532 
FXUS63 KLSX 022317
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
617 PM CDT Fri Aug 2 2019

.SHORT TERM...  (Through Late Saturday Afternoon)
Issued at 354 PM CDT Fri Aug 2 2019

The weather pattern has changed very little in the past 24 
hours...and little change is forecast in the next 24 hours.  A 
strong upper level ridge of high pressure is dominating the weather 
over the western 1/2 of the CONUS with a trough over the east.  The 
mid Mississippi Valley is sandwiched in between these two features 
with northwest flow aloft and high pressure at the surface over the 
Great Lakes and Upper Midwest.  Clockwise flow around the high 
continues relatively cool and dry air (for August) over the forecast 
area.  Expect dry weather to continue tonight and tomorrow 
morning...but there could be some isolated diurnal convection 
Saturday afternoon...primarily across southeast Missouri. 
Temperatures tonight and Saturday just a bit warmer than today's 
with lows in the 60s and highs in the mid and upper 80s.

Carney

.LONG TERM...  (Saturday Night through Next Friday)
Issued at 354 PM CDT Fri Aug 2 2019

Medium range guidance shows the high amplitude blocky pattern 
staying in place through next week, with just a slight shift 
eastward toward the Thursday-Friday time frame.  The GFS and ECMWF 
continue to show a shortwave diving through the Mississippi Valley 
in the northwest flow aloft Tuesday into Wednesday.  This will bring 
much of the the area our next substantial chance for rain.  Current 
ensemble guidance PoPs are in the 20-30% range, and this may be a 
tad low, but timing a shortwave 4-5 days out in northwest flow is 
like trying to say exactly when you're going to sneeze about 2 hours 
in advance.  I stuck with the slight chance/low chance PoPs but we 
can raise them later as confidence increases.  The shortwave should 
amplify the eastern trough allowing another weak cold front to pass 
through the mid Mississippi Valley Thursday.  The warmest 
temperatures of the week should be Sunday through Tuesday in the 85 
to 90 degree range, then increasing clouds and potentially some 
precip should drop temps back a few degrees mainly in the mid 80s.

Carney

&&

.AVIATION...  (For the 00z TAFs through 00z Saturday Evening)
Issued at 617 PM CDT Fri Aug 2 2019

VFR conditions, dry weather, and light NE-E surface winds will
prevail at the TAF sites through the valid period. Patchy fog is
possible near rivers, but probabilities look too low and should be
very brief in occurrence if it does happen. Likewise, there are
low probs for thunderstorms but it is south of the MO river and
not at the terminals at this time. 

TES

&&

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

$$

WFO LSX