Area Forecast Discussion
Issued by NWS Goodland, KS

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FXUS63 KGLD 260826

Area Forecast Discussion
National Weather Service Goodland KS
226 AM MDT THU MAY 26 2016

Issued at 1105 PM MDT Wed May 25 2016

Regarding convective potential during the late night period into
Thursday morning:

A much more stable post outflow air mass has settled over our
CWA, supporting a lull in convective activity at least over the
next 3 hours. A shortwave (apparent on WV imagery), is currently
moving into south central Colorado. This will be a feature of
interest in the next 3-6hr, as latest NAM/RAP/HRRR show this
shortwave deepening and moving over our CWA by 09Z. The surface
low over SE Colorado deepens in response, and shifts a
warm/stationary front north at least near southern CWA. The
combination of WAA along nose of LLJ, positive frontogenesis, and
increasing large scale support from shortwave all could lead to
shower/thunderstorm redevelopment in our southern CWA (to near the
I-70 corridor).

Return flow north of this front bring much higher Tds back into
our CWA, and support MU CAPE values 1500-3000 J/KG (highest in
the southeast) after 09z. Effective sheer will also remain high
due to LLJ (45-55kt). I am concerned that if this set up is
realized parcels in this potential environment could quickly
become severe with elevated supercells and very large hail. The
questions are just: will CinH weaken enough for this to be
realized, and what nature of coverage.

I have adjusted overnight PoPs to account for this and will amend
HWO as well.


.SHORT TERM...(This evening through Thursday)
Issued at 146 PM MDT Wed May 25 2016

Across the forecast area this afternoon...the remnants of the low
cloud deck which lingered over central portions of the
resides only over far eastern zones and continues to thin out. Temps
in areas where clouds have finally left have rebounded nicely by
several degrees. Most of the CWA now in the 70s with some upper 60s
east. Weak ridging over the area giving the region mainly variable
conditions of 5 mph or less.

Going into tonight and on into Thursday...weak shortwave moving
through the Central Rockies at this time...will move at a northeast
vector across mainly northern zones tonight. Models do hint at
potential for some light rw/trw development..but chances do look
thin. Have put in a slight chance for isolated trw/rw concentrating
in locales over NE Colorado and those along the Nebraska/Kansas

This quick moving system will give way to an approaching warm front
going into Thursday morning. Out ahead of this expect
linger isolated rw/trw...along with areas of fog. The focus of the
fog will be from a few hours before sunrise thru the mid morning
hours before burning off.

It will be along and ahead of this frontal boundary that the focus
for the next round of severe wx will be for the afternoon hours.
Going into the afternoon hrs Thursday...increased instability occurs
with the influx of higher dewpts...daytime highs reaching will into
the mid to upper 70s...and strong wind shear. Strong to severe
thunderstorms are expected to develop...and as a result the storm
prediction Center has put the majority of the region into Enhanced
Risk for severe wx...with only a small portion in Slight Risk to the
SW. Have put in enhanced wording for the afternoon hours to reflect

For temps...daytimes highs will range mainly in the mid to upper
70s. Some locales may even reach near 80F in far E/SE zones. Locales
in NE Colorado may only reach near 70F as a result of cloud cover.
Overnight lows tonight will range from the upper 40s the
mid 50s east.

.LONG TERM...(Sunday through Thursday) Issued at 223 AM MDT Thu
May 26 2016

At the start of the extended the upper level pattern is setting up with
a longwave trough moving eastward, out of the Pacific Northwest,
and deepen as it moves over the High Plains towards the end of the
period. On the surface, models are showing a low pressure system
developing, over the High Plains, and moving towards the
northwest with its associated front passing through the area
later in the week.

Chances for convective activity persist across the region throughout
the extended period as instability will be high on Sunday through
Tuesday and moisture return from the southeast. Followed by the
above mentioned pressure system at the end of the period. At this
time, severe weather threat looks low as there seems to be a lack of
a highly sheared atmosphere.


.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1142 PM MDT Wed May 25 2016

Currently: VFR conditions and lull in shower/thunderstorm
activity at both KMCK and KGLD. By 09Z stationary front begins to
lift north and easterly return flow will bring very moist air mass
into over both terminals. There is a potential for stratus/fog
and thunderstorms as this front slides northward. Best chance for
IFR (or lower) will be at KGLD with a delay in stratus/fog
development at KMCK. There is also the potential for stratus to
linger at KMCK through much of the TAF period, though models are
inconsistent and I felt more comfortable leaning towards the more
positive end of guidance at this point. Better thunderstorm
potential tonight is at KGLD, with both terminals expected to be
impacted by thunderstorm activity Thursday afternoon/evening
(possibly severe).


.GLD Watches/Warnings/Advisories...


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