textproduct: NWS Phoenix

KEY MESSAGES

- Below normal temperatures will continue through the weekend before readings warm back closer to the seasonal average for the bulk of next week.

- Aside from a few showers over the mountains of Arizona Saturday, dry and tranquil weather conditions will grace the region through the middle of next week.

- A return to inclement weather with increased rainfall chances is possible towards the end of next week.

SHORT TERM /Today through Sunday/

Early afternoon WV imagery shows elongated, positively tilted troughing over the western Conus with a prominent vorticity center lifting north across the Great Basin, while trailing shortwave energy starts to fill into the height weakness over the Southwest. Behind the initial Great Basin wave, a cold front has cleared eastward into New Mexico with a deep layer of drier air now entrenched over the forecast area. Forecast confidence is excellent that a vorticity center currently descending south along the Sierra range will carve into the trough base over the lower Colorado River valley in the next 24 hours before slowly lifting into the four corners during the weekend. This evolution will ensure H5 heights hover in a 565-572dm range through early next week yielding high temperatures 4F-8F below the daily normals and very comfortable overnight lows. While better quality moisture has already been scoured from the region leaving mixing ratios only 5-6 g/kg, the progression of the midlevel cold core over the mountains of central Arizona Saturday afternoon may squeeze out a few showers, albeit rather inconsequential while leaving lower elevations enjoying a delightful autumn weekend.

LONG TERM /Monday through Friday/

Benign weather conditions will continue well into next week with the lingering trough finally moving out of the region and being replaced by weak ridging to zonal westerly flow. This pattern shift will maintain mostly clear skies and dry conditions, while allowing temperatures to gradually warm back into a near normal range through at least the first half of next week. Expect the bulk of the lower deserts to have daily highs in the lower to middle 80s and lows from the mid 50s to mid 60s during the first half of next week. Model uncertainty grows later next week as there are hints at some moisture return into the region from the southeast, then a potential atmospheric river approaching by next weekend. Either, or both of these moisture sources may eventually help to bring a return to rain chances at some point before the end of the month, but it is too early to have a good idea on timing and/or placement for any weather feature this far in advance.

AVIATION

Updated at 1735Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT: No weather concerns are expected through the TAF period. Westerly to northwesterly winds will persist through the afternoon and evening hours with periods of VRB intermixed. Just past mid-night tonight winds will shift back out of the east, and look to resume typical diurnal tendencies tomorrow. Wind speeds will be aob 07 kts. Skies will be mostly clear with FEW mid level cloud decks developing later in the period.

Southeast California/Southwest Arizona including KIPL and KBLH: No aviation weather concerns are anticipated through the for TAF period. Winds will favor a westerly component at KIPL while KBLH will remain out of the NW. Speeds should remain light around 5-7 kts or lower. FEW passing mid level clouds during the overnight hours at KIPL, otherwise mostly clear skies at both terminals.

FIRE WEATHER

Drier air has spread through the area since yesterday morning resulting in clearing skies and an end to the rain chances. The weather system will still linger across the region over the next couple of days bringing light shower chances to mountain areas Saturday, but no wetting rainfall is expected. Minimum humidity levels will fall into a 25-50% range following good to excellent overnight recovery. Light winds are forecast for today and for much of the area on Saturday with only some breeziness possible early Saturday across the western districts. Overall quiet weather conditions are forecast Sunday into next week with fairly stable humidities and temperatures rebounding back into the normal range by Tuesday.

PSR WATCHES/WARNINGS/ADVISORIES

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