textproduct: NWS Flagstaff

SYNOPSIS

Dry, cool, and windy weather will continue today. Saturday remains cool with less wind. A series of storm systems will impact the region starting Saturday night and continuing through most of next week, bringing chances for showers and thunderstorms at times along with cool temperatures.

DISCUSSION

Strong high pressure has developed over the Great Basin, with a weak low cutting off near the northern Baja coast. This has created strong easterly pressure gradients, and very gusty east to northeast winds in the favored higher terrain and downslope regions. Some of the strongest winds of the event are expected a bit later this morning through early afternoon in these areas, including the Flagstaff region and eventually the Little Colorado River Valley where gusts of 40-55 mph are expected. Gradients will slowly weaken later tonight into Saturday morning, though there will still be gusty winds at times through at least mid day Saturday.

By Saturday evening through Monday, the low off the Baja is forecast to weaken and move slowly northeastward, allowing for some moisture to the south to get pulled in toward our area. There will be a chance of showers and a few thunderstorms at times through this period, especially over higher terrain. Rainfall totals through Monday look light for most areas, with some localized 0.50" amounts in heavier showers.

Tuesday through Thursday - a deeper low pressure system is forecast to develop off the California coast by Tuesday and then slowly move eastward across our region through the end of the week. The result will be increasing chances for showers and thunderstorms at times through the period. Some deeper moisture could be drawn into the system toward Wednesday and Thursday. The latest NBM probabilities of 0.50" or greater rainfall from Wed AM to Fri AM are 50-70% along the higher terrain upslope regions, with 1.00" probabilities in the 30-50% range. Cooler temperatures and gusty south/southwest winds are also expected as this system moves in.

AVIATION...Friday 16/12Z through Saturday 17/12Z

VFR conditions expected. Northeast through east winds through the period. Speeds generally between 15-25 kts, with localized gusts near 35-45 kts through around 02Z. Winds decreasing to 10-20 kts with localized gusts 25-30 kts after 02Z.

OUTLOOK...Saturday 17/12Z through Monday 19/12Z...Mainly VFR conditions expected. Winds will remain elevated out of the east at 10-20 kts through 18Z Saturday, before becoming light/variable through the end of the period. Increasing clouds by Saturday afternoon, with isolated to scattered -SHRA/-TSRA possible Saturday night onward. Brief MVFR in heavier showers.

FIRE WEATHER...Today through Saturday

Cool with gusty conditions. Winds are northeast through east 15-25 mph with gusts 35-45 mph tonight through this afternoon. Locally gustier winds up to 55 mph possible along/southwest of terrain features in Yavapai and Coconino Counties. Winds gradually diminish tonight, then become east through southeast 10-20 mph on Saturday. A slight chance of showers and thunderstorms arrives by Saturday evening. Min RH is 15-35% each day. Daytime temperatures 5-10 degrees cooler than normal.

Sunday through Tuesday...Chance for showers and thunderstorms over the higher terrain on Sunday, with chances increasing and spreading to most of northern Arizona on Monday and Tuesday. Winds are light and variable on Sunday, becoming south 5-15 mph on Monday, then south through southwest 10-20 mph gusting to 30 mph on Tuesday.

FGZ WATCHES/WARNINGS/ADVISORIES

Wind Advisory until 6 PM MST /7 PM MDT/ this evening for AZZ004- 006>008-012>015-037-038.