textproduct: NWS Phoenix

UPDATE

Updated Aviation Discussion.

KEY MESSAGES

- Well above normal temperatures will be seen across the region through at least the weekend with some locations flirting with record highs.

- Dry and tranquil conditions will prevail through at least next week.

SHORT TERM /TODAY THROUGH SUNDAY/

High pressure will continue to be the dominate weather regime over the southwestern CONUS through the end of the week and into the weekend. With atmospheric heights near or above the 90th percentile, a reflection of the amount of warm air throughout the atmospheric column, much warmer-than-normal temperatures will be common across the forecast area. Outside of a few degrees variation at a given point day-by-day, temperatures through Sunday will hold mostly steady in the upper 70s to lower 80s for desert locales. This will be a good 10-15 degrees above normal for the middle of December and a number of daily record highs may be tied with or exceeded in the coming days. As of now, the most likely time and place to see a new daily record high set is Phoenix on Sunday where the current forecasted high is 82 degrees while the record is 78 set in 2010. Some high clouds moving over the region late in the weekend may present a limiting factor toward reaching that 82 degree mark, but given the strength of the ridge, at least tying the record seems almost guaranteed as probabilities for this result are currently at 90%.

LONG TERM /MONDAY THROUGH NEXT FRIDAY/

Very little will change as far as the weather pattern for next week with any weather systems staying across the northern tier states. Models do show a very weak shortwave trough moving either through the ridge or overtopping the ridge early next week, but H5 are shown to only drop briefly to between 580-582dm. This little feature may cause daytime highs to dip more into the mid 70s by next Tuesday or Wednesday, but guidance favors a rebuilding of the ridge again by late next week. This should at least maintain highs in the mid to possibly upper 70s late next week with some potential for reaching 80 degrees again by next weekend. Other than some occasional higher level clouds, the air mass will stay dry across the region through all of next week.

AVIATION

Updated at 2320Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT; and Southeast California/Southwest Arizona including KIPL and KBLH:

No aviation weather concerns will exist through Friday evening. Light winds (generally AOB 7 kts) will follow a familiar diurnal pattern, with extended periods of variability to nearly calm conditions. Clear skies will be followed by FEW-SCT cirrus decks moving in Friday afternoon.

FIRE WEATHER

Warm and dry weather will prevail across the region into next week with temperatures running 8-13 degrees above normal. Winds are expected to remain light every day and follow diurnal tendencies. Humidities over the next week will stay above critical levels with afternoon MinRHs mostly ranging between 20-30%, followed by good overnight recoveries to around 50-70%.

CLIMATE

Daily Record Highs

Phoenix ------- 12/11 81 (1977) 12/12 79 (2010) 12/13 82 (2010) 12/14 78 (2010) 12/15 79 (1969)

PSR WATCHES/WARNINGS/ADVISORIES

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