textproduct: NWS Flagstaff

SYNOPSIS

Warm temperatures and mostly dry weather will continue through the week. Isolated showers are possible across the higher terrain this afternoon, then isolated showers and thunderstorms possible in far eastern AZ on Wednesday. Also, strong winds with dry surface conditions will lead to portions of Critical fire weather on Wednesday.

DISCUSSION...Today

Ridging over the southwestern CONUS remains overhead, but begins to propagate eastward today. Meanwhile a shortwave begins propagating around its western periphery. This wave is bringing a southerly wind shift with a modest moisture increase. For today, just some isolated showers and sprinkles are expected along the high terrain with much of the activity remaining high-based. Also expect daytime temperatures 10-20 degrees and light surface winds as high pressure still is overhead.

Wednesday...The ridge shifts fully to our east, and the axis of the shortwave begins to cross our region. The moisture overhead looks to peak on early Wednesday morning, before drier air slowly overtakes from west to east during the daytime on Wednesday. As such, isolated shower and thunderstorm coverage looks to be more restricted to far eastern AZ on Wednesday afternoon. Also expect temperatures 5-10 degrees cooler than today, but still above normal for this time of year.

The most impactful weather from the approaching shortwave will be gusty southwest winds with relatively dry surface conditions. The current forecast calls for winds peaking at 15-25 mph, gusting up to 40 mph. With the current fuel status and fire danger, low RH, and gusty winds, just enough pieces are in place to support critical fire weather conditions for portions of northern AZ. As such, the Fire Weather Watch has been upgraded to a Red Flag Warning. Still expect near-critical fire weather conditions outside of RFW zones.

Thursday and Friday...As the shortwave moves past our area, flow aloft turns more zonal to end the week. Expect lighter westerly winds, and above normal temperatures. A weak shortwave may move through Friday, but looks to only bring enough moisture for a few daytime clouds. Precipitation does not appear likely through this period.

Saturday and beyond...Into the weekend, another trough is forecast to approach northern AZ. This will bring our next round of gusty winds as well as slightly cooler temperatures. The majority of long term ensemble members keep things dry as this trough approaches, with LREF PoPs staying below 10%.

AVIATION...Wednesday 13/00Z through Thursday 14/00Z

VFR conditions. A few isolated sprinkles or virga showers along the Mogollon Rim and White Mountains through around 02Z. Isolated light rain showers or thunderstorms are expected again Wednesday in far eastern Arizona, east of a KSOW-K0V7 line. Gusty/erratic winds possible near virga or showers. Winds S-SW 10-15 kts with gusts to 20 kts through 02Z, then light and variable or terrain driven overnight. SW winds increase to 15-25 kts with gusts 30-35 kts after 17Z Wednesday.

OUTLOOK...Thursday 14/00Z through Saturday 16/00Z...VFR conditions. Winds SW-W 10-15 kts with gusts around 20 kts Thursday and Friday afternoons.

FIRE WEATHER...Wednesday and Thursday

A Red Flag Warning has replaced the Fire Weather Watch, and has been issued due to higher winds and low afternoon humidity values. Temperatures will decrease over the next couple days but remain 5-15 degrees above average. An isolated shower or dry thunderstorm will be possible along the Arizona/New Mexico border Wednesday afternoon but wetting rains are not expected. Wind SW-W 15-25 mph with gusts 30-40 mph on Wednesday, SW-W 10-20 mph, gusts 25-30 mph on Thursday. Minimum afternoon RH between 5-15% each day.

Friday through Sunday...Warm and dry conditions are expected to continue. Temperatures will be 5-10 degrees above average Friday and Saturday, but near average to 5 degrees above average Sunday as another cooldown moves in. Winds SW-W 5-15 mph on Friday, SW-W 10-20 mph, gusts to 30 mph on Saturday, SW 10-25 mph, gusts 30-40 mph on Sunday Minimum afternoon RH 5-15% Friday and Saturday, increasing to 10-25% Sunday.

FGZ WATCHES/WARNINGS/ADVISORIES

Red Flag Warning from 11 AM MST /noon MDT/ to 8 PM MST /9 PM MDT/ Wednesday for AZZ104-106-107-109-112-113-115-116-139-140.