-- Discussion containing changed information from previous version are highlighted. --
058
FXUS63 KSGF 111029
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
529 AM CDT Tue Jun 11 2024

.KEY MESSAGES...

-  Residual flooding continues after some areas received as much
   as 5 to 8 inches of rain over the weekend.

 - Near-normal temperatures through Tuesday, with highs between upper
   70s to low 80s.

 - Warmer temperatures return later in the week into the weekend,
   with temps potentially reaching 90 on Thursday with the heat
   expected to persist through the weekend, with temps in the
   90s and heat index values between 90 and 100.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 510 AM CDT Tue Jun 11 2024

Current Conditions and Synoptic Overview:

Northeasterly winds are light in the wake of a weak back door cold
front that moved through Missouri Monday afternoon. A surface high
is building throughout the Midwest, with the center of the high
currently over northeast Missouri and sliding eastward. A low-level
high over southeast Kansas complements the surface high in Missouri
underneath a building positively-tilted ridge through the Great
Lakes aloft. A low pressure perturbation is developing over the
Texas panhandle in the mid-levels (best seen on 500mb analysis),
and moisture is being siphoned from the Gulf through the Texas
panhandle and up the Rockies, feeding into another low over
Saskatchewan and Ontario. This is starting to become apparent on
visible and water vapor satellite, with subtle isentropic
ascent sustaining cloud development on the leading edge of the
developing shortwave.


Tuesday and Tuesday night:

The subtle cold front is best observed in the wind shifts and dew
point decreases behind it, but Tuesday will be similarly temperate
to Monday. With the decreased dew points (thus lower RHs) and a bit
of cloud cover, widespread dense fog development is not anticipated,
but patches of fog are possible, especially around river valleys.
Highs will reach the mid- to low 80s, with sun peeking through some
high clouds that build along the warm conveyor belt of the cyclone
moving southeast through Texas. Tuesday night will see lows in the
upper 50s and low 60s, with those daytime clouds clearing out by
sunrise Wednesday. Temperatures will increase through the week
starting Wednesday, likely breaking into the 90s by the weekend.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 510 AM CDT Tue Jun 11 2024

Synoptic pattern and precip chances:

A zonal jet aloft along the US/Canada border will keep things quiet
and effectively "block" any perturbations aloft pushing this far
south from Canada, keeping us mostly dry through the end of the work
week. The only day this week worth watching for precipitation
chances is Thursday, when a shortwave manages to break through the
zonal flow into the Great Lakes. Models trends nudge the shortwave
further south over the last day or so, with indications of a zonal
corridor of instability collocated with a cold front along the
shortwave.

Multiple models indicate a corridor of northwesterly-oriented
instability across the the Iowa/Missouri border along the front as
it surges south. The 06Z NAM is partially in range indicates
instability on the magnitude of 5000+J/kg of CAPE in the center of
this corridor (centered right over the KC metro) Thursday evening,
with 30-40kts of bulk shear. Ensembles agree with the NAM on the
general pattern evolution pretty well - shortwave ejects somewhere
in between Minnesota and Missouri, and severe weather threat
results.

That said, our involvement with this event(both relating to severe
weather and precipitation in general) hinges on the southward extent
of the main shortwave ejection. The instability will be high enough
to support thunder at least and potentially severe weather over our
area, with ample moisture to boot from a robust southerly low-level
jet. The cold front seems unlikely to reach our area at the time we
have the most favorable convective parameters, so if models sustain
an ejection with a southward extent that remains in northern
Missouri, we will either get near nothing or just some showers as
the cold front moves through. However, if models continue to trend
further south with the shortwave ejection and it reaches central or
even southern Missouri, that brings not one but two forcing
mechanisms to support convection (the cold front and synoptic-scale
lift)and complete the severe weather conditions trifecta. The trends
in the upper-level pattern will need to be monitored, because it`ll
only take a slight push southward to bring severe weather into our
backyard. Left PoPs low for Thursday and Friday for right now since
current guidance doesn`t indicate much convective precipitation in
our area.


Temperatures:

As previously mentioned, a cold front will push through the area on
Friday, but a low-level high over the Gulf will swell north beneath
a beefy upper-level ridge. High pressure will build over the
northern Plains behind the shortwave, but the Gulf high will be much
stronger and overpower the northern Plains` influence over the
Ozarks as it sits over Arkansas. Rather than the northerly winds and
cooler temperatures that usually follow a cold front, this southern
high will consistently force warmer air into our area and elevate
temperatures even more into the weekend.

How warm, you ask? Well, the NBM has a very small spread (indicating
high confidence) in high temperatures across the region, keeping all
of southwest Missouri and far southeast Kansas in the low to mid-90s
from Saturday through Monday. The average first date of temperatures
reaching 90 degrees is June 12, so this is almost spot on with
respect to climatology. Confidence is highest in temperatures over
90 degrees on Sunday, with 40-60% chances of 90+ in the pockets of
locally higher terrain and 80-90% chances of 90+ elsewhere.

With this first surge of real heat comes the push for awareness of
potential impacts of heat. One tool that we`ll use and encourage
everyone else to use more and more through the summer is WPC`s
experimental Heat Risk tool, which ranks the impacts of heat on a
scale of 0-4 based on how unusual the heat is for that time of year
and CDC data on heat-related impacts. Thursday through Sunday shows
a moderate (2 out of 4) risk creeping from central Missouri
southward, meaning most heat-sensitive individuals will experience
impacts. By Sunday all of southwest Missouri and southeast Kansas
will experience moderate impacts, with central Missouri seeing major
(3 out of 4) impacts to anyone without ample cooling or hydration,
health systems, and heat-sensitive industries and infrastructure.

If you`re more concerned about values rather than risk, the chances
for heat indices in excess of 95 are above 50% all weekend. There is
a 58% chance that Saturday and Monday will exceed a heat index of 95
degrees, and a 65% chance that Sunday will exceed a heat index of
95. Remember to stay hydrated and cool as you enjoy the warm weekend
or work outdoors. The next disturbance will probably occur sometime
Sunday, but details remain limited beyond that.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
-- Changed Discussion --
Issued at 528 AM CDT Tue Jun 11 2024

Winds will turn southerly in the afternoon, but remain light
(below 10 knots). High clouds will increase through the
afternoon before dissipating overnight into Wednesday morning.
High confidence in VFR conditions through the TAF period.
-- End Changed Discussion --

&&

.CLIMATE...
Issued at 501 AM CDT Mon Jun 10 2024


Record High Temperatures:

June 16:
KSGF: 97/1952
KJLN: 95/2016


Record High Minimum Temperatures:

June 15:
KSGF: 74/2022

June 16:
KSGF: 75/2022

June 17:
KSGF: 76/2016

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
KS...None.
MO...None.

&&

$$

SHORT TERM...Camden
LONG TERM...Camden
AVIATION...Camden
CLIMATE...Camden