


Area Forecast Discussion
Issued by NWS North Platte, NE
Issued by NWS North Platte, NE
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032 FXUS63 KLBF 071202 AFDLBF Area Forecast Discussion National Weather Service North Platte NE 702 AM CDT Mon Jul 7 2025 .KEY MESSAGES... - An Enhanced Risk (level 3 of 5) is in place Monday across much of western and central Nebraska with a threat for significant severe weather possible. - Strong to severe thunderstorms are possible again Wednesday and Thursday, though precise details remain uncertain. - Following a brief heat wave around the middle of the week, temperatures fall to below normal values for the start of the weekend. && .SHORT TERM /THROUGH TONIGHT/... Issued at 359 AM CDT Mon Jul 7 2025 The main concern in the short term will again focus on the threat for severe weather including potential significant severe weather (2"+ hail, 75+ mph gusts, a tornado or two. This morning, anvil blowoff from storms across Colorado and western Kansas continue to overspread the area. The clearing line is arriving into our northwest zones. Upstream, convection is tracking east across far western South Dakota. This is being driven by a weak shortwave trough and associated WAA. Morning high resolution guidance is failing to resolve this activity very well. The background environment shows a modest LLJ across our western zones but this feature is pointed into southwest South Dakota. Through time, this belt of stronger flow should weaken through sunrise and winds veer. Though shear vectors point into our northern zones, weaker instability and stronger inhibition should prevent a repeat of Sunday morning and keep activity north across South Dakota. Today/tonight...as mentioned, strong to severe thunderstorms are likely today for much of the region. The SPC has maintained the Enhanced Risk (level 3 of 5), suggesting higher confidence in coverage and occurrence. Modest ridging remains in place immediately west of the Continental Divide as the next trough begins to move onshore the California Coast. Closer to home, a northern stream disturbance will track east across Montana and into the Dakotas. As this disturbance moves east, a frontal boundary reinforced by surface high pressure will settle south into South Dakota. Southerly flow ahead of this boundary will reinforce a moisture rich environment. As afternoon highs climb into the 80s to near 90F beneath a strong EML with steepening mid-level lapse rates nearing 8.5 C/km, ample instability will develop to the tune of 2500-3500 j/kg MLCAPE. Storms should initiate in two areas by early afternoon: over western South Dakota along this boundary and along the Front Range to the west. With h5 flow nearing 30-40 knots and southerly surface flow, a moderately sheared environment will be in place across the warm sector. Forecast soundings show decent low-level curvature with long/straight profiles above 1km. This would suggest splitting supercells. The combination of steep mid-level lapse rates, strong low-level inflow, LI values nearing -10C, and CAPE distribution with much of it above the freezing level supports the risk of very large hail. This would be maximized with any discrete supercell. As the LLJ increases later in the day, hodographs will enlarge with improving low- level helicity particularly over north central Nebraska with progged values to exceed 100 j/kg by early evening. Adding to this, QLCS tornadoes appear possible later in the evening with 0-3km shear vectors showing ~30 knots line normal shear to any potential MCS. This suggests the tornado potential could persist even beyond the window for discrete convection. Upscale growth appears likely as cold pools merge and progress quickly to the south and east. Though hail and tornado threat should continue through the evening, a transition to primarily a damaging wind threat appears likely. SPC shows damaging wind potential as main motivator for the Enhanced Risk and am in agreement on this. Various CAMs showcase expansive severe wind gusts and pockets of significant magnitudes (75+ mph). Believe this will carry through the evening as one, possibly two mature MCSs track through the area. Leaned heavily on NSSL WRF for PoPs which has two distinct areas of 50%+ merging together this evening. Recent HRRR runs have begun to advertise a similar evolution of storms today, adding to the confidence in the PoPs forecast. As seen in recent days, moisture availability remains at a premium. Precipitable water values remain high, roughly 100-125% of seasonable norms. This suggests the threat for heavy rain again. HREF neighborhood probabilities of seeing > 0.75/hour rain rates near 50% across north central Nebraska and various deterministic solutions suggest expansive 0.25" rainfall with pockets of heavier amounts potentially approaching 2.00". Feel this is fairly representative of what is expected. While this shouldn`t lead to widespread hydro concerns, localized flooding is possible, especially in typical problem spots. Convection appears set to depart the area by early morning Tuesday. Lows tonight should fall into the 50s as cooler air works in from the north. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Issued at 359 AM CDT Mon Jul 7 2025 Tuesday and beyond...upper ridging to the southwest will amplify towards the middle of the week. The local area will reside on the northeast periphery of the upper-level high pressure, leading to general northwesterly flow aloft. Dry conditions are likely Tuesday, siting subsidence aloft and increasing mid-level heights. Temperatures may see a slight bump, but should be comparable to Monday`s values. By Wednesday, a shortwave disturbance will begin to impinge on the ridge which will foster height falls across the area through the day. High temperatures should peak on Wednesday with values in the middle to upper 90s. Do believe some heat concerns will come into play as dew points appear set to climb into the middle 60s. At this time, no Heat Advisory criteria is in the forecast but subsequent forecasts will need to closely monitor this period going forward. The increased moisture will also foster greater potential for rain and thunderstorms. At this time, will need to monitor the threat for severe both Wednesday and Thursday. For now, confidence in occurrence is highest on Thursday where the SPC paints a 15% from central Nebraska up through North Dakota. A secondary trough will arrive by late week and should effectively shunt the dome of high pressure aloft south. This will lead to cooler temperatures with ECMWF Extreme Forecast Index (EFI) suggesting a flip from positive anomalies on Wednesday/Thursday to negative anomalies by Saturday. This is most apparent on Saturday morning where EFI values fall to around -0.8 with non-zero shift of tails. The going forecast for both LBF/VTN suggests daytime temperatures falling to around the 10th percentile in their recorded history so it`ll certainly be on the cooler side for July. Temperatures should moderate quickly with a return to above normal values by the following week. Latest forecast values inherited from the model blend hugs the lower end of the forecast envelope so there remains potential for further increases in the coming days. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 657 AM CDT Mon Jul 7 2025 Main aviation concerns will focus on threat for thunderstorms later today. This morning, patchy fog was noted across central Nebraska including at LBF. This fog was very shallow in nature and impacts are expected to remain minimal over the next few hours before dissipating. Diurnal cumulus should develop around midday but remain in VFR criteria. Then by late afternoon, we`ll monitor the threat for thunderstorms arrive both from the north and from the west. Storms should arrive from the north at VTN by late afternoon, posing a threat for gusty erratic winds and hail while also bringing MVFR and potentially IFR conditions. Storm coverage should remain scattered so there remains a low-end potential activity misses the terminal. Activity from the west will move into LBF around early evening. This activity will also pose gusty erratic wind potential and hail in addition to heavy rain potentially bringing MVFR/IFR conditions. Confidence in magnitude of impacts at either terminal is low so will cover potential windows with PROB30s for now. Expect low stratus to linger after convection clears and potentially maintain degraded flight conditions through the end of the valid forecast period. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...NMJ LONG TERM...NMJ AVIATION...NMJ