571 FXUS63 KDDC 132250 AFDDDC Area Forecast Discussion National Weather Service Dodge City KS 450 PM CST Sat Feb 13 2021 ...Updated Aviation Discussion... .SHORT TERM...(This evening through Sunday night) Issued at 214 PM CST Sat Feb 13 2021 Early afternoon surface and satellite observations show widespread single digit to low double digit temperatures, with a low stratus deck that is expanding back northeastward after eroding over the eastern half of our area this morning. Wind chills are below zero everywhere except our far southwest zones where winds are nearly calm. The main forecast challenge in the short term continues to be the expected winter storm that will impact our area this evening into Sunday afternoon. Water vapor satellite imagery indicates an upper level trough sits just west of the Four Corners region at 19Z, and guidance is in good agreement this trough will push eastward with time providing more than sufficient lift for snow development. Expect snow to enter far western Kansas around sunset, spreading east during the evening hours, and affecting our entire area by midnight. Given the strong arctic airmass in place, snow to liquid ratios will be quite high, roughly in the 20-25:1 range, and this could be conservative. I expanded the Winter Storm Warning northward in our western zones to include Stanton, Grant, Haskell, Hamilton, and Kearny counties to accompany the counties along the KS/OK border where the highest snowfall totals of 6-8+" are expected. Elsewhere, 3-6" are anticipated, with the I-70 corridor seeing the lowest snow totals. Northeast winds will increase modestly overnight, holding in the 10-20 mph range through Sunday morning, and since the snow will be quite light/powdery, at least some blowing and drifting of snow is likely. Snow will taper off from west to east Sunday afternoon, clearing our area completely by sunset. While snow totals are expected to be considerable in several locations, the primary hazard with this storm will be the dangerously cold temperatures/wind chills that will last through Monday morning. Temperatures will rapidly fall through the single digits to well below zero during the overnight period tonight, and as northeast winds increase, wind chills will drop into the -20 to -30 degree range by Sunday morning. During the day Sunday, temperatures will struggle to breach zero, and it is likely many locations will stay below zero until Monday afternoon. A Wind Chill Advisory currently in effect for all counties will upgrade to a Wind Chill Warning at 4 am Sunday that will continue through Monday morning. Some locations west of U.S. Highway 283 could see wind chills as cold as -35 degrees Monday morning. This degree of arctic air will pose a serious threat to life for anyone who becomes stranded outside and away from shelter, and we strongly suggest everyone stays inside unless travel in imperative. .LONG TERM...(Monday through Saturday) Issued at 324 PM CST Sat Feb 13 2021 As mentioned in the short term discussion, Monday morning will be extremely cold, with lows in the -10 to -20 degree range and wind chills in the -25 to -35 degree range. The only saving grace will be the fact that surface winds will be very light as surface high pressure sinks into the central plains. As this happens, the low stratus deck that has plagued southwest Kansas for days is expected to begin deteriorating, and the first hints at widespread partly cloudy skies emerges. However, fresh snowpack will significantly inhibit daytime heating, and afternoon temperatures on Monday will again be in the single digits. Overnight Monday, mostly clear skies and light winds will cause temperatures to crash into the -5 to -15 degree range, and another Wind Chill Advisory will likely be needed through Tuesday morning as wind chills drop into the -15 to -25 degree range. During the day Tuesday, temperatures will begin their slow rebound back to normal as surface high pressure begins to move northeast away from the central plains, and southeast winds resume. Afternoon highs have a decent chance of reaching double digits in all locations, with the western zones potentially flirting with the low 20s. Late Tuesday afternoon, guidance is in reasonable agreement depicting another deep upper level trough digging southeast out of the Great Basin and into the high plains. 12Z runs of the GFS/Canadian suggest another round of accumulating snow is possible overnight Tuesday into Wednesday morning for roughly the southeastern half of our area, while the 12Z ECMWF keeps all precipitation southeast of our area. NBM pops during this time period are in the 15-30% range in our southeastern zones, which seem reasonable, but trends will nevertheless need to be monitored. Wednesday morning will likely be the last morning of widespread below zero temperatures, as overcast skies during the night moderate radiational cooling, and the slow warming trend will continue. Afternoon highs on Wednesday will be in the low to mid 20s with roughly a 5-10 degree increase in afternoon highs each day through the remainder of the long term period. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 432 PM CST Sat Feb 13 2021 MVFR to just above VFR ceilings at all TAF sites under the continued upslope easterlies at the surface and entrenched cold air. Snow will enter the CWA shortly after sunset from eastern Colorado and make its way to GCK and LBL by 02Z and DDC and HYS by 03Z carrying VCSH at those times being spotty in nature. Snow will be more widespread after 06-07Z respectively dropping visibility and ceilings to 1.5-2kft. Northeasterly winds will pick up to 12-15kts at this time lasting through the end of the period due to the increased gradient associated with the shortwave aloft. Expect snow to taper off after 18-20Z west to east with continued MVFR ceilings but improved VFR visibility through the end of the period. The forecast challenge this period will be with how continuous the snow will be determining how low the ceilings and visibility will go and its timing. && .PRELIMINARY POINT TEMPS/POPS... DDC -3 2 -13 3 / 100 100 10 0 GCK -6 0 -16 3 / 100 90 10 0 EHA -4 3 -14 9 / 100 100 10 0 LBL -4 2 -17 3 / 100 100 10 0 HYS -5 2 -12 5 / 90 80 10 0 P28 0 4 -8 5 / 90 100 20 0 && .DDC WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 9 PM this evening to 6 PM CST Sunday for KSZ030-031-043>046-063>066-077>081. Wind Chill Warning from 4 AM CST /3 AM MST/ Sunday to noon CST /11 AM MST/ Monday for KSZ030-031-043>046-061>066-074>081- 084>090. Wind Chill Advisory until 4 AM CST /3 AM MST/ Sunday for KSZ030- 031-043>046-061>066-074>081-084>090. Winter Storm Warning from 9 PM CST /8 PM MST/ this evening to 6 PM CST /5 PM MST/ Sunday for KSZ061-062-074>076-084>090. && $$ SHORT TERM...Springer LONG TERM...Springer AVIATION...Lowe