246 FXUS63 KLBF 182038 AFDLBF Area Forecast Discussion National Weather Service North Platte NE 338 PM CDT Thu Jul 18 2019 .SHORT TERM...(This evening through Friday night) Issued at 336 PM CDT Thu Jul 18 2019 The main concern in the near term will be dangerous heat expected to take place again on Friday. Weak surface low within the zonal flow aloft has led to the development of a dry line across portions of western Nebraska Thursday afternoon. The weak convergent boundary generally invof Hwy 83 will continue to drift east over the next few hours before retreating back west to the higher elevations as the evening progresses. Expect another mild overnight tonight as strong winds aloft help keep the boundary layer mixed out and h85 temperatures climb into the low 30s. Expect lows Friday morning to be similar to those experienced Thursday morning, only falling into the upper 60s to low 70s west to east. The mild start Friday will give temperatures a head start for another very hot and muggy day. Southerly flow in the lowest levels will again pump in high dew points into the area with h85 winds in the 20 to 30 knot range. Both the GFS and NAM solutions mix us out up to h6 across portions of southwest Nebraska and at least h7 elsewhere, leading to air temperatures well into the 90s and even low triple digits for areas along and south of Interstate 80. The limiting factor for any heat concerns may be moisture quality if we manage to overperform on magnitude of low-level mixing. Either way, given magnitude of air temperatures have elected to issue a new Heat Advisory for portions of southwest through north central Nebraska. Expecting a weak surface boundary to set up across the Sandhills, allowing moisture to pool along and potentially provide the focus for isolated thunderstorms during the late afternoon and evening. A modest shortwave will move overhead around the middle of the afternoon, increasing surface and mid-level convergence perhaps enough to break the rather stout cap denoted by h85 temperatures climbing into the mid 30s. A strong storm or two cannot be ruled out should development occur given high instability and moderate deep- layer shear in the 25 to 35 range, strongest in the north. Have kept PoPs low given uncertainty of cap breaking, limiting them to slight chance at the moment. More stout cool front begins to move into the area late Friday. Most model guidance suggests fropa doesn't occur in the local area until Saturday morning, so the influence on local temperatures may not occur until the daytime on Saturday. Expect breezy north winds Friday night with spotty showers behind the boundary. Low temperatures will remain in the 60s and 70s again for Saturday morning. .LONG TERM...(Saturday through Thursday) Issued at 336 PM CDT Thu Jul 18 2019 Beginning 12z Saturday. Surface cool front clears the area by mid- afternoon on Saturday leaving the area in general northerly flow. Much cooler air will work its way into the area as h85 temperatures fall back into the teens. Expect the cooler temperatures to last through the weekend with highs only in the 70s to mid 80s for Saturday and Sunday. Will see periodic chances for scattered rain and thunderstorms during this time as a couple weak disturbances push onto the central high plains. Current thinking is highest PoPs will be Saturday night into early Sunday. Main pattern early next week will be dominated by developing upper- level ridge across the 4-Corners region Monday into Tuesday. This will again put the local area under general north/northwesterly flow. Precipitation chances look be rather limited heading towards mid-week as the developing ridge drifts north and shoves the upper- level jet well north of the area. This will keep storm systems well north of the area as they ride the ridge into the Northern Plains and upper Midwest. Temperatures will steadily increase through the week leading to a return to more summer-like heat towards the end of the forecast period. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 1131 AM CDT Thu Jul 18 2019 Latest satellite and surface obs show clear skies overhead and light, predominantly westerly, winds. Quiet conditions and largely clear skies are expected the next 24 hrs through the TAF period. Westerly winds rest of today will shift and become southerly overnight, albeit remaining light and breezy, as surface low pressure evolves east and extends from western CO into northwest NE. By tomorrow a surface trough is expected to extend from southwest NEB to north central NE with generally southerly winds to the east of the trough and northwest winds to the west. && .LBF WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 8 PM CDT this evening for NEZ007-010-027>029- 038-071. Heat Advisory from 1 PM CDT /noon MDT/ to 8 PM CDT /7 PM MDT/ Friday for NEZ007-010-026>029-037-038-059-069>071. && $$ SHORT TERM...Jurgensen LONG TERM...Jurgensen AVIATION...ET