Area Forecast Discussion
Issued by NWS Springfield, MO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

000
FXUS63 KSGF 281740
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
1140 AM CST Tue Feb 28 2017

...18z Aviation Update...

.SHORT TERM...(Today and Tonight)
Issued at 230 AM CST Tue Feb 28 2017

It continues to look like a messy next 24 hours or so across the
region, with multiple chances for thunderstorms, some of which are
likely to be strong or severe. Expect to see regular updates to
the near term forecast through the day today as mesoscale details
become increasingly clear.

Starting out early this morning, widely scattered elevated
convection has formed across south central Missouri in response to
a strong low level jet punching in from the southwest. Coverage
should remain rather spotty through sunrise, before dwindling
later this morning as the focused ascent moves northeast of the
region. For the most part, this activity should remain below
severe limits, though a couple of stronger storms could produce
hail between a half and one inch.

As mentioned above, a lull in convection is expected later this
morning into at least the early afternoon hours. During this time,
very gusty southerly winds and occasional breaks in the cloud
cover will help boot temperatures well into the 70s, with a few
spots perhaps approaching 80 degrees. See the climate section
below for info on record high temps. Winds should remain just
below advisory criteria, though will not be far off.

The deep southerly to southwesterly flow will advect in higher
dewpoint air, with Tds expected to approach the low 60s by later
this morning into the afternoon, especially south of I-44. Aloft,
an elevated mixed layer, which was clearly evident on the 00Z
sounding last night from Norman, OK, will build into the area as
well. This EML should act as a cap across the area for the morning
and at least part of the afternoon hours, though right now there
is a lot of uncertainty about how long thunderstorm activity will
hold off this afternoon and early evening in the warm sector. This
will be a key detail that will need to be refined later this
morning based on short term guidance, surface ob trends, and a
likely special upper air sounding sometime during the early
afternoon hours.

At this juncture, there appear to be three potential initiation
points for severe thunderstorms from this afternoon into tonight:

1. There may be a window for strong/severe convection across the
eastern half of the CWA by mid-afternoon as convective
temperatures are reached and convection is perhaps aided by a bit
of lift from the low level jet. This is by far the most uncertain
scenario, but if it should come to fruition, any convection that
develops would likely become supercellular very quickly, with some
potential for significant severe given more than sufficient CAPE
and shear.

2. By early to mid evening, supercells may develop across
eastern/northeastern Oklahoma and/or northwest Arkansas and move
northeast into the CWA. This scenario has a bit of support from
various short term, high resolution model guidance, though is far
from certain. Given that supercells would be the preferred mode,
large hail, winds, and tornadoes would all be possible with this
activity.

3. The highest confidence opportunity is with the cold front
itself, which should sweep across the region from late evening
into the overnight hours. A line of strong/severe convection seems
probable along this front, though a few breaks in the line are
certainly possible. High winds would be the most likely hazard
with this line, though a few QLCS-type tornadoes are possible with
any east-northeast surges given 0-3 KM shear vectors pushing 40+
knots.

Any combination of these scenarios is possible later today, so it
will be important to check back for updates as mesoscale details
are further refined.

That front should be east of the area by daybreak on Wednesday,
ending the thunderstorm threat.

Finally, elevated to locally significant fire weather conditions
are expected for portions of the area today given the strong
surface winds. Please see the fire weather discussion below for
more information on this concern, as well as fire weather
conditions for the rest of the week.

.LONG TERM...(Wednesday through Monday)
Issued at 230 AM CST Tue Feb 28 2017

The rest of the workweek looks fairly quiet, with dry and mild
northwest flow aloft. With dewpoints in the 20s and temperatures
remaining above average, this will result in elevated fire weather
conditions at times through Saturday. Temperatures through Friday
will be in the mid to upper 50s, above 5 degrees above average.

By the weekend, southerly flow will return at the surface as
ridging develops aloft. This will help boost temperatures back up
into the 60s on Saturday and to around 70 by Sunday. Rain chances
look to return to the area by the beginning of next workweek.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1140 AM CST Tue Feb 28 2017

Somewhat complicated forecast, especially with convection
impacting the TAF sites. Expect mainly VFR flight conditions
through the period with MVFR/IFR in any convective elements.
Southerly winds will gust to near 40 knots at KJLN and 30 to 35
knots at KSGF and slightly lower at KBBG through the afternoon
hours. These will diminish this evening, but with strong low level
jet will see LLWS developing by late evening.

As for convection there is a conditional chance for scattered
storms late this afternoon through the evening hours. Have
covered this with VCTS for now and these will likely be a short
term update trend if and when they develop. Otherwise, a better
chance for storms exist ahead of an approaching cold front late
tonight, especially from around 05Z through 10Z. Will keep Prob30s
going, but will likely need to raise to tempo`s with later
forecasts as more specific timing can be determined.


&&

.FIRE WEATHER...
Issued at 230 AM CST Tue Feb 28 2017

Elevated to locally significant fire weather conditions are
expected today across the Osage Plains, as south winds gust to
around 40 MPH. Limited to elevated conditions are expected further
to the east today, where surface moisture will be higher.

Widespread elevated fire weather conditions are then expected
Wednesday through Saturday. Winds on Wednesday and Thursday will
be from the northwest to west-northwest, before becoming
southeasterly to southerly Friday and Saturday. Afternoon RH is
expected to fall to around 25 percent Wednesday and Thursday,
but wind speeds should remain below red flag criteria.

&&

.CLIMATE...
Issued at 230 AM CST Tue Feb 28 2017

Here are today`s record high temperatures:

SGF...77/2006
JLN...78/2006
UNO...77/1955
VIH...75/2006

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
MO...Wind Advisory until 5 PM CST this afternoon for MOZ066-077-088-
     093-101.

     Red Flag Warning until 6 PM CST this evening for MOZ066.

KS...Wind Advisory until 5 PM CST this afternoon for KSZ073-097-101.

     Red Flag Warning until 6 PM CST this evening for KSZ073-097.

&&

$$

SHORT TERM...Boxell
LONG TERM...Boxell
AVIATION...Raberding
FIRE WEATHER...Boxell
CLIMATE...Boxell



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.