006 FXUS65 KPSR 051130 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 430 AM MST Thu Jun 5 2025 .UPDATE...Updated 12Z Aviation Discussion. && .KEY MESSAGES... - Hot and dry conditions are expected into next week with lower desert temperatures peaking near 110 degrees on Sunday and Monday. - Areas of Moderate HeatRisk develop by Saturday, likely persisting through the middle part of next week. && .DISCUSSION... Drier air continues to spread into Arizona and far southern California, despite weak troughing centered over central California into the Great Basin. Moisture levels have dropped considerably across south-central Arizona with PWATs now below 1" and surface dew points around 50 degrees. The western deserts are still holding onto some moisture with PWATs between 1-1.2" and a bit higher dew points, but with the lack of any good forcing today the area should stay mostly quiet. Locations into San Bernardino Co. may see some isolated showers or thunderstorms this afternoon, but hi-res CAMs show no activity into Riverside or Imperial Counties. Today will also mark the start of the sub-tropical ridge nudging into our region, which is currently centered over northern Mexico and southern Texas. This ridge will however not fully make its way into our region as the large scale troughing to our north and northwest somewhat keeps it at bay. As the ridge partially moves into our region over the next few days, H5 heights are seen rising from around 582dm today to around 588dm by Sunday. This will gradually push temperatures upward over the next several days with highs around normal today and Friday before peaking Sunday and Monday between 105-109 degrees across the south-central Arizona lower deserts and 106-111 degrees across the western deserts. The peak temperatures should end up around 4-8 degrees above normal, but still at least 5 degrees shy of daily records. The hot temperatures will push most locations into the Moderate HeatRisk category starting Saturday. This weather pattern of the sub-tropical ridge just to our south and a quai-zonal flow regime across the northern tier states should persist through at least the middle part of next week. Ensemble guidance does show our H5 heights lowering a bit into the middle part of the week before a larger trough eventually take shape off the Northwest U.S. late next week. This should knock a few degrees off our temperatures during the middle part of next week and possibly few more by next weekend as temperatures are likely to retreat back to near normal. Dry conditions and near consistently clear skies are expected for all of next week under this pattern. && .AVIATION...Updated at 1130Z. South Central Arizona including KPHX, KIWA, KSDL, KDVT: Light diurnal wind tendencies and mostly clear skies will prevail through today. Wind speeds will mostly remain <10 kts with extended periods of light variability, especially this morning. Southeast California/Southwest Arizona including KIPL and KBLH: No aviation concerns through the TAF period with mostly clear skies prevailing. Winds at KIPL will favor SE directions and S directions at KBLH. Wind speeds at both terminals will remain mostly aob 10 kts. There will be a surge of southerly winds this evening, beginning around 00-02Z at both terminals, that will be capable of pushing speeds to 10-15 kts with gusts into the upper teens for a few hours. && .FIRE WEATHER... Drying conditions and hotter temperatures are expected into the weekend. Afternoon MinRHs will decrease from 15-20% today to 7-12% by Saturday as lower desert high temperatures increase into the lower triple digits, which is near normal range for this time of year. Overnight RHs will also decrease from 30-45% tonight to 25-35% Friday night. Winds should follow fairly typical diurnal tendencies with periodic afternoon upslope gustiness. The dry weather pattern is expected to continue into early next week with temperatures running 5-10 degrees above normal and daily MinRHs mostly in a 5-10% range. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...Kuhlman AVIATION...Benedict/Ryan FIRE WEATHER...Kuhlman