Area Forecast Discussion
Issued by NWS Hastings, NE

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FXUS63 KGID 211029

Area Forecast Discussion
National Weather Service Hastings NE
529 AM CDT THU JUL 21 2016

.SHORT TERM...(Today and tonight)
Issued at 304 AM CDT Thu Jul 21 2016

Quiet conditions remain in place across the CWA early this
morning, with upper air and satellite data continuing to show
ridging being the dominant feature. High pressure aloft remains
centered over the Southern Plains, with the northern extent of the
ridging broken down some near the Canadian border, as a shortwave
disturbance slides off to the east. At the surface, southerly
winds remain in place, with the CWA set up between high pressure
over the eastern CONUS and a trough of low pressure draped through
the High Plains. An outflow boundary from earlier convection near
the CO/KS/NE border has been gradually pushing east, resulting in
a few showers just off to our west. This boundary has been
weakening as it moves east, and while a few sprinkles not out of
the question in the west, will keep PoPs out (for now) and see how
the next few hours go. As expected, been pretty warm tonight, with
3 am obs ranging from the mid 70s to near 80.

Main story for the short term continues to lie with the hot
conditions forecast, with models in good agreement showing little
overall change in the upper level pattern. Much the same for the
surface pattern, southerly winds are expected to remain in place
for most locations through a good chunk of the day , with the
trough axis spending much of the day just off to the west of the
CWA. Exception would be across western portions closer to that sfc
boundary, winds look to be a bit lighter. Overall, made few
changes to forecast highs for today, which remain in the upper 90s
to just over 100 degrees. Combined with dewpoints in the 60s/low
70s, heat index values of 105 to around 112 are expected during
the peak of the afternoon.

Late this afternoon, mainly this evening/tonight, that sfc
boundary along with convergence along an increasing LLJ may be
enough to spark off some thunderstorms. Warm mid level
temps/capping remains in place, but can`t rule out at least a few
storms. Roughly the northern third of the CWA is included in the
SPC Day 1 Marginal Risk, quarter hail/60 MPH winds would be the
primary hazards.

.LONG TERM...(Friday through Wednesday)
Issued at 304 AM CDT Thu Jul 21 2016

Patternwise, an upper level ridge of high pressure across the
central and southern plains Friday will deamplify across our
region late this week, with flow becoming more zonal as a series
of shortwave troughs translate across the northern and central
CONUS. The more zonal regime will be maintained over the weekend
into the first part of next week, then the upper ridge axis will
rebuild over the southwest CONUS with flow becoming northwest
across the Central Plains by the middle of the workweek.

Convection which develops later tonight may linger into the
daytime on Friday, with additional development possible along
surface boundary across south central Nebraska. Not looking for
widespread convection by any means, but just cannot rule out
isolated or scattered storms. Daytime temperatures will remain hot
Friday with h85 temps around 29C and surface dewpoints in the 60s
and 70s leading to highs well into the 90s and topping 100F, with
heat indices in the 105 to 110 degree range. Chances for storms
continue Friday night as convection along the high plains is
expected to migrate eastward on the nose of a 40kt low level jet.

A shortwave trough crossing our region Saturday will bring
continued chances for showers and thunderstorms, and
temperatures are still looking hot in the 90s ahead of an
approaching cold frontal boundary. Will need to monitor whether
cloud cover and only a slight cooling of mid level temperatures
will be sufficient to drop the heat headline. Better mixing in
increasing southerly winds may result in lower dewpoints and heat
index readings and will be something to monitor.

The cold frontal boundary crosses our region Saturday night into
Sunday, with chances for storms continuing along the boundary.
Temperatures drop back several degrees behind the front by Sunday,
ending the prolonged heat spell. Otherwise, heading into next
week temperatures are looking more seasonal with intermittent
chances for storms.


.AVIATION...(For the 12Z KGRI/KEAR TAFS through 12Z Friday morning)
Issued at 524 AM CDT Thu Jul 21 2016

Overall, no significant changes made for this TAF period, with VFR
conditions in the forecast. While thunderstorm chances remain
this evening/overnight, confidence in any impact at the terminals
remains low enough to continue keeping any mention out. Winds look
to continue out of the south for much of the period, before
becoming more variable toward the end as a sfc boundary
approaches. Speeds during the day expected to be around 15 MPH.


.GID Watches/Warnings/Advisories...
NE...Excessive Heat Warning until 7 PM CDT Friday for NEZ039>041-

KS...Excessive Heat Warning until 7 PM CDT Friday for KSZ005>007-



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