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Office: LBF

FXUS63 KLBF 141116 AAA

Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
516 AM CST Thu Dec 14 2017

.SHORT TERM...(Today and tonight)
Issued at 330 AM CST Thu Dec 14 2017

Near term models in good agreement which water vapor imagery
supports today. Stronger wave dropping south over the northern
plains today. Areas of light snow over southwest South Dakota early
this morning will move south into northwest Nebraska this morning.
Better chances north this morning through the noon hour. An inch or
less of accumulation expected. Temperatures will rise through the
afternoon with a light mix of precipitation through the afternoon
across the western Sandhills and southwest Nebraska. Highs this
afternoon in the 30s north with the 40s over southwest Nebraska.
Tight pressure gradient this afternoon with breezy northwest winds
this morning becoming strong this afternoon. Precipitation will
end this afternoon as wave pushes south and skies begin to clear.
Temperatures will fall into the mid teens and 20s tonight.

.LONG TERM...(Friday through Wednesday)
Issued at 330 AM CST Thu Dec 14 2017

The persistent northwest flow aloft that we have seen for the last
couple of weeks, will continue through the weekend into early next
week. Beyond this time, models hinting that upper troughing will
begin to develop across the western CONUS. This could be the start
of a major pattern change as we head toward Christmas.

In the meantime, mild Pacific air will continue to dominate, with
highs in the 40s and 50s the next several days. The exception will
be Sunday, when a bit of arctic air will mix south and hold highs in
the mid to upper 30s. This is actually where we should be normally
for highs this time of year. This bit of colder air will be in the
wake of a shortwave disturbance that will drop quickly southeast
across the central Rockies and then weaken as it moves out into the
southern plains. The models have come into better agreement with
this system, and now keep most of the light precipitation west and
southwest of the area. Will hold on to some low pops across western
and southwest Nebraska Saturday night into Sunday morning, but
chances not looking good at this time. So the continued dry pattern
appears that it will prevail.


.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 511 AM CST Thu Dec 14 2017

Ifr and mvfr cigs with areas of light snow or flurries developing
over northern Nebraska early this morning. Restrictions to
visibility not expected. Less than an inch of accumulation
expected between KKVTN and KONL this morning. Snow will mix with
rain through late morning and then become all rain this afternoon
as temperatures rise. Some MVFR cigs expected over southern
Nebraska this afternoon but mostly VFR conditions. Strong
northwest winds expected this afternoon over western Nebraska.


Issued at 330 AM CST Thu Dec 14 2017

Appears that wind and low humidity will combine to bring elevated
fire weather concerns to southwest Nebraska and the southern
Nebraska panhandle Friday. West winds at 10 to 20 mph and
humidity of 18 to 20 percent will combine to bring the elevated
conditions. Beyond Friday, no elevated or critical fire weather
conditions are expected.




LONG TERM...Taylor

Office: OAX FXUS63 KOAX 141152 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 552 AM CST Thu Dec 14 2017 .SHORT TERM...(Today through Saturday) Issued at 250 AM CST Thu Dec 14 2017 A short-wave trough over the northern High Plains early this morning will track generally south today with the strongest large-scale forcing for ascent focused across central NE. Light precipitation ongoing over western SD as of 0730z will likewise spread southeast, eventually reaching our northwest counties by about mid morning. Initial precipitation type will be snow or a rain-snow mix before transitioning predominantly rain by afternoon. The best chance of measurable precipitation will remain across our western counties today with only slight-chance PoPs from far eastern NE into southwest IA. Any snow accumulation should be low and less than a half inch. Widespread clouds will limit daytime heating with highs mainly in the upper 30s to lower 40s. Tonight, any lingering precipitation should end by mid to late evening as the short-wave trough passes to our south. By Friday, mid-level heights will build with westerly low-level winds supporting the eastward advance of a warmer air mass into the mid- MO Valley. This warming could be offset by some mid and high- level clouds, though highs should rebound back into the mid to upper 40s. Friday night into Saturday, a polar-branch trough will approach the region from the west with an associated cold front settling south into the mid-MO Valley. A mild air mass will remain in place ahead of the front with highs on Saturday in the mid 40s to mid 50s. .LONG TERM...(Saturday night through Wednesday) Issued at 250 AM CST Thu Dec 14 2017 On Sunday, a weakening low-latitude disturbance will eject northeast across the Ozark Plateau ahead of the aforementioned polar-branch trough which will shear east across the northern Plains and upper-MS Valley. The majority of precipitation associated with the former disturbance will remain to our south, though a small part of far southeast NE and southwest IA could get glanced where we will include low PoPs. During the early to middle part of the upcoming week, medium-range guidance suggests that a longer-wavelength trough will amplify over eastern North America. While we could see a brief shot of cooler air associated with the upper-air pattern change, it appears that temperatures will remain above normal. By late next week into next week, the signal for a major western U.S. trough is becoming more consistent. This trend could translate to a potentially wetter and whiter forecast as we approach Christmas. && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) Issued at 435 AM CST Thu Dec 14 2017 A couple of shortwaves will affect the area today. VFR/MVFR conditions (fl025-050) expected along with a little light drizzle near the Missouri River this morning and a little light rain/snow mix this afternoon and this evening. Any precipitation should be light. Winds will be northwest 4 to 13kts. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Mead LONG TERM...Mead AVIATION...Zapotocny
Office: GID FXUS63 KGID 141131 AFDGID Area Forecast Discussion National Weather Service Hastings NE 531 AM CST Thu Dec 14 2017 .SHORT TERM...(Today and tonight) Issued at 420 AM CST Thu Dec 14 2017 Upper air data showing continued northwesterly flow in place across the region this morning. It's not as amplified as it has been, the main upper level ridge axis being located along/just off the west coast, while broad troughing over the eastern CONUS. While conditions across the CWA remain dry early this morning, focus is to the north-northwest, where satellite shows a weaker shortwave disturbance making its way through the Northern Plains. At the surface, the pattern is a weak one, resulting in light westerly to calm winds. Skies are mostly cloudy across the area, helping keep temps up a bit, 3 am obs range from the lower/mid 30s for most locations. Main forecast concern in the short term period comes during the daytime hours, with precipitation chances. Models are in good agreement showing this shortwave disturbance continuing to slide SSE through the Central Plains today. There's not exactly an abundance of moisture for this system to work with, but models have been fairly consistent showing at least scattered precipitation affecting the CWA. Backed PoPs off a bit this morning, the better chances look to be late morning through the afternoon hours. Continue to have the potential for both rain and snow going, but admittedly the forecast is on the cooler side of models/guidance for temperatures, with highs in the upper 30s/mid 40s. Some suggest any snow would be short lived, confined to the very start/end of the day. Either way, not expecting much accumulation, but current forecast has a tenth or two of snow possible across northern portions of the CWA. The light winds in place early this morning will turn more northwesterly with the passage of another frontal boundary, with speeds not as strong as yesterday, but sustained speeds of 15-25 MPH are possible. The strongest winds look to be west of HW 281. Should see plenty of cloud cover through the day. Outside of a lingering slight change PoP this evening, the 00-12Z Friday period is dry. Should see diminishing sky cover, with winds tapering off and again turning more westerly. Overnight lows tonight are expected to fall into the upper teens to lower 20. .LONG TERM...(Friday daytime through Wednesday) Issued at 420 AM CST Thu Dec 14 2017 General overview of this 6-day period: Fourth and final night on the long term desk, and compared to the past few nights there are actually a few more relatively minor forecast changes to discuss, mainly involving: 1) seemingly even less chance of snow from the weekend system (not that we were "talking it up" much to begin with) and 2) some minor upward temp adjustments to a few days. Temperature- wise, our remarkable stretch of mildness marches on, with 5 of these 6 days aimed 10-15 degrees above mid-December normals, and the 1 colder day (Sunday) near-normal at worst. Typically don't discuss matters beyond the end of our official 7-day forecast range here, but for those longing for more "true" December cold, current trends suggest some legitimate below-normal readings COULD be firmly in place by next Fri-Sat (Dec 22-23). Likely/potential weather hazards: With little if any apparent risk of wintry precipitation, and no days that appear as strongly-windy as this past Mon/Wed, the only issue currently worthy of inclusion in our latest Hazardous Weather Outlook (HWOGID) is near-critical fire weather conditions Friday afternoon. Considered introducing this mention 24 hours ago, but now that it's within the Day 2 range, confidence has increased that especially the southwestern 1/3 of our coverage area (CWA) will see a few hours of overlap between relative humidity as low as 18-25 percent and southwesterly wind gusts around 20 MPH or slightly higher. Unless wind speeds trend upward another 5 MPH or so, this setup should be "safe" from meeting critical thresholds that would necessitate Warning issuance. Basic precipitation overview: The vast majority of these 6 days currently remain dry, and with pretty darn high confidence in remaining so. Here 24 hours ago, we discussed how especially the ECMWF was showing potential for perhaps as much as 1-2" of snow Saturday night into Sunday daytime. However, even this more aggressive model has backed off considerably, making it currently appear that even flurries may be difficult to come by (see daily details below for more on this). Thus the single biggest change to the official forecast from the previous version: The entire Sat night period is now dry, and any small chance of snow for Sunday daytime is confined to the morning hours and mainly just in the northwest half of our CWA (and even this appears iffy). HOWEVER, all this being said, want to caution against completely discounting this system altogether yet, as with it still being 3-4 days away, there is: 1) Still time for it to "flip flop" back to showing a little snow...2) Some early hints that perhaps a little pesky light freezing drizzle could try to form Sunday morning. Often times, light (usually non-measurable) drizzle doesn't get formally introduced to forecast products until it gets within 24-36 hours, so this will be something to keep an eye on as the weekend arrives. Basic temperature overview: Above normal remains the overwhelming theme, with most areas aimed somewhere between the upper 40s-upper 50s for highs on most days (10-15 degrees above normal). The only colder exception continues to be Sunday, with only upper 30s-low 40s, but this is technically right at-to-just-above normal. Some modest increases (generally up to 3 degrees) were made to high temps on Friday/Monday/Wednesday based on the latest trends, with values for the other 3 days remaining very similar. As for overnight lows, most nights are aimed mid- upper 20s (generally 5-10 degrees above normal), with Sunday night the main slightly- colder exception with low 20s more common. Will conclude with some day-to-day specifics, particularly focused on the shifting trends for for the weekend system... Friday/Friday night: This will be one of the "nicer" days of the long term, featuring mostly sunny skies (although there likely be some degree of higher clouds), warmer temps than today, and relatively manageable breezes averaging sustained 10-15 MPH/gusts to around 20 MPH. High temps raised around 3 degrees all areas, aimed from around 50 east to mid-upper 50s far west/southwest. Near-critical fire weather thresholds are in play mainly southwestern 1/3. Saturday daytime-Sunday night (the weekend): As discussed above, this time frame has changed the most (at least precip-wise) from 24 hours ago. While 24 hours ago models were depicting a progressive, positively tilted trough advancing fairly quickly southeastward through the Central Plains, now much more emphasis is being put on a southern jet stream branch disturbance ejecting northeastward out of Mexico into the eastern Midwest/OH Valley over the course of the weekend. This in turn significantly slows the incoming northern stream trough approaching from the northwest, and also weakens its overall punch. In the simplest sense, this essentially "splits" precip potential around our CWA to both the east/southeast and west-northwest (by at least a short distance) thus leaving us mainly dry, with remarkably good agreement on this per the latest ECMWF/GFS runs. However, please refer to the caveats mentioned in the "precipitation overview" section above, as at the very least some flurries or even sneaky light freezing drizzle could show its hand around Sunday AM. Confidence is overall-higher in temperature trends for the weekend. Saturday still looks mild, despite the leading edges of a cold front working in with time. By Sunday, the modestly colder air is firmly in place, resulting in clearly the coldest day of the next week, with highs only upper 30s-low 40s and a steady north breeze (not overly-windy though it appears). Monday: It seems lately we have had similar weather conditions repeating themselves every few days, and this continues here, as Monday actually looks relatively pleasant and similar to Friday, with temps rebounding 10-ish degrees from the prior day as westerly breezes return in the wake of the departing weekend trough. Tuesday-Wednesday: Although these days look to remain seasonably-mild and dry with broad ridging aloft the dominant feature, we start to see the very beginning stages of our eventual pattern change to colder weather as flow aloft starts to turn from northwesterly to more west- southwesterly as a large-scale trough develops over the western CONUS. Although subject to plenty of uncertainty at the Day 6-7 range, Tuesday currently looks to feature some of the lightest winds of any upcoming day, while Wednesday appears to feature breezy-to-windy south winds (by then it will have been at least a few weeks since we've had a day with somewhat strong SOUTH winds, as everything strong lately has been out of the northwest). && .AVIATION...(For the 12Z KGRI/KEAR TAFS through 12Z Friday) Issued at 523 AM CST Thu Dec 14 2017 VFR conditions are currently in place at the terminal areas, but models continue to show the potential for MVFR ceilings later this morning. Dayshift will have to monitor the timing, current TAF may be too quick with its arrival. An upper level disturbance swinging southeast through the region today will bring the potential for precipitation, and have a VCSH mention going throughout the day. With models show precip potentially being shower-like in nature, pinning down exact timing/location is difficult. Winds will become more northwesterly this morning, a few gusts around 20 MPH not out of the question during the day. Precip exits to the southeast this evening, VFR conditions look to return. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ SHORT TERM...ADP LONG TERM...Pfannkuch AVIATION...ADP