Scientific Forecaster Discussion
fxus63 ksgf 201954
Area forecast discussion
National Weather Service Springfield MO
254 PM CDT sun Oct 20 2019
Short term...(this afternoon through tonight)
issued at 220 PM CDT sun Oct 20 2019
An upper level low is currently located across the Central Plains
with a trough extending south into the Southern Plains. Surface
low pressure is located across western South Dakota with south to
southeasterly winds across our region. Gulf moisture is starting
to spread to the north into southern Arkansas and Oklahoma. The
moisture will continue to advect north tonight ahead of the
The upper level low will move east across the plains this evening
and will send a cold front through the area late this evening into
the overnight hours. Instability is currently lacking, but as the
Gulf moisture continues to spread north, instability will start
to increase from south to north. Instability will likely continue
to increase across southern Missouri into the overnight hours.
There will be a cap in place through much of this evening, but as
height falls occur with the approaching upper level trough the
cap will begin to weaken. Vertical wind shear will also increase
as the upper level system moves across the area.
Storms are expected to develop along the front across Kansas and
Oklahoma by mid evening and quickly develop into a line. The line
will then race east late this evening into the overnight hours.
Timing: the line may start to affect extreme southeastern Kansas
and far western Missouri by as early as 9 PM and should push east
out of the Waring area in south central Missouri by 6 am Monday
The deep layer shear, the increasing instability, and strong
forcing with this system will support a severe storm risk. With
the storm Mode expected to be in the form of a line, the main
severe risk will be damaging straight line winds up to 70 mph. A
few of the strongest updrafts may also be capable of hail up to
the size of quarters. Strong low level shear will also support the
risk for spin up tornadoes within the line, mainly with surges in
the line to the east or east-northeast. The better severe
potential will be across southern Missouri where the better
instability will be in place generally along and south of I-44.
North of the Interstate instability will be more limited, but with
the strong forcing along the front there will still be an isolated
strong to severe risk.
Some lingering showers may briefly occur behind the front for a
few hours, but drier air will quickly move in limiting the overall
Post frontal rain chances.
Long term...(monday night through sunday)
issued at 220 PM CDT sun Oct 20 2019
Gusty west winds will develop on Monday with gusts to around 35
mph expected at times. A cooler air mass is expected for Monday
and Tuesday with highs in the low to mid 60s and lows in the upper
30s to middle 40s.
An upper level trough will dive to the southeast into the plains
on Wednesday. A head of this system gusty southerly winds will
occur and allow highs to warm to around the 70 degree mark.
The trough and associated cold front will move south through the
area Wednesday night into Thursday night. Showers will develop
across along and behind the front. A colder air mass will spread
into the area on Thursday and Friday with highs in the 50s and
lows in the 30s.
Medium range models differ on the upper level pattern late in the
week into next weekend leaving this period a lower confidence
Aviation...(for the 18z tafs through 18z Monday afternoon)
issued at 1203 PM CDT sun Oct 20 2019
Surface low pressure is located across the plains today. This
will allow south to southeasterly winds to occur with gusty winds
occurring at times. The low and associated cold front will move
east towards the area this evening. Winds may pick up some this
evening ahead of the front. The front will then sweep through the
region later this evening into the overnight hours. A line of
storms will develop along and front and race through the area.
There will be the potential for severe storms especially across
southern Missouri with this activity. Fog also may be possible
ahead of the front.
Behind the front there may be a brief period of lower ceilings but
drier air will work in and could clear by the morning hours. Gusty
west to northwesterly winds will occur behind the front on Monday.