Area Forecast Discussion
Issued by NWS Goodland, KS

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FXUS63 KGLD 280735

Area Forecast Discussion
National Weather Service Goodland KS
135 AM MDT SUN AUG 28 2016

.SHORT TERM...(This afternoon through Sunday)
Issued at 210 PM MDT Sat Aug 27 2016

SW flow remains in place across the plains with a mid-upper level
trough still in place across the desert southwest. Several weak
ripples (shortwave troughs) are rotating through the main flow aloft
with disorganized forcing leading to several pockets of
showers/thunderstorms early this afternoon.

Instability has already increased to 2000-3000 J/KG based on latest
RAP analysis, and thunderstorms have already developed near our
western CWA near this CAPE maxima aided by weak convergence along
surface trough. Shear is relatively weak and is expected to peak
around 30 KTS near 00z, so supercells are much less likely. There
is a region of veering nearing baroclinic zone in our south where
additional development is projected and there may be enough shear
for a more organized cell. Otherwise, the tendency will be towards
slower moving pulse type thunderstorms (large hail/strong winds).
PWATs should increase to 1-1.5" range late this afternoon, so
potential for locally heavy rain exists. Most guidance (other than
NAM) shows coverage peaking in the 00-06Z time frame and then moving
out of our CWA (or dissipating). NAM tries to linger
showers/thunderstorms through Sunday morning, and while there could
still be weak forcing in place decreasing considering the large
consensus towards dry conditions I favored that trend.

There is still poorly correlated precip signal in guidance Sunday
afternoon due to differences on timing of the next mid level vort
max to break out of the southwest and move northeast towards the
plains. NAM is certainly most aggressive, while GFS keeps conditions
dry through the afternoon. There is limited to no higher resolution
support. I kept slight chance/chance PoPs in place in the afternoon
(focused just east of surface trough) to remain consistent and
remain in line with ensembles. If thunderstorms develop we are
looking at similar threats as today with limited effective shear and
moderate instability. Seasonal highs (mid to upper 80s) are

.LONG TERM...(Wednesday through Saturday)
Issued at 123 AM MDT Sun Aug 28 2016

A weak disturbance coming out of the central Rockies on Wednesday
combined with a moist low level southeasterly flow will result in
scattered thunderstorms. Weak instability/shear will keep severe
threat at a minimum. The ridge axis shifts a little further east
on Thursday, but difficult to find any kind of large scale forcing
for convection. Moisture/instability and shear profiles get
better, so if anything can develop there might be a marginal risk
for a severe storm. By the end of the week/start of the weekend
get into more of a southwesterly flow aloft as a stronger
disturbance moves through the northern Rockies. Associated surface
cold front will slide into the area Friday night and may be the
focus for convection through Saturday. Model details not in
particularly good agreement at that time range, so POPs will range
from slight to low chance.

Temperatures start the period slightly below normal but warm to
near normal by the end of the period.


.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1125 PM MDT Sat Aug 27 2016

VFR conditions will prevail through the TAF period at MCK and GLD.
With dewpoints and overnight low temperatures converging in the
middle 50s to middle 60s across the Central High Plains tonight
under partly cloudy skies with light winds, thee is a possibility
of patchy fog developing mainly between 09Z and 13Z early this
morning. Localized IFR conditions are possible across the region,
but have been excluded from the TAF sites at this time. Isolated
thunderstorms will begin to develop around mid day with scattered
thunderstorms possible again Sunday afternoon after about 20Z.
Storms should begin to diminish in coverage after 04Z late Sunday


.GLD Watches/Warnings/Advisories...


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