a steady flow of scattered showers
being generated over southeast NE and moving into northwest MO while
the initial activity weakens as it moves into northeast MO. The HRRR
also holds onto the KS activity as it crosses into west central MO by
18z as well as continuing east into the central portion of the
forecast area. What this all means is a need to increase PoPs and
clouds across the CWA and a need to lower temperatures across the
northern half of the CWA where PoPs are highest. Will monitor
cloud/precipitation trends as there is a good chance we`ll need to
lower temperatures further over the west central CWA.
One last item is we`ve stripped away thunder from the forecast as the
instability is puny and not expected to increase. There may be a
stray cg strike in the far northwest near the southern edge of the
stronger isentropic ascent and where lightning is occurring over
Issued at 351 AM CDT SAT MAY 2 2015
Today/Tonight: Several subtle upper disturbances will move through
the region, aiding in the development of scattered convection. The
most probable locations to receive light measurable precipitation
will be along and north of the Interstate 70 corridor. The most
active period should coincide with the approach of these impulses,
with this morning into the early afternoon one round, and another
possible overnight. Modest instability will gradually increase from
west to east during the day, and therefore a few scattered
thunderstorms will be possible this morning into the evening.
Temperatures should warm well into the 70s during the afternoon,
even with broken cloud cover. Overnight temperatures will remain in
the lower 60s to upper 50s in part to increased moisture advection
and cloud cover.
Sunday/Monday: A large upper trough skirting the US/Canada border
will send a cold front approaching the area by Sunday night. This
will be the primary focus for the most spatially concentrated area
for convection during this period. The front is expected to settle
near northwest Missouri on Monday before stalling, and with strong
daytime heating, convection is expected to develop over NW MO. Deep
layer shear is expected to be rather weak, unless a subtle upper
disturbance not yet resolvable can enhance speeds, although
moderate instability around MUCAPE 1500 J/kg will develop ahead of
the boundary. While severe weather is not likely, a few stronger
storms may evolve during the afternoon and evening hours.
Tuesday through Saturday: An active pattern looks to evolve across
much of the region, albeit severe weather probabilities still appear
low/uncertain at this time. A negatively-tilted shortwave trough is
projected to lift into the Plains Tuesday into Wednesday. In its
wake, continued southwesterly flow will establish over the region,
with several embedded upper disturbances expected to move through.
While specific details are not resolvable in this period for this
particular pattern, it is reasonable to believe several episodes of
convection will be possible for portions of the area. Questions
regarding an initial meridional wind field and the degree of
destabilization limits confidence/signal for severe weather. As for
temperatures, above normal readings are expected to continue, with
highs in the 70s and 80s.
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1228 PM CDT SAT MAY 2 2015
VFR conditions this afternoon despite thick mid level ceilings around
10k ft and showers.
An area of showers with pockets of MVFR ceilings with the heavier
showers will slowly shift east across northern MO this afternoon.
Activity should gradually weaken. Band of spotty showers over eastern
KS will also track east and affect the west central MO terminals
through mid afternoon, then clouds thin out.
Increasingly southwesterly low level jet will advance east overnight.
Expect these winds to reach the ground by mid morning resulting in