Area Forecast Discussion
Issued by NWS North Platte, NE
Issued by NWS North Platte, NE
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084 FXUS63 KLBF 192101 AFDLBF Area Forecast Discussion National Weather Service North Platte NE 401 PM CDT Sat Oct 19 2024 .KEY MESSAGES... - Warmer temperatures and breezy conditions expected to start the week as a storm system approaches the area. Precipitation potential will remain limited to mainly southwest through south central Nebraska. - The only interruption to an otherwise dry forecast beyond Monday is a frontal passage late Tuesday into early Wednesday but recent trends cast doubt on much if any appreciable moisture. - Temperatures return to well above normal values for the latter half of the week with growing fire weather concerns as a result. && .SHORT TERM /THROUGH TONIGHT/... Issued at 401 PM CDT Sat Oct 19 2024 Satellite analysis shows widespread low-level cloud cover across much of the forecast area. This is gradually eroding from the northwest which is allowing temperatures to rebound nicely under sunny skies. Further southeast, under lingering overcast skies, temperatures have struggled to climb with many locations holding firm in the middle 50s. The surface boundary remains southeast of the forecast area, as indicated by a converging line extending from northwest Kansas up through south central Nebraska. This feature is unlikely to move much and it is likely to become washed out this evening as southerly flow increases. A strong LLJ will develop across western Nebraska which will likely limit overnight lows as steady south to southwesterly winds persist overnight. Expect overnight lows to fall into the 40s to 50s which will be nearly 20 degF above normal. && .LONG TERM /SUNDAY THROUGH SATURDAY/... Issued at 401 PM CDT Sat Oct 19 2024 Sunday and Monday...deep cut-off low across the Desert Southwest will begin to translate east into the central and southern Rockies. Enhanced southerly flow will support rapid moisture transport with NAEFS guidance suggesting WV transport exceeding the 90th percentile into western Nebraska. PWATs as a result will respond accordingly with values similarly exceeding the 90th percentile by midday Sunday. Temperatures will climb quickly aloft as h85 climb into the middle teens degC. Height falls increase quickly late in the day Sunday as the h5 trough quickly crosses the central Rockies. While moisture will be on the increase, forecast soundings show a slow saturation of the profile. This is likely due to the greatest moisture transport quickly shifting east as the main low aloft tracks just east of the area. Sunday afternoon highs will climb into the 70s to low 80s with these warmest values east of Highway 183. Precipitation potential has decreased slightly as well, with the greatest forcing now focused across central Nebraska. NBM, EPS, and GEFS probabilities for QPF have decreased locally with a sharp cutoff from the northwest to southeast. Even NBM 90th percentile suggests little precipitation potential northwest of an Ogallala to O`Neill line. Decided to limit the spatial coverage of Chance PoP categories (> 25%) to more closely match peak GEFS/EPS probabilities. As southwesterly flow continues in the mid-levels, lapse rates will steepen and and lead to modest instability across the area while afternoon highs reach the upper 60s to low 70s. While SREF and NAM both indicate widespread instability values nearing the 500-1000 j/kg range, deep layer shear will be limited to around 20 knots. The Storm Prediction Center introduced a Day 3 (Monday) Marginal Risk for portions of the Central Plains. Have no issues with keeping this threat area to our southeast. Precipitation chances peak Monday morning through the afternoon as DCVA is maximized within broad WAA. Again, with thinking that focus is to the east, will limit PoPs across the Sandhills prior to the end of precipitation chances by early Monday evening as the trough axis clears the area. Tuesday and beyond...a deep trough across central Canada will amplify and dive southeast into the Great Lakes. This will deepen a surface low near the Hudson Bay with an attendant cold front extending southwest into the northern Plains. This frontal boundary will move into western Nebraska late Tuesday. Model blend output produces low-end PoPs across our northern zones late Tuesday into early Wednesday. NWP guidance continues to vary on precipitation chances, with ECMWF and EPS solutions depicting some light QPF while the GEFS and GFS keep everything north of the immediate area. Did opt to limit categorical PoPs to Slight Chance (< 25%) given limited confidence and light QPF even from the more bullish solutions. High pressure building in Wednesday will allow a swift end to any precipitation potential and return dry conditions to the forecast. Late week, upstream ridging will amplify with slight northwesterly flow aloft locally. The extended forecast will favor positive height anomalies and thus temperatures warming through the end of the week. Middle to upper 70s for high temperatures appears probable for Thursday and Friday which will approach 20 degF above normal for late October. Though timing remains somewhat in question, a return to troughing in the west will foster a ridge breakdown sometime around Friday or Saturday. This will promote increasing fire weather concerns though precise details remain murky at the present time. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1225 PM CDT Sat Oct 19 2024 Low stratus with IFR/MVFR CIGs will continue to gradually improve this afternoon, with widespread VFR expected to return by tonight. Winds shift southerly this afternoon and this persists through the end of the valid period. Winds then strengthen from the south tomorrow afternoon, with gusts of 20 to 30kts. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...NMJ LONG TERM...NMJ AVIATION...Brown