textproduct: NWS Phoenix

UPDATE...Updated 12z 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/

After multiple days of a messy upper-level pattern across much of the CONUS, current 500mb analysis reveals a relatively more organized look to flow aloft, but the Desert Southwest still finds itself caught in the middle of multiple weather regimes. Low pressure flanks us to the southeast and northwest, while flat ridging remains over the eastern Pacific. The interaction between these different sectors helped squeeze our regional pressure gradient, allowing for enhanced breeziness across much of the region yesterday afternoon and evening.

Elevated winds are expected to continue through this weekend and into next week, with peak gusts likely to occur later today. The highest readings should be focused for areas in and around the Lower Colorado River Valley where observations will reach upwards of 30-35 mph. The combination of these winds, low RHs, and very dry fuels, a Red Flag Warning has been posted for late this morning into the evening hours for those areas in close proximity to the Colorado River, along with the remainder Yuma and La Paz Counties. Even though gusts will be slightly lower elsewhere, gusts will still range between 20-30 mph, which will be more than enough to produce widespread elevated fire weather conditions. The northerly most trough will sweep through the Pacific Northwest before turning to the Northeast once it reaches near the Snake River Valley over the course of the weekend and into the start of next week. Peak gusts will be slightly lower as the gradient slackens, but readings 25-30 mph will be common during this timeframe.

After seeing the regional height field a tad above what is typical for this time of year, the Pacific low will help erode at those positive height anomalies through the weekend. This will allow for temperatures to cool, but this system will remain well off to the north, preventing any noticeable cooldown. Triple digits will be widespread across the lower deserts (which is is nothing abnormal for early June), with readings up to 5 degrees above normal for the hottest spots this afternoon. Readings should hover within a few degrees of normal for Sunday and Monday as afternoon highs range between 99-105F.

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 1110Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT: Elevated westerly winds will once again be the main aviation weather issue later this afternoon through early this evening. The overall wind pattern will follow the typical diurnal tendencies with easterly winds early this morning shifting out of the west by late this morning. Wind speeds will pick up this afternoon as occasional gusts upwards of 20-25 kts will be common before subsiding early this evening. Clear skies will persist through this morning before high cirrus cloud decks move in by this afternoon.

Southeast California/Southwest Arizona including KIPL and KBLH: No major aviation weather issues under increasing high cirrus cloud decks can be expected throughout the TAF period. At KIPL, southeast winds will prevail through at least the mid-afternoon hours before a westerly wind shift materializes during the late afternoon/early evening hours. At KBLH, winds will generally fluctuate between the south to south-southwest. Overall wind speeds will fluctuate between 8-15 kts with afternoon gusts upwards of 20-25 kts expected at KBLH.

FIRE WEATHER

A Red Flag Warning has been posted 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%.

PSR WATCHES/WARNINGS/ADVISORIES

AZ...Red Flag Warning from 9 AM this morning to 11 PM MST this evening for AZZ131-132.

CA...Red Flag Warning from 9 AM this morning to 11 PM PDT this evening for CAZ231.