FXUS64 KAMA 111735 AAB AFDAMA Area Forecast Discussion...UPDATED National Weather Service Amarillo TX 1135 AM CST Mon Dec 11 2023 ...New AVIATION... .SHORT TERM ... (Today through Tuesday night) Issued at 322 AM CST Mon Dec 11 2023 Mild northwest flow will keep conditions dry today with slightly above normal temperatures. Highs will be in the mid 50s to near 60 in some areas. Partly cloudy skies with winds in the 5 to 10 mph range should make for a pleasant day. Cooler air will be on the way as a system approaches and we transition to a more zonal flow aloft. Cloud cover will increase tonight and that will allow for overnight lows to be a bit warmer, but still overall most areas will be below freezing. With the cooler air in place on Tuesday highs will only be in the upper 40s to mid 50s with mostly cloudy skies. An upper level trough will begin to dig down over the Las Vegas area and start to close off on Tuesday night. This along with easterly flow at the surface will being to pump Gulf moisture over the Panhandles and we'll begin to see chances of precipitation starting over the southern Panhandles and gradually transition north. The temperatures early Wednesday morning will be close enough that a rain/snow mix could occur to portions of the northern Panhandles. This will be the start of what looks to be a three day weather event that could bring winter impacts to portions of the Panhandles (See long term discussion for further details). Weber && .LONG TERM ... (Wednesday through Sunday) Issued at 322 AM CST Mon Dec 11 2023 Main headline will continue to be the next system to bring impactful precipitation to the region over multiple days this upcoming work week. Confidence is very high that the Panhandles will see precipitation during the Wednesday to Friday timeframe. The exact amounts remain uncertain as well as the precipitation types. It is not out of the realm of possibility that some locations receive impactful snowfall from this system. Drier and warmer conditions are favored going into next weekend. An upper level H500 low pressure system should be located near the southern tip of Nevada by sunrise on Wednesday morning. This would leave the Panhandles underneath southwesterly flow aloft. At the surface, southerly to southeasterly winds will continue to usher in Gulf moisture across the Southern High Plains and this trend will continue through Friday. Scattered rain showers may be ongoing across portions of the Panhandles on Wednesday morning and should become more widespread by Wednesday night as the low pressure system continues to move east during the day. With the system being well off to the west on Wednesday, temperatures should remain warm enough so that the precip type should mainly be rain. From midnight Wednesday to midnight Thursday there is currently a 30 to 60 percent chance for the central and western Panhandles to see a half inch of rainfall. The upper level low will begin to become cutoff by early Thursday morning near the Arizona/New Mexico state line. With the low continuing to move slowly east, multiple rounds of precipitation will continue to be possible from Thursday through at least mid day Friday based on the latest 11/00z deterministic and ensemble suite of guidance. Latest deterministic suite of guidance is in fairly good agreement on the overall track of the low through Thursday evening. The main area of concern will be where the center of the low tracks from Thursday morning through mid day Friday as this will play a large part in the precipitation types during these days. Currently the GFS is the furthest south solution, which takes the H500 low across southern New Mexico and eventually across portions of west Texas. EC/CMC want to bring the low a bit further north and eventually move the center of low pressure across the Panhandles. If the later scenario comes to fruition, more areas (mainly the central and west) would have the potential to switch from rain to snow during this timeframe. Even if the GFS solution wins out, winter impacts are still possible for portions of the area, just not as much of the CWA. With the low pressure system finally being onshore in time for the 00z soundings this evening, hopefully models will begin to converge on a track on Tuesday. Overall, the system should be east of the Southern High Plains by Friday night. The big question that everyone will be (and is probably already) asking is, what amounts are to be expected with this system. Based on the 11/01z NBM probabilities, a majority of the area has around a 30 to 50 percent chance at receiving an inch or more of liquid precip from this multiple day event. It should also be noted that the typically dry biased GEFS mean is over an inch for the entire area as well. In other words, there is very high confidence in abnormal rainfall for December during these three days. The main area of uncertainty is with regards to potential snow amounts and unfortunately there is a lot of uncertainty. Even though the GFS track of the low may be correct, am hesitant to believe the very low snow accumulations given by the GEFS with the known warm bias and model soundings suggesting snow potential at some locations over multiple hours. Given all this, the potential is certainly there for impactful snowfall from Thursday through Friday, especially for the central and western Panhandles. Be sure to continue to check back for forecast updates throughout the week given the uncertainty with this system and its potential impacts. Muscha && .AVIATION... (18Z TAFS) Issued at 1134 AM CST Mon Dec 11 2023 Winds are expected to remain around 10 knots or less along with VFR conditions. && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 29 54 39 47 / 0 0 50 100 Beaver OK 26 51 33 47 / 0 0 30 90 Boise City OK 24 47 29 42 / 0 0 10 90 Borger TX 29 56 40 50 / 0 0 40 100 Boys Ranch TX 27 54 37 48 / 0 0 40 100 Canyon TX 28 54 38 47 / 0 0 50 100 Clarendon TX 31 54 42 47 / 0 0 50 90 Dalhart TX 23 50 31 44 / 0 0 30 100 Guymon OK 24 50 31 45 / 0 0 20 90 Hereford TX 28 55 38 48 / 0 0 60 100 Lipscomb TX 28 54 37 47 / 0 0 30 80 Pampa TX 30 53 39 45 / 0 0 40 90 Shamrock TX 29 55 40 47 / 0 0 30 80 Wellington TX 30 55 40 48 / 0 0 40 80 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...None. OK...None. && $$ SHORT TERM...89 LONG TERM....05 AVIATION...15