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Office: LBF

FXUS63 KLBF 201113 AAA
AFDLBF

Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
513 AM CST Tue Nov 20 2018

.SHORT TERM...(Today and tonight)
Issued at 356 AM CST Tue Nov 20 2018

A weak arctic front appears to be located between Valentine and
Broken Bow. Areas of fog are forming along the front and areas of
fog are in place early this morning. The front should move east and
exit ncntl Nebraska around 9 or 10 am this morning.

The temperature forecast today uses a blend of the warmer guidance.
That would be the ECS and MAV guidance plus bias correction. We are
expecting full sun conditions and west winds which should support
deep mixing to near 750mb and highs in the 50s.

The temperature forecast tonight uses the guidance blend plus bias
correction for lows in the teens and 20s. A weak sfc low pressure
trof will form on the nrn high plains but precipitable water is
forecast to fall with drier air moving in today through Thursday.
The combination of clear skies, dry air and light winds should
produce an excellent radiation condition.

.LONG TERM...(Wednesday through Monday)
Issued at 356 AM CST Tue Nov 20 2018

A large upper ridge centered over the Great Basin slowly progresses
east this week, lining up with the High Plains early on
Thanksgiving. The ridge is quickly followed by a trough moving
onshore in the Pac NW. A deeper trough then takes aim on the region
over the weekend, digging into the southern Plains and eventually
closing off a low. This system presents the main forecast challenge
as the potential exists for wintry conditions for western Neb during
a busy travel period.

Wednesday through Friday... The warmup peaks Wed and Thu with the
upper ridge directly overhead, strengthening downslope flow at H85,
and a 12C thermal ridge ejecting onto the High Plains. Continued to
trend toward the warmer guidance, resulting in widespread upper
50s/lower 60s for highs. A cold front swings through the area
overnight Thu into Fri. Despite the fropa, weak CAA aloft and fair
skies should keep highs in the 50s for Friday. The main concern is
wind due to 35kt+ flow at H85, efficient mixing, and a PV anomaly
nearby.

Saturday and beyond... The GFS and ECM have come closer with the
handling of the trough, especially with timing, and now the GFS is
closing off the upper low. However, discrepancies still exist, with
the low track being the biggest difference. The ECM has a much
farther northerly track, taking the low across the Neb panhandle and
into NW Kansas, while the GFS rolls across the Four Corners and into
the southern Plains. While confidence has increased in precip for
western Neb, concerns remain in the amounts and p-type. Latest
indications point toward moisture increasing early Saturday across
the panhandle in the form of snow, but warm air gets pulled into the
region during the day. Highs in the mid/upper 40s will be plenty
warm for a transition to all rain. The real CAA takes place later
Saturday with H85 temps dropping to around -10C. Assuming a
deformation band develops on the north side of the low, this would
be prime for snow. The potential certainly exists for an
accumulating event, but the southerly route would result in just a
quick round of light snow or flurries. Regardless, wind will be a
concern as the pressure gradient steepens rapidly invof sfc low.
Northerly winds gusting 35+ mph will cause some issues, especially
on east west routes like I-80. Visibility would be greatly reduced
with any snow factored in. Awareness needs to be raised and have
highlighted in the HWO.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 512 AM CST Tue Nov 20 2018

An upper level ridge of high pressure across the wrn U.S. will
move slowly east today and tonight. Clear skies are expected
throughout wrn and ncntl Nebraska during this time.

&&

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

$$

SHORT TERM...CDC
LONG TERM...Snively
AVIATION...CDC



Office: OAX FXUS63 KOAX 201120 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 520 AM CST Tue Nov 20 2018 .SHORT TERM...(Today through Thanksgiving) Issued at 300 AM CST Tue Nov 20 2018 At 3 AM, ridging was dominating over the Rockies, while a longwave trough remained in place over the eastern U.S. This was producing northwest flow over the central Plains and sending scattered midlevel clouds streaming over Nebraska/Iowa. At the surface winds were light and temperatures ranged from the low teens over west central Iowa to the mid 20s around Lincoln. The ridge over the Rockies will shift eastward through Thanksgiving. With this transition, rising heights and more southerly flow will aid in the return of above average temperatures over the central Plains. Look for temperatures in the 50s (60s in central Nebraska) to dominate Wednesday-Thanksgiving. Accordingly, this will make for excellent Thanksgiving travel conditions, not only locally, but across the eastern two thirds of the U.S. .LONG TERM...(Thursday night through Monday) Issued at 300 AM CST Tue Nov 20 2018 Hopefully everyone is able to enjoy the nice weather over the Thanksgiving Holiday, because it is destined to leave us Friday and this weekend as a pair of shortwave troughs come knocking. Shortwave trough number one should arrive Friday, and looks to be a fairly warm system. Models have been very consistent with the timing of the first shortwave for several days, so confidence in rain on Friday is moderate-high. A second stronger shortwave is expected to impact the central U.S. late Saturday into early Monday. This system will likely be colder, windier, and depending on the track (still several days out) has the potential to bring impactful/accumulating snow to eastern Nebraska/western Iowa. If you have travel plans (especially on Sunday) anywhere in the Nebraska/Iowa/Kansas/Missouri region, you should monitor the forecast closely as the weekend approaches. Confidence in arrival of impactful snowfall over Nebraska/Iowa on Sunday is moderate. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) Issued at 520 AM CST Tue Nov 20 2018 Low-level warm advection on the backside of a departing surface anticyclone has yielded bands of VFR (FL040-060) stratocumulus which are shifting east through eastern NE and western IA as of 11z. Those clouds should move east of the area by late morning with light and variable winds strengthening to 10-15 kt from the southwest by afternoon. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Albright LONG TERM...Albright AVIATION...Mead
Office: GID FXUS63 KGID 201154 AFDGID Area Forecast Discussion National Weather Service Hastings NE 554 AM CST Tue Nov 20 2018 .SHORT TERM...(Today and tonight) Issued at 400 AM CST Tue Nov 20 2018 Cloud cover became a bit more patchy across the local area overnight allowing temperatures to drop into the lower to middle 20s across the majority of the forecast area the past few hours. In addition...have seen some very patchy fog develop in a few spots as a result of clearing skies and light winds...but dense or widespread fog is unlikely and not evident in any of the cameras we have access to...so think any fog that has been able to develop will be quick to dissipate during the morning hours. Later today...expect a nice fall day across the region as temperatures continue to climb and light southwesterly winds are expected. This will be in part due to an upper level ridge of high pressure across the intermountain west that is forecast to track eastward. While the axis of this ridge will not be overhead until later in the week...the mostly sunny skies and modifying airmass should result in most locations climbing into the lower to mid-50 later today. For tonight...seasonable conditions will return with light winds and clear skies allowing temperatures to drop into the lower and middle 20s by early Wednesday morning. .LONG TERM...(Wednesday through Monday) Issued at 400 AM CST Tue Nov 20 2018 A nice start to the extended periods is forecast as the aforementioned ridge of high pressure transitions across the plains Wednesday and Thursday as the next upper level disturbance tracks well to our south. Therefore...above normal temperatures should be the rule for both Wednesday and Thanksgiving day...before the next upper level disturbances tracks northeastward from the southwest and into the Missouri river valley. Still some uncertainty with this next system...but maintained the small rain chances given by model blends this morning as there was no clear reason to ignore them with this upper level system brushing so close to the local area. Later in the weekend things become a bit more interesting as the operational runs of both the EC and GFS both bring a stronger system across the local area. Still plenty of uncertainty with system...as the latest EC has a more northerly track and the GFS continues to have trouble closing off the upper level circulation until it is past the local area...but either way...a winter storm does appear headed for the local area late in the weekend which could bring some accumulating snowfall to the local forecast area as early as Saturday evening. Due to the fact it is a holiday weekend and many people will be on the roads Sunday...decided to mention this potential for accumulating snowfall in the HWO despite forecast totals backing off significantly from previous model runs. Beyond Sunday...dry and seasonably cool weather is forecast to impact the local area for at least the first half of next week. && .AVIATION...(For the 12Z KGRI/KEAR TAFS through 12Z Wednesday) Issued at 552 AM CST Tue Nov 20 2018 VFR conditions with light southwesterly winds are expected through the period as a weak pressure gradient remains across the local area an only a few high clouds will pass across the region from time to time. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ SHORT TERM...Rossi LONG TERM...Rossi AVIATION...Rossi