Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 221821

1221 PM CST SUN NOV 22 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 222 AM CST Sun Nov 22 2015

A surface ridge axis extended across the area early this morning.
Were it not for some mid/high clouds associated with an upper
disturbance, radiational cooling would have led to even lower
temperatures than what was observed across the CWA at 08z.

The surface high pressure center shifts eastward today, allowing
winds to come around from the southwest or south. Scattered
mid/high clouds are possible until an upper trough axis exits the
region. With mostly clear skies and a dry air mass, temperatures
should rebound nicely today with highs reaching the upper 30s to
mid 40s.


.LONG TERM:  (Tonight through Saturday)
Issued at 222 AM CST Sun Nov 22 2015

The early part of the week looks quiet with a gradual warming
trend due to increasingly southerly sfc winds and rising heights.
A strong vort max is forecast to move onshore by 12z Tue and
develop into a large low pressure system over the western CONUS.
This low pressure system as well as a northern stream shortwave
then begin to affect the central part of the country during the
Thanksgiving holiday period, but model solutions continue to show
low continuity from day to day regarding the evolution of these
features and how exactly they will affect the central CONUS.
Although the gridded forecast has consistently carried 30-70% PoPs
for the Thanksgiving holiday period, the specific mechanisms by
which pcpn occurs have been different during each forecast cycle
depending on the latest model runs at the time. This means that
although the PoPs are still relatively high with this forecast
package, there is still low confidence regarding the details the
forecast for the Thanksgiving holiday period.



.AVIATION:  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1148 AM CST Sun Nov 22 2015

Surface ridge extending from southern portions of IL and IN
southwest into northeastern TX will move southeastward. A surface
trough over the northern Plains will move southeastward through
the taf sites late tonight with the s-swly surface wind veering
around to a wly direction after passage of the trough. Just VFR,
mid-high level cloudiness is forecast through the period.

Specifics for KSTL: Sly surface wind will veer around to a wly
direction Monday morning. VFR, mid-high level cloudiness will move
southeastward through the area this afternoon and tonight.





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