Area Forecast Discussion
Issued by NWS Amarillo, TX
Issued by NWS Amarillo, TX
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665 FXUS64 KAMA 201934 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 234 PM CDT Fri Sep 20 2024 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Issued at 304 AM CDT Fri Sep 20 2024 - Thunderstorms will be possible today through Sunday with some of the storms having the potential to be severe, with damaging winds and large hail being the primary concern, with localized flooding becoming possible on Saturday. - Cooler temperatures are likely to be present Sunday with the arrival of the cold front. - Additional thunderstorm chances are forecast early to mid next week. && .SHORT TERM ... (This evening through Saturday night) Issued at 230 PM CDT Fri Sep 20 2024 As of the early this afternoon, radar and satellite were already seeing showers and thunderstorms move in with the lead wave of the incoming upper-level system. Latest expectations for the CAMs continues to see these showers focus mostly in the western and northern portions of the Panhandles with potential to be present clear into the overnight hours. In terms of impacts, CAMs have been very confident very in little MLCAPE being present with some of the higher outcomes still having values under 1000J/kg. The bigger concern for the severe potential today will be more focused on the winds as all the CAMs are suggesting DCAPE values above 1500 J/kg, which would be more then enough to create a 60 to 70 mph gust off a weak collapsing thunderstorm. Secondary to the winds, will be the flooding potential for today as all models see PWAT values rise above an inch today and continue to rise with the approach of the main system. Added to this is will a very good potential to see storms train over areas with flow staying consistent for the day and CAMs suggesting that environment will be favorable to recycle and redevelop storms. While this setup may not result in quick flash flooding, it could be a case of small amounts adding up over time, especially if storms continue into the overnight. Of course this overnight activity will be key to the impacts expected for Saturday when the system arrives in full to the Panhandles. As it stands, CAMs are in agreement that much better MLCAPE will be present across the southwestern portions of the Panhandles, with very good wind shear present in the area as well. What is especially concerning, is that many of these model are suggesting that a chunk of this strong shear is present in the lower-level which indicate better chances for a tornadic event to be present alongside strong severe thunderstorms. However should activity be present through the overnight, then the above mention conditions will struggle to come to fruition under already present cloud cover. Alongside this caveat, will be the final placement of the boundary accompanying the system. At this time, CAMs suggest that it holds north enough to keep the better ingredients present to areas south of the I-40 corridor. However, it is entirely possible that the boundary moves further south than expected and shifts those ingredients south alongside it. Rather, the better chances for impacts may be on the flooding side of the equation. Currently, model agrees that PWAT values will rise even further Saturday, which will bring a majority of the Panhandles to values around 1.25 to 1.5 inches. Added to this will be very similar motion and training that is expected today with potential for storms to last clear into Sunday. Given this and the potential rain from the overnight tonight, it is not out of the question for locations around to Panhandles to average precipitation accumulations of an inch by the time we hit Sunday. Add to this the potential for areas to localized heavier amounts due to thunderstorms, and localize flooding has the better chances to occur over the course of the day. Regardless, expect cooler weather to follow this activity with the northwestern Panhandles looking to drop into the mid 70s for high temperatures Saturday. Meanwhile in the southeast where conditions and activity are not as favored, temperatures could still rise into the 90s for the day. Scoleri && .LONG TERM ... (Sunday through next Thursday) Issued at 230 PM CDT Fri Sep 20 2024 The mid-level trough responsible for the rain chances on Saturday is expected to eject and become imposed within northeastern Colorado by early Sunday morning. Concurrently, this trough`s jet streak is progged to slide northeastward, fostering the development of a sfc high and robust CAA into the CWA. Strong northerly flow in conjunction with modest sfc cyclogenesis in the Permian Basin is expected to yield robust convergence along the cold front. This Strong convergence coupled with ample BL moisture will encourage appreciable chances for scattered convection throughout the day on Sunday. However, the 12z suite of deterministic models exhibit much disparity in the degree of forward advancement of the cold front, owed to previous days coldpool magnitude and subtleties in sfc high strength. If the cold front advances too quickly, then the warm- sector and thus rain chances will be confined south of the CWA. Conversely, some deterministic members slow the progression of the cold front, yielding decent QPF returns in the Southeastern CWA. Moreover, flooding may also become a concern in the latter scenario due to boundary parallel shear and tendency of training storms. POPs ranging from the 40`s to even upper 60`s have therefore been continued for the Eastern half of CWA, Sunday. A brief lull of rain chances will exist on Monday, with the exception of modest POPs across the far northwestern CWA. Appreciable rain chances return on Tuesday afternoon as a positively- tilted trough is progged to encroach on the Southern Plains. Regarding rain prospects on Tuesday, Much uncertainty exists in the degree of return flow and BL moisture. Therefore, POPs on Tuesday have been maintained in the 30`s to lower 50`s, with some likely adjustment with further confidence. Following Tuesday, rain chances depress considerably as the trough departs the CWA. Below average temperatures ranging from the upper 50`s to the upper 70`s are likely on Sunday in the wake of the cold front. Although, some uncertainty exists in the forecasted highs considering cloud cover and possible convection. Additionally, Low`s in the lower 40`s are plausible early Monday morning in the far northern FA, especially if there is little to no cloud cover. Following Sunday High temperatures are expected to rebound to seasonal levels in the 70`s and 80`s through Wednesday. LNJ/SAS && .AVIATION... (18Z TAFS) Issued at 1228 PM CDT Fri Sep 20 2024 As of 12:30 PM, latest radar was already seeing showers push into Western portions of the Panhandles. Current expectations is for these showers to stay within the vicinity of KDHT before spreading out to KGUY later this afternoon. These showers and thunderstorms are expected to be present through afternoon and possibly the overnight for both terminals where it is likely to see brief impacts. KAMA, on the other hand, has chances to see impacts as well, but current confidence is not high enough to include latest package. Otherwise, expect better chances for showers and thunderstorms to follow Saturday with the oncoming of the expected system. && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 68 88 59 68 / 10 70 90 40 Beaver OK 70 87 55 66 / 20 70 90 50 Boise City OK 61 75 49 59 / 40 80 90 20 Borger TX 70 92 59 71 / 10 80 90 40 Boys Ranch TX 65 84 57 68 / 20 80 90 30 Canyon TX 65 88 59 69 / 10 70 90 40 Clarendon TX 68 91 62 73 / 0 50 80 60 Dalhart TX 61 75 51 63 / 40 80 90 20 Guymon OK 65 81 51 63 / 20 80 90 40 Hereford TX 65 87 59 69 / 10 80 90 30 Lipscomb TX 70 93 60 70 / 10 60 90 60 Pampa TX 68 89 59 69 / 10 70 90 50 Shamrock TX 69 94 64 74 / 0 40 70 70 Wellington TX 70 96 67 79 / 0 30 60 70 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...None. OK...None. && $$ SHORT TERM...11 LONG TERM....99 AVIATION...11