textproduct: NWS Flagstaff

SYNOPSIS

Overall dry, breezy, and hot conditions are forecast through Tuesday. A slight chance for showers and thunderstorms returns by the middle of the week.

DISCUSSION

Strong high pressure begins to build over the area starting tomorrow, centering over the Arizona/New Mexico/Mexico border region. The strength of the ridge looks to peak around Tuesday or Wednesday in the 594-597dm range, definitely strong but not unheard of this time of year as late June early July often sees some of the warmest, if not the warmest temperatures of the season. So needless to say, above average temperatures will be in play for most of the week, especially early week where it'll peak at about 10 degrees above normal. This will likely bring temperatures above 110 down in the depths of the Grand Canyon where an Extreme Heat Watch is in place for Monday and Tuesday. The dry air in place right now will also give us some good diurnal temperature swings, possibly as much as 50 degrees in places like South Rim of the Grand Canyon and Bellemont. Winds will be light, generally southwesterly 10-20 mph, with gusts 25-30 mph which should help with keeping the area out of critical fire weather the next couple days.

By Tuesday afternoon an increase in moisture on the return flow side of the high moves in which will help drop the temperatures a degree or two by the later half of the week. It could also bring some high elevation afternoon showers/storms, current POPs between 10-30% Wednesday through Friday.

By Saturday a broad trough moving across the northern tier of the country will help suppress the ridge a bit to the south which will shut off the monsoon moisture. The winds aloft will switch westerly which will bring in considerably drier air and some stronger winds. Will have to monitor next weekend closely to see if fire weather could become a concern.

AVIATION...Saturday 20/18Z through Sunday 21/18Z

Mainly VFR. Daytime minor HZ/FU possible near KFLG and periods of overnight MVFR possible near KSEZ in HZ/FU due to a wildfire. Winds S/SW 10-20 kts with gusts 25-30 kts through around 02Z, then decreasing to less than 10 kts overnight.

OUTLOOK...Sunday 21/18Z through Tuesday 23/18Z...Mainly VFR. HZ/FU possible around KFLG during the day, and near KSEZ overnight due to a wildfire. Winds W/SW 10-20 kts with gusts up to 25 kts each day, becoming VRB 5-10 kts overnight.

FIRE WEATHER...This afternoon through Monday

Very dry and breezy conditions will bring areas of critical fire weather to eastern Arizona through early this evening, with near-critical fire weather elsewhere. A Red Flag Warning will remains in effect for portions of the Little Colorado River Valley and Chuska Mountains through 6 PM MST/7 PM MDT. Winds decrease slightly on Sunday and Monday, becoming southwest to west 10-15 mph with gusts to 25 mph. Very dry and warm conditions persist with minimum RH 4-10%.

Tuesday through Thursday...Breezy with gradually increasing moisture and continued above normal temperatures. Slight chance (10%) of thunderstorms along the Mogollon Rim and White Mountains Tuesday afternoon. Thunderstorm chances increase to 20-40% over all of northern Arizona for Wednesday and Thursday. Southwest through west winds 10-20 mph with gusts around 25 mph each day. Minimum RH 10-15% on Tuesday, then 15-20% Wednesday and Thursday.

FGZ WATCHES/WARNINGS/ADVISORIES

Extreme Heat Watch from Monday morning through Tuesday evening for AZZ006.

Red Flag Warning until 6 PM MST /7 PM MDT/ this evening for AZZ111-113-114.