FXUS65 KPSR 162329 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 429 PM MST Fri Oct 16 2026 .UPDATE...00Z Aviation Discussion && .KEY MESSAGES... - Wind advisories continue across portions of the region through Saturday morning with gusts occasionally over 35 mph resulting in areas of blowing dust and difficult travel for high profile vehicles. - A slight chance of light rain will arrive into parts of south- central Arizona over the weekend with the better chances focused over higher terrain locations. - A Pacific low pressure system moving into the Southwest during the middle of next week will lead to much better rainfall chances with the possibility of a few embedded thunderstorms, as well as cooler temperatures && .SHORT TERM /Today through Sunday/... As full latitudinal troughing deepens over the eastern Conus, a mature high amplitude Rex block remains established over the western half of the country. This pattern continues to promote strong sfc high pressure over the central Rockies/high plains, and combined with inverted low pressure emanating from the Gulf of California, an intense pressure gradient has developed across the CWA. An H9-H8 30- 50kt easterly LLJ has weakened early this afternoon as the thermal enhancement has deteriorated, but lingering gusty winds and lofted dust will continue to impacts many areas through the overnight. While lower elevations will experience partial decoupling and much weaker winds after sunset, ridge tops and the typical wind prone areas will likely continue to record gusty winds pushing advisory criteria through the overnight. The combined effect of a significantly loosened pressure gradient and thicker clouds compromising mechanical mixing will preclude advisory criteria beyond Saturday morning. The aforementioned Rex block will slowly open this weekend with the negative height anomaly propagating from southern California into northern Arizona. This places south-central Arizona within a very favorable left front jet quadrant with a weak cold core skirting the forecast area indicative of periods of robust ascent. The underlying southwest flow will also concurrently import thick moisture through the H7-H5 layer such that total column PWATs reach 1" by Saturday afternoon. While these parameters would generally support widespread light rain, a very dry sub-cloud layer resulting from the persistent downsloping easterly winds will battle the ability for precipitation reaching the ground. Nevertheless, given the ascent structure and magnitude of midlevel moisture, some light showers should reach the surface Saturday afternoon through Sunday morning with the best chances over higher terrain areas east of Phoenix where sfc to cloud base depths are minimized. Otherwise, partial clearing will slowly advance through the forecast area Sunday with moisture and ascent lifting into northern Arizona. && .LONG TERM /Monday through Thursday/... The ridge comprising the northern portion of the Rex block will push eastward early next week as the upper low weakens into an open wave and becomes absorbed into the mean southwest flow. Lingering light showers may continue to affect orographically favored areas of the eastern CWA Monday aided by the next piece of subtropical jet energy rounding towards the Southwest from the eastern Pacific. If activity does develop, total accumulations are expected to be fairly minimal. By Tuesday, deep troughing and strong negative height anomalies will amplify and intensify along the west coast, however confidence is exact the timing and depth of this feature remains low to moderate. As a result, notable forecast temperature spread exists during the middle of next week, in addition to uncertainty in rainfall timing and amounts.At this time, the preponderance of model evidence points towards Wednesday and Thursday as the most likely to experience showers and embedded thunderstorms ahead of the trough passage and the introduction of much cooler, below normal autumnal temperatures. && .AVIATION...Updated at 2330Z. South Central Arizona including KPHX, KIWA, KSDL, and KDVT: Gusty E'rly winds and reductions to slantwise visibility will continue to be the main aviation concerns through Saturday afternoon. Gusts 25-30 kt, with sporadic higher gusts, will persist until after sunset before decreasing slightly overnight. However, breeziness will will not cease completely, though it should be less frequent compared to the daylight hours. Instances of little to no gusts at the surface could create localized LLWS impacts due to continued enhanced flow aloft. More persistent breeziness will reemerge late Saturday morning before a more noticeable downtrend in speeds takes place late in the forecast window. Mostly clear skies this evening will give way to considerable cloud cover overnight. Southeast California/Southwest Arizona including KIPL and KBLH: Outside of some marginal breeziness at KBLH, operational impacts should be minimal over the next 24 hours. Flow at KIPL will switch between NE and NW, while KBLH will experience a persistent NE component through Saturday afternoon. FEW mid-level cloud decks this evening will give way to more considerable cloud cover tonight. It is not out of the question that an isolated VCSH is seen over the region this evening, but chances are currently less than 10% so any mention of rain has been excluded from the TAFs. && .FIRE WEATHER... Strong east winds will continue through Saturday across southern Arizona with the most pronounced gusts over mountain tops of eastern districts during the overnight and early morning hours. Gusts 40-45 mph may be common over these locations with a portion of these winds building into lower elevations by late morning. Speeds will slowly decrease through the day with even weaker winds Sunday through the middle of next week. Light showers are possible this weekend, and particularly over eastern districts, but the chance for wetting rain is low (~10%). The strong east winds will result in minimum humidity levels 20-30% Saturday, but increasing closer to a 30-50% range thereafter. Overnight recovery should be good to excellent. A Pacific weather disturbance will bring increased chances of wetting rainfall, breezy winds, and cooler temperatures during the latter half of next week. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Wind Advisory until 11 AM MST Saturday for AZZ547-552-553-555- 557-558-560>562. CA...None. && $$ SHORT TERM...18 LONG TERM...18/Ryan AVIATION...RW FIRE WEATHER...18/Ryan