Area forecast discussion
National Weather Service St Louis MO
336 am CDT Friday may 24 2013
Short term...(through late this afternoon)
issued at 315 am CDT Friday may 24 2013
The elongated surface high currently stretching through the Upper-
Middle MS valley will continue to dominate the sensible weather as
it slowly moves eastward. This system will continue to bring below
average temperatures...but unlike yesterday...today there will be
abundant sunshine resulting in warmer temperatures.
Glass
Long term...(tonight through wednesday)
issued at 315 am CDT Friday may 24 2013
The upper air pattern will undergo progression and deamplification
over the weekend into Monday resulting in an extended period of
unsettled weather for parts of the County Warning Area. The plains upper ridge
will progress eastward into the MS valley today and then flatten
beginning tonight as a series of weak short waves top the ridge and
spill northeastward within the weak west-northwest flow aloft on the downstream side.
The biggest problem is the models show a fair amount of spread in
the timing/position of these waves tonight through Monday. The low
level warm air advection regime will get underway tonight in the wake of the
retreating surface high/low level anticyclone...however moisture
return looks to be delayed a bit until Saturday. With this in
mind...I have to believe the European model (ecmwf) is a bit agressive with quantitative precipitation forecast
early on. However by midday Saturday...an intensifying warm air advection regime
and southwesterly low level jet should accelerate the moisture transport and ascent
across the area interacting with the migratory short waves...
resultng in multiple waves of showers and thunderstorms from
Saturday into Monday. The highest threat area looks like the
northern third to half of the County Warning Area. Finally on Tuesday the warm
front lifts north of the area as the upper ridge builds from the
lower MS valley into the eastern U.S. Bringing much warmer
temperatures and lesser precipitation chances until late next
week.
Glass
&&
Aviation...(for the 06z tafs through 06z Friday night)
issued at 1129 PM CDT Thursday may 23 2013
Dry and VFR conditions are expected through the taf period. Surface
high will cause winds to be light and variable tonight before become
east-southeasterly on Friday as the high moves to the east.
Specifics for kstl...dry and VFR conditions are expected the next
30 hours with light winds.
Britt
&&
Lsx watches/warnings/advisories...
MO...none.
Illinois...none.
&&
$$
Weather forecast office lsx
