Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 280903

Area Forecast Discussion
National Weather Service Saint Louis MO
403 AM CDT THU JUL 28 2016

.SHORT TERM...  (Through Late This Afternoon)
Issued at 301 AM CDT Thu Jul 28 2016

Convection across northeast MO and west central IL has dissipated
early this morning. Most of the convection was southeast of the
forecast area, associated with a slow moving, compact upper level
low/vorticity maximum.  Additional scattered convection will
develop late this morning and this afternoon as the atmosphere
destabilizes ahead of a weak northwest flow shortwave. It appears
that the best coverage of showers/storms will occur across
southeast MO and southwest IL. High temperatures today will be
similar to yesterdays highs, maybe a degree or two cooler.


.LONG TERM...  (Tonight through Wednesday)
Issued at 301 AM CDT Thu Jul 28 2016

Convection tonight may be mainly during the evening hours, with
slightly cooler low temperatures due to potentially less cloud
cover. The threat for convection will continue on Friday and
Friday night as shortwaves carve out an upper level trough over
the central US. Temperatures on Friday should be slightly cooler
due to the increased cloud cover and potentially better coverage
of precipitation. There may be less chance of convection on
Saturday and Saturday night as the upper level trough axis shifts
east of the region and a surface ridge noses into our area from
the Great Lakes region. Precipitation chances may increase again
for Sunday and Sunday night due to low-mid level warm air
advection and as a warm front shifts northeastward through our
area. Convection should become more suppressed for the first half
of the next work week as an upper level ridge tries to build
northeastward into our area. This along with southerly surface
winds will lead to warmer temperatures rising above normal values.



.AVIATION...  (For the 06z TAFs through 06z Thursday Night)
Issued at 1132 PM CDT Wed Jul 27 2016

Isolated showers and thunderstorms may affect the terminals
tonight and into the day on Thursday. Low coverage and fairly
nebulous forcing makes pinning down if and when storms may affect
the terminals difficult to say the least...particuarly looking out
more than a few hours. Did add a VCTS group in for early in the
period. Continued mention of fog at KCOU and KUIN but with higher
cloud cover than previously not have in for the
metro TAFs. Weak frontal wave will move through the area on
Thursday with a continued chance of showers/storms. Behind
this...should be slightly lesser chances of rain along with winds
becoming northwesterly.


Added a VCTS group due to isolated storms firing near the
terminal. Possibility exists pretty much through most of the TAF
period of convection affecting terminal. Heavier thundershowers
if they hit the terminal could bring brief periods of IFR visbys.
Outside of this is expected to remain VFR along
with light/variable winds. Northwest winds are likely by late
Thursday behind a weak sfc low.





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