Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus63 ktop 231130 
afdtop

Area forecast discussion
National Weather Service Topeka Kansas
630 am CDT Mon Oct 23 2017

..update to aviation forecast discussion...

Short term...(today and tonight)
issued at 315 am CDT Mon Oct 23 2017

Water vapor satellite loop this morning at 0730z showed the upper
trough moving across the northern plains. At the surface, a cold
front extended from eastern North Dakota southwest into southern
Wyoming while a pre-frontal trough was present across western Kansas
into northeast Nebraska. Drier air was noted to the west and
northwest of the cwa this morning. A breezy and windy day is
expected today in the wake of the cold front moving through this
morning. A strong pressure gradient will develop behind the front
with sustained winds of 20 to 30 mph with gusts around 42 mph in
north central Kansas. Gusts to around 35 mph are expected elsewhere
across northeast and east central Kansas. The winds will decrease
into the 10 to 20 mph range this evening. Highs today will be in the
60s with lows tonight in the lower 40s.

Long term...(tuesday through sunday)
issued at 315 am CDT Mon Oct 23 2017

Progressively colder this week as a series of cold fronts push into
the area. Looks like any significant precip chances will hold off
though. Cold air advection remains in place into Tuesday with a highly amplified
western ridge and eastern trough pattern in place. Have bumped up
winds a bit for the Tuesday time frame as trending down winds may
occur a bit slower considering the amplified pattern in place.
Probably not looking at advisory level criteria, but strong enough
winds in place to still keep elevated fire danger through Tuesday
afternoon. Frost in areas could become a concern Tuesday night and
early Wednesday morning. No headlines planned for now but something
to keep an eye out for.

Warming occurs into Wednesday as it will be the nicest day all week
temperature wise. Highs top out slightly above normal in the lower
70s to perhaps mid 70s over north central Kansas. Significant and more
highly amplified trough digs into the northern plains Thursday
pushing another cold front into the area during the later part of
the day. Didn't make any increases to the winds with this forecast
as it is somewhat unclear about strength of the caa, but do have
temps for Friday night suggesting a widespread hard freeze over the
area (with temps in the mid to upper 20s) and then perhaps again
Saturday night with longer nights and potential for good radiative
cooling to take place within a colder Canadian airmass overspreading
the area as winds do calm. Unclear about exact sky coverage for
this time with northwest flow aloft and how much spill over from the
ridge may take place. But, at this time, it does appear any
significant moisture that could help to produce precip with this
frontal system is probably too low to be much of a factor outside of
some cloud cover. Currently all deterministic solutions remain in
agreement for no significant chances of precip. This is backed up
by ensemble data suggesting a similar outcome. Therefore, keeping a
dry forecast for the end of the week. Return flow develops into
Monday with near normal temps into the early part of next week.

&&

Aviation...(for the 12z tafs through 12z Tuesday morning)
issued at 630 am CDT Mon Oct 23 2017

Main concern for the terminals this forecast will be winds.
Initially a cold front will move through the terminals through 16z
with low level wind shear around 1 kft agl expected. Winds will increase to near
18kts with gusts to 30 kts before decreasing toward 03z to around
10 kts. Low level wind shear is expected to develop again after 03z again around
1 kft agl. VFR conditions are expected through the period.

&&

Fire weather...
issued at 315 am CDT Mon Oct 23 2017

Cold front moving through the area this morning will shift winds to
the northwest and increase to the 20 to 30 mph range with gusts
around 40 mph across north central Kansas and around 35 mph
elsewhere. In addition drier air will mix down from aloft and yield
relative humidity values in the lower to mid 20 percent range
west of a Marysville to Manhattan to Council Grove line. Non
critical fuels and minimum relative humidity remaining above 20 percent today so
will not go with a red flag warning for today. However very high
fire danger is expected across north central and parts of
northeast Kansas today.

&&

Top watches/warnings/advisories...
none.
&&

$$

National Weather Service Glossary of Abbreviations