597 FXUS64 KAMA 102348 AAA AFDAMA Area Forecast Discussion...UPDATED National Weather Service Amarillo TX 648 PM CDT Wed Oct 10 2018 .AVIATION... For the 00Z TAFs, a developing cold front will slide south and settle across the forecast area tonight. Moist, low level upslope flow will begin this evening and persist through Thursday, resulting in MVFR to IFR cigs along with patchy fog at the terminal sites. 02 && .PREV DISCUSSION... /Issued 405 PM CDT Wed Oct 10 2018/ SHORT TERM (through 7am Thursday)... Clouds expected to increase from north to south tonight as developing cold front arrives. Strong low-level moist warm air advection atop frontal surface will act to produce a widespread overcast by sunrise. Patchy fog may develop across western sections late tonight. Overnight low temperatures expected in the mid-30s northwest to mid-40s southeast. Cockrell LONG TERM (Thursday through Tuesday)... Noteworthy items continue to be the precipitation chances going forward as well as the frost/freeze potential which could in turn lead to snowfall (or perhaps a wintry mix at times) this weekend. Snowfall *could* potentially be the first "accumulating" snowfall of the season if it pans out. Most of the forecast area could see freezing to below freezing temperatures Sunday night. Upfront, Thursday and Friday precipitation chances are not as clear cut as the later periods. These chances are moreso spotty and less in coverage, and to be quite frank...less likely to occur in the broader scheme and hence the "spotty chances". Upper level pattern starts southwesterly (Thursday) and then a quasi- zonal/split flow pattern appears (Friday-Fri night) over the Panhandles as remnants from Hurricane Sergio traverses over the Rockies and makes it way over West Texas. Lacking any noteably energy aloft Thursday/Friday and a moisture deprived atmosphere (minus near surface moist layer) confidence is not all that high for Thursday. May end up being just socked in with low clouds all day. Increasing to 20-25 percent for PoPs Thursday night/Friday morning as there is some semblance of a front pushing east from the Texas/New Mexico border eastward though Friday which may result in better chances for the Panhandles. Saturday and Sunday is where all the real "fun" begins. Potential widespread rainfall Saturday as Sergio starts to have full affect around the local area. Upper level energy will have diminish somewhat by this time, but vorticity maximum should become evident just south of the area and hence the heaviest rainfall as well. Isentropic lifting across the Panhandles may result in southern portions of the Texas Panhandles accumulating some appreciable amounts if the track of the upper level low doesn't move farther south. If one were to take a blend of the GFS and European, upper level vort max and energy should pass just south of the forecast area. Broad speaking rainfall amounts of 0.50" to 1.50" may be possible for the southern half of the forecast area. Potential flooding could result as well due to preexisting saturated soils. One large caveat is if the track continues its trend south we may have a potential "busted" forecast with rainfall staying south of the area. NAM is depicting a more southerly track than the GFS and European and hence less precipitation for the local area. Track concerns also make forecasting the wintry precipitation difficult. Cold airmass comes in Saturday night/Sunday morning behind the cold front. High temperatures on Sunday could vary greatly over the local area. Some areas may struggle to get out of the 30s. Our snow chances will be greatly correlated to the airmass and temperature profile. So some concerns here on the timing of the front and depth of cold layers versus warmer air. Snow--or perhaps a mix of precip-- could play into the forecast, but too early to latch on to anything at this time. Went with broad brush of snow/rain chance across portions of the area Sunday and Sunday night where the colder airmass is more likely. Changes are almost certain to come in the next 48 hours. Guerrero && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && $$