textproduct: NWS Phoenix

UPDATE

Updated Aviation

KEY MESSAGES

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

- Temperatures warming over the weekend, reaching a slightly above normal category by early next week.

SHORT TERM /TODAY THROUGH MONDAY/

Water vapor satellite imagery and 500 mb RAP analysis show the core of the system now over eastern Utah, and continuing its journey northeastward over the Four Corners region. As the low pushes past into the Northern Plains, negative height anomalies over our region will slowly erode and give way to near to slightly above climatological normal H5 heights, and quasi-linear flow aloft over the weekend. This will lead to one last day of below normal temperatures this afternoon, with the lower deserts in the low to mid 90s. Heights will continue to increase throughout the weekend with Sunday between 582-585 dam, and temperatures mostly in the upper 90s with localized areas between 100F-101F. Very narrow spread remains on the latest probabilistic NBM guidance as confidence is excellent that temperatures will continue to warm in response to an upper level ridge building over Central CONUS and positive height anomalies over the Desert SW. In turn, to kick off the work week afternoon highs are forecasted to be 101F-105F, or slightly above normal and localized areas of moderate HeatRisk will develop.

LONG TERM /TUESDAY THROUGH FRIDAY/

By Tuesday, upper level ridging will already be present centered over Central CONUS and will lead to temperatures 2F-4F degrees above normal for early June. Localized areas of moderate HeatRisk will persist throughout the week as high temperatures will remain very steady with only a 1F-2F degrees difference day to day. Otherwise, skies will be mostly clear throughout the week which will help cooling overnight, where lows will be near to 1F-2F degrees above normal. By Friday and heading into next weekend, temperatures will begin to cool by a degree or two in response to a cut off low developing over Northern Mexico.

AVIATION

Updated at 1125Z.

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

No major weather issues will exist through Sunday morning under clear skies. Confidence is very good that winds will obtain a westerly fetch across the Phoenix area by late morning, then persisting into late evening/overnight before switching back to east. Across SE California, winds will generally oscillate between W/NW during the overnight/early morning, and S/SE during the afternoon/evening. Gusts should be minimal to absent this TAF period.

FIRE WEATHER

Lighter winds following mostly diurnal upslope/upvalley and nocturnal drainage patterns will prevail, with typical afternoon breeziness for late May/early June. Below normal temperatures today will quickly warm to near normal Sunday and slightly above normal early next week. Afternoon minRHs will be in the 10-20% range areawide today, then further decrease to an 8-15% range Sunday. Afternoon minRHs will commonly bottom out in the single digits areawide early next week. Overnight recoveries will begin to be less robust, decreasing into a 25-45% range tonight, and then in the 20- 35% range early next week.

PSR WATCHES/WARNINGS/ADVISORIES

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