Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 031737

1237 PM CDT Sun May 3 2015

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 346 AM CDT SUN MAY 3 2015

Isolated thunderstorms developed this morning shortly after 06Z in
warm/moist advection within the low level jet. Vad wind profiles as
well as water vapor imagery shows a mid level wave around 700 mb
moving across central Kansas at 08Z. Latest runs of the HRRR and RAP
move the isolated convection east into Missouri by 12Z-13Z. After
this early morning round of convection, the rest of the day should
be dry with clouds gradually decreasing through the early afternoon
hours. Deep mixing today along with warm advection will yield highs
in the low to mid 80s. Main thermal axis sets up from New Mexico
through north central Kansas into northeast Nebraska today. Winds
will increase by mid morning as pressure gradient increases. Surface
front moves southeast into western Kansas this afternoon while it
moves little across Nebraska. Expect afternoon heating out west will
overcome convective inhibition for scattered storms to develop.
These will remain to the west of north central Kansas into the early
evening hours. Models eject weak waves northeast across western
Kansas into southern Nebraska overnight. Expect convection to fire
along the front in Nebraska tonight with outflow pushing south into
north central and northeast Kansas. Southerly low level jet will
help to develop scattered showers and thunderstorms overnight. Shear
is marginal 20 to 30 kts overnight with MUCAPE 800-1000 J/kg. Expect
some strong storms are possible with a few severe storms not out of
the question later this evening across north central Kansas. Hail
and winds will be the main hazards. Lows tonight will be mild with
readings in the lower 60s.

.LONG TERM...(Monday through Saturday)
Issued at 346 AM CDT SUN MAY 3 2015

A wet pattern looks to be setting up for this upcoming week with
several chances for precipitation all the way into next weekend.

By Monday, a mid-level ridge will stretch across the Southern Plains
and southeastern U.S. with a surface low centered over southwest
Kansas. Models show the associated cold front extending into north
central Kansas and southeast Nebraska, however the last few models
runs have shown this front becoming fairly stationary over northern
Kansas Monday into Monday night, limiting the southeastern extent of
precipitation chances across the CWA. As a result, have continued to
diminish PoPs across far east central Kansas through that period
with likely PoPs along the KS/NE border with the stationary
boundary. There continues to be the potential for some strong to
severe thunderstorms to develop along this stationary boundary
Monday afternoon into Monday evening as storms should be
surface-based due to little to no inhibition present. The NAM
continues to be the most aggressive with the amount of available
moisture, thus increasing the parameters for severe thunderstorms.
However, CAPE values could reach upwards of 1000-2000 J/kg with
decent low-level lapse rates. However, 0-6km bulk shear continues to
look fairly weak with most models showing upwards of only about
30kts. The main concern with any strong to severe storms will likely
be some large hail and potentially some locally heavy rain as
thunderstorms may train across north central Kansas into the evening
and overnight hours with the low-level jet looking to be parallel to
the boundary.

The mid-level ridge should stretch further northward into the
Central Plains Monday night into Tuesday, helping to push the cold
front northward into Nebraska and further limiting the precipitation
potential across the southeastern portions of the forecast area. At
this time, Tuesday looks to show the best potential for being dry
across much of the forecast area. However, focus quickly shifts to
the southwest where a mid-level trough will be beginning to lift
northeastward across the High Plains through Wednesday and into the
Northern Plains by Wednesday night. At the surface, a low pressure
system will strengthen across the High Plains but looks to become
anchored over that region through mid to late week, resulting in
persistent southerly surface winds advecting warm, moist air into
the region. The combination of this steady stream of moisture and a
frontal boundary that will likely remain hung up just west of the
forecast area through much of the remainder of the week will help to
support continued scattered shower and thunderstorm chances through
the end of the week. While there is decent model agreement with the
timing and tracking of the mid-level trough and the development of
weak embedded waves within the pattern by late week, there is less
agreement with the surface features in when the associated cold
front will become tilted enough to move into the forecast area
during the latter part of the week. Due to the low confidence in
this boundary placement, have lowered PoPs some from the consensus
blend but still have chance PoPs in for the entire forecast area
through Saturday. This fairly stationary surface pattern should
result in fairly similar temperatures throughout the week with highs
in the 70s/near 80, lows in the upper 50s/low 60s, and dewpoints in
the 50s and 60s.


.AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon)
Issued at 1229 PM CDT SUN MAY 3 2015

The main aviation concern for the afternoon will be the strong and
gusty southerly winds. These will diminish around sunset. Winds
likely strong enough overnight to minimize the possibility of wind
shear conditions. With the frontal system just off to the North of
the terminals, there is some suggestion that KMHK, KTOP/KFOE
terminals could at least see some VCSH or perhaps VCTS, but this
would be high based and confidence is to low at this point to
carry in the TAFs. This is something to stay tuned to though if
planning transit to or from the terminals.




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