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000
FXUS63 KLSX 192009
AFDLSX

Area Forecast Discussion
National Weather Service St Louis MO
Issued by National Weather Service Kansas City/Pleasant Hill MO
309 PM CDT Fri Apr 19 2024

.KEY MESSAGES...

- Seasonably cool weather is forecast through the weekend, with
  frost potential both Saturday and Sunday nights.

- Dry weather expected until next Tuesday.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 309 PM CDT Fri Apr 19 2024

Dry but seasonably cool conditions are expected through the
short term. This will come as a surface ridge of high pressure
extending from the northern Plains into the Ohio River Valley
will dominate the sensible weather through the short term. Lows
tonight, with light winds and mostly clear skies, will fall
into the mid 30s to lower 40s. Continuing modest cold air
advection tomorrow will keep temperatures on the cool side with
highs in the mid 50s to mid 60s. Tomorrow night, the area
becomes more under the influence of the surface ridge allowing
for another night of good radiational cooling. This will drop
temperatures into the 30s CWA-wide and as such, a frost advisory
will likely be needed for much of the forecast area.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Issued at 309 PM CDT Fri Apr 19 2024

The surface ridge of high pressure will continue to be the main
feature of interest as we move into the beginning extended
period. The surface ridge will continue to dominate the area on
Sunday providing weak mixing. As such, temperatures are only
expected to rise into the upper 50s to mid 60s. The ridge axis
moves directly over the forecast area Sunday night providing
another night of good radiational cooling as temperatures again
fall into the 30s. A frost advisory will again likely be needed
Sunday night. The surface ridge finally will slide south of the
area by Monday afternoon allowing WAA to get underway. This will
allow temperatures to return to near seasonal normals with highs
in the mid 60s to near 70. Monday night into Tuesday, a upper
level trough will dig from the northern Plains into the Upper
Midwest forcing a cold front into the area. This will bring the
next chance for showers and thunderstorms. Severe weather is
not anticipated as MUCAPE values of 400J/kg will be a limiting
factor. Will the cold frontal passage not expected until later
in the day Tuesday, highs should still reach the upper 60s to
lower 70s. Conditions will dry out for Wednesday as a surface
ridge builds into the area under northwest flow aloft keeping
highs in the mid 60s to near 70. Thursday, a upper level trough
will dig from the Great Basin into the eastern Rockies lead
shortwave ejecting out ahead of this system will move into the
area bringing the next chance for thunderstorms. Storm activity
will hold highs in the mid 60s to near 70.


&&

.AVIATION /18Z TAFS THROUGH 00Z SUNDAY/...
Issued at 1221 PM CDT Fri Apr 19 2024

VFR conds will prevail thru the TAF pd as sct clouds around
10kft are expected thru 23Z-01Z before few to sct high are
expected for the remainder of the TAF cycle. Winds will be out
of the 7-12kts (with gusts to 20kts at KSTL, KUIN, KCPS) thru
23Z-01Z when winds will diminish to 3-8kts and back to the NNW.
Tomorrow btn 14Z-16Z winds will against increase out of the NW
to 10-15kts with gusts to 20kts.

&&

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

&&

$$

SHORT TERM...WFO EAX
LONG TERM...WFO EAX
AVIATION...WFO EAX