Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
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707 FXUS65 KPSR 270519 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 1019 PM MST Sun May 26 2024 .UPDATE...Updated 06z Aviation Discussion... && .SYNOPSIS... Generally quiet weather conditions will continue over the next week, with temperatures warming to above normal as early as tomorrow and continuing into the weekend. Typical afternoon breeziness will become somewhat stronger going through the middle of the week, but nothing out of the ordinary. && .DISCUSSION... Persistent troughing has finally exited the region, as latest satellite shows the trough axis over eastern New Mexico this afternoon. Clear skies will continue through most of this week as ridging builds over the region. Temperatures will warm as a result, with highs reaching above normal levels (upper 90s for this time of year) as early as tomorrow. Thus, expect afternoon temperatures in exceed 100 degrees, with chances for 105+ the greatest for Tuesday. Typical afternoon breezes will continue throughout the week, with some enhancements with the next weak trough that moves across western CONUS mid-week. Mid-level heights will build to around 585-588 dam across Arizona, peaking on Tuesday, as the main ridge axis sets up east of the region across the Rockies. The ridging will weaken going through the middle and latter portions of the week as the next troughing feature traverses across western CONUS, with the strongest negative height anomalies remaining well off to the north across the Pacific Northwest. As a result, generally zonal flow across the Desert Southwest will enhance the afternoon breeziness starting Tuesday, and continue through the rest of the week as zonal flow persists. Temperatures will cool slightly, but either neutral or slightly positive height anomalies persisting across the region will only result in cooling of a few degrees (highs will remain a few degrees above normal). Chances of 105+ degrees are currently greatest on Tuesday across the lower deserts (30-70%), with 20-40% chances Wednesday-Saturday according to the latest NBM guidance. Thus, areas of Moderate HeatRisk (20-40% coverage) continue to be advertised for Tuesday across the lower deserts, with smaller areal coverage (10-20%) of Moderate HeatRisk, confined to southeastern California, through the rest of this week. The latest ensemble guidance is in excellent agreement through at least Wednesday, so the sensible weather impacts of Minor-Moderate HeatRisk and increasing breeziness across the region, are expected to come to fruition. For the winds, afternoon gusts are certain to range between 20-30 mph for most areas, with some localized higher gusts (probabilities of 35 mph or greater are highest in the southwest corner of Imperial County at around 40-60%) peaking on Wednesday. Some more noticeable spread begins on Friday, where either the troughing feature lingers over western CONUS, or retreats northward going into this weekend as ridging builds back into the region. The trend seems to be some rebound in mid-level heights, which would suggest temperatures warming again going into next week. Currently, these slight differences are only resulting in NBM interquartile spreads of 3-5 degrees for the high temperatures going through this weekend, where highs for central Phoenix would remain in the mid-100s should the middle of the road (i.e. 50th percentile) solution occur. && .AVIATION...Updated at 0515Z. South-Central Arizona including KPHX, KIWA, KSDL, KDVT: No aviation weather concerns are expected through the TAF period. Winds will continue to exhibit the typical diurnal tendencies with speeds generally remaining under 10 kts, although a few occasional gusts into the mid-teens cannot be ruled out once again on Monday afternoon. Skies will remain clear through tonight before a FEW passing high clouds move through the region during the day on Monday. Southeast California/Southwest Arizona including KIPL and KBLH: No aviation concerns are expected during the TAF period. At KIPL, winds are expected to remain out of the west through the overnight before switching out of the southeast by early Monday morning. Wind are expected to shift out of the west once again early Monday evening. At KBLH, winds will generally prevail out of the south to south-southwest. Speeds will generally remain light aob 10 kts, although gusts near 20 kts are likely at KIPL for a period on Monday evening. Skies will remain clear through tonight before some passing high clouds move through the region Monday morning. && .FIRE WEATHER... Hot and dry weather 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 starting on Monday and readings will generally top out between 100-105 through the remainder of the week. MinRH values will range between 10-15% today before falling to 10% or less across the central and western deserts from Monday onwards. Overnight recoveries will continue to range from poor to fair at around 25-40%. Winds are expected to remain lighter through tomorrow, but a bump in breeziness could result in pockets of elevated fire weather concerns going through the middle of the week (peaking on Wednesday) ahead of tamer afternoon breeziness heading into this weekend. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...Young AVIATION...Lojero FIRE WEATHER...Young/Salerno