Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 290648

148 AM CDT Mon Jun 29 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 148 AM CDT Mon Jun 29 2015

Weak surface low just northeast of STL will continue moving
eastward.  The thunderstorms have shifted east or south of our
forecast area, with only a few lingering showers between STL and
SLO.  Some fog has developed across west central IL and northeast MO
between UIN and HAE where the temperature has fallen into the 60s
and the wind has become light.  Will likely get at least isolated to
widely scattered showers and a few storms across our area this
afternoon as the atmosphere destabilizes with weak northwest flow
shortwaves moving southeastward through our area.  It appears that
the best coverage will be across northeast MO and west central and
southwest IL where there will be cooler mid level temperatures
associated with the upper level trough and hence better lapse
rates.  High temperatures today should also be a little cooler
across this area as well.


.LONG TERM:  (Monday through Next Sunday)
Issued at 347 PM CDT Sun Jun 28 2015

(Monday through Tuesday)

NW flow aloft will continue early this weekend. Much like
yesterday...some isolated to scattered showers/thunderstorms are
expected to develop primarily in the afternoon/early evening hours
each day with the higher threat along and east of the Mississippi
River which will reside under cooler temps aloft. Slightly below normal
to near normal temperatures expected each day with highs in the

(Tuesday Night through Sunday)

More active weather is still anticipated for midweek beginning late
Tuesday night into early Thursday. A more vigorous shortwave trough
will transverse the lower Missouri River Valley and interact with
strong low-level warm/moist advection. Thunderstorms are likely
Wednesday and Wednesday night with the axis of highest probabilities
through central and southeastern Missouri.

Northwest flow will continue through next weekend with more showers
and thunderstorms possible each period. Another shortwave looks to
affect the bi-state area on Friday/Friday night. Still have high
chance PoPs for now as there is some temporal differences between
the GFS/EC/Canadian.

Pattern for the 4th of July weekend looks fairly similar to
Monday/Tuesday of this week with slightly below normal temperatures
for highs and diurnal instability helping develop convection each



.AVIATION:  (For the 06z TAFs through 06z Monday Night)
Issued at 1204 AM CDT Mon Jun 29 2015

Specifics for KUIN, KCOU: Fog is possible overnight, especially at
KUIN. Some IFR to MVFR stratus was also noted on satellite imagery
rotating around the back side of a surface low, but the western
edge looks ragged and it`s not clear how long flight restrictions
would last at KUIN once the stratus reaches the terminal. The
stratus should remain well north of KCOU. Winds will become
northwesterly around the back side of a departing surface low,
then back again late in the period.

Specifics for KSTL, KSUS, KCPS: A few thunderstorms have developed
near the St. Louis metro area terminals at TAF issuance, but these
should only affect the terminals for the next 1-2 hours. Fog is
possible overnight, especially at KSUS. Initially southwesterly winds
will become westerly to northwesterly once a surface low moves
into Illinois later this morning. Diurnal cu is expected during
the day. Winds will back again late in the TAF period.





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