Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 101745
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1245 PM CDT Thu Jul 10 2014

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 358 AM CDT THU JUL 10 2014

A remnant MCV from earlier thunderstorms in central and eastern NE
is currently tracking over the forecast area. It has continued to
weaken over time leaving only scattered rain showers. The mid level
shortwave is still forecast to track southeast over eastern KS later
this morning. Ahead of the wave a low level jet has focused a
majority of the isentropic lift over western and central KS. This
area of lift as well as limited elevated instability will spread
eastward, while individual storm motion remains southeastward.
Confidence is rather low regarding how far east these showers and
thunderstorms will actually reach or if redevelopment will take
place over central KS later this morning. The high res models have
struggled with the ongoing convection, and continue to trend
westward keeping most of the precip confined to central and
southeast KS through late morning. By mid day most of the activity
should have exited the forecast area given subsidence behind the
wave leaving just partly cloudy skies. This will allow for high
temperatures to reach the mid to upper 80s. Later today the low
level jet eventually shifts over eastern KS and that combined with
daytime mixing should lead to wind gusts up to 20 to 30 mph. The mid
levels quickly transitions to zonal flow through out the day as a
weak wave tracks over the Dakotas. This evening isentropic lift
focuses over northeast KS as the low level jet veers ahead of the
northern wave. This could cause isolated showers and thunderstorms
to form in that area before moving eastward.

.LONG TERM...(Friday through Wednesday)
Issued at 358 AM CDT THU JUL 10 2014

Friday through Saturday, a broad upper level ridge will amplify
across the southern plains. The surface front should remain north of
the CWA along with any weak upper level troughs rounding the
periphery of the H5 ridge axis. It will be hot with highs in the mid
to upper 90s on Friday and mid 90s Saturday. Heat indices may
reach 100 to 105 degrees during the afternoon hours of Friday.

Saturday night through Sunday Night, An intense upper low across
north central Canada will begin to dig south, this will slowly
amplify a longer wave length upper trough across the upper
Midwest and mid MS river valley. The upper flow will begin to
become northwesterly across the northern and central plains. A
weak front is progged to move southward across the CWA late
Saturday night through Sunday. The NAM model is the fastest with
FROPA, forecasting the front moving southward across the CWA Saturday night.
The ECMWF and GEM have the front moving southward across the CWA
Saturday morning, while the GFS has FROPA occurring Sunday
afternoon. If the NAM, ECMWF and GEM are more accurate solutions,
the best chance for isolated to scattered thunderstorms will occur
Saturday night into Sunday morning. If the GFS were to verify then
the best chance for showers and thunderstorms would be Sunday
Afternoon. ATTM, I`m leaning towards the ECMWF solution. Highs
Sunday will be a bit cooler with the first weak front. Highs will
reach the upper 80s to lower 90s with light northeast winds.

Monday through Monday night, The intense upper level trough west of
Hudson Bay, Canada will dig southward across the northern Great
Lakes. H5 troughs will rotate southeast across the plains and cause
a stronger front to push southward across the CWA Monday and Monday
night. The combination of surface convergence ahead of the front and
ascent ahead of the H5 trough will provide for a chance for showers
and thunderstorms across the CWA Monday into early Tuesday
morning. Highs on Monday ahead of the front will reach into the
upper 80s to lower 90s. If the front is a bit faster then highs
along the NE border on Monday may only reach the lower to mid 80s.

Tuesday and Wednesday will be much cooler as a surface ridge of high
pressure builds southward across the plains. Low-level CAA will keep
highs in the mid 70s across much of the CWA. May see a slight warm
up on Wednesday as the center of the surface ridge axis moves across
eastern KS. Highs on Wednesday will be in the mid to upper 70s.
Lows Tuesday night will drop into the mid to upper 50s across much
of the CWA.

&&

.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1245 PM CDT THU JUL 10 2014

VFR conditions anticipated. May see occasional low-end gusts at
times over the next several hours as mixing increases and a few CU
form. Hard to rule out any high-based convection mainly for TOP
and FOE after 04Z but expect formation to be to the northeast.

&&

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

$$

SHORT TERM...Sanders
LONG TERM...Gargan
AVIATION...65






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