Area Forecast Discussion
Issued by NWS Amarillo, TX
Issued by NWS Amarillo, TX
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250 FXUS64 KAMA 282322 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 622 PM CDT Tue May 28 2024 ...New AVIATION... .SHORT TERM ... (This evening through Wednesday night) Issued at 1232 PM CDT Tue May 28 2024 Multiple outflow boundaries are apparent via multiple means which resulted from last night`s MCS and this morning`s elevated convection. Much of the area is seeing either no clouds (western Panhandles) or partly cloudy skies, but there are pockets of mostly cloudy skies. Nonetheless, dew points are in the 50s to low 60s across much of the area with temperatures already climbing into the 80s as of 12 PM. The quality of low-level moisture may wane some as diurnal mixing occurs, but MLCAPE values between 1500-2500 J/kg should be achievable by mid to late afternoon. By then, the westward moving outflow should be over or just west of Amarillo as a dryline pushes east into the southwestern TX Panhandle, and the cap should be sufficiently eroded for thunderstorms to develop. Forecast wind profiles are favorable for the development of supercells (effective shear 40-50 kts, 180 degree turning of the winds from surface to 500mb). However, weak low-level shear is expected this afternoon which creates a straight hodograph, suggesting splitting supercells would be favored. Given the moderately unstable environment, steep lapse rates, and decent shear within the hail growth zone, hail up to Tennis Balls (2.50") will be possible. Given the steep lapse rates below mid-level moisture which increasingly becomes drier and warmer toward the surface, damaging winds will also be possible, with some wind gusts between 70-80 mph possible. The tornado threat is certainly mitigated by the previously mentioned weak low-level winds, but can`t rule out a tornado with any right-moving supercell that can latch onto a boundary. However, current thinking is that any right-moving supercell would move out of the CWA given its motion and the currently favored area of convective initiation (southwest TX Panhandle). A secondary round of strong to severe thunderstorms may begin in the late afternoon hours. A shortwave trough will approach the northwestern combined Panhandles, developing thunderstorms in southeastern Colorado. These thunderstorms may be discrete/semi- discrete initially but grow upscale once they move into the northwestern combined Panhandles. These storms should also strengthen owing to moving into greater instability. Here, very large hail and damaging winds may be the initial threat but as the storms grow upscale, damaging winds should become the primary threat with large hail just below it. Can`t rule out a 70-80 mph wind gust early on in the MCS`s life. The strong to severe thunderstorm threat should wane past around 9-10 PM, but can`t rule out an additional strong to severe thunderstorm before Midnight. Isolated areas of flash flooding may be possible in urban areas, or with any slow right-moving supercell, given the very moist environment. Vanden Bosch && .LONG TERM ... (Tomorrow through next Monday) Issued at 1232 PM CDT Tue May 28 2024 A temporary break in the activity going into the day on Wednesday for most areas as a small amplitude ridge moves over the Panhandles. Later Wednesday night, a disturbance moving over the central Rockies may provide a chance for some showers and thunderstorms, but this would favor the far northern combined Panhandles. Going into Thursday, our next chance for more widespread strong to severe thunderstorms return. Will have to watch observational trends closely, including cloud cover, LL moisture return, etc. Overall setup appears to have a dryline setting up near the TX/NM stateline with a good easterly sfc flow. Latest data indicate with this that the dryline to help initiate thunderstorm chances should first start in the western Panhandles before moving east throughout the afternoon hours. The environment at this time should support a high CAPE and relatively low shear environment, which would favor severe weather parameters being large hail and damaging winds as the primary threats. Boundary convergence may enhance low level winds for a tornado threat as well. With PWAT values nearing the 99th percentile, and not a strong of steering flow, training and/or back building thunderstorms with heavy rainfall rates may also cause localized flooding. We will also be watching a cold front moving south the second half of Thursday which can also be a local catalyst of lift for thunderstorm development as well. Thunderstorm chances continue Friday into the weekend as the main southern CONUS synoptic pattern remains in place. Exact timing and ingredients for how strong thunderstorm may get will be determined as we get closer with time as more data is available. Temperatures on Friday will be below average, but for the remainder of the forecast period, temperatures will be above average. Meccariello && .AVIATION... (00Z TAFS) Issued at 507 PM CDT Tue May 28 2024 Showers and thunderstorms will continue to impact the combined Panhandles through the early part of this 00Z TAF period. KDHT and KAMA are expected to see thunderstorms by the time this period starts with thunderstorms impacting KGUY maybe another hour or two into the period. Winds are expected to be easterly to southeasterly around 12 to 15 kts with possible variations and gusts caused by the thunderstorms. Initial thunderstorms may be severe with large hail and damaging winds possible. Later towards 06Z storms may pass but multiple rounds will be possible through 12Z but with less severe potential. Tstorms, may be on and off allowing for conditions to change through out the 12 hour period through 12Z. Have stayed optimistic with the TAFs from 06Z through 12Z, with amendments possibly needed. Chances for thunder return again after 18Z. 36 && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 86 58 76 61 / 70 50 30 50 Beaver OK 81 58 79 60 / 40 70 30 40 Boise City OK 83 53 78 57 / 70 70 40 40 Borger TX 87 59 80 62 / 70 70 30 50 Boys Ranch TX 90 58 80 62 / 70 50 40 50 Canyon TX 89 57 76 60 / 80 50 30 40 Clarendon TX 85 58 74 60 / 80 50 40 50 Dalhart TX 86 54 79 58 / 60 70 40 40 Guymon OK 82 55 79 58 / 50 80 30 50 Hereford TX 93 57 81 62 / 70 40 30 40 Lipscomb TX 81 59 78 61 / 40 50 40 50 Pampa TX 83 58 76 61 / 60 60 30 50 Shamrock TX 83 59 77 62 / 50 50 40 50 Wellington TX 86 60 78 62 / 60 50 40 50 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...None. OK...None. && $$ SHORT TERM...52 LONG TERM....29 AVIATION...36