986 FXUS64 KAMA 191950 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 250 PM CDT Mon Apr 19 2021 .SHORT TERM...Tonight through Tomorrow... Synopsis: A strong cold front will result in windy and cold conditions this afternoon and overnight. The initial wind shift is already moving through the Oklahoma Panhandle, well ahead of schedule. The main surge of cold air will arrive later this evening. North winds of 25 to 35 mph will be common with peak gusts around 40 to 50 mph possible. Some very light winter precipitation is possible mainly between 8 PM and 8 AM. This could include some brief freezing drizzle and light snow flurries. There is a low chance of a light dusting of snow across the Oklahoma Panhandle, but accumulations are not expected for locations further south. Overall impacts should be minimal to none. Details: Latest upper level WV depicts generally broad cyclonic flow across the CONUS with an elongated positive tilt trough diving south through the Great Basin region. A pronounced shortwave was moving through ID into the northern parts of UT and western CO. Another weaker wave was moving east across the Big Bend region of Texas. At the surface, a strong cold front was moving south across KS, and the initial wind shift had already crossed into the OK Panhandles as of 19z. The stratus deck associated with this feature was stalled in west central KS, but high based CU was forming along the boundary in OK. Temperatures north of the boundary were in the 40s and 50s, with low 70s common to the south. The airmass ahead of the boundary was also very dry with dew points in the low 20s, so no showers or storms are expected with this first wind shift which should be through the Panhandles by or before 9PM (well ahead of the fastest models). The main cold surge is still expected to occur late this evening and overnight, and the delineation of this colder air can be seen on the GOES Day Cloud Phase RGB currently moving through northwest KS. This is where near freezing temperatures are also being sampled with a deck of low stratus. The stratus will move in this evening and expand across the area as the Idaho shortwave moves across the Rockies and attempts to pivot to a more neutral tilt as it moves over the central plains. The mid level moisture showing up over WY and northwest CO is expected to clip the northern zones tonight. Forecast soundings vary some on the quality of this moisture, but most suggest that any saturation of the DGZ will be brief with the strongest dynamic lift remaining north of the Panhandles. That being said, worse case scenario suggest that around 1" of snow accumulation is possible in the northern OK Panhandle. Most likely scenario which most CAMs agree with is a light dusting mainly on grassy surfaces. Further south into the Texas Panhandle the mid level moisture is much more limited. However, the lowest 100mb does saturate with the secondary surge of cold air which suggest freezing drizzle is possible briefly before the layer cools below -8 degrees and snow flurries commence (freezing drizzle is also possible early on in the north). However, a dry layer right off the surface as indicated by most model soundings may prevent drizzle from occurring at all, so have included patchy mention only. The north winds will see an increase behind the initial wind shift this afternoon and evening due to modest pressure rises. However, it is still expected that the stronger pressure rises will occur between 03z and 12z Tuesday. The big change here is that models have come way down from yesterday, keeping 1 hour pressure rises mostly below 3 mb as the surface low can't strengthen as fast with the faster frontal passage. So while windy conditions are expected (25 to 35 mph), high wind warning values are not expected (the 850mb winds now only peak around 40 knots). Temperatures will plunge below freezing behind the front this evening and overnight. The hard freeze and freeze warnings look good as no changes were made. The windy conditions will also promote wind chill values in the teens and single digits into Tuesday morning. Breezy winds will continue through Tuesday morning with gusts near 25 to 35 mph, but should gradually decrease as a surface ridge approaches from the north. Temperatures are expected to recover into the 50s, but will need to watch cloud cover that may be more persistent than currently forecast. Ward && .LONG TERM...Tuesday Night through Sunday... The extended looks for a series of mostly dry waves but warmer temps signaling spring may finally be here to stay. Tuesday night will see a mid level shortwave come across the Panhandles. This in conjunction with surface winds turning upslope as the surface high pressure builds in, will bring an increase in cloud cover. While this cloud cover will provide some slow down to the radiational cooling, expect the clouds will not prevent the temps from lowering to below freezing for most of the area, with some areas in the northwest in Hard Freeze Warning criteria. Wednesday will see the surface winds become southerly which will help with some WAA. However, Pacific moisture will be streaming into the area as our upper level flow becomes zonal as a trough digs into southern California. This will maintain mostly cloudy skies through the day and prevent much diurnal heating. A piece of the trough out west looks to get picked up by the mid level flow and come across the area as a shortwave Wednesday night into Thursday. A lee side low looks to build with this shortwave and bring breezy conditions as the pressure gradient tightens. On the eastern side of the low pressure, the moisture advection will meet the lift and bring some precip chances mostly to OK, but the eastern Panhandles may catch the fringes of the precip. Depending on the timing of the wave, if it is overnight when temps are coldest, the northeastern sections may see some snow flakes. With the area being only on the fringes of the good moisture, no impacts or accumulations would be expected if anything is received. Models are in some disagreement with the timing of the shortwave, so we may continue to see variations in the precip chances, locations, and type accompanying it. Meanwhile, the other portion of the energy left behind in southern California digs further south towards the Baja by Friday. Mid level flow starts to turn southwesterly as this system shifts eastward. Much like the last system, timing of the trough axis going through the Southern Plains is in disagreement. What the models do agree on is that this system will kick the lee side low out to slide across the area and behind the surface low will be a cold front. The air mass won't be much of a hindrance to temps though as the northerly winds aren't progged to be long lasting. The weekend will continue to see shortwaves moving through the flow. The dry line looks to make a come back starting Friday and going through the weekend as well. So perhaps the Panhandles will finally be out of winter's grip and move into spring. The temperature trends suggest at least the extended looks more like spring as we will warm through the period and finally see temps overnight remain above freezing by Thursday morning for most and by Friday morning for everyone. Beat && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 28 50 29 54 35 / 10 10 0 0 10 Beaver OK 28 50 29 55 35 / 30 10 0 0 10 Boise City OK 23 47 27 54 31 / 30 10 0 0 10 Borger TX 31 52 31 58 38 / 10 10 0 0 10 Boys Ranch TX 28 52 29 58 36 / 10 10 0 0 10 Canyon TX 27 51 28 54 34 / 10 10 0 0 10 Clarendon TX 31 52 32 52 38 / 10 5 0 0 10 Dalhart TX 24 48 26 55 30 / 10 10 0 0 10 Guymon OK 26 50 29 56 34 / 30 10 0 5 10 Hereford TX 28 51 28 56 34 / 10 5 0 0 10 Lipscomb TX 28 51 29 56 36 / 20 10 0 0 20 Pampa TX 28 49 29 54 36 / 10 10 0 0 10 Shamrock TX 31 53 31 55 37 / 10 5 0 0 10 Wellington TX 32 55 33 55 39 / 10 5 0 0 10 && .AMA Watches/Warnings/Advisories... TX...Hard Freeze Warning from 1 AM to 9 AM CDT Tuesday for the following zones: Carson...Dallam...Deaf Smith...Hansford... Hartley...Hutchinson...Lipscomb...Moore...Ochiltree... Oldham...Palo Duro Canyon...Potter...Randall...Roberts... Sherman. Freeze Watch from late Tuesday night through Wednesday morning for the following zones: Armstrong...Carson... Collingsworth...Dallam...Deaf Smith...Donley...Gray... Hansford...Hartley...Hemphill...Hutchinson...Lipscomb... Moore...Ochiltree...Oldham...Palo Duro Canyon...Potter... Randall...Roberts...Sherman...Wheeler. Wind Advisory from midnight tonight to 6 AM CDT Tuesday for the following zones: Dallam...Deaf Smith...Hartley...Moore... Oldham...Palo Duro Canyon...Potter...Randall...Sherman. Freeze Warning from 1 AM to 9 AM CDT Tuesday for the following zones: Armstrong...Collingsworth...Donley...Gray... Hemphill...Wheeler. OK...Hard Freeze Warning from 1 AM to 9 AM CDT Tuesday for the following zones: Beaver...Cimarron...Texas. Freeze Watch from late Tuesday night through Wednesday morning for the following zones: Beaver...Cimarron...Texas. && $$ 7/16