textproduct: NWS Phoenix

UPDATE

Updated Aviation Discussion.

KEY MESSAGES

- Temperatures will cool trend through the weekend reaching below normal levels for several days early next week.

- Unusually strong winds will impact the region through Sunday resulting in areas of blowing dust and critical fire weather conditions.

- More tranquil weather conditions and a slow warming trend will arrive during the middle of next week.

SHORT TERM /Today through Monday/

Current GOES Mid-level WV imagery shows broad troughing across the west coast with the core of the system over the coastline between Washington state and Canada. This system will continue pushing inland through the weekend, tightening the pressure gradient causing breezy to windy conditions over the weekend. Winds will be strongest today as there are also multiple shortwaves embedded in the upper level low and will work their way through the trough over the weekend. Peak gust speeds will be in the southwestern corner of Imperial Valley, however, widespread windy conditions will be present across the Lower Colorado River Valley area as well. Due to this wind advisories will remain in effect through today along the Lower Colorado River Valley areas, and through Sunday night in the far southwestern portion of Imperial County. Expect winds between 25- 35 mph and gusts up to 55 in these areas. These winds can make travel difficult for high profile vehicles and may produce localized dense blowing dust. Otherwise, in conjunction to the elevated winds, very dry conditions will promote elevated to critical fire weather conditions, especially in the eastern higher terrain/ Gila County. That being said a Red Flag Warning remains in effect through Sunday evening.

This large, and seasonably strong troughing feature will also bring temperatures trending to below normal starting Sunday and into early next week. H5 heights today will be between 588-591 dam dropping to between 582-587 dam by Sunday. Resulting in temperatures 5F-10F below normal, quite the treat for late June.

LONG TERM /Tuesday through Saturday/

Once the Pacific trough settles over the Western CONUS negative height anomalies will remain in place over the Desert SW through early to mid week at the latest. The negative height anomalies will keep temperatures between 98F-103F or around 4F-7F below normal for this time of year. Guidance shows temperature beginning to climb back towards normal by Thursday as the trough begins to be displaced by the subtropical high building to the region's SE, returning H5 heights to near seasonal normal. By the next weekend afternoon highs will yet again be in the 105F-110F range.

AVIATION

Updated at 1740Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT: The primary aviation weather concern will be gusty southwesterly winds during the afternoon and early evening, under clear skies. Winds have already veered out of the south southwest this morning and will remain southwesterly through the rest of the day into the overnight hours. Late afternoon/early evening gusts will peak around 25 kts. Gusts will subside by 03-05Z across the terminals, remain generally below 10 kts overnight, with moderate confidence in a later than usual, brief SE switch around sunrise at KPHX. Winds are then likely to shift south then southwest within a few hours after sunrise Sunday and develop gusts by late morning.

Southeast California/Southwest Arizona including KIPL and KBLH: Strong, gusty winds out of the SW or W will continue to be the main aviation concern through the next 24 hours under clear skies. Gusts between 25-35 kts will be common, peaking during the afternoon at KBLH and late afternoon/evening at KIPL. Temporary surface VIS restrictions due to lofted/blowing dust will be possible with the stronger gusts, though confidence is too low to include MVFR or lower VIS in the TAF. Winds will gradually decrease through the overnight period, possibly becoming light and VRB for a period early Sunday morning at KBLH.

FIRE WEATHER

Elevated to critical fire danger will continue today due to low humidity, very warm temperatures, and afternoon upslope/upvalley breezy conditions. Red Flag Warnings have been issued today through Sunday for much of the area. Expect MinRHs to stay close to 5-15% for the next several days. Winds will again increase this evening with gusts in the 20-35 mph range and locally higher over higher terrain areas. Winds are likely to peak on this evening with gusts commonly reaching 25-40 mph. These windy and dry conditions will combine with the very dry fuels to create a risk of extreme fire behavior. Temperatures will cool this weekend reaching slightly below normal levels starting Sunday and lasting into early next week. Winds are expected to gradually diminish next Monday into Tuesday.

PSR WATCHES/WARNINGS/ADVISORIES

AZ...Red Flag Warning until 8 PM MST this evening for AZZ131.

Wind Advisory until 11 PM MST this evening for AZZ530-533.

Red Flag Warning until 8 PM MST Sunday for AZZ133.

CA...Red Flag Warning until 8 PM PDT this evening for CAZ231.

Wind Advisory until 11 PM PDT this evening for CAZ564>567-569- 570.

Wind Advisory until 11 PM PDT Sunday for CAZ562.