Area Forecast Discussion
Issued by NWS North Platte, NE

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41
000
FXUS63 KLBF 202028
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
328 PM CDT Fri Oct 20 2017

.SHORT TERM...(This evening through Saturday)
Issued at 328 PM CDT Fri Oct 20 2017

The main weather story over the next day or so is the upper ridge
exiting the Plains and the associated surface cold front sweeping
across the region.

This evening and tonight... Maintained chc PoP with the fropa after
06z across the Sandhills with schc SW Neb. Forcing, lift, and fgen
are rather strong given the stout mid level shortwave combined with
the front. However, the overall moisture profile is lacking with
bouts of dry air either in the low or mid levels. Forecast soundings
suggest marginal instability to support a rumble of thunder, but it
doesn`t coincide with the best moisture. Kept min temps above
guidance to account for increased cloud cover and elevated winds.
Trended winds up with the fropa for pressure rises of 2mb/hr, H85
winds near 40kts, and 1.5 PVU dropping to 550mb.

Saturday... Kicked out all PoP by 18z as strong subsidence/
isentropic downglide takes over. General agreement among the model
suite with CAA of 10C at H85 from 00z Sat to 00z Sun. Max temps
split MAV/MET, but temps could be underdone depending on sky cover,
downsloping winds, and a hint of a weak thermal ridge riding off the
Rockies late in the day. Elevated fire weather conditions continue
in the panhandle where RH`s approach 20% with gusty northwest
winds.

.LONG TERM...(Saturday night through Friday)
Issued at 328 PM CDT Fri Oct 20 2017

Strong radiational cooling will offset the warming effects of
westerly downsloping winds early on Sunday.  Based off the latest
available guidance, lows in the upper 20s to lower 30s appear
likely.  River valleys and northwest Nebraska will be the coolest
sites just after daybreak, especially if we decouple early.
Increasing subsidence with a transitory mid level ridge will
suppress cloud development on Sunday.  With full sunshine in place
and forecast westerly downsloping winds, highs will rebound back
into the 70s for most locations.  The downsloping winds will dry the
lower troposphere with relative humidity during the peak heating
hours in the 20s across the forecast area.  20-ft winds are
generally forecast at 15 mph or less, so the threat of large fire
growth is minimal at this point. It should be noted however that
winds are forecast to increase slightly late afternoon over far
western portions of zone 204 Sunday afternoon, near critical fire
weather conditions are possible there and will be watched closely.

A cold front will cool temperatures slightly early next week, but
bring in some breezy conditions.  Wind gusts in excess of 25 mph are
possible Monday afternoon, but the cooler temperatures will allow
for higher minimum relative humidity.  The roller coaster of
temperatures continues mid week as another transitory ridge builds
northeast across the central plains.  After cooler temperatures
Tuesday, highs return back into the 70s Wednesday.  The warm
downsloping winds will dry the lower troposphere again to near
critical thresholds with some wind forecast Wednesday afternoon.  A
strong cold front arrives late Wednesday night.  Strong winds from
the northwest will accompany the frontal passage with cooler
temperatures for Thursday.

Precipitation chances round out the work week as an upper trough
crosses the plains, but model consistency is not the best, so those
chances are marginal/conditional at this point.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1219 PM CDT Fri Oct 20 2017

Wind is the primary aviation weather concern across western and
north central Nebraska through Saturday afternoon. South winds
will be quite gusty this afternoon and evening ahead of an
approaching cold front. A brief lull at ground level late this
evening may cause low level wind shear. The front will push
through overnight and rapidly strengthen and switch the winds to
northwesterly, generally around 21/06z at GRN, 21/09z at LBF and
VTN, and by 21/12z at BBW and ONL. Rain showers are possible along
and behind the cold front, but cigs and visby should remain VFR.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...Snively
LONG TERM...Jacobs
AVIATION...Snively



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.