Area Forecast Discussion
Issued by NWS Topeka, KS
FXUS63 KTOP 250108
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
708 PM CST TUE NOV 24 2015
.SHORT TERM...(This Evening through Wednesday)
Issued at 703 PM CST TUE NOV 24 2015
Weak upper wave was entering western Kansas this afternoon with only
some high cloud ahead of it in a rather dry troposphere. Changes
were coming however with stratus working its way NNE into central
Oklahoma with gusty south winds from central Texas to eastern
Nebraska and lower 40s dewpoints into southern Kansas, while surface
pressures were rising in central Montana.
Lower level moisture will be the main player tonight into Wednesday
afternoon as south winds persist. Stratus deck under dry air aloft
slowly builds down with increasing moisture convergence/depth
supporting increasing chances for very light precip in drizzle
developing in the overnight hours into Wednesday. Could also have
some fog late tonight into Wednesday morning in far western areas
where weaker winds exist and clouds could be thinner for near-
surface saturation and convergence combination. For temps, have
generally lowered the range of lows and highs in gusty winds and
cloud tonight and little insolation Wednesday.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 703 PM CST TUE NOV 24 2015
Wednesday Night Through Friday...A challenging forecast is in
store for the Thanksgiving holiday, which will likely result in
travel concerns across the region.
By Wednesday night, the strong closed mid-level low will be
advancing toward the western Rockies, which will help to push an
area of low pressure and associated cold front eastward across the
area. Ahead of this cold front, expect increased lift and deeper
saturation across eastern Kansas, which will support rain showers
developing Wednesday night with these showers becoming more
widespread overnight into Thursday. Periods of moderate to heavy
rain will be possible, especially across eastern Kansas through
Thanksgiving day, with upwards of 1 to 2 inches of rain possible.
Models show the cold front nosing into north central Kansas by
Wednesday night and slowing tracking eastward, likely exiting the
CWA by early afternoon Thursday. There are still some minor timing
issues with the frontal passage, which will affect how quickly the
cold air surges into the region. Winds will quickly shift to the
north behind the front and will remain gusty at upwards of 25-30mph.
These breezy northerly winds will support decent cold air advection
into the region through the day on Thursday, with temperatures
across north central Kansas likely falling from early Thursday
morning through all of Thanksgiving Day. Locations in east central
Kansas may warm up to around 60 degrees mid-day before falling.
These falling temperatures combined with a pronounced warm-nose will
result in rain gradually transitioning to a wintry mix of freezing
rain, sleet, and possibly even some light snow (light snow only
possible across extreme north central Kansas). Precip accumulations
are challenging with this system, especially possible ice
accumulations. While there is still uncertainty in these
accumulations, there is the potential for some locations across
portions of north central Kansas to receive upwards of around 0.25"
of ice accumulation. Any light ice accumulation will have travel
impacts for the holiday, so have issued a Winter Storm Watch for the
northwestern two-thirds of the CWA from 18Z Thu through 12Z Fri.
Temperatures Thursday night will likely plunge into the mid 20s to
low 30s with continued breezy northerly winds supporting persistent
cold-air advection across the area through Friday. With Friday highs
only reaching into the 30s and with models still holding light
precipitation across the area, will likely still see areas of rain,
freezing rain, or sleet continuing through Friday, so that will
result in continued travel hazards.
Friday Night Through Tuesday...Beginning of the period starts off
with a cut- off low over NW CONUS with upper-level SW flow over
northeast Kansas. This low is forecast to move towards the
northern Plains through the weekend, greatly affecting
precipitation type and chances over the weekend and early next
week. On Friday night, temperatures will fall into the mid to
upper 20s leaving chances for mixed precipitation for most of the
CWA. As for the rest of the period, with thermal profiles most of
the weekend showing low level temps near freezing, have kept a mix
until Monday. Dry conditions return late Monday night.
.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 519 PM CST TUE NOV 24 2015
MVFR ceilings are expected to develop later this evening at all
terminals. Light drizzle is also expected to develop near dawn
Wednesday morning. IFR ceilings will be possible throughout the
day on Wednesday, especially with heavier pockets of drizzle.
However, will defer IFR conditions to later outlooks due to low
confidence in intensity of drizzle.
Winter Storm Watch from Thursday afternoon through late Thursday
night for KSZ008>012-020>024-026-034>039.