Area Forecast Discussion
Issued by NWS Topeka, KS

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000
FXUS63 KTOP 170521
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1121 PM CST Thu Feb 16 2017

...AVIATION UPDATE...

.SHORT TERM...(This evening through Friday)
Issued at 301 PM CST Thu Feb 16 2017

An upper level ridge across the central and northern high plains
will move east into the mid and upper MS river valley by Friday
Afternoon. An upper level trough embedded within the southern branch
of the upper level jet will lift northeast from far west TX into
north TX and southern OK by 00Z SAT. The stronger ascent and
moisture advection necessary for rainshowers will be well to the
south of the CWA across eastern OK and eastern TX.

This afternoon temperatures have warmed into the lower to mid 70s.
We may see another degree or two temperature rise through 3 to 4 PM.
A surface trough extended from the upper Midwest southwest into
east central KS. The surface pressure gradient was tight enough this
afternoon across east central KS for southwest surface winds to
reach around 20 MPH with some gusts of 25 to 30 MPH.

Tonight, south-southwest winds of 5 to 15 MPH will keep overnight
lows mild with lows only dropping down into the upper 30s to lower
40s.

Friday, expect another warm day with highs in the lower to mid 70s.
There may be some weak residual moisture advection ahead of the
upper low lifting northeast across central TX, therefore the mixing
may not be as deep as Today. Surface winds will be 10 to 20 MPH from
the south-southwest with gusts to around 25 MPH.

.LONG TERM...(Friday night through Thursday)
Issued at 301 PM CST Thu Feb 16 2017

The long term period continues on track to support well-above normal
temperatures. Every day through next Thursday has highs of 60
degrees or warmer while the current normal high temperature is in
the mid to upper 40s. On Saturday, a weakening closed low will drift
across the Plains south of the forecast area but will provide very
little in the way of sensible weather locally. Upper ridging quickly
amplifies overhead on Sunday and have increased temperatures a bit
for Sunday as 850 temps are forecast to be even warmer than today
with plenty of sunshine. See some potential for RH to go lower than
forecast on both Saturday and Sunday as there will be dry air
immediately above the boundary layer, and this will be an element to
watch as these days approach...although it seems the wind/RH combo
is not particularly likely to reach red flag criteria. Sunday night
into Monday, a two-piece storm system is forecast to enter the
Plains states, but a majority of model guidance is splitting the
energy as one chunk gets absorbed into the northern stream of the
upper jet while the southern extent of the system detaches and
closes off into south Texas. Have maintained at least some
precipitation chances for the local area, but the best forcing will
be both south and north of here. Instability appears to be limited
owing the weak mid level lapse rates. Far eastern KS probably has
the best chance to see more than a tenth of an inch of rain.

There is virtually no cold air intrusion as this storm system passes
with the northern stream of the jet forecast to lift back to the
north. There is strong model agreement in a well-organized jet
streak and vort max dropping into the northwest and amplifying over
the Four Corners region by Wed/Thur. This system appears quite
interesting for the local area as current indications point to it
taking on a negative tilt with quite a bit of moisture advection
into the area and steep lapse rates aloft. This will likely lead to
instability along with strong forcing and will probably see
thunderstorms develop as the upper wave/dryline move through. There
are also signs that cold air will spill in on the back side of the
system and could see a change over to winter-type precipitation.
This will be highly dependent upon an uncertain storm track, but at
least some potential exists.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1121 PM CST Thu Feb 16 2017

VFR conditions should persist with dry air in place and no real
low level moisture advection progged by the models. Surface winds
have been stronger this evening than forecast soundings would
suggest. RAP and NAM soundings still show the inversion steepening
over the next few hours so LLWS remains probable.

&&

.FIRE WEATHER...
Issued at 522 PM CST Thu Feb 16 2017

Wind speeds have subsided this evening and with temps continuing
to cool, red flag conditions will abate. Therefore will let the
red flag warning expire at 6 pm this evening. However southwest
winds are expected to remain in the 10 to 20 MPH range overnight,
especially on the tops of the Flint Hills. So there could still be
some concern overnight with RH values only recovering to about 70
percent.

Issued at 301 PM CST Thu Feb 16 2017

Friday, there may be a slight amount of residual moisture return at
the surface and 850mb which may allow RHs to remain above 20
percent. Winds will be marginal for Red Flag conditions. Though,
much of the area will have a very high rangeland fire during the
afternoon hours on Friday. All outdoor burning should be postponed
on Friday.

&&

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

$$

SHORT TERM...Gargan
LONG TERM...Barjenbruch
AVIATION...Wolters
FIRE WEATHER...Wolters/Gargan



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