textproduct: NWS Phoenix

UPDATE

Updated 06Z Aviation Discussion.

KEY MESSAGES

- After a slight "cooldown" through this weekend, temperatures will hold relatively steady at near to slightly above normal levels through most of the upcoming week. - Dry conditions under a mix of clouds and sunny skies will prevail over the next several days.

- Locally breezy conditions will be common across the region this weekend and into the front half of next week, particularly across the lower Colorado River Valley and higher terrain communities of Arizona.

SHORT TERM /Today through Monday/

Current 500mb analysis and GOES mid-level WV imagery show the first of two systems that will sweep across the Pacific NW now centered over NW Washington and the Canadian boarder. Down here in the Desert SW, the region remains sandwiched between this approaching system in the NW, and the previous cut-off low which in now ejecting northeastwards into the plains out of northern Texas. This has lead to tightening in the pressure gradient resulting in breezy to windy conditions across the region throughout the weekend. Breezy to locally windy conditions will peak this afternoon/evening with speeds between 30- 35 mph in Yuma, and La Paz Counties and the lower Colorado River Valley, while elsewhere across the region can expect gusts between 20-25 mph. Along with these gusty conditions, fuels are very dry with minimum RH's hovering near to slightly below 10%. Due to the combination of there factors a Red Flag Warning is in effect for Yuma, and La Paz county, and along the Colorado River until 11 PM MST/PDT. Winds will relax, slightly, on Sunday but widespread elevated fire weather conditions will persist even once the warning expires.

The system in the Pacific NW will help erode positive height anomalies over the region through the weekend, however temperatures won't see a huge drop off in temperatures as the system will remain well to our north. However temperatures will "cool" to hover between 100F-105F degrees starting Sunday and into the upcoming workweek. These temperatures are still be 2F-3F degrees above normal with widespread Minor to locally Moderate HeatRisk.

LONG TERM /Tuesday through Friday/

Based on what the ensembles continue to show, it looks like conditions for through the middle of the upcoming week will be just about the same was what will be seen over the next few days. Models indicate that another shortwave will traverse the Pacific Northwest, helping to keep the pressure gradient relatively tight, allowing for the continuation of breezy conditions, mainly for the Lower Colorado River Valley and high terrain communities once again. Daily peak gusts may reach upwards of 25-30 mph through next Thursday. With continued dry conditions, elevated to near critical fire weather conditions max last through the next 5-6 days. Temperatures will not budge much either, with the NBM showing afternoon highs ranging between 100-107 degrees during the entirety of next week. Any subtle changes in the position of the follow-on trough may result in forecast changes in the next few days, mainly concerning winds and temperatures as dry conditions appear all but certain for at least the next week.

AVIATION

Updated at 0515Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT: Gusty westerly winds will be the primary aviation weather concern during the TAF period. Typical diurnal winds are expected overnight tonight before southerly winds begin to increase mid/late morning Sunday. Breezy westerly winds are once again expected for Sunday afternoon (gusts in the upper teens to around 20 kt). SCT to at times BKN high clouds will persist through the period.

Southeast California/Southwest Arizona including KIPL and KBLH: No significant aviation weather concerns are expected through the next 24 hours under SCT high clouds. Current NW winds at KIPL will go SE tomorrow morning before going SW tomorrow evening. Wind speeds at KIPL will generally be aob 10 kt through the period. At KBLH, winds will favor the S to SSW through the period. Overall wind speeds, at KBLH, will fluctuate between 7-15 kts with afternoon gusts upwards of 20-25 kts expected.

FIRE WEATHER

A Red Flag Warning is in effect for portions of SW Arizona and areas around the Lower Colorado River Valley for this afternoon and evening. Dry fuels, RHs around 10%, and gusts upwards of 35 mph will result in critical fire weather conditions for these areas. Elsewhere, gusts 20-30 mph will be common, resulting in elevated fire weather conditions for much of the region. Outside of Saturday, daily breezy conditions, albeit not as strong as today, can be expected through at least the front half of next week, resulting in a prolonged period of elevated fire weather conditions. MinRHs will hold steady close to 10% across the region, while overnight recoveries only offer poor to modest recovery, with MaxRHs near 15-45%, with the western portions in the higher range.

PSR WATCHES/WARNINGS/ADVISORIES

AZ...Red Flag Warning until 11 PM MST this evening for AZZ131-132.

CA...Red Flag Warning until 11 PM PDT this evening for CAZ231.