Area Forecast Discussion
Issued by NWS Topeka, KS

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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
FXUS63 KTOP 211124

Area Forecast Discussion
National Weather Service Topeka KS
624 AM CDT Tue Mar 21 2017

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 256 AM CDT Tue Mar 21 2017

Today and Tonight, An upper level trough across the upper Midwest
will dig southeast across the Great Lakes States and amplify. The
resulting CAA across the northern and central plains will cause a
surface ridge of high pressure to build southward towards eastern KS.
The low-level CAA by northeast surface winds will bring a drier and
cooler airmass southwest across the CWA. Highs Today will only
reach the mid 50s along the NE border with highs around 60 for areas
along and south of I-70. Skies will be partly to mostly cloudy with
mid and high level clouds.

Tonight, the surface ridge will slowly shift east into MO. Most
models continue with a dry east-northeast low-level flow across the
CWA. There may be some weak isentropic lift at the 295-300K level
for some light rain-showers and if the precip can make it through
the dry low-levels then wet-bulb cooling may cause a bit of snow to
mix in at the low-levels. The only models show QPF across the
western counties is the GFS. The WRF solutions keep any measurable
precip west of the CWA and as it moves east into a drier low-level
air mass it dissipates towards 12Z. Overnight lows will be around 33
degrees across north central and northeast KS with mid  to upper 30s
across east central KS.

.LONG TERM...(Wednesday through Monday)
Issued at 256 AM CDT Tue Mar 21 2017

Finally start to see a more active pattern weather wise as we go
later into the month, as a series of systems make their way across
the central part of the country. Wednesday marks the start of the
transition as the frontal boundary keeps highs only near 50 but
then retreats northeastward as the next upper longwave trof
approaches the southwestern states. Could see a few showers as it
does so, but chances are low and precipitation light. Could see a
rumble of thunder as the boundary lifts north of the area and
leaves most locations dry for the afternoon with warm southerly
winds and highs in the 70s.

ALthough still some variance in their details, both the EC and
the GFS bring the upper low and stacked surface low into the high
plains by 12z Friday, bringing a chance for rain across our area.
The system remains rather dynamic, but struggles to tap into
respectable instability. Could still bring some low topped strong
storms across eastern Kansas on Friday afternoon and evening as
the dryline and possibly the triple point move through, depending
on where the track of the surface low ends up. As colder air wraps
around behind the departing system, transition from thunder to
rain and highs go from 70s Friday to the 50s to low 60s on

Sunday brings a break between systems, but not for long as the
next wave rolls quickly out of the Central Rockies possibly
bringing a chance for rain as early as Sunday evening to our
western counties. Again will be a question of how much instability
comes northward before it sweeps east, but worth mentioning this
one could bring a chance for a strong storm as well, with better
directional shear progged than its predecessor. Highs Sunday and
Monday forecast in the 60s.

Speed of the next fast moving shortwave trof varies by nearly a
day between extended models, but would bring the next round of
rain chances mid week next week.


.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 621 AM CDT Tue Mar 21 2017

VFR conditions are expected throughout the period. Northeasterly
winds will increase near 14Z with sustained at 10-15 knots and
gusts 20-25 knots. Winds are expected to decrease this evening
back to 10-15 knots.


Issued at 256 AM CDT Tue Mar 21 2017

There will be a very high rangeland fire danger across the northern
and central counties of the CWA this afternoon, with the greatest
coverage along the I-70 corridor through the mid and late afternoon
hours. Minimum RHs will drop into the 25 to 35 percent range and
northeast surface winds will increase to 15 to 20 MPH with some
gusts up near 30 MPH. Any planned burns may become uncontrollable
wild fires.




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