Area Forecast Discussion
Issued by NWS St. Louis, MO
FXUS63 KLSX 111831
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
1231 PM CST THU FEB 11 2016
.SHORT TERM: (Through Late Tonight)
Issued at 1230 PM CST Thu Feb 11 2016
A northwest flow shortwave now dropping southeastward into western
SD will move quickly through our area tonight. Light snow will
spread southeastward into northeast MO early this evening, then
through the St Louis metro area around midnight. Still looking like
a quick shot of dry, powdery snow with most places picking up to 1
inch of accumulation, but there may be a narrow band of 1-2 inches
extending from near IRK southeast through the St Louis metro area.
Latest NAM and HRRR model runs have the band a little further west
than previous model runs. Most of the accumulating snow should
shift southeast of our forecast area by 12Z Friday. Low
temperatures will be similar to the previous night, and around 5
degrees below normal.
.LONG TERM: (Tonight through Wednesday)
Issued at 225 AM CST Thu Feb 11 2016
...Light Snow Expected This Evening...
Next shortwave will be diving southeast in a similar manner to
yesterday`s and provide the area with another round of light snow.
It appears that this snow will be a little later in its arrival with
the main window of accumulation occurring from 6 pm to Midnight.
Once again have about an inch, give or take a few tenths, of snow
accumulation forecast from northeast Missouri to southwest Illinois.
This includes the Greater St. Louis Metropolitan Area.
Snow should taper off after midnight from northwest to southeast,
with a few flurries possible Friday morning. Thereafter, a very
cold air mass builds into the region Friday night and Saturday.
Low temperatures below zero are certainly possible Saturday
morning across the northern CWA.
The arctic high pressure quickly moves east though and by
Saturday night we could already have a band of warm advection snow
racing across the CWA. Better chance of accumulating snow appears
to occur on Sunday, but to be honest, medium range model guidance
has been flip flopping all over the place with this system the
past five days and still hasn`t landed on a common solution. Best
to leave PoPs at a chance for the period in question and give it a
few more runs before trying to nail down specifics.
Warm up looks on tap next week as the pattern changes with highs in
the 50s and maybe even 60s!
.AVIATION: (For the 12z TAFs through 12z Friday Morning)
Issued at 544 AM CST Thu Feb 11 2016
VFR flight conditions expected today with band of cigs from 4-5kt
feet stretching from northern MO into southern Il slowly sinking
south this morning. In the wake of these clouds, mid-high clouds
will move into the area this afternoon in advance of the next
fast-moving system. Another band of light snow will spread into
the region early this evening and exit the area after 09z. KUIN
and the St. Louis region terminals will likely have a period of
MVFR- IFR flight conditions. Impacts at KCOU are a bit more
uncertain and MVFR conditions appear to be possible. Snow amounts
will be similar to yesterdays event, averaging near 1 inch.
Specifics for KSTL:
VFR flight conditions are expected today with band of cigs from
4-5kt during the morning. In the wake of these clouds, mid-high
clouds will move into the area this afternoon in advance of the
next fast-moving system. Light snow will spread into the terminal
mid-late evening and exit the area after 09z, bringing a period
of MVFR-IFR flight conditions. Snow amounts will be similar to
yesterdays event, averaging near 1 inch.