textproduct: NWS Flagstaff

SYNOPSIS

For the beginning of this week, expect hot and slightly drier conditions. Isolated to scattered showers and thunderstorms remain possible each day across the higher terrain of eastern Arizona. Towards the middle of the week, expect slightly cooler conditions with gradually increasing shower and thunderstorm activity.

DISCUSSION

Our period of somewhat decreased monsoonal activity will continue today and tomorrow as strong high pressure is parked over Arizona. While the magnitude of the high is weakening slightly, northern Arizona will remain in a relatively drier and capped environment. We are not totally dried out, so expect isolated to scattered showers and thunderstorms each afternoon/evening along the higher terrain Flagstaff and eastward, with the best coverage in the White Mountains.

The primary hazard today and tomorrow remains to be the heat. Some locations saw their warmest temperatures of the year so far on Saturday, and a few daily records were broken. With the high slightly weakening over the next few days, daytime temperatures will be just a few degrees cooler. However, temperatures will remain hot enough for the Extreme Heat Warning and Heat Advisory to remain in effect until at least Monday evening. Be sure to drink plenty of fluids and avoid prolonged outdoor activity if you can!

The high continues to weaken and elongate on Tuesday. Below normal monsoonal moisture is expected to linger, and the forecast calls for isolated to scattered storms constrained higher terrain of eastern Arizona. The slight cooling trend also continues, and most heat headlines will be over by Tuesday. Though temperatures at Phantom Ranch look to stay high enough, and the Extreme Heat Warning for the Grand Canyon below 4000 feet will continue through Tuesday evening. The high is forecast to shift during the middle to later part of this week, however, there is considerable uncertainty with the exact placement. Clusters are split between a wetter scenario where the high is centered more to our north, or a drier scenario where the high is centered more to our northwest. The grand ensemble consensus is for an increase in shower and thunderstorm coverage starting Wednesday and continuing through the weekend, but there is plenty of room for the exact details to change. Be sure to stay tuned for further updates!

AVIATION...Sunday 02/06Z through Monday 03/06Z

VFR conditions expected. Isolated showers/storms along the Mogollon Rim and White Mountains between 19Z and 02Z. Winds mostly light and variable overnight, becoming westerly at 10-15 kts in the afternoon. Gusty and erratic winds possible near showers/storms.

OUTLOOK...Monday 03/06Z through Wednesday 05/06Z...VFR conditions, isolated showers/storms 18Z to 03Z each day near the White Mountains, dry elsewhere. Winds light and variable 5-15kts. Gusty and erratic winds possible near showers/storms.

FIRE WEATHER...Today and Monday

Hot with low-grade monsoonal conditions. Isolated to scattered showers and thunderstorms each afternoon/evening over the higher terrain of eastern Arizona. Daytime winds are west through northwest 5-15 mph on Sunday, then southwest through west on Monday. Minimum RH is 10-20% deserts, 20- 30% mountains.

Tuesday through Thursday...Slightly cooler with increasing moisture. Isolated to scattered showers and thunderstorms over the higher terrain of eastern Arizona on Tuesday. Coverage of storms increases and expands westward on Wednesday and Thursday. Daytime winds generally SW-W at 5-15 mph on Tuesday and Wednesday, becoming light and variable on Thursday.

FGZ WATCHES/WARNINGS/ADVISORIES

Extreme Heat Warning until 8 PM MST /9 PM MDT/ Monday for AZZ005- 018-037-038.

Extreme Heat Warning until 8 PM MST Tuesday for AZZ006.

Heat Advisory until 8 PM MST /9 PM MDT/ Monday for AZZ009-010- 012>014-040.