571 FXUS63 KLBF 080915 AFDLBF Area Forecast Discussion National Weather Service North Platte NE 415 AM CDT Fri Oct 8 2021 .SHORT TERM...(Today through Saturday) Issued at 414 AM CDT Fri Oct 8 2021 Above average temperatures are expected across the area today despite an increase in mid and high level clouds. A long wave trough continues to push onshore from the PacNW northward into western Canada with a flattened upper ridge aloft remaining in place across the Plains. With the area coming under increasingly southwesterly flow aloft, mid and high level moisture was streaming northeast contributing to the trend for increasing cloud cover through the day. With lowering pressures along the lee of the Rockies through the day as a result of the increasing flow aloft, southerly winds will return through the day. Despite the cloud cover, daytime heating will be sufficient to mix out shallow low level moisture across the Panhandle and portions of southwest NE. This will lower RH values across these areas and with southerly winds increasing somewhat, elevated fire weather conditions will temporarily be in place in those areas by mid afternoon. However the mid and high level cloudiness does not favor a more concerning fire weather setup but will have to monitor areas of potential clearing in those areas through the day. Max temps well above average again with 80s across the area. A few sprinkles may be possible in far northern NE this morning though ceilings seem to be in the 8-10k ft range. Several potent short waves are embedded in the southwesterly flow aloft and will move into the northern Plains tonight as the main upper low moves into the northern Rockies. This will provide larger scale forcing for ascent across the High Plains from MT southward to western KS. However a limiting factor for more widespread precip in western and north central NE is the dry low level initially, though the increasing LLJ tonight will bring in additional moisture. In addition, the broad area of lowering heights across the northern Plains will limit prominent sfc boundaries and a focus for sfc based initiation. Will include the small chances for showers in the northern area closer to the larger scale ascent overnight with some support for mid level forcing after 00Z. There is also support in CAM solutions for this idea. Will have to monitor a transient area of mid level frontogenesis across the Sandhills into central NE overnight co-located in an area of favorable lapse rates aloft for elevated convection overnight. Confidence on this is low due to a lack of moisture to support anything other than mid level cloudiness. Low temps again tonight will be much above average for this time of year. Saturday will see continued progression of the upper low aloft across the northern Plains and the most potent PV anomaly in the southern end of the long wave trough initiating upper low development across the southern Plains by Sunday. This effectively splits the trough with our area remaining primarily dry between the two systems. However it will allow for a cold frontal passage Saturday and high temps cooling 5-10 degrees, though still above average for this time of year. .LONG TERM...(Saturday night through Thursday) Issued at 414 AM CDT Fri Oct 8 2021 The longer term forecast will be encomapssed by a major pattern change and better chances for precipitation across the area, with temperatures returning to closer to average early in the period, then below average by mid week. Hemispherically a shift toward higher wave number in the next 7 days will mean a more progressive weather pattern and generally more active across the Plains. The aforementioned long wave trough across the center of the CONUS Saturday will fragment into one upper low ejecting across the upper Midwest and Great Lakes area, while the southern end deepens and moves east across the southern Plains through Monday then rapidly ejects through the mid Mississippi valley Tuesday. The southern system is an important player in that the strong cold front associated with the upper system will shove moisture southward into southern TX. As mentioned, western and north central NE will remain dry through Monday night with temps remaining close to average. As southern system ejcts, a more potentent long wave trough moves onshore and digs south into the 4-corners area by Tuesday. The low level moisture will return very quickly and set the stage for active weather across the Plains including severe weather potential somewhere on the Plains Tuesday. The determinstic solutions are in slightly better agreement this morning and ensemble clustering techniques favor a solution which is supportive of a strong negatively tilted system emerging onto the Plains by mid week. As the systems evolves, a warm frontal position could lie across southwest NE by Tuesday afternoon and with the return of moisture would be supportive of a decent convective event, though more fine scale details are still needing to be worked out. Ensemble differences seem to lie in how strong the system will ultimately be and hence how quickly it moves out. While these details get worked out, confidence will be higher in better precipitation chances in the mid next week period, but certainly a good signal for a strong wind event Wednesday, followed by much cooler temperatures than what we've seen so far in October. Much lower confidence in severe weather evolution Tuesday and Tuesday night and whether enough cold air can work into the system to provide chances for at least a mix of snow in the far northwest zones late Wednesday. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1119 PM CDT Thu Oct 7 2021 VFR conditions will prevail the next 24 hrs across western and north central Nebraska. Winds will remain light at 10 kts or less. There will be some increase in high level cloudiness. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Stoppkotte LONG TERM...Stoppkotte AVIATION...Taylor