Area Forecast Discussion
Issued by NWS Springfield, MO
FXUS63 KSGF 120824
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
324 AM CDT Sat Jul 12 2014
.SHORT TERM...(Today and Tonight)
Issued at 321 AM CDT SAT JUL 12 2014
The main story for today will be hot temperatures as upper level
high pressure builds in from the central and southern Plains.
Models indicate 850 mb temperatures in the 19-22 Celsius range
today which will warrant low to mid 90s for highs. The good news
is that drier air will tend to advect in from the southwest and/or
mix down...which will keep heat indices from getting out of
control. We are generally looking at afternoon heat indices in the
middle 90s to around 100 degrees.
Models do indicate an area of low level convergence and enhanced
MLCAPE across the far eastern Ozarks this afternoon. Short range
models also indicate an eroding cap with sufficient mid/upper
level relative humidities for convective development. High
resolution models also back convective potential...thus we have
inserted a slight chance for afternoon showers/thunderstorms
mainly east of Highway 63.
Any convection will quickly die off this evening with the loss of
daytime heating and mid-level dry air advection working in from
the west. Shower and thunderstorm development looks probable up
across the Corn Belt tonight with this activity seeping south into
northern Missouri late. We believe this activity will stay north
of the Missouri Ozarks through sunrise.
.LONG TERM...(Sunday through Friday)
Issued at 321 AM CDT SAT JUL 12 2014
A significant pattern change will commence starting late this
weekend as that upper level high gets shunted back into the
western United States. The upper level flow will become
northwesterly as early as Sunday across the Midwest as strong
upper level low pressure drops down towards the northern Great
Lakes. Models are consistent in dropping a cold front into the
Missouri Ozarks later Sunday with this front then temporarily
stalling somewhere across southern Missouri or northern Arkansas
by Monday. Scattered showers and thunderstorms are expected with
this initial front. Deep layer shear will be a little on the weak
side for a widespread severe threat, but a few strong to severe
storms may be able to develop if instability is sufficient.
Temperatures ahead of the front will still be on the hot side
Sunday...especially across southern Missouri.
A stronger cold front will then plow southeast through the area
later Monday as that upper level low pivots across the western
Great Lakes. This will bring another opportunity for showers and
thunderstorms to the Ozarks. Deep layer shear should be a bit more
respectable by Monday, thus at least a limited threat for strong
to severe storms seems warranted.
Medium range models then indicate that second front overtaking the
first front and then pushing into the I-20 corridor by Tuesday
morning. This should spell an end to precipitation across the
Ozarks by Tuesday morning. Meanwhile, a much cooler and drier air
mass will overspread the area as Canadian high pressure builds in
from the northern Plains. High temperatures in the 70s and lows in
the 50s look quite probable for the middle of next week. Only a
slow warming trend is expected towards the end of next week as
northwesterly flow aloft hangs on.
.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1154 PM CDT FRI JUL 11 2014
VFR conditions are expected for the next 24 hours and beyond as
high pressure aloft settles over the region. Winds will remain
southerly with passing mid/high level clouds. A scattered diurnal
cumulus field is also expected, though mainly east of the TAF