Scientific Forecaster Discussion
fxus63 klsx 140133
Area forecast discussion...updated
National Weather Service Saint Louis MO
833 PM CDT sun Oct 13 2019
issued at 833 PM CDT sun Oct 13 2019
Forecast on track and only minor adjustments made for this update.
Clear skies and light winds are forecast as a cold front pushes
deeper into our region: extending from east-central Illinois through the
stl Metro area and into southeastern Kansas. This front is proceeding
dry and cloudless. This frontal boundary is expected to stall
around southern Illinois and just south of I-70 in Missouri through most
of Monday before pushing north as a warm front Monday night.
The cooler airmass tonight and Monday will only deliver a
glancing blow to our region with minimal temperature change from
persistence. Thus, persistence will not be a bad starting point
for mins tonight and maxes on Monday. Only minor changes of a
degree or two are expected, with min temps tonight from the mid
30s to the lower 40s, and Max temps on Monday from the mid 60s to
the lower 70s.
Short term... (through late Monday night)
issued at 305 PM CDT sun Oct 13 2019
Weak cold front currently moving through region will stall out
just south of forecast area by early Monday morning. In the
meantime, clear, dry and cold weather will persist tonight with
lows still at least 10 degrees below normal, in the mid 30s to low
On Monday, stalled frontal boundary will lift slowly northward
through the forecast area with winds veering to the southeast to
south by late afternoon. Not a lot of warm air advection with this boundary, so
highs will only be a few degrees warmer than today's highs, but near
normal in the mid 60s to low 70s.
In the meantime, next upper level system will begin to drop
southeastward through the upper Midwest with associated cold front
moving into northwestern MO by daybreak on Tuesday. Low level
moisture will be on the increase ahead of front on nose of llj, but
will remain rather limited with this system. So just kept low chance
pops for areas along and north of I-70 after 06z Tuesday with mainly
showers and some thunderstorms expected. Lows Monday night will be
in the upper 40s to mid 50s.
Long term... (tuesday through next sunday)
issued at 305 PM CDT sun Oct 13 2019
Upper level trof will continue to deepen and dig southward on
Tuesday, lifting surface low towards Great Lakes region. Associated
cold front will slide through forecast area with increasing chances
of showers and storms, especially Tuesday afternoon through Tuesday
evening, before front exits region. Depending on where the front is
on Tuesday, will have a wide range of temperatures from the low 60s
far north to the mid 70s far southeast.
With northwest winds returning to the region behind cold front and
surface ridge building in, temperatures will dip into the upper 30s
to low 40s for lows Tuesday night.
Colder weather returns on Wednesday with highs only in the 50s,
about 10 to 15 degrees below normal. Another cold night Wednesday
night with lows between 35 and 40 degrees.
By Thursday, with surface ridge moving off to the east and upper
level ridge building in, will see moderating temperatures for the
last part of the work week and into next weekend.
Extended models are indicating another weak system sliding through
region Friday night through Saturday with a chance of showers and an
even more robust system possible for last half of weekend with more
Aviation... (for the 00z tafs through 00z Monday evening)
issued at 550 PM CDT sun Oct 13 2019
VFR conditions and dry weather is expected to prevail at the taf
sites through the valid period. Light west surface winds will become
light southeast by midday Monday.