Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 131118

Area Forecast Discussion
National Weather Service Topeka KS
618 AM CDT Tue Mar 13 2018

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 315 AM CDT Tue Mar 13 2018

Water vapor satellite loop shows a mid level shortwave trough moving
across northeast Kansas this morning at 07Z. Associated high clouds
were moving southeast and were already clearing in north central
Kansas. At the surface high pressure was centered in North Dakota
extending south into the southern plains this morning.

Today, high pressure will continue to build southward into eastern
Kansas resulting in another day with temperatures in the 50s and
northerly winds generally 10 mph or less through the day. Tonight
the center of the high will slide south across eastern Kansas this
evening then into the southern Plains later tonight. Return flow on
the back side of the low develops across eastern Kansas overnight,
Expect temperatures to bottom out in the mid 20s overnight then
begin to rise as winds become southwest late in the night.

.LONG TERM...(Wednesday through Monday)
Issued at 315 AM CDT Tue Mar 13 2018

Mid and long range forecast period will be characterized early on by
fire danger threats and at least some potential for thunderstorms
Thursday night into early Friday morning (although not expected to
be severe).

High pressure will slide to the south and reside over the southern
Gulf Coast states.  Mid to upper flow pattern over the Central
Plains transitions from northwest flow to an amplified ridge pattern
taking control for the mid range forecast period.  With
southwesterly flow returning around the aforementioned high pressure
to the south and working in concert with flow over the Rockies, a
lee trough will strengthen to the west of the forecast area and
gradient flow will increase.  Have bumped up the winds slightly for
Wednesday more in line with MOS solutions.  Deeper mixing over north
central into northeastern areas will allow for high temps to
probably approach or break the 70 degree mark.  See Fire Weather
section for specific Fire Weather details.

As the next Pacific trough digs into the Western CONUS mid to late
week, a lead shortwave will eject out of the Rockies by late
Thursday into Friday time frame. Right now there could be enough
instability to suggest that thunderstorms (elevated in nature)
could develop in the evening on Thursday. So, have kept mention of
thunder in the forecast. Surface low and baroclinic zones slide
mainly south of the forecast area, so that leaves the cool side in
play. Of course at this point, ensemble data begins to diverge in
solutions regarding the exact outcomes with higher standard
deviations suggesting data is less reliable. But, cool enough
temps could allow for a rain/snow mix to enter extreme
northeastern portions of the area as the upper wave broadens and
pushes frontal features to the southeast of the area into Saturday
morning. Should see a rebound in temps again on the weekend with
60s once again after the brief Friday cool down. Less confidence
in the next weather system to round the western trough by late
weekend, but most precipitation should remain liquid to start
again with a short window of a rain/snow mix as temps cool on the
wrap around side of the system with frontogenetical response
zones. Ultimately, this pattern (if it holds) leads to another
set up with northwesterly flow regime aloft with somewhat cooler
temps in the beginning of next week.


.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 618 AM CDT Tue Mar 13 2018

VFR conditions are expected through the forecast period. Winds
light north under 10 kts becoming south after 09Z Wednesday.


Issued at 315 AM CDT Tue Mar 13 2018

Dew point temperatures will drop into the teens to around 10 degrees
this afternoon, along with temperatures in the 50s will see the
minimum RH this afternoon range from 18 to 27 percent. Winds will be
in the 5 to 11 mph range from the north. Very high fire danger is
expected south of a Minneapolis to Abilene to Emporia line this
afternoon. High fire danger is expected elsewhere.

There is still some uncertainty in how much actual moisture is
allowed to return Wednesday. But, most plume data from the SREF
and GEFS plumes suggest moisture return will increase into the
afternoon hours Wednesday at least partially countering the mixing
effects into the afternoon. Thus, only expecting Very High Fire
danger at this time. However, there is a hint in the 00Z ECMWF run
that moisture may have some trouble returning this far north by
Wednesday afternoon. If that is the case, then one could expect
more in the way of fire danger concerns to develop into the
afternoon hours. Will have to refine this portion of the forecast
over the next 24-36 hrs, but is important to watch at this point.
Thursday could also see high fire danger over portions of north
central and east central Kansas, but overall threats look to be
minimized compared to Wednesday.




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