textproduct: NWS Phoenix

KEY MESSAGES

- Dry conditions with well above normal temperatures and mostly clear skies will prevail through most if not all of next week. - Periods of breezy winds are expected across the area with the most widespread breeziness later next week.

SHORT TERM /TODAY THROUGH SUNDAY/

A strong upper level ridge continues to slide eastward into the Desert Southwest with 585dm H5 heights over southern California, or into the 97th percentile of climatology. The ridge axis will fully move over our region Saturday night into Sunday, but the ridge will also be weakening. Forecast H5 heights of 582-584dm and sunny to mostly sunny skies over most of the region this weekend will help to drive temperatures higher. Most lower desert spots will climb into the upper 70s today before topping out around or just above 80 degrees Sunday. The current forecast high of 82 degrees for KPHX on Sunday is only one degree shy of the daily record for Feb. 1st. Winds will also still be breezy at times this weekend, mainly during the morning hours and focused over the Arizona high terrain and other ridgetop locations.

LONG TERM /MONDAY THROUGH NEXT SATURDAY/

Model guidance continues to trend warmer with less chances for any weather systems impacting the Desert Southwest next week. The upper level ridge this weekend will weaken and push to the east by Monday with very broad upper level troughing briefly moving in from the southwest. This will help to lower heights slightly and in turn bring daytime highs back down into the upper 70s for the lower deserts on Monday. Guidance also shows a slug of upper level moisture moving across the region Sunday night through Monday night bringing a decent amount of mostly thin high clouds.

By Tuesday, an even stronger upper level ridge is expected to nudge northeastward into the Western U.S., while a piece of lingering upper level energy to our south and southwest forms a cut-off low by Wednesday morning. As a result, another Rex block will take shape Wednesday into Thursday with the center of the ridge strengthening further and slowly drifting from northern California through Nevada. The position and the strength of the ridge will result in another round of downslope warming and drying for much of our region. The latest NBM forecast highs for Tuesday-Thursday are once again warmer than yesterday's runs with readings between 78-82 degrees Tuesday, 80-84 degrees Wednesday, before dropping back to 77-81 degrees starting Thursday.

Ensembles show good consensus with the ridge now dominating through at least midweek before allowing the blocking pattern to somewhat break down Friday into next Saturday. The cut-off low that forms early in the week should eventually come back into or near our region by Friday, but it is heavily favored to be an open wave by that point with not enough energy or moisture to bring any rain chances. After the midweek blocking pattern breaks down, ensembles do start to show potential for another (weaker) Rex block and cut-off low for next weekend. Initial forecast thinking and trends over the past few model runs show this next disturbance is also likely to bypass our region to the south.

AVIATION

Updated at 0530Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT: No aviation concerns under mostly clear skies are anticipated through the period. Winds will remain easterly overnight with speeds mainly aob 6 kts, but may become elevated closer to 8 kts after sunrise Saturday morning. Another later than normal westerly shift is expected by 00Z-01Z Sunday.

Southeast California/Southwest Arizona including KIPL and KBLH: No aviation concerns under clear skies can be expected through the TAF period. Winds will be primarily N-NE at KBLH and W-NW at KIPL with speeds aob 7 kts. Periods of calm and vrb winds will also be common at both sites.

FIRE WEATHER

Dry weather conditions will prevail through next week, with MinRH values in the 10-20% range most afternoons. There will be a subtle moisture increase late this weekend into Monday, but MinRH values only increase to 20-25% at best. Overnight recoveries will remain poor to fair with humidities mostly between 30-55%. Gusty easterly winds will mainly affect ridgetop areas over the eastern districts this weekend with light winds on Monday. The weather pattern will again support breezy daytime conditions mid to late next week. Temperatures will warm further this weekend with lower desert highs likely topping 80 degrees in many locations.

CLIMATE

Phoenix, AZ Daily Record High Temperatures.

2/1 83 (2003) 2/2 82 (2025) 2/3 86 (2025) 2/4 86 (2025) 2/5 87 (1963)

PSR WATCHES/WARNINGS/ADVISORIES

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