Area Forecast Discussion
Issued by NWS North Platte, NE
Issued by NWS North Platte, NE
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140 FXUS63 KLBF 162335 AFDLBF Area Forecast Discussion National Weather Service North Platte NE 635 PM CDT Mon Sep 16 2024 .KEY MESSAGES... - Windy conditions persist across central and western Nebraska tonight and especially through Tuesday. There is increasing potential for gusts at or above 45mph by late Tuesday afternoon. - High confidence for thunderstorms with locally heavy rainfall to move out of the panhandle early Tuesday evening and continue moving across central Nebraska into early Tuesday night. Increasing potential for wind gusts at or above 60mph west of Hwy 83, and 75mph or higher from near Chappell thorugh Hyannis to near Merriman westward. - While confidence still remains low, the potential for widespread rainfall this weekend is increasing across central and western Nebraska. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 425 PM CDT Mon Sep 16 2024 With central and western Nebraska remaining under largely the same synoptic regime for the past several days, conditions heading into tonight will be quite similar to the last few days. There is a pool of unstable air across the region with CAPE values around 2500J/kg generally west of I-80, though it is difficult to realize this convective potential as a convective cap remains in place. However a dry line just off to our west will nudge eastward a bit to near Hwy 83 and as the low level jet amplifies this should should provide enough lift to trigger isolated/widely scattered thunderstorms this evening into tonight. Streamlines currently show focused convergence to our south from northeast CO into KS and meso guidance indicates convection will initiate here and push up form the south this evening. The best potential for thunderstorms will generally be from Imperial through North Platte to Burwell and southward though coverage will remain sparse. 0-6km bulk shear will be sufficient to support some organization and there is sufficient instability for an isolated storm to produce large hail. However steep low level lapse rates and DCAPE values around 1400J/kg will support efficient outflow production so expect strong gusty winds from any convection. As the low level jet moves eastward tonight it will take the convection with it and eventually off to our east by daybreak. Guidance has been quite consistent over the past few days advertising a good signal for a hot windy day tomorrow. Temperatures aloft into the 90th percentile will support afternoon highs in the lower and middle 90s, while low level winds are approaching the 99th percentile and EFI/ST guidance maintains a signal supporting strong gusty winds across the region. Given the strength of the low level flow in the mixed layer evident in Bufkit, probabilistic guidance appears to be underestimating gust potential as it caps the best probabilities in the 35 to 40mph range. Expect a higher ceiling on gusts tomorrow with gusts at or above 45mph by late Tuesday afternoon. This will generate elevated to potentially near critical fire weather conditions mainly west of Hwy 83 despite minimum humidity values remaining above critical levels at 25 to 35 percent. By late Tuesday, thunderstorms are expected to develop over the high terrain to our west and move through the panhandle into the western sandhills toward evening. The environment will remain very favorable to support efficient wind production with steep low level lapse rates and robust DCAPE values. Thunderstorms will have potential to produce wind gusts at or above 75mph mainly from near Chappell through Hyannis to near Merriman, with potential for gusts at or above 60mph extending eastward to Hwy 83. Precipitable water values will also be rising into the 99th percentile so storms are expected to produce widespread rainfall with locally heavy downpours. The storms will be moving rather quickly and look to be exiting the region to the east shortly after Midnight. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Issued at 425 PM CDT Mon Sep 16 2024 Confidence remains high in the overall blocky pattern prohibiting an initial deep trof moving in from the Pacific from making eastward progress past the Rockies and forcing it northward into Canada, followed by a second deep cutoff low that will have more success moving across the mountains and into the Plains this weekend. Ensemble guidance seems to be trending toward a solution favoring the low to pass over or just south of Nebraska this weekend, which is favorable for widespread precipitation across the region. However there is still considerable spread in QPF plumes so confidence remains low, and the exact track of the surface low will determine if there is any threat for severe storms. EFI/SoT guidance has a QPF signal which supports the concept of a low confidence event with little agreement in ensemble members, though any event may potentially be significant with large positive departures from the internal ensemble system mean. So after a brief break with mostly dry conditions Wednesday and Thursday, expect a return to unsettled conditions with potential for showers and thunderstorms Friday and continuing through the weekend with potential for impactful weather Saturday and Sunday. There is higher confidence in the temperature regime with temperatures at or above normal through the latter portion of next week, becoming cooler with readings below normal for the weekend. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 630 PM CDT Mon Sep 16 2024 VFR conditions will prevail through the next 24 hours, however winds will remain strong this evening through Tuesday. There will be areas of LLWS east of both forecast terminals, for areas east of HWY 83, with LLWS around 40 to 45 kts, this evening through early Tuesday morning. SFC winds across the entire forecast area will be strong out of the south around 15 to 20 kts sustained with gust of 35 kts or greater, with the strongest winds Tuesday afternoon into Tuesday evening. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...MBS LONG TERM...MBS AVIATION...Gomez