Area Forecast Discussion
Issued by NWS Goodland, KS

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FXUS63 KGLD 181007

Area Forecast Discussion
National Weather Service Goodland KS
407 AM MDT Tue Jul 18 2017

.SHORT TERM...(Today through Thursday night)
Issued at 319 AM MDT Tue Jul 18 2017

The primary forecast concerns in the short term are the hot
temperatures and high heat index values each afternoon.

High pressure aloft strengthens from the central Rockies across
the central plains through Wednesday and then moves east over the
plains as a short wave trough begins to move into the back side of
the ridge over the central Rockies on Thursday.

A lee trough remains generally in place along the front range
during this time. This will keep warm southerly winds in place
near the surface while the high pressure aloft directs storms
mainly across the northern sections of the forecast area this
afternoon and evening. A few storms are also possible over the
northwestern sections on Thursday as the pattern shifts east and
storms moving off the Rockies lift into southwest Nebraska during
the late afternoon and evening.

With dewpoints across portions of the area remaining in the middle
60s today along with high temperatures in the lower 100s, heat
index values around 105 are possible late this afternoon. As a
result, will keep the current heat advisory intact as is for
today. Through Thursday, overnight low temperatures are expected
to recover to between 70-75 over the eastern half of the forecast
area while high temperatures across mainly the eastern portions of
the forecast area rise back into the lower 100s. Current forecast
dewpoint temperatures decrease a few degrees over the next few
days, with resulting heat index values also lowering a few
degrees. The bottom line is we will be close to needing a heat
advisory the next few days, but have chosen to not issue any
further heat advisories beyond today at this point.

.LONG TERM...(Friday through Monday)
Issued at 218 AM MDT Tue Jul 18 2017

Friday and Saturday: Ridge flattens out and slides east on Friday,
giving way to slightly cooler temperatures for the western half of
the CWA. Temperatures to the east are still expected to climb into
the upper 90s to just over 100 degrees. A theta-e boundary will push
from northwest to southeast and serve as an axis for thunderstorm
development during the afternoon. Relatively good agreement is in
place among the global models with the placement of this boundary,
that will precede a cold front that is expected to move through on
Saturday. The GFS seems to be having a difficult time pinning down
the instability and is giving inconsistent values; however, the
Canadian seems to be consistent over several runs, giving CAPE
values in the 1500 to 2000 J/Kg range Friday afternoon with deep
layer shear nearly non-existent between all models. For Saturday, we
are looking at a weak cold front that will bring another chance of
thunderstorms across the area.

Sunday: Cold front stalls and weakens over the central Plains,
keeping showers and thunderstorms in the forecast through the day.
With the flow patter remaining well north of the region, the front
will continue to weaken and eventually give way to building high
pressure to the west. Rain chances will wind down Sunday night and
early into Monday morning.

Monday and Tuesday: High pressure builds to the west, pushing the
remnant frontal boundary out of the region Monday morning. Model
agreement for this time period is weak at best but the general
consensus builds weak high pressure over the Plains with occasional
weak troughs expected to move through the region. Temperatures will
gradually rise each day with guidance keeping highs generally in the
upper 80s.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1116 PM MDT Mon Jul 17 2017

VFR conditions forecast for the TAFs. Storms will continue moving
east away from KMCK through the night. Otherwise southerly winds
will be fairly light.


KS...Heat Advisory from 1 PM this afternoon to 8 PM CDT this evening
     for KSZ002>004-014>016-028-029.

NE...Heat Advisory from noon MDT /1 PM CDT/ today to 7 PM MDT /8 PM
     CDT/ this evening for NEZ079>081.



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