Area Forecast Discussion
Issued by NWS Amarillo, TX
Issued by NWS Amarillo, TX
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974 FXUS64 KAMA 182331 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 631 PM CDT Wed Sep 18 2024 ...New UPDATE, AVIATION... .UPDATE... Issued at 631 PM CDT Wed Sep 18 2024 A weak surface boundary/trough remains from roughly Beaver down through Claude across the eastern Panhandles. Along this trough, a few showers and isolated storms have attempted to form early this evening, but have struggled likely due to mid level lapse rates only being around 6 to 6.5. A low level jet is forecast to start to increase upwards of 30 to 40 kts during the evening hours which may aid in attempting to sustain or slightly increase in strength any convection that may remain across the Panhandles. That trend will be watched over the next few hours, but in general it appears the severe threat should decrease with time as these storms have struggled early this evening. Only minor changes were made to the ongoing forecast with this update. Muscha && .KEY MESSAGES... Issued at 342 AM CDT Wed Sep 18 2024 Severe thunderstorms are possible across the eastern half of the area late this afternoon and evening, with damaging winds and large hail the primary hazards. Above normal temperatures will continue through Friday, trending closer to or even a little below normal in some locations for the weekend into early next week. A new system is expected to create showers and thunderstorms across the area late Friday afternoon through Saturday night. && .SHORT TERM ... (This evening through Thursday night) Issued at 221 PM CDT Wed Sep 18 2024 As of early this afternoon, surface observations are starting to see the expected dryline form across the eastern portions of the Panhandles. Latest model expectations continue to see this boundary as our main lifting mechanism for our activity this evening. In terms of impacts, most storms will likely be concentrated on the eastern extent of the boundary, with timing placing initiation as early as 4 to 5 pm this evening. On the eastern side of the boundary, general consensus between the CAMs is placing around 1000 to 2000 MLCAPE across the area, which may not be a hefty values but should be the enough to prompt concerns of severe hail. As for DCAPE, values are running around 1500 J/kg or greater for the eastern extent, which would put us more in favor of strong damaging winds. What is interesting, however, is that the more favored ingredient for the day will be the wind shear with agreement seeing at least 40 kts of effective bulk shear present for this afternoon. This variable only gets more favorable as we head into the evening hours thanks to the presence of a low-level jet that looks to pick after 7 PM tonight. This jet could help keep storms running into the later hours of the day despite the lack of daytime heating. What is also concerning is the combination of the higher shear, low-level jet, and boundary present could bring about the right mixture to see a spin-up on a thunderstorm this evening. However, the confidence on this notion is very low given that everything would have to align just right to even result in a quick spin-up. Regardless, the storm potential will heavily rely on the final position of the dryline boundary and how sharp it actually is. Meanwhile, Thursday continues to trend towards a more drier day with model agreement seeing the upper-level ridge strengthen with the approaching trough. This should push a majority of the Panhandles to the western side of the dryline where conditions will breezy but overall quiet for the day. The only expectation to this dry forecast maybe the far southeastern Panhandles, which may could stay east of the boundary for the day. Otherwise, look for another warm day with afternoon high temperatures in the mid to upper 90s. Scoleri && .LONG TERM ... (Friday through next Tuesday) Issued at 221 PM CDT Wed Sep 18 2024 All eyes turn to the approaching cutoff low over southern California on Friday. Low level moisture will continue to be brought northward on Friday. The axis of greatest 700 mb theta-e will be found north south across eastern New Mexico. Would expect thunderstorms to develop over eastern New Mexico during the afternoon on Friday and then the southwest flow aloft should bring some of those thunderstorms into the western Panhandles. On Saturday the upper low moves from Arizona to southeast Colorado by late Saturday night. As the upper low approaches and moves just to our north expect even more low level moisture to be brought northward and this combined with the upper level dynamics moving across should provide the stage for numerous showers and thunderstorms Saturday into Saturday night. It will be interesting to see if this cutoff low actually tracks northeast from Arizona or if it will take more of an easterly track and then lift northeast as it moves out onto the plains. There is not much of a kicker upstream to help lift the system out and it does seem to be completely cut off from the upper flow which would also lend to more of an easterly track before lifting. If the upper low can move more easterly, then we may see an even better chance at getting richer moisture back and we may have a better sheared environment. In fact, looking at the inter-quartile of the surface based CAPE for Saturday afternoon in the LREF shows an almost 1000j/kg range across much of the western 2/3rds of the Panhandles. The upper level system pulls away from the Panhandles early Sunday morning and a cold front moves through effectively turning off the precip. Monday should be a dry day in between systems. Another system then moves southeastward across the Panhandles on Tuesday which could bring another round of precipitation. && .AVIATION... (00Z TAFS) Issued at 631 PM CDT Wed Sep 18 2024 VFR conditions are forecast at all sites. Initially gusty winds will decrease over the next few hours and there after should remain around 15 kts or less. Wind direction will become sporadic for KDHT/KGUY during the morning hours around sunrise with northerly winds eventually turning back to southerly to southeasterly. Clear skies should prevail with some high clouds at times. Muscha && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 66 96 68 96 / 10 0 0 0 Beaver OK 65 95 62 98 / 10 0 0 10 Boise City OK 56 87 57 91 / 0 0 0 10 Borger TX 67 100 67 100 / 10 0 0 0 Boys Ranch TX 61 95 65 96 / 0 0 0 10 Canyon TX 65 95 66 95 / 10 0 0 0 Clarendon TX 68 97 69 97 / 20 10 0 0 Dalhart TX 55 91 59 91 / 0 0 0 10 Guymon OK 58 92 58 95 / 0 0 0 10 Hereford TX 64 96 66 95 / 0 0 0 10 Lipscomb TX 69 98 67 99 / 20 0 0 10 Pampa TX 67 97 66 96 / 10 0 0 0 Shamrock TX 69 99 70 98 / 20 10 0 0 Wellington TX 70 100 71 100 / 20 10 0 0 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...None. OK...None. && $$ SHORT TERM...11 LONG TERM....15 AVIATION...05