Area Forecast Discussion
Issued by NWS Goodland, KS
FXUS63 KGLD 291234
Area Forecast Discussion
National Weather Service Goodland KS
634 AM MDT MON AUG 29 2016
Issued at 634 AM MDT Mon Aug 29 2016
Added patchy fog to eastern parts of CWA based on obs at Hill
City and decent correlation with RAP/HRRR. I also made a minor
adjustment to POPs to match development along outflow boundary
moving toward the western and central parts of our CWA
.SHORT TERM...(Today through Wednesday Night)
Issued at 238 AM MDT Mon Aug 29 2016
As of 3 am CDT, 2 am MDT, skies across the Tri-State region are
partly to mostly cloudy. Latest WSR-88D radar imagery indicates a
few showers and isolated storms developing generally east of Highway
25. Another area of showers/storms was developing over southeast
Colorado, drifting north into east central Colorado. Temperatures
are in the 60s across the region. Light south winds are currently
observed. At the surface, a weak trough of low pressure was centered
over eastern Colorado. Aloft, an upper level low is centered over
northwestern New Mexico and southwestern Colorado. A weak shortwave
trough is moving across the High Plains, likely aiding in current
Over the next 3 days, expect chances for thunderstorms to persist as
the upper level low slowly lifts northeast across the High Plains.
At this time, it is quite difficult to pinpoint exactly where and
when the best chances for precipitation will occur. Over the past
two days, the slightest difference in upper level forcing was the
difference between showers/storms and little/no activity. Storms
that develop today and Tuesday will be capable of heavy rains due to
precipitable waters in excess of 1.40 inches for many locations. Due
to this atmospheric moisture content and slow storm motions, flash
flooding could become a cause for concern.
For today, morning thunderstorm activity should gradually diminish
as the low level jet weakens. However, a shortwave trough should be
moving in from the south. A brief lull in activity is possible
before convective initiation this afternoon. High-resolution
guidance indicates two favored areas of development: 1. generally
south and east of a line from Oberlin, Kansas to Cheyenne Wells,
Colorado just ahead of the strongest upper level forcing, and 2.
Along the surface trough axis from southwest Nebraska to near Limon,
On Tuesday, models remain persistent in forecasting more widespread
precipitation and chances for heavier precipitation across northwest
Kansas as the decaying upper low lifts northeast into the region.
Anticipate Tuesday to be the most active in terms of precipitation
On Wednesday, a cold front should begin sliding into the region from
the north to northeast. This front may not have an impact on the
area until Wednesday evening when it begins slipping into southwest
Nebraska. The primary impact should be dry air advection and a
gradual end in precipitation chances from north to south.
As for severe potential, a few strong to severe thunderstorms will
be possible each day due to the elevated amount of instability.
However, wind shear will be quite weak so would not expect any
widespread or organized severe weather threat. At most, a few pulse-
type storms capable of marginally severe hail and a damaging
downburst would be the primary threats.
.LONG TERM...(Thursday through Sunday)
Issued at 1242 AM MDT Mon Aug 29 2016
Upper ridge over the central plains to start the period will break
down by the end of the week to be replaced by a broad
southwesterly flow aloft across the western half of the conus.
Storm track of the stronger upper systems will remain across the
northern plains, but weaker systems embedded in the southwesterly
flow will bring low chances for thunderstorms just about every
day of this forecast period. Shear/instability forecasts suggest
only marginal risks for severe storms, but both parameters do get
better with time and by Sunday might see more of a risk, provided
synoptic scale forcing is there, which is uncertain. Temperatures
start the period near normal but rise to above normal by the weekend.
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 540 AM MDT Mon Aug 29 2016
Near-term aviation concern is thunderstorms affecting KMCK. Based
on current motion and radar trends, storms should move away from
KMCK by 13z and out of the vicinity by 14z. Both sites may
observed afternoon/evening storms today. Am unsure on exact
development locations but recent runs of the HRRR indicate
widespread development across the region. For now, due to low
confidence, issued a forecast with a PROB30 group for storms. By
the end of the forecast period, widespread stratus may spread in
from the southeast. KMCK is most likely to be impacted out of two
TAF sites. Timing is a little in doubt so have not included in
this TAF cycle.