Scientific Forecaster Discussion
fxus63 kgid 192352
Area forecast discussion
National Weather Service Hastings NE
652 PM CDT Sat Oct 19 2019
Short term...(this evening through sunday)
issued at 316 PM CDT Sat Oct 19 2019
It's been a very nice fall day with temps in the 65-70 degree early
this afternoon, with nearly full insolation. Winds have been
relatively light, thanks to surface high pressure sliding southeast
The weather pattern will undergo changes heading into Sunday/Monday
as a strong low pressure system emerges from The Rockies and
crosses the plains. Southerly low level flow increases across our
region late tonight and could see some light rain shower activity
develop in the warm air advection regime toward Sunday morning.
The upper low pressure system is expected to track along the NE/South Dakota
border Sunday (followed closer to the GFS/European model (ecmwf) solution vs the
farther north nam)...and could continue to see a few showers and
possibly a thunderstorm during the day. Precip chances are not
great with our area primarily in the dry slot of system...with
just 20-30 percent chances for precip mainly in our
northern/eastern zones. The latest Storm Prediction Center day 2 outlook has removed
our eastern zones from the general thunder category, however model
instability parameters still indicate the presence of some instability
(east of Hwy 281) and have maintained a slight chance for a storm
in the aftn.
South winds with gusts 25-30 mph Sunday morning will transition
west with a progressing surface trough, with the west winds
steadily increasing in the aftn in our western zones with gusts
25-35 mph. Relative humidity values in our SW zones are forecast
to drop to the 20-25 percent range, which would place this area
in near critical fire weather conditions...if fuels/grasses were
drier. Aside from the wind and a hit or miss chance for a shower,
the day isn't looking too bad temperaturewise with mild temps
averaging in the 60s.
Long term...(sunday night through saturday)
issued at 316 PM CDT Sat Oct 19 2019
The upper low pressure system will continue to trek east Sunday
night, with the associated cold front pushing south through our
area overnight. The fropa will be a noticeable one, marked by
strong/gusty northwest winds which will remain intense into
Monday...with wind speeds of 25-35 mph and gusts of 50 mph. The
strong wind potential continues to be highlighted in the severe weather potential statement. Also
Monday, our SW zones will again see aftn low relative humidity in
the low 20th percentile which could be a concern in areas where
fuels are dry given the expected wind speeds. Post frontal temps
Monday will be cooler in the 50s.
Tuesday is shaping up to be a decent day in between systems, then
cooler air and small chances for precip return with another system
late Wednesday into Thursday. The end of the workweek into the
first part of the weekend should see a dry and warming trend ahead
of another cold front/upper trough arriving around the 27th.
Aviation...(for the 00z kgri/kear tafs through 00z sunday)
issued at 652 PM CDT Sat Oct 19 2019
Busy taf period, particularly in terms of wind.
Tonight: VFR. Clr skies to start the period will give way to incr
high clds after midnight, bec broken-overcast around 12k ft by dawn. Will
see a rapid incr in low level wind shear (llws) in the 10-12z time
frame from west to E, with winds around 50-55kt around 1500ft above ground level.
Sfc winds will also incr, with S wind gusts 20-25kt or higher by
dawn. Confidence: high.
Sunday: VFR. Broken to overcast clds around 10k ft or higher continue
through the morning. May see a few shwrs with trough passage
12-15z, but kept out of tafs for now given low chcs. Low level wind shear should
dissipate with passage of trough around 15-16z, but gusty sfc
winds will continue as mixing incr. Winds will veer from S mid-
morning, to west-southwest by mid-afternoon, with peak gusts 25-30kt with
passage of trough 14-17z and again 20-22z due to deep mixing.
Confidence: medium to high.