Area Forecast Discussion
Issued by NWS Topeka, KS

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KTOP 060528
AFDTOP

AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1128 PM CST Mon Dec 5 2016

...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Tuesday)
Issued at 258 PM CST Mon Dec 5 2016

Tonight through Tuesday ...

The region was wedged between surface high pressure across the
eastern U.S. and surface low pressure across eastern
Colorado/western Kansas.  With this surface pattern in place, a
decent pressure gradient was over the CWA, resulting in southerly
winds gusting upwards of 25-35mph. The early morning cloud cover
across far east central Kansas finally cleared out by early this
afternoon, so the combination of clear skies and breezy southerly
winds allowed afternoon temperatures to rise into the low/mid 50s.

A mid-level trough was noted across the Northern Plains and it will
progress eastward toward the Great Lakes region tonight through
Tuesday.  This advancing trough will help to push the surface low
pressure and associated cold front into north central Kansas this
evening, progressing east of the CWA overnight. Some of the short-
range models are trying to suggest some light precipitation
developing on the back-side of the front. However, the moisture and
lift look to be very limited so have kept a dry forecast going for
tonight.  The pressure gradient looks to increase once again right
behind the front, so could have some gusty northwesterly overnight
into Tuesday morning.  The cloud cover should scatter out from west
to east across the CWA overnight. With limited cloud cover expected
across north central Kansas tonight, have dropped temperatures a bit
with lows ranging from the mid 20s to around 30 degrees from
northwest to southeast across the CWA. Northwesterly winds will
diminish during the afternoon as surface high pressure advances into
the central U.S.  However, these winds will still usher cooler air
into the region with high temperatures cooler than the seasonal
normals with readings in the upper 30s to low 40s.

.LONG TERM...(Tuesday night through Monday)
Issued at 258 PM CST Mon Dec 5 2016

By Tuesday night, surface high pressure will be located over eastern
Kansas and shifting eastward overnight.  Northwest winds will be
ushering in colder air through the night allowing temperatures to
drop into the low 20s.  A mid-level trough swings across the Central
Plains Wednesday bringing chances for precipitation.  Models have
been relatively inconsistent with this system, with QPF amounts in
almost all models less of that than in previous runs.  Soundings
indicate a good amount of dry air near the surface that will need to
be overcome before any snowfall would reach the ground, which would
greatly affect snow amounts.  Another inhibitor to snow will be that
while most models saturate the column by early afternoon, at this
time, the best lift and forcing look to be diminishing.  Cross
sections are still indicating that 600-700mb frontogenesis does
interact with mid level instability near this time so there could be
an enhanced area of snowfall during a short time in the afternoon.
Overall, however, the system looks to be progressive through the
area which would decrease snow totals from previous forecasts.
Because of the bitter cold air, snow to liquid ratios are higher
than average which may allow for still some accumulating snow even
with the lower QPF amounts seen. The best chances look to be in the
morning to mid-afternoon, with perhaps the best chances in north
central and central Kansas.  For now, it looks like between a
dusting and two inches will be possible with the system.  As always,
keep checking for updates.

Cold air advection continues through Thursday with highs Wednesday
in the upper 20s and low 30s, and even colder high temperatures
Thursday in the mid 20s.  Both of these nights, lows will be in the
teens to single digits.  As for wind chill values these nights,
expect them to be around zero or below.  Elongated high pressure
moves across the area Friday shifting winds back from the south in
the morning.  This will not provide much of a warm up, however, with
highs only reaching the upper 20s.  Mostly zonal flow sets up for
the area Saturday with a warm up into the 40s seen.  By Sunday,
models disagree a bit with the GFS bringing a shortwave trough
skimming over the northern plains early morning Sunday, while the
ECMWF stays much more zonal with the overall flow.  Either way, it
looks to be a mostly dry weekend with highs in the 40s both Saturday
and Sunday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1124 PM CST Mon Dec 5 2016

VFR conditions are likely through the TAF period with a small
chance for brief MVFR cigs between 06Z-08Z. Gusty northwest winds
are expected through this afternoon in the 18-25 kt range before
decreasing around 23Z.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Hennecke
LONG TERM...Heller
AVIATION...Barjenbruch


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.