Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 260838

Area Forecast Discussion
National Weather Service North Platte NE
338 AM CDT Sat May 26 2018

.SHORT TERM...(Today and tonight)
Issued at 338 AM CDT Sat May 26 2018

Temperatures will be the main focus for the forecast. Warm dry heat
ridge over head today. 850mb temperatures have increased 1C to 2C
over yesterdays maximums. Strong southeasterly flow this afternoon
advecting warmer drier air from Kansas.  Have bumped up surface
temperatures into the mid to upper 90s. Heat indicies in the mid to
upper 90s today and will require no highlights. Minimum relative
humidities falling to around 20 percent over western Nebraska this
afternoon but green up will keep fire weather below. Strong cap and
limited moisture will keep western Nebraska dry over night. Lows
tonight in the 60s.

.LONG TERM...(Sunday through Friday)
Issued at 338 AM CDT Sat May 26 2018

The amplified ridge over the Great Plains and a closed low over the
Great Basin/Rocky Mountains dominate the synoptic pattern aloft. The
low gets absorbed by the large scale trough early in the week as the
trough brushes the northern Plains. After a brief period of quasi-
zonal flow, a new ridge builds over the central U.S. late week. At
the surface, a lee trough is poised to traverse Nebraska over the
weekend, then gets dragged through with the upper trough/wave. High
pressure then regains control in the wake of the fropa.

Sunday... Nudged highs down a degree or so due to increased
cloudiness and slightly cooler H85 temps (25C compared to 28C on
Sat). Decent low level southeast winds (moisture advection and
upslope flow/enhanced lift) combined with increasing fgen in the mid-
levels may result in earlier convective initiation. Regardless,
forecast highs remain near 90F west and lower 90s east. Precip-wise,
thunder potential still looks good. Instability has backed off
somewhat compared to Thu evening model suite, but CAPE is still more
than sufficient (2500+ j/kg). Shear really kicks up late evening
with backing sfc winds, LLJ developing, and 40kt H5 flow. Southerly
cloud layer mean wind is nearly parallel to the lee trough, which
supports quick evolution from supercell to multi-cell/clusters and a
dual hail/wind threat.

Monday/Memorial Day... Also tempered highs a notch into upper 70s
far NW Neb to mid 80s along Hwy 83 corridor to upper 80s central
Neb. Leftover convection from Sun night may still be in play early
in the day for north central, while lingering outflows and strong
destabilization/weak cap result in TSRA chances throughout the day.
Precip chances look best in the evening and night due to proximity
of upper trough, potentially the max instability (3000+ j/kg), and
continued moisture advection (dew points in the lower 60s). Forecast
soundings are somewhat concerning 00-06z with strong veering winds
in the low levels (250+ of 0-1 helicity) and 30 kts of 0-1km shear.
In short, can`t rule out a tornado. As the night wears on, flooding
threat increases with near record PWAT and upscale growth into
multicell clusters.

Tuesday... The cold front finally pushes through the forecast area,
which keeps highs near seasonable readings (upper 70s) and precip
chances high. Can`t rule out briefly severe storms again due to
instability, but shear weakens quite a bit.

Wednesday and beyond... Temps rebound into the 80s and precip
chances are relatively slim with the upper ridge rebuilding and
surface high nearby.


.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1158 PM CDT Fri May 25 2018

VFR conditions will prevail through the TAF period. Clear to
mostly clear skies will continue over the next 24 hours. Light
winds will prevail overnight with winds increasing out of the
south late Saturday morning through the afternoon up to 15 kts,
strongest in the eastern Panhandle and far western NEB.




LONG TERM...Snively
AVIATION...Roberg is the U.S. government's official web portal to all federal, state and local government web resources and services.