textproduct: NWS Flagstaff

SYNOPSIS

Warm temperatures and dry weather will continue through the weekend. Isolated to scattered high-based showers and thunderstorms across the higher terrain on Monday. Expect typical southwest breezes each afternoon, with increasing winds and cooler temperatures arriving around midweek.

DISCUSSION

A ridge builds across the Desert Southwest today, bringing warming temperatures with afternoon southwest breezes. The ridge moves to our east by Sunday as a weak low pressure develops off of Baja California. Overall the weekend looks to remain dry with warmer temperature and southwest winds around 10-20 mph each afternoon. With the flow turning more southerly, expect some decent moisture advection into the upper and mid levels, which will result in some clouds developing through the day, especially on Sunday. Low levels remain very dry so even if some precipitation is able to fall, it will likely evaporate before reaching the ground. Best chances for a shower remain towards the White Mountains on Sunday (<15% chances).

Moisture continues to increase in the southerly flow ahead of the approaching low pressure system. The low moves to the east and lifts across the region on Monday into Tuesday. This brings some chances for high-based showers and thunderstorms for Memorial Day, mainly along and north of the Mogollon Rim. Dry lightning and gusty outflow winds look to be the main hazards with any storms that develop as the moisture overall doesn't look all that impressive. Amounts will range from a trace to around 0.25", with most places seeing around 0.10" or less.

Drier conditions return for Tuesday as the low lifts to the north and east, though a few lingering showers may remain across eastern Arizona. Gusty southwest winds will continue with winds around 10-20 mph gusting to 20-30 mph through the afternoon on Tuesday, increasing slightly for Wednesday and Thursday with gusts 30-40 mph possible those days. Temperatures will gradually warm through the end of the week, staying near to slightly below normal.

Another low looks to develop over the Pacific Northwest around midweek, dropping down into the Great Basin towards the end of the week. The low looks like it may become closed off, and as a result, confidence in the track is low at this time. Details should become clearer as we move into the new week. Stay tuned!

AVIATION...Saturday 23/12Z through Sunday 24/12Z

VFR conditions. Light winds this morning, then SW-W winds 5-15 kts with gusts to 20-25 kts after 18Z, then light winds after 03Z.

OUTLOOK...Sunday 24/12Z through Tuesday 26/12Z...Mainly VFR conditions. ISO virga showers on Sunday, then SCT high-based -SHRA/-TSRA Monday afternoon and evening. Gusty and erratic winds and brief MVFR conditions INVOF storms. SW-W winds 5-15 kts with gusts to 20-25 kts each day.

FIRE WEATHER...Today and Sunday

Dry and warm with west to southwest winds around 10-20 mph each day. Minimum afternoon RH between 5-15% today, increasing to 10-20% on Sunday.

Monday through Wednesday....Moisture increase on Monday as a weather system passes through the area, then drier conditions return for Tuesday and Wednesday. Expect isolated to scattered showers and thunderstorms across much of northern Arizona. Dry lightning and erratic outflow gusts will be possible. Outside of storms, southwest winds at 10-20 mph on Monday, then southwest winds at 10-20 mph with gusts to 30 mph on Tuesday, increasing to 15-25 mph with gusts to 35 mph Wednesday.

FGZ WATCHES/WARNINGS/ADVISORIES

None.