Area Forecast Discussion
Issued by NWS Springfield, MO
FXUS63 KSGF 062339
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
639 PM CDT Sun Jul 6 2014
.SHORT TERM...(This Evening through Monday)
Issued at 317 PM CDT SUN JUL 6 2014
Mesoscale convective vortex (MCV) from the remnants of this
morning`s convective complex continues to slowly slide southeast
through the Missouri Ozarks this afternoon. After a brief lull in
the activity, scattered showers and storms are redeveloping,
generally east of the highway 65 corridor. This scattered activity
will continue into the evening, gradually shifting to the
southeast with time.
Our recent spat of challenging near term forecasts continues
tonight. Looking at the suite of high resolution short term
models, additional shower/thunderstorm development is expected
across Iowa and northern portions of Missouri/Illinois this
evening. The question with this activity is its eventual movement.
Storm motion vectors do hint at the potential for southward
propagating system. The westward extent of thunderstorm
development to our north as well as timing of when this activity
becomes organized into a linear system are the biggest concerns.
Most models keep the risk to our east, but there are a couple of
models that suggest a weakening, but southward moving system
entering from the north late this evening into the overnight
hours. In addition to this, we will need to continue to monitor
the exiting MCV as persisting isolated to scattered thunderstorm
development is possible with this feature. The bottom line is
there are conditional risks for additional showers and storms
tonight. Have trended toward the consensus with keeping any storms
that fire to our north and northeast out of the area, and
maintaining at least low PoPs in the vicinity of the MCV.
After a mix of sun and clouds to start Monday, we should see a
decent amount of sunshine Monday afternoon. This will result in a
hot and humid day. 12z MOS guidance has come in quite warm. With
850mb temps nearing the mid 20s Celsius, this is possible.
However, given how green we are and some difficult mixing as high
as 850mb, have gone on the low end of the very warm guidance.
Widespread low/mid 90s are expected. Factor in the humidity and
heat index values will be around 100 degrees in most locations.
Widely scattered thunderstorm development remains possible from
areas east of the Highway 65 corridor tomorrow. Strong instability
and weak shear do lend a risk for a few pulse storms capable of
localized downburst winds.
.LONG TERM...(Monday Night through Sunday)
Issued at 317 PM CDT SUN JUL 6 2014
Our active weather pattern and forecast challenges then continue
Monday night into Tuesday as a few thunderstorm complexes develop
along a cold front to our north. 12z suite of model output is a
bit further south with the front tomorrow night. A complex of
thunderstorms is expected to develop across southeastern Nebraska
and northeastern Kansas Monday evening. Forward propagating system
motion vectors are to the east/southeast. As a result there is
the potential northern portions of the forecast area (generally
along/north of Highway 54) could be clipped by this activity. With
a very unstable airmass in place (MUCAPE well in excess of 3000
J/kg) and low level theta-e differences near 30K, the risk for
severe wind with this system will be of concern. Mesoscale tweaks
to the forecast will continue to refine the risk of severe storms
Monday night, so this will be one to keep an eye on.
The cold front will gradually move though the area on Tuesday and
remain the focus for additional shower/thunderstorm development
across the area through Tuesday night. The consensus of the 12z
suite of model output does push this front through the area enough
to warrant mentioning little to no chance of rain on Wednesday. It
should be noted, however that this front will return back to the
north during the Thursday/Friday time frame and once again become
the focus for periodic chances of showers/storms. This boundary
will exit to the northeast in the Friday/Saturday time frame and
we will return to typical July heat/humidity.
.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 619 PM CDT SUN JUL 6 2014
VFR conditions are expected through Monday with low level wind
shear late tonight and early Monday morning being the main impact.
There is an outside shot that a line of thunderstorms could push
south into the region late tonight and early Monday morning. We
have elected to omit that threat from the TAFs given such a low
probability of occurrence. Southerly winds will continue with late
morning and afternoon gusts approaching 20 knots.