Area Forecast Discussion
Issued by NWS Hastings, NE
Issued by NWS Hastings, NE
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152 FXUS63 KGID 271138 AFDGID Area Forecast Discussion National Weather Service Hastings NE 638 AM CDT Mon May 27 2024 .KEY MESSAGES... - Mainly dry and seasonably warm next few days. - Shower and thunderstorm chances increase Wednesday eve/night as activity shifts eastward off the High Plains. Overall-best chances come Thursday-Friday with our next frontal system. - This frontal system could bring our next chance for strong to severe weather, though the combination of instability and wind shear don`t appear to be unusually strong at this time. - Off and on thunderstorms and seasonably mild conditions continue into next weekend, though confidence on details is quite low due to significant model differences of the evolution of troughing over the N Rockies/Plains. && .DISCUSSION... Issued at 445 AM CDT Mon May 27 2024 Quiet conditions and pleasant temperatures in place for your early Memorial Day Monday. There`s a weak upper disturbance evident over the Sandhills of central Nebraska, per current satellite imagery, moving SE. This could bring a transient batch of mid level cloudiness, and perhaps a few sprinkles, through the area this morning, but this is extremely minor. By afternoon, strong heating will promote deep mixing and some breezy NW winds, esp. for areas along/N of I-80. Forecast soundings suggest these areas will be able to mix down some gusts up to around 30 MPH. Temperatures will be seasonably warm thanks to abundant sunshine and dry low levels, likely topping out in the mid 70s north, to mid 80s south. Rising upper heights will keep the quiet and mild/warm conditions going through Tuesday, and likely Wednesday, as well, for most locations. The exception could be over the SW 1/3rd of the forecast area, generally SW of a line from Lexington to Beloit, where some low end rain chcs (20-30%) creep in. These areas will be on the N fringes of mid level warm air advection/isentropic ascent. The main focus should remain over E CO into W/SW KS. Return S/SE flow increases on Wednesday in response to deepening sfc troughing to the lee of the Rockies. However, it appears that the best moisture return - likely rather modest for late May - will be confined to areas W of the forecast area over the High Plains. Diurnal heating and BL moistening will likely be sufficient to allow for scat convection to develop during the aftn hrs, with modest Wrly upper flow steering activity slowly E during the eve, perhaps aided by incr low level jet. Think the majority of this activity will remain off to our W, but perhaps decaying storms can make it into W zones late, before weakening. Models indicate better chances for rain will come Thu/Thu night with the arrival of a weak cold front. Continued Srly flow and advection of steep lapse rates should lead to stronger instability over a larger area by late aftn/eve, but the area looks to remain on the SE periphery of stronger mid level flow, which could limit the overall deep layer shear and more high end severe potential. Nonetheless, strong veering with height will probably be enough to provide adequate shear for at least SOME severe potential. This will probably be more of the Marginal/Slight risk variety - though the area is not officially outlooked due to model differences in timing and placement. The front itself looks rather weak, so it`s southward push may be dependent on the coverage/strength of Thu`s convection. Latest indications are that it may not go very far, so rain chances continue into Fri in otherwise favorable, though modest, SW to zonal upper flow. Since the push of cool air is weak, should still rise into the 70s Fri aftn. Forecast confidence really dips beyond Fri due to model differences and progression of upper trough from the N Rockies into central/northern Plains. Recent GFS runs favor a stronger, but progressive, frontal push on Saturday that would pose a significant risk of thunderstorms, whereas the EC is weaker and, thus more nebulous with the forcing, but still offers some convective potential. Since the EC is weaker, it favors a continued warm/unstable airmass and more thunderstorm chances through at least Sun and Mon. General indications are that upper ridging and warmer/drier pattern will set up in about 7-9 days. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 638 AM CDT Mon May 27 2024 VFR through the period. Lgt W-NW winds early this morning will bec brzy by midday, and esp this aftn with sustained winds 12-17kt, and gusts 25-30kt. Quiet conditions and decreasing winds are forecast for this evening. Confidence: High. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ DISCUSSION...Thies AVIATION...Thies