964
FXUS63 KLSX 170349
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1049 PM CDT Sun Jun 16 2024

.KEY MESSAGES...

- Temperatures will remain above normal into next weekend with the high
  temperatures mainly in the 90s. Heat index values on Monday
  will range from the mid 90s to around 100 degrees.

- There will be a chance (20 to 40%) of showers and thunderstorms each
  day through Wednesday and again next Sunday.


&&

.SHORT TERM...  (Through Late Monday Night)
Issued at 205 PM CDT Sun Jun 16 2024

Temperatures have warmed into the 90s across the area this afternoon
in south-southwesterly surface flow with dewpoints around 70.  The
combination of the temperature and the humidity are causing heat
indices to run in the mid 90s to around 100 degrees.   Low
temperatures the next two nights will be similar to this morning`s
with readings in the low-mid 70s.  Highs tomorrow may be held back
by a few degrees, particularly over the southern CWA as the HREF is
showing increasing mid-high clouds moving in from the south.
Dewpoints will be similar tomorrow as they are today, so heat index
values will range from the middle 90s to around 100 degrees.

A MCV has moved just north of our area with a well developed cumulus
field to its south across Missouri.  There may be a short window for
an isolated shower or thunderstorm to develop in the uncapped 1500-
2500 J/kg MLCAPE over our area this afternoon over central and
southeast Missouri.  A better chance (20-30%) for scattered showers
and thunderstorms will be on Monday when the NAM/GFS are showing a
weak vort max moving north through the area in the increased moist
flow.

Britt

&&

.LONG TERM...  (Tuesday through Next Sunday)
Issued at 205 PM CDT Sun Jun 16 2024

There continues to be reasonable agreement between the global models
that there will be a steady flow of Gulf moisture into the area on
the back side of the upper high over the East Coast.  This will
bring chances (20-30%) of mainly daytime showers and thunderstorms
over the area on Tuesday and Wednesday.  These chances will decrease
as the model guidance has been consistent in showing an upper high
retrograding back into the area Thursday into Saturday.  Chances
will increase again by late next weekend as an upper trough and
attendant front will move through the Midwest, albeit with different
timing.  The LREF currently brings this system through next Sunday
which will increase the chances (30-40%) for showers and
thunderstorms.

Temperatures on Tuesday and Wednesday will not be as warm with the
expected rain chances and increased cloud cover, but temperatures
later in the week are expected to climb back into the mid-upper 90s
as the upper high moves back over the region.  Dewpoints are
expected to remain in the 60s which are forecast to keep maximum
afternoon heat indices around 100 degrees.  Temperatures will be
slightly lower on Sunday with the front moving into the area.

Britt

&&

.AVIATION...  (For the 06z TAFs through 06z Monday Night)
Issued at 1048 PM CDT Sun Jun 16 2024

Light winds expected overnight under continued mostly clear sky.
Winds pick up a bit out of the south Monday morning with some
afternoon cumulus expected as well. Winds don`t die off as much
Monday night but VFR should continue.

Kimble

&&

.CLIMATE...
Issued at 328 AM CDT Sat Jun 15 2024

Daily High Temperature Records:
                 |=== June 16 ==|=== June 17 ==|
St. Louis (KSTL) | 100 F (1952) |  99 F (1944) |
Columbia  (KCOU) |  99 F (2006) | 100 F (1936) |
Quincy    (KUIN) | 102 F (1936) | 103 F (1918) |


&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&

$$

WFO LSX