Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
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436 FXUS65 KPSR 290507 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 1007 PM MST Tue May 28 2024 .UPDATE...Updated 06Z Aviation Discussion. && .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 0505Z. South-Central Arizona including KPHX, KIWA, KSDL, KDVT: Winds will follow their typical diurnal patterns with some extended periods of light and variable winds. Wind speeds will generally be aob 10 kt through the TAF period, however, some periodic gusts into the teens will be possible once again tomorrow afternoon. FEW- SCT high clouds will clear out tomorrow afternoon. Southeast California/Southwest Arizona including KIPL and KBLH: At KIPL winds will mainly be out of the west through the TAF period whereas at KBLH winds will be out of the south to southwest. Winds at KIPL will gust into the low 20s through the overnight hours, with speeds returning to aob 10 kt through the mid- to- late morning and afternoon hours. Then, around 00Z tomorrow night winds will once again gust into the mid 20s for the evening and into the overnight hours. At KBLH, wind speeds will be aob 10 kt through the TAF period. FEW high clouds will clear out through the overnight hours. && .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...Berislavich FIRE WEATHER...Salerno