textproduct: NWS Flagstaff

SYNOPSIS

Look for dry and windy conditions today in advance of a weather disturbance that will deliver cooler temperatures, breezy conditions and a chance of showers and thunderstorms from Tuesday into Wednesday. Fair and warmer weather returns for Thursday and the weekend.

DISCUSSION

Low pressure was centered over the California coast this morning, approach Arizona today then move across the area from Tuesday into Wednesday. High pressure returns for the end of the week.

For today...The California low will draw closer ushering in strengthening pressure gradients and a cooler air mass. As a result, winds will be quite a bit stronger than on Sunday, generally south to southwest at 15-25 mph with gusts of 30-40 mph. The higher wind speeds in the ranges shown will mainly be observed from the Mogollon Rim northward. Daytime high temperatures are expected to drop by 5-10 degrees compared to Sunday due to a cooler air mass but also mid- to high-level clouds spinning off the low which will limit the amount of sunshine. Moisture will gradually increase through the day but it is expected that any shower activity will hold off until Tuesday.

From Tuesday into Wednesday...The center of the California low will move across Arizona from west to east. The low will bring with it even cooler air aloft along with upward dynamics. As a result, we're looking at a good chance of showers on Tuesday focused from the Mogollon Rim northward. The threat of thunderstorms will arrive in the afternoon as daytime heating helps create additional instability. The low weakens and moves to the southeast on Wednesday with only a lingering slight chance of showers and thunderstorms. Storm total liquid equivalent precipitation amounts will be somewhat limited generally in the 0.10-0.20 inch range for the entire system. Daytime temperatures will drop another 5-10 degrees on Tuesday with the passing low but rebound on Wednesday as the low heads southeastward. Winds will remain breezy from the southwest at 10-20 mph gusting to 30 mph on Tuesday but as the low weakens and moves to the southeast lighter northwest winds will develop on Wednesday.

From Thursday onward...Generally dry and warmer as a shortwave ridge moves across the southwest United State from Thursday into Saturday.

AVIATION...Monday 04/12Z through Tuesday 05/12Z

Expect mainly VFR conditions. Winds S at 10-20 kts until 15Z then becoming S to SW at 15-25 kts gusting to 30-35 kts. Winds diminishing to SW at 10-20 kts after 02Z. In addition, after 03Z, Look for increasing -SHRA and local MVFR conditions along and south of a KFLG-KRQE line.

OUTLOOK...Tuesday 05/12Z through Thursday 07/12Z...Mainly VFR conditions. Expect scattered -SHRA and isolated -TSRA on Tuesday, especially east of the I-17 corridor and toward the Four Corners. Activity tapering off Tuesday night with only a slight chance of -SHRA/-TSRA on Wednesday. Stronger showers may produce brief MVFR conditions. Winds SW at 15-25 kts gusting to 30 kts on Tuesday, becoming NW at 10-20 kts on Wednesday.

FIRE WEATHER...Today and Tuesday

Expect dry conditions today with scatters showers and isolated thunderstorms on Tuesday. South to southwest winds at 15-25 mph with gusts of 30-40 mph today, decreasing to 10-20 mph gusting to 30 mph on Tuesday. Minimum RH between 15-30% today, increasing to 25-50% on Tuesday.

Wednesday through Friday...Look for isolated showers across northeast Arizona on Wednesday, elsewhere dry. Dry conditions spreading across all of northern Arizona for Thursday and Friday. Winds generally west to northwest at 5-15 mph each afternoon. Minimum RH between 15-25% on Wednesday, decreasing to 10-20% for Thursday and Friday.

FGZ WATCHES/WARNINGS/ADVISORIES

None.