Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
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119 FXUS65 KPSR 280540 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 1040 PM MST Mon May 27 2024 .UPDATE...Updated 06z Aviation Discussion... && .SYNOPSIS... Quiet conditions are in store as high pressure encompasses much of the western United States during the majority of the next seven days. A weak trough will begin to traverse the region Wednesday but will result in almost no noticeable changes in conditions outside of perhaps a minimal increase winds. Widespread triple- digit heat is expected across the Desert Southwest, with very little change in day-to-day temperatures through at least the upcoming weekend. && .DISCUSSION... Current analysis reveals high-pressure building over the Desert Southwest and much of the western CONUS to start the week. This ridging pattern is projected to build further over the next few days, with heights aloft rising to 583-585 dam over our forecast area. This amplification will result in a continued warming trend as temperatures for today are forecasted to be a few degrees higher compared to what was observed yesterday, with afternoon highs ranging between the high 90s to around 103F across the lower deserts. Further, albeit slight, day-to-day warming will continue for Tuesday, as forecasted highs for lower elevation locations will range between 100-105F. Global model guidance indicates a weak, quick-moving shortwave trough traversing the western CONUS by Wednesday. The best energy with this disturbance will pass well off to our north, with the greatest height falls/coldest air focused over the Pacific Northwest and Northern Rockies. This system would provide very little in the way of change/impacts across the region, except for perhaps a degree or two decrease in temperatures as heights aloft drop slightly. Regardless, surface to 500mb thickness values will remain above climatological normals, suggesting that temperatures will also remain above normal, with afternoon highs between 100-105F, even with the passage of the weak trough. There could be a slight uptick in breeziness each afternoon, but overall wind gusts are expected to remain below 25 mph with the exception of far western Imperial County where gusts could reach as high as 35 mph Wednesday and Thursday afternoons. Model cluster analysis agrees that amplified ridging will reemerge by the latter half of the upcoming weekend, pushing heights aloft up once more, helping to keep temperatures hot across the region. NBM temperature forecasts keep highs between 100-105F for both Saturday and Sunday, with potentially further warming for the start of next week. Clusters are not in complete agreement with how strong the ridge may become, but the potential exists for the ridge to become further amplified, which may result in the first 110F temperatures this year for some areas. The 75th percentile of the NBM has temperatures in Phoenix reaching that mark by next Wednesday, but it is too early to say with confidence if temperatures will reach that point by next week. && .AVIATION...Updated at 2350Z. South-Central Arizona including KPHX, KIWA, KSDL, KDVT: No major aviation weather concerns are expected through the TAF period under mostly clear skies. Winds will continue to exhibit diurnal tendencies with speeds generally aob 10 kts, although some periodic gusts in the mid to upper teens will be common Tuesday afternoon once again. There will likely be extended periods of light and variable directions as well. Southeast California/Southwest Arizona including KIPL and KBLH: No major aviation weather concerns are expected through the TAF period under mostly clear skies. At KIPL, winds will mostly be out of the west, with a period of southerly winds Tuesday afternoon. At KBLH, winds will mostly be out of the south to southwest. Winds will generally be light below 10 kts through Tuesday morning with periods of variability, with gusts picking up to near 20 kts at KBLH during the afternoon and at KIPL during the early evening hours. && .FIRE WEATHER... Hot and dry conditions will persist through this week with temperatures topping out around 5 degrees above average. Daily highs will reach the century mark in most lower desert locations beginning today with widespread readings between 100-105 persisting through the remainder of the week. MinRH values will be 10% or less across the central and western deserts each afternoon and overnight recoveries will continue to range from poor to fair at around 25- 40%. Winds are expected to generally remain below 15 mph, but a bump in breeziness could result in pockets of elevated fire weather concerns by the middle of this week (peaking on Wednesday). && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...Salerno/RW AVIATION...Lojero FIRE WEATHER...Young/Salerno