Area Forecast Discussion
Issued by NWS Hastings, NE
FXUS63 KGID 221721
Area Forecast Discussion
National Weather Service Hastings NE
1121 AM CST Wed Feb 22 2017
.SHORT TERM...(Today and tonight)
Issued at 617 AM CST Wed Feb 22 2017
Aloft: Aircraft and 00Z soundings showed the Westerlies were
fairly zonal across the CONUS. A 120 kt jet streak extended from
CA-WY with multiple low-amplitude shortwave trofs on the N side of
it. A more substantial trof was approaching the W coast. The flow
overhead will become more anticyclonic tonight as this trof moves
inland today and progresses further inland tonight. A 700 mb low
will form after midnight and will be over S-cntrl WY by 12Z/Thu.
Surface: Low pres was along the SD-MN border with a cool front
extending across the Sandhills int CO/UT/NV. As the low conts
moving E...the cool front will pass thru the fcst area this
morning. It will become stationary from W-E across cntrl KS as lee
cyclogenesis occurs over CO.
Today: This is the last unseasonably warm day. This has been a
long stretch that really began back on the 10th. This will be the
8th straight day with high temps of at least 60F. Temps will
still be within 5F of record highs...but will fall short.
GRI: 76 in 1982
HSI: 75 in 1982
Variable cloud cover today with patches of thick cirrostratus
drifting thru. Overall...p-m/sunny. Less wind than yesterday over
Fire Wx: I contemplated removing the "near critical" in the HWO as
MOS and GFS/NAM time-height cross sections show weaker wind fields
vs. yesterday. However...after further assessment for the fire wx
fcst...I blended MOS winds with some of the 07Z RAP which has
higher winds in the BL. The RAP did an outstanding job with
magnitude of the PKWNDs yesterday. With deep mixing expected again
today...believe it is wise to maintain "near critical" mention N
and E of the Tri-Cities. This area could be very close to critical
(Red Flag) conds today.
Tonight: Increasing clouds. Lows will still be above frzg. Lift
from QG forcing and enhanced by strengthening WAA/Fgen could
result in some sprinkles or lgt rain toward dawn N of Hwy 6 with
the greatest chance NW of a line from LXN-ODX.
.LONG TERM...(Thursday through Tuesday)
Issued at 326 AM CST Wed Feb 22 2017
Focus is on the return of rain and snow Thursday and Friday as a
storm system crosses the Central Plains. Upper low pressure in the
central Rockies early Thursday will emerge onto the plains during
the day with the closed system tracking across Nebraska.
Isentropic lift increases ahead of the approaching system with
rain developing initially Thursday, with the rain mixing with and
changing to snow as cold air is drawn south Thursday evening and
night. Models continue to show the presence of instability in our
southeast zones Thursday afternoon and while a rumble of thunder
is not completely out of the question, have not included in the
forecast due to an isolated nature and short duration potential.
The track of the winter storm system across Neb lifting northeast
into nw IA brings the heaviest snowfall across northern Neb.
Currently have snow amounts in the 3 to 5 inch range in the Ord
and Greeley areas with amounts tapering off to an inch or less
south of Interstate 80. Will need to monitor storm track as a
southward shift would bring higher snow amounts to our northern
zones. At this time the GFS is the most aggressive with even
higher snowfall potential, but have stayed closer to NAM/GFS/SREF
which are all fairly consistent with amounts around the 4 inches
in our north. Winter headlines may be needed in the near future
given the expected accumulating snowfall and strong north wind
gusts of 30 to 40 mph accompanying the snow Thursday night into
The snow gradually tapers off from west to east through the day
on Friday with conditions drying out returning to seasonal
February weather over the weekend. Temperatures trend warmer next
week ahead of a western trough and there is an outside chance for
precipitation with a lead wave crossing the plains Monday night.
.AVIATION...(For the 18Z KGRI/KEAR TAFS through 18Z Thursday afternoon)
Issued at 1116 AM CST Wed Feb 22 2017
Not much going on this afternoon and into the evening. There could
be a few cirrus moving through the area. Later tonight there will
be an increase in clouds and they will lower to MVFR late tonight
and tomorrow morning could get into the IFR heights. There is an
off chance for some light rain, but should have little impact on
visibilities until the very end or past the end of the period.