Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 180457

National Weather Service Topeka KS
1157 PM CDT TUE MAY 17 2016

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Wednesday)
Issued at 255 PM CDT TUE MAY 17 2016

Persistent area of rain has finally pushed east of the area this
afternoon with subsidence overspreading the area to break up cloud
cover. This has allowed temperatures to warm slightly into the lower
60s especially in northern and western parts of the area. This
slight warming will actually help support another round of light
showers or sprinkles this evening as a weak front comes into
northern Kansas from Iowa and Nebraska. The warming will allow
surface parcels to become weakly unstable which should allow shallow
convective updrafts to develop with light precip possible. This
activity should wane by mid evening but areas especially north of I-
70 can expect a few showers and sprinkles. See a good chance for
clearing skies after midnight...and if skies do clear there is
potential for fog to develop as winds become light with the moist
ground conditions. Current suggestions are for patchy fog but it
could become dense especially in valleys if skies clear. Wednesday
will be dry with the main forecast question being in how warm it
will get. Low level moisture profiles suggest that morning mixing
will result in cloud development by mid morning. This will probably
scatter out by afternoon, and current forecast of highs in the
mid/upper 60s depends on that clearing. If cloud cover remains
thicker then will end up a few degrees cooler.

.LONG TERM...(Wednesday Night through Tuesday)
Issued at 255 PM CDT TUE MAY 17 2016

On Wednesday night a mid level trough will move over the Great Lakes
region, while another trough begins to eject over the southern
plains. At the surface a high pressure ridge axis will extend
across the area from the Great Lakes region. During the day that
high pressure will gradually retreat eastward allowing return flow
to develop. In the afternoon the trough approaches from the
southwest therefore increasing the mid level lift. An increase in
moisture will support an area of showers associated with the trough
as it tracks over the area through the overnight. Lapse rates are
fairly weak during this timeframe therefore do not expect much of a
chance for thunder. Behind the trough on Friday diurnally driven
instability showers may be possible with steep low level lapse rates
and residual moisture in place.

On Saturday an upper ridge builds over the central US allowing most
locations to dry out and warm into the mid to upper 70s. Not far
behind the upper ridge will be another deep through over the western
US. Within the southwest flow aloft weak shortwaves may trigger
storms along the dry line that will become established across
western KS on Sunday. There is a chance these storms try to maintain
strength long enough to reach central KS. Although the storms will
likely weaken with the loss of daytime heating, but the veering low
level jet may support elevated showers and storms on Sunday night
further in eastern KS. These showers and storms may linger into the
late morning. On Monday afternoon a trough tracking over the
northern plains will drive the dry line further east. Deep layer
shear will also move slightly eastward as the upper ridge holds over
the MS valley. Return flow will be well established so dew points
could reach the upper 60s. Steep lapse rates in the southwest flow
aloft will support high instability as well. This means storms that
form along the dry line will have a chance of becoming severe. The
placement of the dry line may vary through out this forecast if the
pattern remains similar. Not much is forecast to change on Tuesday
so the threat for severe storms stays around especially with more
shortwaves ejecting from the western mid level low pressure.


.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 1154 PM CDT TUE MAY 17 2016

Light winds and a moist ground may cause some ground fog to
develop at the terminals through the early morning hours. High
clouds were moving east-northeast but were dissipating as they
moved into central KS, therefore skies may stay mostly clear as
lows drop into the mid 40s and with dewpoints remaining in the mid
40s patchy dense fog may form, with the best chance at the TOP
terminal. Once the fog mixes out between 13-14Z WED conditions
will be VFR.


.TOP Watches/Warnings/Advisories...


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