Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 191103
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
603 AM CDT Mon Jun 19 2017

...AVIATION UPDATE...

.SHORT TERM...(Today and tonight)
Issued at 317 AM CDT Mon Jun 19 2017

07Z water vapor imagery shows northwest flow across the central and
northern plains with the mid level ridge over the west coast. At the
surface, a broad area of high pressure was over the central plains
with the deeper moisture shunted south along the Red River and to
the south. Regional radars show some light returns across southern
NEB and north central KS. This appears to be a result of some weak
mid level warm air advection coincident with some saturation at 9 to
10 KFT.

For this morning, RAP and NAM isentropic progs show the mid level
lift persisting through the morning and moving southeast across the
forecast area. Meanwhile forecast soundings keep relatively dry air
below the mid level forcing. There does not appear to be any
instability above the level where the weak forcing is occurring.
Therefore an intensification is not anticipated and think that there
may be some sprinkles through the morning and possibly into the
early afternoon. With this in mind have POPs less than 20 percent
with a chance for sprinkles in the forecast. Once the light precip
dissipates or moves south, northwest flow aloft is progged to
persist with little indication of significant forcing. So think
tonight should remain dry. Highs today are expected to be a little
warmer than yesterday based on some weak low level warm air
advection. However the mid clouds could make the temps forecast be a
little tricky if they stick around into the afternoon. Based on
mixing the boundary layer to near 800MB, have highs in the lower and
middle 80s. Lows tonight are expected to be in the lower 60s. Some
weak southerly winds and warm air moving north is forecast to keep
temperatures a little warmer tonight.

.LONG TERM...(Tuesday through Sunday)
Issued at 317 AM CDT Mon Jun 19 2017

By Tuesday, surface high pressure will be shifting southeast of the
CWA and advancing into the southeastern U.S.  The central U.S. will
still be under northwesterly flow aloft as the mid-level trough
continues to shift east of the Great Lakes region. Models show an
embedded shortwave developing along the western edge of the trough
axis and sliding southward along the western edge of the Great Lakes
Tuesday into Tuesday night.  This embedded shortwave trough will
help to push a weak surface boundary toward the NE/KS border Tuesday
afternoon into Tuesday evening. While moisture looks to be limited
near this weak boundary, cannot rule out the potential for some
isolated precipitation to develop near the boundary, so have
extended slight chance PoPs along the entire NE/KS border.

By Wednesday, the mid-level flow becomes more zonal over the central
U.S.  Models show a few weak embedded waves developing within this
zonal flow mid-week and skimming across portions of the forecast
area.  The first such wave looks to track across the area Wednesday
night with additional waves moving in Thursday night.  Precipitation
chances increase Thursday through Friday as models show a cold front
slowly sliding southeastward across the CWA, which will provide
additional lift for thunderstorm development.  However, models are
highly variable with the timing and tracking of this front, so
confidence remains low with when the best potential for showers and
thunderstorms will be during that Thursday through Friday time
period.  Model solutions become even more divergent by this weekend
as there are significant differences in the surface pattern and how
deep the passing mid-level trough will be across the central U.S.
Some models suggest a secondary boundary tracking across the area on
Saturday while other models simply show additional embedded
shortwaves within the mid-level trough axis helping to ignite some
scattered thunderstorm chances.  As a result, confidence remains low
with the weekend forecast PoPs.

As for temperatures:  as surface high pressure advances into the
southeastern U.S. on Tuesday, southwesterly surface winds through
Thursday will support a warming trend with high temperatures rising
back into the low/mid 90s and possibly even some upper 90s across
central KS.  This southerly flow will also support steady moisture
advection into the region, with dewpoints rising into the mid/upper
60s Wednesday and Thursday.  As a result, heat index values mid-week
may reach into the upper 90s to around 100 degrees for portions of
the CWA.  The frontal passage on Friday will provide relief to the
heat, with high temperatures dropping back into the 80s and possibly
even into the 70s for this weekend.

&&

.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 603 AM CDT Mon Jun 19 2017

Radar returns appear to be fairly isolated and may not even be
reaching the ground. So aside from the stray sprinkle this
morning, VFR conditions should prevail due to dry low levels
within the surface ridge axis.

&&

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

$$

SHORT TERM...Wolters
LONG TERM...Hennecke
AVIATION...Wolters



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