textproduct: NWS Phoenix

KEY MESSAGES

- Temperatures today will be near normal before warming to slightly above normal for the upcoming workweek.

- Lighter, more seasonable wind speeds with only modest afternoon breezes will be common this weekend and likely persist through much of this upcoming week.

SHORT TERM /TODAY THROUGH WEDNESDAY/

Upper-level imagery and 500mb RAP analysis show quasi-linear flow over AZ and southern CA, with a swath of dry air over the region. The low that has been progressing northeastwards to the north of our region over the past few days is now well into central WY. This has helped alleviate the breezy to windy conditions, returning the region to a more typical pattern of light winds, with an occasional breezy afternoon for the upcoming week.

Quasi-linear flow will persist throughout today leading to near normal temperatures across the lower deserts, ~100F. By Monday an omega block pattern will begin to develop as high pressure builds centered over the central Plains, and a deep low pressure system develops in the Gulf of Alaska area. By Monday, as this high pressure builds, H5 heights over the lower deserts will climb into the 585-588 dam range, resulting in afternoon highs slightly above normal or between 101F-105F degrees. This pattern will remain in place through at least mid week, due to this temperatures day to day will only vary by 1F-2F degrees. With temperatures returning to the above normal category, isolated areas of Moderate HeatRisk will develop across portions of the lower deserts (most notably across the Lower CO River region). Remember to practice smart heat safety by drinking plenty of water and electrolytes and limiting your time outdoors (especially during the afternoons). Otherwise, the ample dry air aloft along with calmer winds will keep skies mostly clear and aid in radiational cooling at night. Expect morning low temperatures to be in the mid to upper 70s through much of the upcoming week.

LONG TERM /THURSDAY THROUGH SATURDAY/

Model ensembles are in good agreement that the upper level ridge over the Central Plains will begin shifting eastwards as early as Wednesday, then afterwards a cut off low will develop Thursday in Northern Mexico and is what will help temperatures trend back towards normal late next week. Afternoon highs Thursday will not feel the full effect of this developing low as H5 heights will remain between 582-585 dam. While these heights will be slightly lower than earlier in the week temperatures will remain generally between 101F-104F degrees. Starting Friday temperatures will begin returning to near normal, ~100F, as heights continue to lower slightly in response to the developing low to the south of the region. These near normal temperatures are likely to persist through next weekend.

AVIATION

Updated at 0520Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT; and Southeast California/Southwest Arizona including KIPL and KBLH:

No aviation concerns are anticipated through the forecast period under clear skies. Winds will follow typical diurnal trends at all terminals with speeds remaining generally less than 10 kts. There may also be extended periods of calm and VRB conditions overnight and prior to the onset of any wind shifts.

FIRE WEATHER

Light winds will mainly follow their diurnal upslope/upvalley and nocturnal drainage patterns through most of this upcoming week. Some occasional breeziness is expected as well. Near normal temperatures today with temperatures rising to slightly above normal by Monday and will stay slightly above normal through at least the upcoming workweek. MinRHs will be around 5-10% today and are expected to remain in that range through the workweek. Overnight recoveries will will be around 20-35% throughout the workweek, with the driest day expected mid week.

PSR WATCHES/WARNINGS/ADVISORIES

AZ...None. CA...None.