Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 05/14/22


Area Forecast Discussion
National Weather Service Phoenix AZ
438 PM MST Fri May 13 2022 .UPDATE...Updated 00Z Aviation Discussion. .SYNOPSIS... High pressure will build over the region through the upcoming weekend, resulting in significant warming. High temperatures across the lower deserts are expected to surpass 100 degrees beginning Saturday and continuing through the first half of next week. Seasonably dry conditions will persist through the period with mainly clear skies. && .DISCUSSION... As it has been advertised during the past several days, the big weather story as we head into the weekend will be the building heat as a ridge of high pressure settles across the western CONUS. Latest PHX ACARS sounding depicts significant warming of the lower troposphere compared to 24 hours ago. Therefore, high temperatures for today will solidly be about 10 degrees warmer compared to 24 hours ago, with highs in the middle to upper 90s expected across the lower deserts under mostly clear skies. As the ridge continues to amplify into the weekend, surface temperatures will jump another 5-10 degrees as the 850 mb temperatures push up to 24-28C across the local area. This will translate to high temperatures of between 101-104 degrees for Saturday and between 103-106 degrees for Sunday. It still appears we will fall short of tying/exceeding the daily record for Sunday, with the probability of occurrence from the NBM remaining low (<20%). A weak shortwave will move over the region late Sunday into Monday, which will help increase breezes with wind gusts potentially exceeding 20 mph at times late Sunday afternoon into Sunday evening, especially over southeast California. This wave will also provide some slight cooling, with high temperatures for Monday expected to be a degree or two lower compared to Sunday. As a polar trough becomes situated off the PAC NW coast during the early to middle portion of next week, a more quasi-zonal flow will set up across the region, with heights aloft remaining nearly steady. NBM continues to depict high temperatures across the lower deserts hovering between 100-102 degrees. As we head towards the end of next week, the aforementioned polar trough will then move over the western CONUS. The ensembles, however, continue to show variations in terms of the positioning as well as the degree of amplification of this trough. Nevertheless, it does appear likely that high temperatures will fall back below 100F with an increase in winds. && .AVIATION...Updated at 2338Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Generally quiet aviation weather is expected. Skies will be clear today with just a few high clouds overnight and into Saturday. Current light westerly winds to shift to typical easterly drainage winds around/just after midnight at most locations, with KPHX likely 8-9Z. Winds to revert back to typical diurnal westerly winds by 20- 21Z Saturday with light westerly winds persisting well into Saturday night. Southeast California/Southwest Arizona including KIPL and KBLH: Generally quiet aviation weather is expected. Skies will be clear today with just a few high clouds developing overnight. At both KIPL and KBLH winds will be light westerly to northwesterly overnight, then become northerly again on Monday morning at KBLH and light/variable at KIPL. Winds at both TAF sites to become southeasterly Saturday afternoon, then revert back to westerly to southwesterly Saturday evening. Speeds will generally be at or below 8 kts. && .FIRE WEATHER... High pressure building over the area through the weekend will result in well-above normal temperatures with very dry air prevailing. Temperatures through most of the forecast will be 5-10 degrees above normal. Min afternoon RHs values will be less than 5% through Sunday, recovering to between 5 and 10% into next week. Overnight RH recovery will be poor through this weekend, only topping out in the 15-25% range. There will be a slight improvement in Max RHs next week with overnight shallow moisture fluxes from the Gulf of California. Areas near the Lower CO River Valley will see the greatest Max RH improvement, to around 40-50% by midweek, with elsewhere only to 20-30%. Light winds can be expected through Saturday with the typical afternoon breeziness in the teens. A slight increase in winds is expected late Sunday, when gusts could occasionally exceed 20 mph, especially across SE California as a weak weather disturbance moves across the region. Otherwise, winds will generally be light to locally moderate through the middle of next week. Winds could increase once again by the end of next week as a stronger weather disturbance moves across the western states. && .CLIMATE... Record highs later this week: Date Phoenix Yuma El Centro ---- ------- ---- --------- 5/14 107 in 1927 113 in 1927 110 in 1927 5/15 107 in 1937 109 in 1937 107 in 1934 5/16 106 in 1997 109 in 1956 108 in 2014 && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook, Twitter, and at weather.gov/phoenix DISCUSSION...Lojero/Benedict AVIATION...Percha/Hodges FIRE WEATHER...Lojero/Benedict CLIMATE...18