Area Forecast Discussion
Issued by NWS Goodland, KS
FXUS63 KGLD 302323
Area Forecast Discussion
National Weather Service Goodland KS
523 PM MDT FRI SEP 30 2016
.SHORT TERM...(This evening through Saturday)
Issued at 1236 PM MDT Fri Sep 30 2016
An upper level short wave trough moves through the apex of the
persistent upper ridge in place over the high plains region during
the day on Saturday. Models hint at an area of showers moving off
the Palmer Divide area during the Saturday afternoon and evening
with another area of thunderstorms possibly developing along a
weak dryline in place over the panhandle region of Texas and
Oklahoma. A few of these storms may extend north far enough
through southwest Kansas and into northwest Kansas to track
across the southern reaches of the forecast area late in the day.
But with a mostly dry airmass with available moisture confined
mainly between 700-500MB, have gone ahead and kept the period
between Tonight and Saturday dry.
.LONG TERM...(Saturday night through Friday)
Issued at 233 PM MDT Fri Sep 30 2016
Saturday night-Sunday Night: Ridging continues to dominate these
periods ahead of deepening upper low. Result should be stable dry
air remaining in place. A stray elevated dry thunderstorm couldn`t
be ruled out Saturday evening in our south, but confidence was too
low to introduce mention. Temperatures will remain above normal,
with Highs Sunday in the lower 80s and lows during these periods
trending upwards of 50 or warmer. Lows on Sunday night may approach
60F, which is almost 20F above normal.
Monday-Monday night: As upper low deepens, surface low pressure will
deepen. Strong deep unidirectional southerly gradient will be
established. Deep dry adiabatic mixing should support stronger gusts
around 45 mph over parts of our CWA. Tds behind surface low/dry line
should also decrease, and combine with mid 80F afternoon temps to
produce RH values 20 percent or lower. This is just above RFW
criteria, however considering the nature of the winds if RHs were
low enough me may need to consider issuance. Cold front should shift
through the region Monday night, and guidance is showing
increasing precip chances despite relatively dry air mass in place.
Storms would be elevated based on soundings, and considering depth
of dry layer coverage could be impacted. Instability will be
somewhat limited through Monday night, so severe threat should be
Tuesday-Tuesday Night: There is larger uncertainty on Tuesday and
Tuesday night regarding the position of the cold front and this
will have a large impact on severe potential during these periods.
Temperatures should be within seasonal normals in the 70s (upper
60s in our west). Latest GFS shows main CAPE axis well east of our
CWA, while ECMWF still shows this back towards the Colorado border
Tuesday afternoon. This is a very dynamic system and effective
bulk shear values could exceed 50kt. If front were to slow down
this could set the stage for increased severe potential,
particularly in the east favoring possible supercells early in the
event eventually merging into a potential squall line. Ultimately
the threat could end up remaining east of our CWA, so this will
need to be monitored for changes either way.
Wednesday-Friday: There may be a brief shot of
shower/thunderstorms on the back side of the departing upper low
associated with secondary jet streak. Otherwise,these periods
should remain dry due to shortwave ridging. Consensus favors
seasonal temperatures in the upper 60s (Wed) to the mid 70s (Fri).
There is the potential for frost conditions Wednesday and Thursday
nights at low lying spots in our west.
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 523 PM MDT Fri Sep 30 2016
Conditions...VFR w/ a SCT-BKN150-200 cloud deck.
Winds........SSE around 10kts. Gusts up to 20kts for KGLD 00z-12z
Saturday...and after 18z Saturday.