textproduct: NWS Phoenix

KEY MESSAGES

- Near normal temperatures today warm to slightly above normal tomorrow and will be near to slightly above normal through this upcoming week.

- Dry conditions with mostly sunny skies and light seasonal winds with occasional afternoon breeziness are expected through this upcoming week.

SHORT TERM /TODAY THROUGH WEDNESDAY/

Upper-level water vapor satellite imagery and 500mb RAP analysis show an omega block starting to develop with a strong closed low in the Gulf of Alaska, another strong closed low over New England, and a ridge starting to develop across central CONUS. With the omega block starting to develop upper level heights across the Desert Southwest have started to rise with flow aloft becoming more southwesterly vs quasi-zonal. H5 heights across AZ and southern CA range from 580-584 dm, which is around 4 dm more than H5 heights yesterday. This increase in heights aloft will result in temperatures continuing to warm. Afternoon high temperatures will be near normal today with highs in the upper 90s to around 100 degrees across the lower deserts and in the 90s across the higher terrain areas.

The omega block pattern will continue to amplify and looks to maximize during the middle of the week, when the hottest temperatures of the week are expected. As a result of the amplifying pattern H5 heights look to climb to 585-588 dm over our region and thus temperatures will climb to slightly above normal on Monday and then warm another degree or two for Tuesday and Wednesday. Afternoon high temperatures will be in the 100-105 degree range across the lower deserts and in the mid to upper 90s to around 100 degrees across the higher terrain areas during the first half of the workweek. Morning low temperatures will also be on the rise this week with morning lows ranging from the mid 60s to mid 70s across the lower deserts and the upper 50s to mid 60s across the higher terrain areas. The combination of these morning lows and afternoon highs will result in localized areas of Moderate HeatRisk developing as early as Monday, mainly across the Lower CO River Valley. As temperatures warm, remember to practice smart heat safety by drinking plenty of water and electrolytes and limiting your time outdoors (especially during the afternoons).

Aside from the warming temperatures, with high pressure building over our region, dry conditions with mostly clear skies will continue through at least the middle of the week. With no weather systems moving through the region, wind speeds will follow typical diurnal trends along with seasonal light wind speeds and occasional modest afternoon breeziness.

LONG TERM /THURSDAY THROUGH SATURDAY/

Model ensembles are in good agreement that the upper level ridge over the Central Plains will begin shifting eastward 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 1715Z.

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

No aviation weather concerns under generally clear skies can be expected throughout the TAF period. The overall wind pattern will follow the typical diurnal tendencies with speeds generally aob 10 kts along with extended periods of light variability to even calm conditions.

FIRE WEATHER

Light winds will mainly follow their diurnal upslope/upvalley and nocturnal drainage patterns through most of this upcoming week. Some occasional modest afternoon breeziness is expected as well. Temperatures will be near normal today before rising to slightly above normal for the majority of the upcoming workweek. MinRHs will be around 5-15% through the upcoming week with poor overnight recoveries (15-35%). The driest days (lowest humidities) are expected mid week.

PSR WATCHES/WARNINGS/ADVISORIES

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