Area Forecast Discussion
Issued by NWS Goodland, KS
FXUS63 KGLD 261142
Area Forecast Discussion
National Weather Service Goodland KS
542 AM MDT FRI AUG 26 2016
.SHORT TERM...(Today through Sunday Night)
Issued at 232 AM MDT Fri Aug 26 2016
As of 3 am CDT, 2 am MDT, skies across the Tri-State Region are
overcast. Temperatures are in the mid to upper 50s. Winds are light
and variable. Latest WSR-88D imagery indicates precipitation-free
conditions throughout western Nebraska, eastern Colorado and most of
western Kansas. At the surface, high pressure is centered over
southeastern South Dakota, sliding slowly to the east. Aloft, a
shortwave trough is quite evident on water vapor imagery, located
over eastern Utah and on an easterly course. It is this disturbance
that is expected to bring active weather to the region today and
For today and tonight, widespread thunderstorms are expected to
traverse the region. As the shortwave trough, currently located over
eastern Utah, spreads east, am expecting widespread thunderstorm
development over eastern Colorado. High-res guidance indicates
SBCape of 1500 J/kg, 850-500 mb Lapse Rates of 6-7 C/km, and 0-6 km
Bulk Shear of 30-40 kts by this afternoon. These parameters suggest
that there should be some storm organization and a few storms could
be strong/severe. In addition, there is some low-level veering of
the winds and some guidance members indicate favorable 0-3 km
helicity for the possibility of a tornado. Do have concerns that
storms may develop into a linear complex before a tornado threat is
able to develop but this should be monitored closely. Storms should
peak between 3 pm MDT and 9 pm MDT today before activity gradually
slides east tonight. The primary threats with storms will be large
hail, damaging winds, and heavy rainfall.
Behind the storms tonight, a moist boundary layer is expected. With
some clearing skies and radiational cooling, am expecting patchy fog
to develop. Some members of high-resolution guidance are hitting on
dense fog along the Colorado border where conditions are most
favorable. Unfortunately, it is tough to highlight an exact area for
fog potential at this time due to possible clouds and concerns on
how far temperatures will actually drop.
On Saturday, another weak disturbance is forecast to move across the
High Plains. A more unstable airmass may be in place as low-level
moisture should be higher thanks to recent rainfall and advection
from the southeast. Thunderstorms should develop over southeast
Colorado and spread northeast across east Colorado and northwest
Kansas. Once again, a few strong to severe thunderstorms are
possible. Wind shear is forecast to be weaker Saturday so am not as
concerned about storm organization and persistence. The primary
threats from these storms should be marginally severe hail and
Thunderstorms are possible once again Sunday afternoon and evening.
Instability parameters are about the same as Saturday. However, wind
shear is even weaker due to weak winds aloft. A few strong storms
would be possible but the severe threat looks lower. Sunday should
be the warmest day over the next 3 days with highs climbing into the
upper 80s to lower 90s.
.LONG TERM...(Monday through Thursday)
Issued at 203 AM MDT Fri Aug 26 2016
Thunderstorm chances continue into the start of the extended period
before dry conditions return to the High Plains midweek.
Temperatures look to slowly climb through at least Thursday.
Early next week, mid level ridging begins to establish itself over
the High Plains. Some monsoonal moisture should be available on the
western periphery of the ridge as disturbances pass through the
flow, with a boundary stalled south of the area. Kept slight/low
chance PoPs Monday through Tuesday night for mainly the southern and
eastern portions of the CWA.
An upper trough pushes onto the west coast on Tuesday as a second
trough digs south over the eastern CONUS from Canada. The ridge
sharpens between these features through the end of the period, with
the west coast trough slowly advancing east while the east coast
trough creeps south. The region will remain under the ridge and dry
weather looks to persist Wednesday through Thursday.
Temperatures start out in the mid to upper 80s on Monday, gradually
rising into the low 90s in time for Thursday. Low temperatures
remain in the mid 50s to mid 60s.
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 542 AM MDT Fri Aug 26 2016
MVFR conditions recently developed at KGLD. Light fog also
developing around KMCK. Anticipate any MVFR conditions to rapidly
improve by 15z. A disturbance moves through this afternoon,
leading to widespread thunderstorm development over Colorado.
Storms should form into a complex/line and affect TAF sites during
the late afternoon/evening hours. Anticipate heavy downpours,
gusty winds, and potentially MVFR cigs/vis with the storms.
Storms exit the region this evening. Boundary layer moisture
becomes quite high after midnight due to moisture advection and
recent rains. Expecting stratus/fog development early tomorrow
morning. Remain unsure on how low cigs/vis fall. Further
refinements will be needed in later TAF issuances.