Area Forecast Discussion
Issued by NWS Springfield, MO
FXUS63 KSGF 072105 AAA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
305 PM CST Sat Dec 7 2013
.SHORT TERM...(This Evening through Monday Night)
Issued at 305 PM CST SAT DEC 7 2013
A very cold day across the region. After a start in the lower
single digits above zero, gradual warming has been observed with
afternoon highs generally around 20 degrees (give or take). Skies
started the day sunny, but high clouds have been on the increase
from the southwest since the late morning hours.
A tricky forecast for tonight with continued cold temperatures and
light precipitation expected. A shortwave currently over the lee
of the central Rockies will eject east/northeast into the Midwest
over the next 24 hours. Large scale height falls will spread over
the region, aiding in weak large scale lift. In the lower levels,
the airmass is rather dry, but as isentropic upglide increases
tonight, moisture will increase. The combination of modest
moistening and weak large scale lift will result in scattered snow
showers developing across the area late this evening through the
overnight hours. With temperatures remaining in the teens, snow to
liquid ratios will remain high (15:1 or so), which will result in
a few tenths of an inch of snow which will likely end up blowing
around with east/southeast winds of 5 to 15 mph.
Still concerned about light freezing drizzle potential as we head
into Sunday. Models continue to indicate a lack of cloud ice for
much of the next 24 hours. Tonight, the depth of the cold airmass
in place will ensure precipitation remains of the frozen variety
(snow/snow grains), however as the airmass modifies a bit under a
warm air advection regime Sunday, precipitation type increasingly
favors freezing drizzle. The good news is that we are not looking
at a widespread heavy drizzle, just patchy light drizzle producing
trace/thin glaze. Nevertheless, a little icing can go a long way
so those traveling will want to remain cognizant of patchy icing.
Precipitation will end Sunday evening with yet another upper level
wave moving through the Midwest Monday night. The global models
(GFS/ECMWF) have picked up on this with this morning`s 12z runs
and we have included a mention for light snow during this time.
Like tonight, just looking at a few tenths of an inch of
Temperatures will remain a big challenge over the next few days.
Combination of cloud cover and modest warm air advection will
prevent much of a temperature drop tonight and only modest warming
on Sunday. Overall, highs in the 20s and lows in the teens will be
common the next few days.
.LONG TERM...(Tuesday through Saturday)
Issued at 305 PM CST SAT DEC 7 2013
Northwest flow will continue through the late next week. Another
ripple or shortwave in the flow may traverse across the southern
U.S. by Friday into Saturday. This may bring a slight chance for a
precip over southern Missouri Friday night. Most of the precip will
be to the south and east of our area. There may be a slight chance
for some wintry precip with temperatures below freezing Friday
night but confidence is low at this time.
Temperatures will be very cold next week with a gradual warming trend
by the end of the week. The coldest overnight readings will be
Wednesday and Thursday mornings with low to mid teens expected.
Where there is still snow on the ground...temperatures will
likely by in the single digits. Temperatures may warm above
freezing for afternoon highs by the middle to end of next week.
.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.