textproduct: NWS Phoenix

KEY MESSAGES

- Unseasonably warm temperatures will be seen today with highs well into the 80s, or around 15 degrees above normal.

- Breezy northeasterly to easterly winds have developed today and are expected to reach their strongest Thursday morning with wind gusts between 20 and 30 mph across the lower deserts and upwards of 30 to 40 mph across the higher terrain.

- Above normal temperatures and overall dry weather should prevail through at least the weekend before a pattern change later next week brings cooler temperatures and potential precipitation chances.

SHORT TERM /TODAY THROUGH THURSDAY/

The Rex Blocking pattern over western CONUS and the eastern Pacific continues today with a closed high centered over northern NV and a closed low just west of the Baja. The high has strengthened today and has caused H5 heights to rise to 582-584 dm across AZ. This strengthening high pressure and rising heights aloft has resulting in warming temperatures. As of 2pm MST/1pm PST, temperatures are 2-5 degrees warmer than they were at this time of the day yesterday, with highs in the low to mid 80s across the lower deserts and in the mid 60s to low 70s across the higher terrain. Gusty easterly/northeasterly winds have also helped to increase temperatures across the region today. Gusts so far today have generally been in the 20 to 30 mph range. Phoenix has reached 84 degrees so far today, and with a couple more hours of heating and the breezy conditions we could see that temperature climb a couple more degrees and possible tie the current record of 86 degrees, set last year.

Heading into tonight and overnight into Thursday, the aforementioned closed low will attempt to move into the ridge over our region. This will result in a tightening pressure gradient and development of an easterly low-level jet. We could very well see a 30-45 kt low-level jet form tonight as indicated by the HREF, but a strong nocturnal inversion should limit what makes it to the surface. Unsheltered higher terrain areas and ridgetops may see wind gusts at times of 35- 45 mph. Wind Advisories are not being issued due to the higher uncertainty and likelihood of the highest gusts (and closer to advisory level winds) just being along the ridgetops. Portions of the lower deserts should see winds pick up during the overnight hours with occasional gusts between 20-30 mph before more consistent breezy to windy conditions settle in after mixing later in the morning. The low-level jet will gradually weaken late morning into the early afternoon hours allowing winds to diminish throughout the afternoon.

In addition to the higher wind gusts, the low attempting to move into our region will also bring an area of high level moisture (15- 25 kft). This will result in an abundance of clouds into our region. The clouds will move into SE CA and SW AZ during the late morning hours and into south-central AZ during the late afternoon/early evening hours. Since this layer of moisture will be around 10 kft some virga showers and areas of sprinkles are possible. However, the abundance of dry air at the surface will limit this activity. Heights will lower tomorrow as the low attempts to move into the region, this in addition to the cloud cover will keep temperatures slightly cooler. Afternoon high temperatures for tomorrow are only forecasted to be in the upper 70s to low 80s across the lower deserts.

LONG TERM /FRIDAY THROUGH NEXT THURSDAY/

Model uncertainty remains a big part of the forecast for the weekend into next week. Models are confident the cut-off low moving into our region Thursday into Friday will quickly weaken and become an open wave before somewhat absorbing another weakening trough peeling off from the main flow off the coast of California. Models yesterday were hinting at the potential for a restrengthening of a new cut-off low forming from the two pieces of energy, but now they are backing off this potential solution. The latest runs do still show a brief closed low forming to our southwest by Saturday, but trends are now showing a much weaker system and progressing it farther to the south instead of coming back into or near our region. Any PoPs the NBM had introduced yesterday for Sunday and Monday are now mostly gone. Temperatures from Friday through Monday are expected to stay quite stable with highs mostly in the upper 70s to the lower 80s.

Forecast uncertainty increases even more for the rest of next week as the potential Pacific trough that may move into our region is now looking less impressive. The timing is still about the same with the trough moving through our region from the west around next Wednesday and Thursday, but ensembles have backed off on the QPF potential for now. Given this is still a week away, we should not put much stock in the guidance for another few days.

AVIATION

Updated at 2320Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT: Elevated E'rly winds will prevail through the TAF period, including the overnight hours with speeds generally between 10-15 kts. Gusts will not be as frequent after sunset and through the overnight hours but will reemerge by Thursday morning, with readings around 20-25 kts. Minor LLWS impacts are anticipated tonight, with magnitudes around 20-25 kts. Skies will be clear through most of forecast window before SCT-BKN decks begin to fill in Thursday afternoon.

Southeast California/Southwest Arizona including KIPL and KBLH: No aviation concerns are expected during the next 24 hours with increasing clouds filling in tonight. Winds at KIPL will favor a N'rly component before backing to the W this evening. At KBLH, N'rly winds will be common through much of the period with perhaps a few gusts near 20 kts developing late Thursday morning.

FIRE WEATHER

Unseasonably warm temperatures and overall dry conditions will persist through the end of the workweek. Today will see highs well into the 80s with MinRHs of 10-15%. Winds have increased today out of the east northeast with gusts around 20-30 mph. Winds will pick up further tonight through Thursday morning with wind gusts as high as 30-40 mph across portions of the eastern districts. Gusts upwards of 45 mph, mainly along the ridgetops across the eastern districts. Humidities will improve going into Thursday and then again Friday with MinRHs 15-20% Thursday and 20-25% Friday. Lighter winds with fairly stable humidities are expected for the weekend.

CLIMATE

Phoenix, AZ Daily Record High Temperatures.

2/4 86 (2025) 2/5 87 (1963)

PSR WATCHES/WARNINGS/ADVISORIES

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