Area Forecast Discussion
Issued by NWS Springfield, MO
FXUS63 KSGF 071747 AAA
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1147 AM CST Sat Dec 7 2013
...Update to Aviation Section...
.SHORT TERM...(Today and Tonight)
An incredible airmass was positioned across a large majority of
the North American continent. Temperatures over the Ozarks had
fallen into the single digits this morning. With a deep snow pack
south of Interstate 44, some locations may fall below zero prior to
Observations up across the northern Plains were measuring
temperatures between -20 and -30. This is just amazingly cold,
especially for the first week of December.
More air from the Arctic Circle will spill into Canada and the
lower 48 over the next few days. Water Vapor over the North Pole
was depicting a strong cross polar trajectory, directed into
central and western Canada. So it may be a few days before we warm
up and melt the existing southern Missouri snow pack.
Before we discuss weather for the upcoming work week, lets go over
some minor snow and freezing drizzle chances for tonight into
A speed max was making landfall over the California coast this
morning, which will quickly shift into the Ozarks Region late
tonight into Sunday. This feature will provide sufficient lift for
some light snow and freezing drizzle.
Not a whole lot of moisture will be available to this system,
however, there should be enough for light precip.
By Sunday morning, all of the models suggest that a dry slot will
spread across the southern half of Missouri. This will eliminate
cloud ice for snow. However, areas of freezing drizzle can not be
ruled out. We don`t think this freezing drizzle will be too much
of a concern. Although we can not rule out some patchy ice on
roadways. Any snow that falls tonight will add little to no
.LONG TERM...(Monday through Friday)
Another shot of unusually cold air will surge into southern Missouri
on Monday, likely causing overnight lows early Tuesday morning to
fall below zero again in some spots with deep snow pack.
Northwest flow will persist through Thursday allowing a near
continuous pipeline of Arctic into the Ozarks. It`s going to stay
cold all week, with highs in the 20s, and lows in the single
digits to lower teens all week.
There could be a chance for some precipitation by next weekend, as
models have been signaling the approach of another wave. Given the
fast dynamic flow, we`ll likely see some major changes in model
data this far out.
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1146 AM CST SAT DEC 7 2013
Low confidence, tricky forecast for the next 24 hours for area
aerodromes. High level moisture is on the increase as a
broken/thin cirrus deck is invading from the southwest. Mid and
high level moisture will continue to increase with time this
afternoon and evening as a weak disturbance moves toward the
Midwest. This will result in chances for light precipitation
(flurries/freezing drizzle), mainly overnight tonight and Sunday
morning at JLN/SGF/BBG. Have continued to use PROB30 groups to
highlight the lower confidence in the chances for this
precipitation. This weak system will fight dry air in place across
the region, and the main brunt of this particular system will be
focusing on areas to our north. Ceilings will lower to MVFR late
this evening, with IFR possible at BBG Sunday morning. IFR
ceilings look to hold off at JLN/SGF until after the TAF cycle.