Area Forecast Discussion
Issued by NWS North Platte, NE

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FXUS63 KLBF 280520
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
1220 AM CDT SUN AUG 28 2016

.SHORT TERM...(This evening through Sunday)
Issued at 354 PM CDT Sat Aug 27 2016

Fair weather conditions are expected across western and north Central
Nebraska tonight. Despite decent low level moisture in the area, a
southerly low level jet should keep the boundary layer mixed just
enough that fog is not expected to develop. It is possible that a
few patches could develop in areas where winds completely decouple,
but we`ll leave out of the forecast at this time due to the isolated
nature if any fog develops.

The mix of sunshine and moisture will lead to an unstable atmosphere
Sunday afternoon. A weak subtropical disturbance will approach the
area during the afternoon, with isolated to scattered thunderstorms
expected to develop across southwest Nebraska. Brief heavy rain
appears possible with PWATS around 1.25" and K Index values of 40 to
45C. Severe storms are unlikely due to weak shear.

.LONG TERM...(Sunday night through Saturday)
Issued at 354 PM CDT Sat Aug 27 2016

Sunday night through Tuesday...the upper low across Arizona drifts
northeast through KS...Srn and Ern Neb. The model consensus favors
Cntl and Swrn Neb for scattered showers and thunderstorms. Upper
level winds are not favorable for severe storm development
suggesting a multicell environment...15-30kt in the 500-300mb layer.

Extensive midlevel cloudiness at times will keep highs in the mid
and upper 80s Monday and Tuesday. The NAM12 indicates some potential
for morning stratus. Dew points are expected to gradually rise into
the 60s south and east. Northwest Neb is expected to remain dry with
dew points in the 50s during the day. The dryline should retreat
west in the evening and overnight. The fog forecast is uncertain.
The NAM12 visibility product keeps the fog across Cntl Neb but this
could change so fog would be best forecast day to day.

Tuesday night through Saturday...south winds continue through
Saturday which is very unusual since it marks seven days in a row of
southerlies. Sfc dewpoints in the 60s continue with the potential
for upper 60s Saturday according to the ECM. A blend of bias
corrected guidance and model data keeps dew points in the low to mid
60s with a dryline mostly north and south across Wrn Neb.

The models indicate winds aloft increase late in the week as a long
wave trof develops along the west coast. A strong upper level ridge
develops over the North Pacific...597+ dm and this could be a block
as the models hold this ridge in place through day-10. A check on
severe weather potential suggests some potential Friday as an
impulse lifts through the Srn Rockies. Generally isolated showers
and thunderstorms are expected across Srn and SCntl Neb closer to
the better forcing moving through KS. The temperature forecast of
80s for highs represents the loss of intense daytime heating which
would support warmer highs and thunderstorm chances.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1217 AM CDT Sun Aug 28 2016

Fog signatures have backed off in later runs tonight and
confidence is low that they will develop over western and north
central Nebraska. Some BR is possible with 4 to 6 miles
visibilities over southwest Nebraska between KIML and KLBF.
Ceilings aoa 10k ft are expected over the same area through the
late morning into early afternoon with isolated thunderstorms
possible. Left TSTMs out of TAFs given the isolated nature of
these storms. Have removed low-level wind shear at KVTN as low
level jet is not as strong as it was forecast earlier.

&&

.LBF Watches/Warnings/Advisories...
None.
&&

$$

SHORT TERM...Taylor
LONG TERM...CDC
AVIATION...Power/ET



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