771 FXUS63 KLBF 041747 AFDLBFArea Forecast Discussion National Weather Service North Platte NE 1247 PM CDT Sat Oct 4 2025
.KEY MESSAGES...
- Critical fire weather conditions are expected Saturday with Red Flag Warnings for much of west central Nebraska as a result.
- A Marginal Risk (level 1 of 5) for severe weather remains in place across western Nebraska late Saturday afternoon and evening with damaging winds the main concern.
- Much cooler temperatures will bring more Fall-like conditions for Sunday and Monday before temperatures slowly recover to near-normal by mid-week.
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.SHORT TERM /THROUGH TONIGHT/... Issued at 402 AM CDT Sat Oct 4 2025
Active weather expected across much of the region today in advance of and behind a strong cool front.
Early this morning, breezy south winds were observed across western and central Nebraska. This was in response to a strong LLJ overspreading the area as h85 heights tighten. Local VWPs (KLNX, KUEX, KGLD) all show 25-35 knot flow around 100m AGL and these magnitudes should increase through daybreak with a slight shift east. To the north, the frontal boundary was already moving into southwest South Dakota and will continue to shuffle south slowly through the afternoon before stalling across the central Panhandle through central South Dakota. Southerly flow will persist into this feature and with h85 flow strengthening to 30 to 40 knots, expecting strong kinematics to stir up low-level mixing. This will boost daytime highs into the upper 80s to lower 90s once again. The difference between today and Friday is increasing mid-level dry air which should effectively mix down to the surface. This will promote a localized area of afternoon humidity minimums falling to around 20 percent (+/- 2%). Forecast soundings show deep mixing, potentially as high as 3km AGL. With strong unidirectional flow within the boundary layer, winds will be strong and persistent with gusts up to 45 mph. Further east, where moisture is greater, mixing may be a little more limited and this may limit the strongest winds from the low-level speed max from reaching the surface. This will need monitored closely as 50+ knot flow resides around 1-2 km up and should mixing tap into these stronger winds, gusts may potentially approach 60 mph (High Wind Warning criteria). This threat extends then to southwest Nebraska as the LLJ strengthens once again. NBM probabilities for exceeding 48 knots once again remain around 50-75% but do not encompass a large spatial coverage. Therefore, will forgo Wind Headlines but folks should be wary of strong crosswinds on east- west routes.
Regarding thunderstorm potential...as the cool front settles south, moisture increases from a Pacific airmass in its wake. Forcing aloft increases as the main h5 trough lifts north and east across the Front Range. While temperatures remain warm through late afternoon and evening, lapse rates are fairly limited and with the deep boundary layer, instability will be poor. HREF mean MUCAPE values remain at or below 500 j/kg. Though deep layer shear is strong, this limited instability will likely limit the overall scope of thunderstorm threats. The Storm Prediction Center (SPC) maintains a Marginal Risk (level 1 of 5) with a slight eastward shift towards a North Platte to Ainsworth line and points west. Again, the background environment...deeply mixed boundary layer, strong flow aloft, poor instability...suggests more of a damaging wind threat than severe hail threat. Earlier runs of the HRRR which suggested isolated cells early has backed off on this thought with scattered to widespread convection nearly from the start. Rainfall potential has also increased, likely due to richer boundary layer moisture behind the front and increased storm coverage/duration into the evening. The going forecast now paints 0.15" or greater total QPF for the western Sandhills and amounts around 0.50" for far western Cherry/northeast Sheridan Counties. PoPs should quickly decrease after Midnight as the trough axis lifts north and east and the surface front settles south and east of the area. Cooler air will quickly infiltrate the area with lows returning to the 40s west of Highway 83 and lower 50s to lower 60s to the east.
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.LONG TERM /SUNDAY THROUGH FRIDAY/... Issued at 402 AM CDT Sat Oct 4 2025
Sunday and Monday...much cooler temperatures are expected as modest Canadian high pressure noses in from the northwest. Elongated troughing will extend from the central valley of California up through the Northern Plains but overall northwesterly flow will persist. Highs fall into the 60s and 70s for Sunday, decreasing further to the 50s for Monday. Precipitation chances return early Monday as the frontal boundary from Saturday stalls south across Kansas and easterly upslope flow allows for scattered showers and a few weak thunderstorms to percolate. No severe weather is expected and as central high pressure passes to the east, the orographic lift will subside and dry conditions will return for much of the daytime.
Tuesday and beyond...temperatures will slowly climb towards the middle of the week as ridging builds along the Gulf Coast. A few weak disturbance will round the upper-level high pressure and may present a few limited chances for precipitation but PoPs inherited from the model blend remain limited to Slight Chance (< 25%) owing to low confidence. Similarly, precise temperatures remain somewhat in question as NBM inner-quartile spreads approach 10F for the latter half of the week. This is largely due to notable discrepancies between deterministic and ensemble guidance. For now, inherited temperatures hug the cooler end of the forecast envelope but pattern recognition suggests these values will likely climb slightly in the coming days.
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.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1241 PM CDT Sat Oct 4 2025
Strong gusty southerly surface winds will be of concern through this evening for areas along and east of a VTN to IML line. Low-level wind shear develops this eveing along and east of a VTN to LBF line, this will end by late evening. Also of concern will be a line of scattered thunderstorms that will move quickly to the northeast this evening, mainly for areas along and west of a VTN to LBF line. As winds switch to gusty northwest Sunday morning, some MVFR ceilings may push southward into north central Nebraska after sunrise.
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.FIRE WEATHER... Issued at 402 AM CDT Sat Oct 4 2025
Critical fire weather conditions will exist Saturday, largely due to very strong wind gusts ahead of a cool front. Red Flag Warnings remain in effect for all fire weather zones in the local forecast area as a result.
Early morning winds are already showing gusts around 20 to 30 mph and these should continue through daybreak with strengthening during the day. As an elongated surface low forms/deepens along the frontal zone later today, winds will increase due to a tightening pressure gradient ahead of a cool front which should settle along/near a line from the central Panhandle into the Sandhills then up into south central South Dakota. While low-level moisture advection will be strong across eastern Nebraska, the stronger southerly flow further west will promote stronger kinematics with mixing heights approaching 10kft across southwest Nebraska into the central/eastern Sandhills. As daytime highs climb into the upper 80s to lower 90s, the deeper mixing will promote drying as dew points fall to the upper 30s/near 40F. This will drive afternoon humidity minimums to around 20 percent with a few locations seeing upper teens for a few hours. While this remains above critical levels, strong winds with gusts up to 45 mph will likely support erratic behavior and the rapid spread of any fire starts. Eventually by late afternoon, convection across the Panhandle and southwest South Dakota will propel the frontal boundary south and east. Precise timing of this frontal passage is medium confidence at best but thoughts are Zone 204 should be cleared by around 8-9pm MDT and Zone 206 cleared by 10pm-Midnight CDT. Richer boundary layer moisture will exist behind this feature and while an abrupt wind shift from south to northwest will accompany this front, moisture will quickly increase as well with many locations likely seeing > 80% relative humidities before Midnight CDT. Earlier concerns about dry lightning have decreased with heavier QPF and the quick to increase boundary layer moisture. Have a few locations near 0.50" closer to the Pine Ridge but wetting rain potential (> 0.25") remains limited outside Zone 204 and far western Zone 208. Winds should remain strong out of the south ahead of the front but once FROPA occurs, expect a fairly steady decrease with many locations seeing < 20 mph winds the remainder of the night. Humidity recovery appears to be good for all of western Nebraska with 80% for all by daybreak Sunday and many locations surpassing 90%.
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.LBF WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 10 PM CDT /9 PM MDT/ this evening for NEZ204-206-208>210-219.
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SHORT TERM...NMJ LONG TERM...NMJ AVIATION...Taylor FIRE WEATHER...NMJ
NWS LBF Office Area Forecast Discussion