Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
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852 FXUS65 KPSR 282000 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 100 PM MST Tue May 28 2024 .SYNOPSIS... Dry and mostly tranquil conditions will be the norm over the next several days as highs across the lower deserts reach into the triple digits. A weak disturbance will pass north of the region Wednesday into Thursday but will result almost no noticeable change in day- to-day conditions outside of a slight increase in regional winds. This hot and quiet pattern will persist into this weekend and likely into next week. && .DISCUSSION... Atmospheric analysis reveals ridging entrenched across much of the western CONUS, promoting dry and tranquil conditions across the Desert Southwest, which will continue for today. Temperatures this afternoon will be a few degrees warmer compared to where they were yesterday due to heights aloft continuing to increase day-by-day. Lower desert high temperatures will range generally between 100-105 degrees, helping to increase the coverage of Moderate HeatRisk for parts of the region, especially for areas around the Phoenix metro, Colorado River Valley, and Imperial Valley. If you plan to be outside for a prolonged period during the hours of peak heating, be sure to take frequent breaks and hydrate often. A weak, transient trough will pass over the western CONUS Wednesday, with the greatest energy focused over the Pacific Northwest and northern Rockies. Outside of a slight increase in the regional pressure gradient leading to some nuisance breeziness during the afternoon, and perhaps a degree or two drop in temperatures compares to Tuesday, little to no sensible weather changes will occur with this system. Afternoon highs on Wednesday will range from the upper 90s to around 103 degrees across the lower deserts. With the aforementioned system moving over the the Plains by Thursday, heights aloft will rebound slightly, allowing for a small rebound in temperatures as highs that afternoon will range between 100-105 degrees once again. Friday looks to be much of the same, albeit a degree or two warmer, with daytime highs between 102-106 degrees. Some global ensembles are now hinting at another weak trough traversing the western CONUS by this weekend, but keep the greatest associated height falls/coldest air well off to our north, this time focused over southern Canada, yielding almost no changes for regional conditions. Model clusters, even with the passage of a trough, agree that heights aloft over our forecast area will remain climatological normals, which help keep the streak of triple-digit heat going into the weekend. Clusters also agree that an amplified ridge will develop by next week, suggesting that a continuation of dry, tranquil, and hot conditions is in store for next week, with some areas potentially seeing their first 110 readings since last September. The NBM 75th percentile has Phoenix reaching that point by next Wednesday, but it is still too early to say with confidence that temperatures will reach that high. && .AVIATION...Updated at 1715Z. South-Central Arizona including KPHX, KIWA, KSDL, KDVT: No aviation weather concerns are expected through the TAF period under FEW-SCT high clouds this evening and overnight. Winds will continue to exhibit diurnal tendencies with speeds generally aob 10 kt sustained, although some periodic gusts in the mid to upper teens will be common this afternoon once again. There will likely be extended periods of very light speeds 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 FEW-SCT high clouds by this afternoon. At KIPL, winds will mostly be out of the west, with light and variable winds favored through the rest of this morning and into the afternoon. At KBLH, winds will mostly be out of the south to southwest. Gusts are expected to increase to around 20 kts this afternoon at KBLH and this evening at KIPL. && .FIRE WEATHER... Hot and dry conditions will persist through this weekend with highs topping out around 5 degrees above normal each afternoon. MinRH values will remain at or below 10% across the central and western deserts and overnight recoveries will continue to range from poor to fair at around 25-40%. Winds are generally expected to remain below 15 mph, but an uptick 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...RW AVIATION...Smith/Whittock FIRE WEATHER...Salerno