Area Forecast Discussion
Issued by NWS Amarillo, TX
Issued by NWS Amarillo, TX
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049 FXUS64 KAMA 301946 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 246 PM CDT Thu May 30 2024 ...New MESOSCALE UPDATE, SHORT TERM, LONG TERM... .MESOSCALE UPDATE FOR Severe Weather... Issued at 246 PM CDT Thu May 30 2024 * Synoptic Overview: Scattered storms, some of which may become supercellular, will develop in eastern NM to the western TX Panhandle early to mid afternoon and expand eastward, likely into an MCS with all hazards possible today. Storms should clear out of the Panhandles by midnight, although there`s a small chance that some overnight storms could occur again in the southern Panhandles. * Mesoscale: MCS exiting to the southeast has created and outflow of stable air over the central and eastern Panhandles. Meanwhile areas west of Amarillo to Dumas have been working with a more unstable airmass with multiple attempts at early afternoon convection in a highly sheared environment has lead to failed attempts at storms right along that boundary. As we continue to heat up, and shear aloft gradually weakens, it will promote a much better environment for sustainable convection. Additionally a fairly stout shortwave will approach the Panhandles during peak heating and will interact with the dryline in eastern NM and allow for further convection to trigger. Storms along this boundary will be working with increasing favorable ML CAPE values (~2500- 3000 J/kg), effective shear (~30-40kts), and helicity (~150 m2/s2 ). Storms are expected to merge from multi- cells to an MCS around 6 to 8 PM time most likely around the Amarillo to Guymon line. * Threats: Hail is expected to range from 1 to 2", however can`t rule out a supercell producing hail in the 2-3" range. Given the well mixed boundary layer wind gust up to 70 mph will be possible. The tornado threat, while low, looks to be more focused in the southwest where lower LCLS, and higher effective shear/helicity values prevail. Overall, profiles are not the most ideal for tornadoes, but certainly not impossible, especially with a lone supercell that could attach itself to the boundary in the west. Flash flooding can`t be ruled out, but the probabilities are not high enough to note a watch other than the southeast Panhandles, which already received abundant rain this morning. Other areas that received rain don`t have the highest confidence that storms will hit, given the more scattered nature from an Amarillo to Guymon line, and west. * Timing & Location: Timing of storms to start will be in the 1 to 4 PM range for the western Panhandles, with the central Panhandles in the 3 to 7 PM time frame, and eastern Panhandles in the 6 to 8 PM time period. There is a wider range for the western and central Panhandles as convection is already attempting to start in the west but is failing to hold given stronger shear and weaker instability. * Summary: Severe storms likely to start in the west to northwest and gradually expand to the southeast through the evening. All areas have a chance to see storms. Primary threat is large hail and damaging wind, but will not rule out a possible landspout and/or tornado, and localized flash flooding. The more likely area to see flooding will be the southeast where a flood watch will be issued, due to recent rains and higher probabilities of storm coverage. Weber && .SHORT TERM... (This evening through Friday night) Issued at 246 PM CDT Thu May 30 2024 Friday will see continued rain showers and thunderstorms starting in the early morning as overnight convection persist into the morning hours. This activity will tapper down for the late morning and early afternoon time allowing for instability to recover. This should prime the environment for a trough passing across during the late afternoon through evening time allowing for another round of rain showers and thunderstorms. The instability and dynamics associated with this trough are on the marginal side with shear of 15-20 m/s and CAPE 1500-2000 J/Kg. However these marginal indices should still prove sufficient to allow for strong to severe thunderstorms. The main threat from these storms will be large hail and damaging winds, while the threat of tornados will be extremely low it cannot be ruled out. Overall lower levels of moisture on Friday should mitigate the chance of high rainfall from the thunderstorms so flash flooding is very unlikely but cannot be fully ruled out. Winds through Friday will be on the light side and mainly out of a easterly direction. Saturday will start of similar to Friday with overnight rain showers and thunderstorms persisting into the early morning hours. These storms will then mostly clear out by the mid morning hours allowing for instability to recover. A trough will move through the area during the afternoon to evening hours bringing another round of very unstable conditions. This trough will be stronger than Friday more along the lines of Thursday which lends further credibility to the dynamics. The dynamics themselves look to have CAPE values of 3000 to 4000 J/Kg, shear of 25 to 35 m/s, helicity of 250 to 300, and a curved hodograph. Translated into layman terms the environment will be supportive of powerful rotating updrafts that can lead to supercells. The winds will help fuel the thunderstorms by shifting to the SE bringing moisture (aka the fuel) to the panhandles. The main threat from the strong to severe thunderstorms will once again be large hail and damaging winds, tornados will have a low chance of occurring as the lowest level shear does not look favorable. With the moisture being pushed into the area high rainfall rates may occur with the thunderstorms which in turn can causes flash flooding. The thunderstorms are likely to form in the western panhandles during the mid afternoon becoming more numerous through the rest of the afternoon as they move eastward. These storms should then in large have departed eastward out of the panhandles during the overnight hours. Temperatures for Friday and Saturday will stay nearer to normal with the passage of the troughs. Highs on Friday will be in the lower to mid 80s while Saturday will be warmer with highs in the mid to upper 80s. && .LONG TERM... (Saturday through next Wednesday) Issued at 246 PM CDT Thu May 30 2024 Next week has a high chance of being overall drier time compared to the current week as the bulk of the moisture shift to the east. This doesn`t mean there wont be any activity as moisture in the eastern panhandles should still be sufficient to spark off isolated rain showers and thunderstorms. These rain showers and thunderstorms would be possible during the afternoon to evening hours of Sunday, Monday, and Tuesday. However, during this time a strong cap looks to be in play across much of the panhandles that could limit or outright prevent any rain shower or thunderstorm from forming. IF any thunderstorms is able to form despite the powerful cap then the environment will be supportive of strong to severe thunderstorms. The main threat during this time remains large hail and damaging winds with tornado chance being extremely low to none. Going further to Wednesday and Thursday the pattern becomes very uncertain making the forecast fuzzy at best. The two most probable solution is either a deep trough moving through the plains causing more rain showers and thunderstorms or a large ridge bringing hot and dry conditions to the plains. Currently the trough and wetter solution has the most support in different models so that is currently more reflected in the forecast. However if the ridge becomes more probable the forecast will shift to reflect the hot dry conditions. SH && .AVIATION... (18Z TAFS) Issued at 1234 PM CDT Thu May 30 2024 Thunderstorms possible at the TAF sites over the next 4 to 8 hours. Overall, the best chances for timing would be in the 19-00z time period, but would note that storms have the potential to still be persistent as late as 2z. Tempo groups have been assigned for each site to account for best probabilities, and will adjust as need for real time storm development. After storms move through winds will be light and variable for the most part through the end of the TAF period. Severe wind gusts would be possible with thunderstorms. Weber && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 57 83 59 87 / 50 20 40 20 Beaver OK 58 81 57 87 / 90 20 30 20 Boise City OK 53 81 53 86 / 30 40 50 40 Borger TX 59 86 61 90 / 80 20 40 20 Boys Ranch TX 58 85 59 91 / 40 30 40 30 Canyon TX 56 82 57 87 / 40 20 40 30 Clarendon TX 58 80 60 83 / 70 40 30 30 Dalhart TX 54 83 55 87 / 30 30 40 30 Guymon OK 55 82 56 87 / 70 20 50 30 Hereford TX 56 84 58 89 / 30 20 40 30 Lipscomb TX 58 81 59 85 / 90 20 30 20 Pampa TX 57 82 60 85 / 90 20 30 20 Shamrock TX 58 81 60 84 / 90 40 30 20 Wellington TX 59 81 61 85 / 80 50 30 20 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...Flood Watch from 7 PM CDT this evening through late tonight for TXZ014-015-019-020. OK...None. && $$ SHORT TERM...98 LONG TERM....98 AVIATION...89