886 FXUS65 KPSR 291923 AFDPSRArea Forecast Discussion National Weather Service Phoenix AZ 1223 PM MST Mon Sep 29 2025
.KEY MESSAGES...
- A dry and quiet weather pattern will prevail throughout the week with near zero rain chances.
- Temperatures will gradually warm from near normal to slightly above normal by the latter half of this week as a ridge of high pressure builds over the region.
- A dry weather system passing north of the region will bring breezy conditions and slightly cooler temperatures this weekend.
&&
.SHORT TERM /TODAY THROUGH TUESDAY/... The latest water vapor satellite imagery as well as streamline analysis depict a weak upper-level ridge across the region. A much drier air mass has settled into the region with mostly clear skies being observed. Temperatures this afternoon will continue to be slightly below normal with highs in the lower 90s across the lower deserts.
For Tuesday, a broad trough will be situated over the Pacific Northwest with quasi-zonal flow in place across the Desert Southwest. Weather conditions will continue to remain dry and tranquil. Temperatures will continue to warm a couple of more degrees to more seasonable levels with highs reaching the mid 90s across the lower deserts.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/... From mid to late week, ensemble and deterministic models are in agreement that a high amplitude ridge will build over the Desert Southwest while a cutoff low develops over California. 500 mb hghts will gradually increase to around 588-590 dam by the end of the week resulting in highs across the lower deserts increasing from the mid 90s on Wednesday to the upper 90s to around 100 degrees by Thursday and Friday. Global models continue to indicate the aforementioned shortwave trough eventually diving across the Great Basin this weekend which will result in a slight cool down and breezier conditions across southcentral AZ. Given the trajectory of this system remaining north of the forecast area and the lack of any adequate moisture return, dry conditions with near zero precipitation chances are expected to persist.
&&
.AVIATION...Updated at 1710Z.
South Central Arizona including KPHX, KIWA, KSDL, and KDVT: No aviation concerns are expected through Tuesday morning. Winds will favor light and diurnal trends with periods of variability, especially during directional shifts. Other than a FEW afternoon CU aoa 8k ft and some high cirrus moving in tonight, skies will be mostly clear.
Southeast California/Southwest Arizona including KIPL and KBLH: No aviation concerns are expected over the next 24 hours. Winds will favor light and diurnal trends, with extended periods of VRB to calm conditions. Other than a FEW afternoon CU and some high cirrus moving in this evening, skies will be mostly clear.
&&
.FIRE WEATHER... Temperatures will gradually warm above normal through the middle of this week as a ridge of high pressure builds over the forecast area. Expect much drier conditions to materialize each day with MinRHs ranging from 25-35% this afternoon and falling to around 15-25% through the end of this week. Overnight recovery will range from fair to good tonight and generally remain in the fair category through this week. Winds will follow light and diurnal tendencies for the next several days with some modest afternoon upslope gusts.
&&
.PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. &&
$$
SHORT TERM...Lojero LONG TERM...Salerno AVIATION...RW FIRE WEATHER...Salerno
NWS PSR Office Area Forecast Discussion