Area Forecast Discussion
Issued by NWS North Platte, NE
Issued by NWS North Platte, NE
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332 FXUS63 KLBF 180819 AFDLBF Area Forecast Discussion National Weather Service North Platte NE 319 AM CDT Tue Jun 18 2024 .KEY MESSAGES... - A Marginal Risk of severe thunderstorms this afternoon along the eastern edges of the CWA, mainly along a line east of western Frontier County to southwestern Custer County to Garfield, Wheeler and southwestern Boyd counties. - High temperatures nearly 10 to 20 degrees below seasonal average are expected Wednesday in the wake of a cold front. - An active pattern keeps chances of showers and thunderstorms through the end of the week. At this time, the severe potential is uncertain. && .SYNOPSIS... Issued at 317 AM CDT Tue Jun 18 2024 Upper air analysis and satellite imagery place an upper level trough over the western United States, with the trough axis through Utah and Arizona. Western Nebraska sits just to the east of the eastern edge of the trough, in an area supportive of divergence aloft. Early this morning, storms are noted over the Dakotas under areas of greatest divergence aloft. At the surface, a low pressure system is observed over western Nebraska early this morning, with a warm front extended across southern South Dakota, and a cold front trailing to the southwest across north central Colorado. && .SHORT TERM /THROUGH WEDNESDAY NIGHT/... Issued at 317 AM CDT Tue Jun 18 2024 The low pressure system over western Nebraska early this morning will continue tracking eastward. As the low tracks to the northeast, the cold front will track across the region this morning, which will help diminish the gusty winds observed overnight. The cold front will be the focus for severe weather potential later this afternoon, though the more active severe weather appears to be well east of the region, focused more over eastern Nebraska. Given the proximity to the cold front, the Storm Prediction Center has placed portions of the region in a Marginal Risk (level 1 of 5) for severe weather this afternoon. This area is roughly along and east of a line from western Frontier County to southwestern Custer County to Garfield, Wheeler and southwestern Boyd counties. Latest CAM guidance suggests the best potential for precipitation this afternoon will be over the portions of north central Nebraska in the Marginal Risk. Although there is a Marginal Risk across the region, the severe weather threat is very conditional on storms being able to initiate this afternoon. Forecast soundings from the CAMs show quite a robust cap, meaning any storms that could potentially form will more than likely be elevated in nature. The main severe weather concerns would be for large hail and strong thunderstorm winds, but again, conditional on storms initiating west of the cold front. Otherwise, the cold frontal passage this morning will keep things more on the mild side this afternoon, with temperatures climbing into the 70s across most of the region, with a few spots breaking 80 degrees. As the cold front pushes east, it is eventually expected to stall around Iowa and Missouri. As the front stalls, clouds continue to back build over the region, providing building cloud cover throughout the afternoon and overnight. Overnight and through Wednesday night, another round of showers and thunderstorms is expected to form and track across the region. At this time the severe weather threat is low. Of note for Wednesday, is the cool post frontal environment settling over the region. Temperatures are only expected to climb into the 60s across most of the region, with perhaps a few areas breaking 70 degrees. These temperatures are below our seasonal average by around 10 to 20 degrees. As stated above, there will also be another chance for precipitation during this cooler period Wednesday into Wednesday night. While the cooler temperatures will limit any severe weather concern, it could be a catalyst for efficient rain production for showers and locally heavy rain. At this time, the best potential for locally heavy rain appears to be areas east of Highway 83. && .LONG TERM /THURSDAY THROUGH MONDAY/... Issued at 317 AM CDT Tue Jun 18 2024 The upper level pattern remains fairly supportive of rain through the end of the week. The upper level trough remains fairly stationary over the western United States through the end of the week. Guidance suggests the potential for a few small shortwaves to potentially eject out of the main trough, which could be a catalyst for showers and thunderstorms through the end of the week. By Friday afternoon, the trough is expected to begin lifting and tracking to the northeast. This leads to upper level ridging beginning to set up later in the weekend into early next week. As the upper level ridging settles in, temperatures are expected to begin climbing back to seasonal averages starting Friday and through the weekend, returning back to above average early next week. Timing and exact values will continue to be refined in further forecasts, but for now, expecting a return to warmer and drier conditions early next week. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 105 AM CDT Tue Jun 18 2024 The primary concern this TAF period will be strong southerly winds gusting at or above 40kt along with low level wind shear through the first part of the valid period. A cold front will push through TAF sites toward daybreak and push the axis of the low level jet eastward, shifting winds to the northwest and ending the low level wind shear. While winds behind the front will still be gusty for a while, speeds will gradually relax behind the front through the afternoon. Flight conditions will be VFR except for a couple of hours either side of the frontal passage as a band of clouds moves through with the front. KVTN will see CIGs on the lower side of MVFR but the best potential for IFR is just to the north in South Dakota. KLBF will be on the low side of VFR with probabilistic guidance indicating only a 30 percent chance for sub-VFR conditions. Will monitor sky trends closely and amend if needed before the new TAF issuance at 12Z. There may be some widely scattered showers with the frontal passage, along with potential for some diurnal convection later this afternoon. However indications are that the coverage will be quite sparse so will maintain dry conditions this valid period and amend if trends in radar or surface observations begin to favor more coverage of precipitation. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Richie SHORT TERM...Richie LONG TERM...Richie AVIATION...MBS