Area Forecast Discussion
Issued by NWS Springfield, MO

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FXUS63 KSGF 241126 AAA
AFDSGF

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SPRINGFIELD MO
626 AM CDT Fri Apr 24 2015

...Updated Aviation Section...

.UPDATE...
Issued at 626 AM CDT FRI APR 24 2015

Narrow band of convection has finally fired across portions of
southeastern Kansas, northeastern Oklahoma and northwestern
Arkansas. Isentropic upglide in the 300-310K layer matches up
nicely with current placement and timing of convection. The lift
isn`t all that strong, but certainly good enough given 400-800
J/kg of elevated CAPE. This activity is moving into a slightly
more hostile environment, with dry air at the midlevels and
lessening CAPE. That said, this activity is bringing its own
moisture to the party for the time being and should be sustained
well into southwestern Missouri this morning. Low level easterly
flow over central Missouri and the eastern Ozarks will be a bit
more formidable to overcome, as a result showers/storms should
become more diffuse and weaken in this area during the mid/late
morning hours.

Given marginal CAPE and instability, severe weather is not
expected this morning. That said, the occasional perky updraft
will yield small hail from time to time.

Will continue to massage PoPs this morning for timing.

&&

.SHORT TERM...(Today and Tonight)
Issued at 312 AM CDT FRI APR 24 2015

Breezy southeast winds ahead of an approaching warm front are
helping to keep temperatures rather mild this morning, with readings
only falling into the low to mid 50s as of 3 AM.  While the surface
warm front remains well to our southeast, the 925 and 850 fronts are
starting to lift northeast over the region this morning, and short
term guidance continues to suggest that the associated isentropic
ascent will eventually result in showers and thunderstorms
developing across the region closer to daybreak.  While a smattering
of hail will be possible with any of these elevated thunderstorms,
the overall severe weather risk this morning appears quite low.

Convection that develops during the pre-dawn hours will push east
during the morning today, with additional activity possibly moving
in from Arkansas later this morning into this afternoon.  Confidence
in the coverage of this southern activity is low, however, and it`s
quite possible that the afternoon hours end up being dry for many
locations.

By late afternoon and early evening, convection should then fire
along the dryline across central Kansas and Oklahoma, as well as in
the vicinity of the triple point, which will likely be located
somewhere in the vicinity of Topeka, KS.  The overall trend in
guidance over the last 12-24 hours has been to keep the dry line
further west through the afternoon and evening hours, suggesting
that it may take some time this evening/tonight before convection
arrives in the SGF CWA.  This overall trend has been noted by SPC
with their Day 1 Outlook, which now only includes extreme western
Missouri and southeastern Kansas in the Slight Risk area.

In all likelihood, convection will arrive late this evening into the
overnight hours in the form of several clusters/areas of activity.
Shear isn`t an issue with this system, so we will need to carefully
watch for any supercell structures, as well as any line segments
that bow out to the east for a conditional wind/tornado threat.
Steep mid level lapse rates will lend themselves to a threat for
hail, though overall lackluster instability will probably limit this
threat.

.LONG TERM...(Saturday through Thursday)
Issued at 312 AM CDT FRI APR 24 2015

The surface low will then push east across central Missouri during
the morning hours Saturday, with the associated cold front sweeping
across the forecast area.  We will likely see convection strengthen
and/or redevelop along the front as it moves across the CWA, with
any associated severe threat highly dependent on frontal
speed/timing.  Slower timing will give areas ahead of the front a
better opportunity to destabilize, while quicker fropa may keep the
bulk of the convection to our east.

High pressure will nose into the area on Sunday, and with a bit of
shortwave ridging aloft, it doesn`t look like a bad end to the
weekend, with dry conditions and temperatures generally in the 60s.

Rain chances will then return to at least far southwestern Missouri
Monday and Tuesday, as a shortwave diving south across the Great
Basin closes off and slowly tracks east across the southern Plains.
Right now it looks like the forecast area will be on the northern
edge of the rainfall, though any shift north or south with the
system will have a significant impact on rain chances, so stay
tuned.

Beyond Tuesday, the region looks to once again be situated on the
western edge of the Great Lakes/eastern CONUS trough, resulting in
generally dry conditions and seasonable temperatures.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 626 AM CDT FRI APR 24 2015

Primary forecast concern this morning will be incoming scattered
showers and storms. See the update section above for the
particulars. Expectations are for a brief period of showers/storms
this morning, with quieter conditions from late this morning into
much of this afternoon. Any visibility or ceiling restrictions this
morning will be brief and likely only down into the MVFR level.
South winds will be rather gusty today and remain gusty well into
tonight. Next opportunity for storms will come in the mid/late
evening time frame. Low level wind shear will once again be a
concern. Heading into the overnight hours tonight, there is some
question regarding the potential for stratus. Signals are mixed at
this point, and as a result we will slow play the mention of
stratus for the time being and update as confidence increases.

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&

$$

UPDATE...Gagan
SHORT TERM...Boxell
LONG TERM...Boxell
AVIATION...Gagan




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