Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus63 ksgf 171727 

Area forecast discussion
National Weather Service Springfield MO
1227 PM CDT Sat Aug 17 2019

Short term...(today and tonight)
issued at 300 am CDT Sat Aug 17 2019

A large area of intense showers and thunderstorms stretched from
northern Kansas into northwest Missouri, mainly just north of our
County Warning Area however it was beginning to move into Vernon, St Clair and
Benton counties. These storms had formed in an area of high
instability (mu CAPES of 3000-4000j/kg) and on the nose of a
strong low level jet. Overall instability is much lower and more
convective inhibition exists across our area, therefore thinking
that storms will gradually weaken as they enter our area however
locations north of US Highway 54 could experience some rainfall
and a few stronger storms early this morning.

A few items to hone in on today will be cloud cover, high
temps/heat index values, and any isolated precip potential during
the day.

As is typical with large areas of convection, there will likely be
left over outflow boundaries and/or small mesoscale disturbances
from current convection to the north, this could move south into
the area during the day today and provide an isolated chance for
a shower/storm. Feel like the chance is pretty small at this time
given that the area will be strongly capped with 700mb temps
around 12c. Only a few cams show an isolated shower/storm across
the area later today. Significant amount of high cloudiness may
initially exist across the area as well from current storms and
may hinder temps somewhat, however do feel that if precip is
absent, as is forecast, then high temps will indeed reach the
lower 90s across a large part of the area. Surface dewpoints
across the western half of the area look to climb through the
lower to potentially middle 70s which could produce heat index
values near 100-104, much like what occurred in northeast Oklahoma
yesterday. No heat advisory planned for today.

It does look like additional showers and storms may again develop
across Kansas and northwest Missouri overnight into early Sunday
morning as the low level jet develops. This may creep into the
far northwest part of our cwa, however thinking most locations
will remain dry at this point with very muggy conditions.

Long term...(sunday through friday)
issued at 300 am CDT Sat Aug 17 2019

Forecast is more complicated for Sunday as it appears that we
could be dealing with some left over convection approach the area
from the north during the day or night. Models differ on timing
and placement. Instability values would be rather high and a
severe threat would develop if storms moved in during the
afternoon or evening. Some models keep the area dry until
overnight when a low level jet develops therefore lots of
uncertainty in this timeframe. This also would have implications
on forecast high temps and heat index values. Currently have highs
in the lower 90s and may heat index values between 100-106 from
east to west respectively across the area Sunday, therefore if
precip holds off then a heat advisory would likely be needed
across the western portions of the area. Storm Prediction Center does have a slight
risk for severe storms for the area Sunday into Sunday night.

Monday and Tuesday are looking overall drier and hot/humid as the
center of the mid level ridge and stronger capping moves closer
to the area. High temps will likely be in the Lower/Middle 90s
with heat index values in the 100-110f range across the area and
heat advisories look likely.

The mid level ridge does look to slide west a bit during mid week
Onward which will place our area in line to receive disturbances
from the northwest and increase our precip chances along with
slightly cooler temps to finish the week.


Aviation...(for the 18z tafs through 18z Sunday afternoon)
issued at 1223 PM CDT Sat Aug 17 2019

Showers will dissipate early this afternoon around the Joplin
Aerodrome. VFR conditions are expected to persist this afternoon
and this evening across all of southern Missouri. Winds will
increase out of the southeast into the 10-15 knot range.

A complex of thunderstorms may then push into parts of southern
Missouri late tonight and Sunday morning. Confidence is still
fairly low regarding timing and location of storms. Thus, we have
elected to insert a prob30 group at Joplin and Springfield to
cover this potential.

Surface winds should remaining prevailing from the southeast
through Sunday morning, however winds may be gusty and erratic
around storms.


Sgf watches/warnings/advisories...


National Weather Service Glossary of Abbreviations