Area Forecast Discussion
Issued by NWS Amarillo, TX
Issued by NWS Amarillo, TX
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312 FXUS64 KAMA 151114 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 614 AM CDT Sun Sep 15 2024 ...New AVIATION... .KEY MESSAGES... Issued at 341 AM CDT Sun Sep 15 2024 Above normal temperatures will continue for much of the upcoming week. Isolated showers and thunderstorms are possible late this afternoon and tonight across most of the area. Showers and thunderstorms are possible just about every day through Saturday. However, coverage and probabilities of precipitation may differ significantly on a daily basis. && .SHORT TERM ... (Today through Monday night) Issued at 341 AM CDT Sun Sep 15 2024 Widespread 90-100 degree temperatures continue for today across the Panhandles due to strong ridging, very warm 850mb temperatures, and breezy southerly winds. As with the past two days, there will be a lack of significant forcing mechanism in order to get showers or thunderstorms to develop... however, given the anomalous heat, convective temperature should be reached this afternoon such that isolated to scattered showers or thunderstorms will be possible across the Panhandles. Unlike the past two days, some dry air aloft (around 700mb) is being advected into the Texas Panhandle tonight and into the morning hours. The GFS/ECMWF/NAM suggest that this dry airmass will be wiped out by a more moist airmass moving in from New Mexico in the late afternoon hours. This drier air aloft may inhibit showers and thunderstorms from developing in the early to mid afternoon hours, but if the moisture aloft moves in by the late afternoon into the early evening hours, we may see shower and thunderstorm development. To make confidence worse, CAMs are also not in good agreement regarding where/when/if showers and thunderstorms will develop. Have opted to give 10-15% PoPs across the Panhandles, with 15-20% PoPs in the northwestern combined Panhandles where more CAMs agree the most on some kind of activity occurring. Also similar to the past two days, forecast soundings show an inverted-V signature once the moisture aloft arrives, suggesting the potential for wind gusts up to 55 mph. Again, can`t entirely rule out a wind gust up to 60 mph but there is a very low chance (<5%)for that given the meager instability. However, given that the potential development for showers and thunderstorms looks to be later in the day compared to previous days, the window for a strong wind gust looks to be narrower as activity should weaken with the cessation of daytime heating. Monday, a seasonably robust upper-level trough dips down into the West Coast states while a lee surface trough develops in eastern Colorado. This will lead to breezy winds especially for the northwestern combined Panhandles. Highs look to be around 2 degrees cooler than today, but once again still well above average. There will once again be a chance for showers and thunderstorms across the Panhandles, but there is currently very low confidence regarding where they will develop. Most of the 00z CAMs are suggesting the better chance for development will be in the eastern combined Panhandles rather than the western combined Panhandles which is what the NBM is showing. A likely explanation for this is that the CAMs are picking up on a sharpened surface trough in the eastern combined Panhandles, and the converging surface winds may be just enough to get thunderstorms to develop. Will opt to leave the NBM`s PoPs in for now as it is hard to be sure at this time that the surface trough will remain in the Panhandles, but introduction of higher PoPs may be needed later. Vanden Bosch && .LONG TERM... (Tuesday through Saturday) Issued at 341 AM CDT Sun Sep 15 2024 The first upper level low pressure system embedded in the larger scale western states upper level trof initially progged to be in the vicinity of northeast Nevada at 12Z Tuesday is forecast to translate northeast into Montana by 12Z Wednesday, then head into far southern Canada towards Wednesday evening. The trailing energy associated with this first storm system is expected to graze the southern high plains and help generate showers and thunderstorms across New Mexico early Tuesday afternoon. These showers and storms are then expected to move eastward across our forecast area later Tuesday afternoon and night, with precipitation ending and having moved east of the region by around 12Z Wednesday. There will likely be a relative minimum in precipitation chances for the OK and TX Panhandles on Wednesday and Thursday as the large scale western states upper level trof reloads with another upper level low pressure system progged to dig southward to around southern California by Thursday morning. This particular feature is expected to track east northeast towards the central plains region Friday into Saturday. As this occurs, chances for showers and thunderstorms increases again for the area, mainly Friday and Friday night. The threat will then decrease on Saturday as the second storm system heads into the central plains. Medium range models and corresponding ensembles are in general agreement with the overall upper level pattern. However, differences in timing and track of these two storm systems were noted. NBM pops and temperatures are reasonable and reflect the above synoptic scale reasoning. Further adjustments to the long term periods are anticipated as time gets closer and numerical weather models converge on a more common solution with respect to timing and track. 02 && .AVIATION... (12Z TAFS) Issued at 612 AM CDT Sun Sep 15 2024 VFR conditions are expected through this forecast period. There is a 10-20% chance for showers and thunderstorms after around 23z at all terminals, but confidence in occurrence and timing is too low to include in the TAFs at this time. Otherwise, winds will generally be out of the south at 10-15 kts with gusts up to 25 kts throughout the day. && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 95 64 93 65 / 10 10 0 10 Beaver OK 96 63 92 64 / 10 10 20 10 Boise City OK 92 60 89 62 / 0 20 10 10 Borger TX 100 66 97 67 / 10 10 10 10 Boys Ranch TX 96 63 94 65 / 10 10 10 10 Canyon TX 94 62 92 64 / 10 10 0 10 Clarendon TX 94 63 92 65 / 10 10 0 10 Dalhart TX 92 59 90 60 / 10 20 0 10 Guymon OK 95 62 94 63 / 10 10 10 10 Hereford TX 95 62 93 64 / 0 10 0 10 Lipscomb TX 96 64 93 66 / 10 10 10 10 Pampa TX 94 64 92 64 / 10 10 10 10 Shamrock TX 95 64 92 65 / 10 10 0 10 Wellington TX 97 65 94 66 / 10 10 0 0 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...None. OK...None. && $$ SHORT TERM...52 LONG TERM....02 AVIATION...52