509 FXUS63 KGID 082338 AFDGID AREA FORECAST DISCUSSION National Weather Service Hastings NE 638 PM CDT Sun Mar 8 2020 .SHORT TERM...(This evening through Monday) Issued at 257 PM CDT Sun Mar 8 2020 Turning wet tonight with chances for showers/isolated storms and possibly a wintry mix... We've rounded out the weekend with another day of warm/windy weather with afternoon temps well into the 60s to mid 70s, accompanied by southerly wind gusts of 25-35 mph. In warm air advection late this aftn, the NAM suggests the potential for an isolated shower/thunderstorm, however chances for precip ramp up after dark and continue into Monday in increasing lift/dynamics due to the combination of an advancing cold front progressing shortwave trough across our region. High resolution models are in agreement with convection developing in our southern/western zones late this evening, with precip expanding in coverage during the overnight hours. The presence of elevated instability of a few hundred J/KG will be sufficient for thunderstorm development and while severe weather is not expected, cannot rule out the potential for small hail as the freezing level lowers in the cooler post frontal airmass. What's interesting on the latest model runs is both the NAM/GFS close a H7 low across Nebraska by 12Z Monday and the NAM maintains a stronger and colder solution than the more progressive (and warmer) other models. The NAM solution is concerning and brings the potential for wintry weather mainly in the form of sleet/snow and possible light accumulations across portions of our western/northern cwa. The GFS/ECMWF thermal profile are more similar and warmer but it's hard to ignore the post frontal cold air as depicted by the NAM and this will have to monitored closely tonight. Attm, have went with a model blend which favors a warmer thermal profile with less potential for wintry weather, but still have some rain/snow/wintry mix for portions of our western/northern zones. The precip ends transitions to all rain again Monday morning before ending from west to east late morning into Monday aftn as the upper trough axis departs. Temps have trended cooler for highs with readings averaging in the 40s/low 50s. .LONG TERM...(Monday night through Sunday) Issued at 257 PM CDT Sun Mar 8 2020 Behind the departing wave late Monday, surface high pressure builds southeast across the Central Plains and heights rise aloft. In return flow, a low level jet strengthens along the high plains providing enhanced lift in a warm air advection regime leading to shower development to our west Monday night. This precip is expected to move into our area late Monday night into Tuesday morning. Instability is lacking this far east but precip type is a concern with surface temps near or below freezing and forecast reflects a mixed precip type with the potential for rain/freezing rain and sleet. Confidence is not high on how impactful this may or may not be as temperatures will be on the upswing with increasing clouds/moisture...then Tues the precip transitions to all rain as temps warm. Light precip/rain chances carry into Tuesday night with a progressing northern stream shortwave trough, then the forecast dries out for Wednesday. In a progressive pattern, another disturbance brings additional rain chances Thursday, then attention turns to the cutoff low lifting out of the desert southwest the latter part of the workweek/into the weekend. The latest ECMWF has a farther south track of the system than the GFS, filling/weakening the system as it tracks across KS whereas the GFS favors a farther north track across Neb. This will be something to keep an eye on given the potential for widespread precip (rain/snow). Depending on the track, precip should be moving out Saturday morning or shortly thereafter so next weekend isn't looking like a washout. Temps will be noticeably cooler than what we just experienced with readings averaging in the 40s for highs. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday) Issued at 638 PM CDT Sun Mar 8 2020 High clouds are moving in from the south across the area. Lower clouds will move into the area as a cold front moves through the region tonight. Along and behind this front, showers with a chance for some thunder will be possible at both terminals from around 04-05z through morning. As the front moves through southerly winds will become northerly and breezy. Ceilings during the overnight hours are expected to become MVFR and persist into the afternoon hours Monday before surface high pressure builds in and clouds move off to the east. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...Fay LONG TERM...Fay AVIATION...Billings Wright