Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 301126

626 AM CDT Wed Jul 30 2014

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 305 AM CDT WED JUL 30 2014

Early Wednesday morning, a strong short wave trough was gradually
moving east across the Oklahoma panhandle. There is ample moisture
associated with this system. However, persistent dry northerly flow
has been in place across the northern Plains and into northeast
Kansas. This drier and cooler air has kept the forecast area
generally dry, but has also put a temperature gradient in place with
a band of persistent frontogenesis hovering across the region since
Tuesday morning. This frontogenesis intensified a bit this morning
amidst a moist mid-level airmass with very weak instability,
resulting in a band of showers even with embedded pockets of
moderate rain. The higher resolution model guidance has been
performing well in handling these features over the past 30 hours
and solutions through today seem quite reasonable and have leaned on
those solutions heavily. That said, expect this band of showers to
persist and slowly shift south and east this morning, with a
weakening trend after around 15Z. While the frontogenesis will be
weakening at this time, the short wave will get a bit closer to the
area so could see scattered showers persist into the afternoon,
although likely with less coverage than early this morning. Also,
the precip potential area will continue to shift south through the
day, likely focused south of I-35 by early afternoon. A "rain-out"
should not be expected for any part of the forecast area, but
typically less than 2 hours of total shower activity for any given
point. Daytime warming will be limited by cloud cover, especially in
east central KS, and highs will range from the upper 70s to lower
80s. Expect gradually clearing skies overnight along with light
winds. Lows should drop into the upper 50s to lower 60s for the
entire area, with the coolest temps north.

.LONG TERM...(Thursday through Tuesday)
Issued at 305 AM CDT WED JUL 30 2014

Surface ridge axis settles over northern MO by Thursday as the upper
trough continues to rotate over the northern Great Lakes region.
Weak embedded waves translate through the northwest flow across the
Midwest Thursday evening through Saturday. Guidance is still varying
between runs on small amounts of QPF versus completely dry during
this period. The latest run of the NAM is too aggressive, possibly
owning to convective feedback while the GFS/ECMWF/GEM are further
east with the optimal mid level lift. Sounding profiles also
suggest copious amounts of dry air to overcome so will continue
with a dry forecast through Monday evening.

The next, more poignant upper trough and cold front dips southeast
across the western high plains beginning Tuesday. Decided to trim
back precip chances as the latest GFS ensembles have slowed on
timing of the wave until Wednesday. The ECMWF is still on track to
impact north central areas on Tuesday and will therefore leave a
slight chance mention.

After high pressure brings light and variable winds Thursday through
Saturday, surface trough begins to build over the northern plains,
returning the southerly flow and warming temperatures. After highs
gradually rising into the middle 80s through Sunday, 90s return
Sunday through Tuesday.


.AVIATION...(For the 12Z TAFs through 12Z Thursday Morning)
Issued at 622 AM CDT WED JUL 30 2014

Shra remains scattered near TAF sites, and a few showers may
impact the sites through around 15Z, although flight conditions
are likely to remain VFR even during shra. Expect the vast majority
of the 12Z-15Z time frame to be dry. Showers move south and
decrease through late morning with VFR and light winds thereafter.
There is a small chance for reduced vis after 09Z, mainly at MHK,
but this will depend on how much clearing/drying takes place tonight.




SHORT TERM...Barjenbruch
AVIATION...Barjenbruch is the U.S. government's official web portal to all federal, state and local government web resources and services.