Area Forecast Discussion
Issued by NWS Topeka, KS

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811
FXUS63 KTOP 190345
AFDTOP

AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1045 PM CDT MON JUL 18 2016

...Updated to near term forecast through tonight...

.UPDATE...
Issued at 1039 PM CDT MON JUL 18 2016

Large MCS is becoming increasingly organized over western NE and
far northeast CO late this evening. While Corfidi vectors do have
a bit of a southerly angle to them, the larger scale wave forcing
this activity is moving sharply toward the north and the
instability axis seems to extend almost due east. Forecasting
soundings for north central KS indicate that a cold pool would
have to be quite deep in order to lift parcels to the LFC later
tonight, and while it appears unlikely, have included a slight
chance for thunderstorms in northern KS on the off chance that the
outflow makes its way into the area with enough energy to maintain
a few thunderstorms. Short range models, specifically the HRRR and
experimental HRRR now have some run-to-run consistency in
developing weak warm advection showers and perhaps a thunderstorm
in parts of eastern KS after 1 AM. This also seems to be a
questionable idea but not completely unreasonable given a bit of
moisture aloft and weak but persistent isentropic lift so have
included a few hours of a slight chance for thunderstorms in
eastern KS early this morning as well.

&&

.SHORT TERM...(This Evening through Tuesday)
Issued at 329 PM CDT MON JUL 18 2016

At 20Z, water vapor imagery shows a cloud band with moisture
streaming into the Central Rockies with another cloud band stretched
from the northern Central Plains into the Ohio Valley up through the
New England States.  Some storms still along the stationary boundary
at the surface into northwestern MO and extreme southeastern IA.
Storms also beginning to fire over the foothills of the Rockies into
the panhandle of Nebraska.

In northeastern Kansas, forecasting a mostly dry period in the short
term as heights continue to rise steadily overnight into the day on
Tuesday.  An MCS may develop overnight associated with the storms
previously mentioned over the Rockies.  These should stay to the
north of the outlook area tonight though as the LLJ convergence is
focused to our northwest.  Only the NAM brings some of this activity
close to the area with all the other short term guidance taking the
storms on a northerly track into northern Nebraska and northwestern
Iowa overnight.  Therefore, not expecting much if any influence from
a cold outflow to impact our area even though there is a brief
period of isentropic lift that advects over the the region on the
315K to 320K surface.  Lack of mid level moisture should keep storms
to the north.  That said, do expect temperatures to increase again
tomorrow into the mid to upper 90s with dewpoints into the upper 60s
and low 70s.  This should continue to put heat index values into the
105F range while lowest heat index values will be at or above 75F.
Have kept heat advisory going for the evening and have upgraded to a
heat warning starting Tuesday afternoon as many days of at least
heat advisory heat index values are expected.  The bottom line is
the heat will be the main forecast concern through the period.

.LONG TERM...(Tuesday Night through Monday)
Issued at 329 PM CDT MON JUL 18 2016

Tuesday night through Thursday...

With upper high centered over the Southern/Central Plains during
this period, and no real low-level convergence features expected
to impact eastern KS, expect dry weather to continue. With
dewpoints from the upper 60s to mid 70s, and afternoon high
temperatures in the 96 to 103 degree range, afternoon heat indices
should be in the 103 to 108 degree range. Overnight lows are only
expected to fall to the mid to upper 70s.

Thursday Night through Monday...

A stout upper-level ridge will continue to be center of the central
United States through the end of the week. High temperatures will
soar into the upper 90s and lower 100s Friday afternoon. These very
hot temperatures coupled with high dewpoints, heat indices will
range from 105 to 110 degrees (possibly warmer). Saturday becomes a
bit tricky as both the EC and GFS  bring a weak cold front through
portions of the area. Not only would it "cool" temperatures back
into the lower to middle 90s, but precip chances also increase. The
front appears to stall out in the vicinity of the outlook area for
the remainder of the weekend. Guidance suggests weak 500MB waves
will traverse the CWA along the surface boundary. Therefore, have at
least slight chance PoPs across the area, along with cooler
temperatures.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 640 PM CDT MON JUL 18 2016

VFR conditions are likely through the TAF period. Winds at 800
feet AGL will approach 35 kts between 04Z-11Z but should stay just
less than LLWS criteria.


&&

.TOP Watches/Warnings/Advisories...
Excessive Heat Warning from 1 PM Tuesday to 7 PM CDT Friday for
KSZ008>012-020>024-026-034>040-054>056-058-059.

Heat Advisory until 1 PM CDT Tuesday for KSZ008>012-020>024-026-
034>040-054>056-058-059.

&&

$$

UPDATE...Barjenbruch
SHORT TERM...Drake
LONG TERM...Baerg/GDP
AVIATION...Barjenbruch



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