Area Forecast Discussion
Issued by NWS Hastings, NE

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FXUS63 KGID 232058

Area Forecast Discussion
National Weather Service Hastings NE
358 PM CDT TUE AUG 23 2016

.SHORT TERM...(This evening through Wednesday)
Issued at 345 PM CDT Tue Aug 23 2016

We have a small window late this afternoon into the evening where
we stand the slight chance of a shower/thunderstorm. Taking a look
at the cumulus field currently, it will take another couple of
hours before we have much of a chance of thunderstorm development,
as vertical extend is limited. Latest meso-analysis indicates that
we have plenty of CAPE in our eastern CWA (more than 4000 J/kg)
and loss of, or in the process of losing convective inhibition.
Wind shear is weak, however. The time window is limited as we will
enter a region of subsidence in between two waves, as the cumulus
field we currently have is associated with the departing first
wave within southwest flow.

By overnight, short-wave ridging aloft should preclude
precipitation, despite a cold front that will be cutting through
the CWA. This front will give us quite a range of dewpoints by
early Wednesday morning, with near 50 expected in our northwest to
mid 60s in our southeast, ahead of the cold front. The next
shortwave trough will arrive Sunday, and with generous MUCAPE, I
expect a good chance of precipitation to occur north of the front
as it stalls somewhere near the state line. By afternoon, we
should have sufficient instability and shear to be aware of severe
potential as well. Any severe weather would mainly be in the
afternoon and evening. The location of severe weather will be
highly dependent on where, when, and if the front stalls. We also
have the potential for some heavy rain with some cells. Expect
slightly cooler than normal temperatures north of the front as sky
cover along with airmass change will make it seem a bit more like

.LONG TERM...(Wednesday night through Tuesday)
Issued at 345 PM CDT Tue Aug 23 2016

More chances of rain are on the way as we receive multiple waves
of energy are still expected. A slow warming trend will occur as
temperatures eventually rebound to near normal.


.AVIATION...(For the 12Z KGRI/KEAR TAFS through 12Z Wednesday morning)
Issued at 717 AM CDT Tue Aug 23 2016

General overview:
Although VFR ceiling/visibility is expected the majority of the
period, there are a few caveats involving mainly the possibility
of brief sub-VFR conditions in either thunderstorm activity, brief
lower stratus, or both of these. Moving on to more specifics...

As at least one set of model guidance depicted (while others did
not), at least a patchy MVFR stratus ceiling has developed in the
general area and could move into either terminal soon. As a
result, have introduced a TEMPO group through 16z to cover this
MVFR possibility, which may or may not be sufficiently long to
cover it. Otherwise, obviously any passing thunderstorm activity
later this afternoon/evening could at least briefly reduce
especially visibility below VFR, and this will need monitored as

Thunderstorm potential:
It appears that overnight/early morning activity has departed off
to the north. As a result, the main window of opportunity for
possible convection is focused from 22z-04z late this
afternoon/tonight, and this is being advertised with a
basic/generic "vicinity" mention (VCTS) for now. This could
feature a severe storm risk with hail/wind potential, but this is
HIGHLY conditional.

Winds/low level wind shear:
Surface winds will remain fairly breezy from the south through
much of the period, with gust potential over 20kt for much of the
day. However, confidence in wind trends decreases by evening.
Although an eventual switch to prevailing northerly breezes should
occur behind a passing front, the presence or lack of thunderstorm
activity could easily alter the local wind fields noticeably from
current expectations, including the possibility of brief very
strong gusts. There could be some fairly "minor" low level wind
shear during the latter half of the period, but nothing that
appears worthy of TAF inclusion at this time.


.GID Watches/Warnings/Advisories...


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