000
FXUS63 KGID 161127
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
627 AM CDT Sun Jul 16 2017

.SHORT TERM...(Today and tonight)
Issued at 344 AM CDT Sun Jul 16 2017

Another short-term forecast is largely governed by the sub-
tropical ridge aloft. However, there is a closed low meandering
through this ridge, heading toward our area, as models have been
predicting, and eventually becoming an opening wave. However, it
appears that this feature is slowing a bit, and may perhaps effect
our far western areas late tonight, if at all with a slight
chance of showers and thunderstorms. Good agreement among models
here. Not too much support for anything strong or severe. Fairly
typical temperatures are again to be expected with highs in lower
to mid 90s and lows tonight in the upper 60s to around 70.

.LONG TERM...(Monday through Saturday)
Issued at 344 AM CDT Sun Jul 16 2017

The most notable feature early next week will be a compact cutoff
low that will move northeast out of western Kansas into central
Nebraska during the day Monday, gradually weakening into an open wave
as it does so. Compared to yesterday, it appears that the timing of
this low is about 6 hours slower than it was yesterday, and the
ECMWF is even slower than that. This makes the thunderstorm
prospects a little more favorable for central Nebraska, as it will
likely impact the area near peak heating on Monday, allowing for
scattered thunderstorms to develop and persist through the evening.
I think this is reflected in the latest Superblend, with PoPs now at
least in the 40s.

In addition, it appears this will bring us a marginal risk for
severe weather. NAM has MLCAPE values around 2000-2500 J during the
afternoon. The approaching wave will also make for favorably backed
low-level winds and locally enhanced helicity, but limited deep-
layer shear values of only 20-25 kts may end up being a big limiting
factor. Relatively slow storm motion and localized PW values of
over 1.7" should also make for some efficient rainfall any
thunderstorms that develop.

Storms should clear out of the area Tuesday morning, likely allowing
high temperatures to reach the mid to upper 90s and heat index values
to approach the low 100s.

Tuesday night, a strong low-level jet is forecast to develop across
the area, but the best convergence will be across northern Nebraska.
Therefore, there is only a slight chance for thunderstorms along the
I-80 corridor, gradually increasing as you move northward across the
state.

The upper-level ridge axis is expected to move into the area for
Wednesday which should make for dry weather. This will also likely
make Wednesday the warmest day of the week. High temperatures will
be in the upper 90s to low 100s for most of the area, and heat index
values will approach advisory criteria in the low 100s.

A weak front may bring slightly cooler temperatures to central
Nebraska on Thursday, but this will likely stall out before bringing
much relief to southern Nebraska or northern Kansas. The upper ridge
gradually begins to break down late Thursday into Friday, allowing
for slight thunderstorm chances to creep back into northern and
north-central Nebraska. By next weekend, we should continue to
transition back into more zonal flow aloft, hopefully bringing more
meaningful precipitation chances to the area.

&&

.AVIATION...(For the 12Z KGRI/KEAR TAFS through 12Z Monday)
Issued at 626 AM CDT Sun Jul 16 2017

VFR conditions are expected under continued influence of the
subtropical ridge aloft. Some storms could develop the last few
hours of the forecast to the west of KEAR from an embedded upper
low approaching, but any thunderstorm activity should remain west.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&

$$

SHORT TERM...Heinlein
LONG TERM...Mangels
AVIATION...Heinlein