textproduct: NWS Phoenix

KEY MESSAGES

- Slightly above normal temperatures will persist today before warming closer to 10 degrees tomorrow and early next week as high pressure builds over the region.

- There is a chance of a few showers and storms Monday across the eastern Arizona high terrain.

- Temperatures will trend back towards normal by late next week as another weather system approaches the region.

SHORT TERM /Today through Monday/

Current mid-level water vapor imagery and objective analysis show the shortwave trough has traversed through the northern Plains while ridging continues to build and is now at the doorstep of the the Pacific Northwest coast. As this ridging progresses inland over Western CONUS, temperatures will steadily climb in response. Today afternoon highs across the lower deserts will be in the upper 80s to lower 90s. By Sunday the axis of the ridge will over much of the desert SW driving temperatures into the mid to upper 90s, but will remain below the century mark. Another shortwave trough will sweep through the region on Sunday, helping bring an increase in moisture along with it. This will bring PWAT anomalies to near 200% of normal in the eastern portions of Arizona. However, current NBM PoPs, and additional model guidance have pushed chances (10-15%) of showers and isolated storms to Monday night across the eastern third of AZ. Otherwise to start off the workweek Monday can expect a slight dip in temperatures, with afternoon highs in the low to mid 90s, with localized areas in the upper 80s, with plenty of cloud coverage thanks to the upper level moisture.

LONG TERM /Tuesday through Friday/

The moisture introduced to the region over the weekend will linger through much of the week, but progressively drying each day before another surge of moisture is expected late next week. Otherwise, ridging will remain the dominate pattern over the region, leading to above normal temperatures, especially in the earlier half of the week with afternoon highs climbing back into the mid to upper 90s. By Friday another troughing feature will approach the region helping cool temperatures back towards normal, and PWATs increasing to near 299% again heading into next weekend.

AVIATION

Updated at 0515Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT: The main uncertainty during the TAF period concerns atypical wind shifts during the overnight hours, mainly at KPHX and KIWA. At these sites, terrain influences may cause a deviation in E'rly flow, resulting in switch to a W'rly component. A TEMPO group at KPHX reflects enough confidence that this switch will at some point occur, but timing may need to be adjusted through the night. KIWA does not typically see an overnight W'rly switch with this type of setup, so a VRB group is used to reflect the uncertainty. E'rly winds will prevail during this timeframe at KSDL and KDVT. Marginal LLWS impacts are possible Saturday morning, but should remain below TAF thresholds. An E'rly component will then common at metro terminals by late morning, perhaps with even a few gust. SCT high clouds will prevail through most of the forecast window.

Southeast California/Southwest Arizona including KIPL and KBLH: No aviation concerns are expected during the next 24 hours. Winds at bother terminals will swap between NW and NNE through Saturday evening with a few isolated gusts, mainly KBLH during the late morning hours. SCT high clouds will be common across the region before clearing takes place later in the forecast window.

FIRE WEATHER

Generally dry weather and above normal temperatures will persist during the next several days. Afternoon MinRHs will fall to near 10% through Saturday before increasing slightly on Sunday and Monday as moisture increases. The increase in moisture will result in some shower and thunderstorm chances, mainly confined to the eastern third of AZ. Lighter winds are expected today before easterly winds increase Sunday morning, particularly across the higher terrain areas of south-central AZ. Lighter winds return for early next week.

PSR WATCHES/WARNINGS/ADVISORIES

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