Area Forecast Discussion
Issued by NWS Springfield, MO
FXUS63 KSGF 112021
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
321 PM CDT Fri Jul 11 2014
.SHORT TERM...(This Evening through Sunday) Issued at 317 PM
CDT FRI JUL 11 2014
A moderately strong upper level ridge is extending from the southern
Rockies eastward across the central Plains into the mid Mississippi
Valley. This ridge coupled with a warm and humid southwesterly flow at
the surface will keep the Missouri Ozarks and far southeastern
Kansas in a partly cloudy...hot and humid weather pattern for this
weekend. It is very likely that many locations will see the warmest
temperatures observed yet this year with highs in the middle 90s and
heat indices approaching 100.
.LONG TERM...(Sunday Night through Friday) Issued at CDT FRI JUL
Sunday night will bring the beginning of a change as the upper ridge
flattens out in response to an unseasonably strong upper level closed
low pushing southward from central Canada into the north central
tier of States and the western Great Lakes. This low will push the
first surge of cooler air and the possibility of convective
activity southward into central Missouri on Sunday Evening and then
into southern Missouri later on Sunday Night into early Monday.
Models are in good agreement with the overall pattern with some
differences on timing.
Forecast Computed Surface Cape values run in the 3000J/KG to
4000J/KG range early Sunday Evening (less later at night) and Most
Unstable (MU) cape values run in the 2000J/KG to 3000J/KG range well
into the evening. However...zero to six km bulk shear values are
generally in the 20 to 25kt range with zero to one km Helicity
values generally run under 50M2/S2...limiting organized storms. With
forcing with the front and instablity the severe weather potential will
be with staight line winds associated with a line of storms and
possibly moderately large hail.
This front will continue to push southward through the area later
Sunday Night into Monday as the aforementioned upper vortex swings
southeastward through the Great Lakes into southeastern Canada.
Expect the chance of some stable post frontal precipitation and
possibly some convective activity as a subsequent push of cold air
surges southward and the trailing edge of the upper vortex swings
southward through central Missouri.
Do not expect any Hydrological issues at this point as this front
will be transient. Moisture return is good but not outstanding and
we will have had a few days to begin to dry out surface soils in any
case. Will keep a close watch on this system as it evolves over this
Later Monday Night into Wednesday Night will bring a welcome stretch
of unseasonably cool weather as a very expansive Canadian high
pressure system, more typical of early fall, pushes southward
between the Appalachian Ridge and the High Plains. This cold front
will likely push all the way to the Gulf Coast, which is not common
in mid July.
A gradual warming trend will then set in with afternoon highs
warming to near 80 degrees on Thursday and into the lower 80s on
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 1230 PM CDT FRI JUL 11 2014
For the KSGF, KJLN, and KBBG TAFS...VFR conditions are expected
across the area this afternoon through Saturday morning and beyond.
South to southwesterly winds will occur through the TAF period and
may increase above 12kt at times at the KSGF and KJLN TAF sites.
Scattered mid to high level clouds will occur through today
clearing out tonight into Saturday morning.