textproduct: NWS Phoenix

KEY MESSAGES

- High pressure over the region will cause temperatures to warm back to near normal this weekend and eventually slightly above normal by the middle of next week.

- Periods of breezy to locally windy conditions can be expected across southcentral and southwestern AZ through this weekend with gusts reaching 20-30 mph at times.

- Dry weather with zero rain chances will persist through this weekend and into much of next week.

SHORT TERM /TODAY THROUGH SUNDAY/

GOES mid-lvl WV imagery and RAP40 500 mb analysis show the ridge of high pressure continuing to build over Southern CA and the Great Basin region as the low pressure system from earlier in the week has retrograded slightly to the SW and is now positioned over western TX and NM/Mexico boarder. This has established easterly flow aloft in addition to the advection of very dry air. PWATs across the lower deserts are forecasted to be generally below 1", and with the strong subsidence overhead any chances for additional rainfall ahead is essentially zero. With the high to our north and low to the SE of our region, the main impact will be elevated easterly flow due to the established pressure gradient. This will lead to gusty easterly winds this afternoon and expected to last through the weekend with speeds reaching up to 20-30 mph with peak gusts likely reaching 35 mph across the higher terrain of southcentral AZ.

The high pressure building over the region is expected to drive H5 heights to between 588-591 dam or just into the 90th percentile of climatology for this time of year, especially in SoCal and into northern AZ. Temperatures in response will be above normal as afternoon high temperatures in South-central AZ will be in the mid to upper 90s while SoCal will be slightly higher, into the upper 90s to even reaching into the low 100s in localized areas. While the upper atmosphere is relatively dry, surface dew points remain in the mid 50s keeping overnight lows 6F-10F degrees above normal.

LONG TERM /SUNDAY THROUGH THURSDAY/

Deterministic and ensemble guidance shows the 500 mb ridge axis flattening as a weak trough passes through the Intermountain West early next week before rebuilding over SoCal and the Great Basin region again by mid- week. As this pattern evolves, there may be a brief dip in temperatures on Monday before significant warming occurs from Tuesday into Thursday. Highs across the western deserts will likely remain in the low 100s Monday and Tuesday before topping out around 100-105 degrees as early as Wednesday. The lower deserts of southcentral AZ will also see temperatures gradually rise from the low to mid 90s Monday and Tuesday to around 100 degrees by mid-week. Overnight lows will also be warm, generally remaining in the low to mid 70s. Overall, daily temperatures are expected peak around 4-8 degrees above normal mid to late next week. Subsidence aloft and dry air in the mid lvls should keep a lid on any potential convective, even over the AZ higher terrain and thus rain chances will remain near zero each day next week.

AVIATION

Updated at 1747Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:

Easterly winds will prevail through the TAF period under mostly clear skies. Surface wind speeds will be lightest during the overnight hours, while during the daylight hours speeds will be around 8-13 kts with gusts to around 20 kts and be strongest during the late-morning/early-afternoon hours. Speeds will be slightly stronger Saturday, with gusts up to 20-25 kts.

Southeast California/Southwest Arizona including KIPL and KBLH:

No aviation weather impacts expected under mostly clear skies. Wind directions will favor an E'rly component at KIPL through this afternoon and then light VRB through the overnight. At KBLH, a N-NE wind is favored, with speeds around 5-10 kts.

FIRE WEATHER

Dry conditions with near normal temperatures are anticipated through this weekend with a steady warming trend expected from the beginning to middle of next week. MinRHs will mostly range from 15-25% over the western districts to 25-35% for the eastern districts with good to excellent overnight recoveries. A persistent breezy easterly gradient wind will develop across the region today and persist for the next several days. Morning to early afternoon wind gusts in the 20-30 mph range will become common.

PSR WATCHES/WARNINGS/ADVISORIES

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