textproduct: NWS Phoenix

UPDATE

00Z Aviation Discussion.

KEY MESSAGES

- Unseasonably warm temperatures will be seen today and Wednesday with highs reaching around 15 degrees above normal.

- Breezy northeasterly to easterly winds are expected Wednesday and Thursday with wind gusts between 20 and 30 mph across the lower deserts and upwards of 35 to 45 mph across the higher terrain.

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

SHORT TERM /TODAY THROUGH WEDNESDAY/

A Rex block has set up over the eastern Pacific and far western CONUS. The low pressure is set up just west of the Baja with the high centered over coastal north-central CA. The high has strengthened today as this Rex block set up, with H5 heights rising to around 584 dm early this afternoon, and H5 heights around 580 dm over AZ. The high is expected to continue to strengthen heading into tomorrow, maximizing around 585-586 dm, and around 581-583 dm over AZ. After the slight cool down from yesterday and with the strengthening high, temperatures will warm back up a few degrees. Afternoon high temperatures today will be in the upper 70s to low 80s across the lower deserts. With the high continuing to strengthen tomorrow, further warming is expected. Temperatures tomorrow will warm into the low-to-mid 80s. In fact, the NBM is forecasting a high of 84 degrees in Phoenix, which is 2 degrees shy of the record set just last year. The latest NBM gives Phoenix a 50% chance of at least tying the record and a 30% chance of breaking it.

In addition to the high pressure strengthening, the low pressure will also be strengthening which will cause a tightening pressure gradient and increased winds to our region. Winds will be out of the NE/E all day and the downsloping easterly winds could help to drive temperatures up a degree or two. Winds will gust upwards of 20 to 30 mph across the lower deserts with higher speeds up around 30 to 40 mph across the higher terrain, with highest gusts across the peaks.

LONG TERM /THURSDAY THROUGH NEXT MONDAY/

The cut-off low to our southwest should begin to move toward our region later Wednesday before opening up and moving in on Thursday. An upstream Pacific trough will also help to eject the ridge to the east starting Thursday. This shift will quickly lower heights across the Desert Southwest while also adding some high cloudiness from southwest to northeast on Thursday. However, the warm air mass in place will be hard to dislodge as daytime highs are only expected to dip back into the upper 70s starting Thursday.

Model guidance shows broad upper level troughing remaining over the region through Friday with decent potential of the upstream Pacific trough and the former cut-off low merging into a new cut- off low or at least a closed low somewhere near or over our region this weekend. Guidance is still heavily favoring a continuation of the dry pattern despite the potential of the cut-off low. However, some members show the low strengthening enough this weekend to actually pull some meaningful moisture northward resulting in some rain chances by late Sunday. Although this does seem like a possibility, chances are still quite low for any rain chances this weekend or even into early next week. Models are still trying showing another one or two upstream Pacific troughs moving toward or even into our region at some point next week, but the timing keeps getting pushed back. The latest shows any decent rain chances now mostly pushed back until the middle of next week. Until this happens temperatures will remain above normal.

AVIATION

Updated at 2350Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT: No aviation weather concerns under mostly clear skies are expected through the forecast period. Winds will follow typical diurnal trends through tonight with easterly flow becoming established between 03Z-05Z. Winds will then become more elevated after sunrise Wednesday morning up to around 10-11 kts, with gusts between 15-20 kts possible through mid-afternoon. East winds will prevail through the latter half of the period.

Southeast California/Southwest Arizona including KIPL and KBLH: No aviation weather concerns are expected throughout the TAF period. At KIPL, light westerly winds are anticipated overnight before transitioning to N-NE by Wednesday afternoon. At KBLH, light NW winds will become more elevated out of the NE around the same time Wednesday afternoon.

FIRE WEATHER

Unseasonably warm temperatures and dry conditions will persist through midweek. MinRHs will mostly be between 10-15% today and tomorrow. Overnight recoveries will remain poor to fair, generally in a 35-55% range. Winds will begin to increase today across southeast California and the Arizona higher terrain before becoming breezy areawide starting Wednesday. Gusty easterly winds to as high as 25-35 mph will be possible across the eastern districts for Wednesday and 35-45 mph Thursday. The western districts will see more of a north northeasterly component with gusts around 25-30 mph. Improving humidities and lighter winds are expected Friday into the weekend.

CLIMATE

Phoenix, AZ Daily Record High Temperatures.

2/3 86 (2025) 2/4 86 (2025) 2/5 87 (1963)

PSR WATCHES/WARNINGS/ADVISORIES

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