Area Forecast Discussion
Issued by NWS Springfield, MO
FXUS63 KSGF 300502
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1202 AM CDT SUN AUG 30 2015
Issued at 0702 PM CDT SAT AUG 29 2015
We are finally starting to see convection develop early this
evening across far southwestern Missouri. This trend is expected
to continue into this evening as a low level jet stream
strengthens and noses into northern Arkansas and south-central
Missouri. Isentropic upglide along the nose of this jet will lift
elevated air parcels which should be relatively uncapped. We will
have to watch for locally heavy rainfall potential as focused lift
could remain over the same general area for a 3-6 hour time frame.
We have also added the mention of patchy fog late tonight and
early Sunday morning across western Missouri and extreme
southeastern Kansas. Light winds and the presence of a low level
baroclinic zone should result in at least patchy fog development.
If clouds can stay away from this region, there would be the
potential for dense fog.
.SHORT TERM...(This Evening through Tonight)
Issued at 253 PM CDT SAT AUG 29 2015
All is quiet on radar as of mid afternoon but high resolution
forecast models like the HRRR, RUC, and the ARW continue to
suggest that widely scattered convection will develop along a
southwest to northeast line across southwestern Missouri to the
Lake of the Ozarks area by late afternoon and early evening.
Mid level shear axis will continue to very slowly move across the
area. Modest instability of around 1500 J/KG has develop across
southwestern Missouri where sunshine occurred early this
afternoon. Shear is rather weak though. Sounding analyst shows
some low level drier air which could suggest some gusty winds may
be possible with the strongest convection that develops.
Will mention a limited threat for gusty winds and small hail with
the strongest convection late this afternoon and evening. No
severe weather is anticipated. Lightning will be the main hazard
along with brief heavy downpours. A few scattered showers may
linger across portions of the Missouri Ozarks through the night
.LONG TERM...(Sunday through Saturday)
Issued at 253 PM CDT SAT AUG 29 2015
No major changes to the forecast offered by the 12z suite of model
output. Will continue to monitor the weak shear axis aloft that
will linger over/near the area into the first half of next week.
QPF signature is erratic and random from the models, and the main
upper level features at play support an isolated to widely
scattered chance of diurnal showers/storms. Most locations will
remain dry, but it will be something to keep in mind.
Otherwise, a broad ridge of high pressure will spread across the
Midwest and temperatures will warm to above average. Certainly
nothing out of the ordinary for late August/early September. Highs
each day will be a few degrees either side of 90, with lows in the
mid 60s to low 70s.
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1150 PM CDT SAT AUG 29 2015
A weak upper level disturbance will keep the threat for scattered
showers and thunderstorms going across southern Missouri into
Sunday. The best chance for storms through dawn will be around
Branson where a TEMPO group was inserted.
Meanwhile, confidence in MVFR fog has increased for the Joplin
area. We have therefore gone with prevailing MVFR (versus the
TEMPO group from earlier). There is still potential for IFR fog
late tonight if enough clearing can take place.
More thunderstorms will then be possible in the heating of the
day Sunday afternoon. MVFR and brief IFR conditions can be
expected around any storms.
Surface winds will remain light through Sunday evening out of the
southeast to south.