textproduct: NWS Flagstaff

SYNOPSIS

Hot and drier conditions will return for much of the week with isolated showers and thunderstorms, mainly along the higher terrain each afternoon and evening. Moisture returns with moderate monsoon activity expected over the weekend.

DISCUSSION

High pressure remains centered across New Mexico early this morning but is expected to drift to the west through Wednesday, elongating and becoming centered over Arizona. The high starts to sink to the south and east as we head into the weekend.

Today...The high remains centered to our east early this morning, but it has started to slowly drift to the west. While the shift in the high will eventually scour out some of the moisture over the region, we should still have enough across our region to expect some isolated showers and thunderstorms to develop through this afternoon and evening. Activity looks to be largely confined to the higher terrain for today.

Wednesday through Friday...The high elongates and drifts to the west, eventually centering over Arizona. The position of the high is not favorable for storm activity and moisture begins to diminish across the region. Best chances for any storms will remain across the higher terrain from the Mogollon Rim through the White Mountains. Overall, most areas will remain dry through the end of the week. Expect hotter temperatures to return as the high strengthens with maximum temperatures into the 100s in the valleys and into the 80s across the higher terrain. An Extreme Heat Warning remains in effect for the lower elevations of the Grand Canyon and Yavapai County, for areas below 4000 feet, for Wednesday through Friday.

Saturday through Monday...Models continue to show the high sliding to the south and east of the region by the weekend. This shift should become more favorable for moisture advection into the region and as a result will bring increasing chances for showers and thunderstorms across the forecast area.

AVIATION...Tuesday 25/12Z through Wednesday 26/12Z

Mainly VFR conditions. ISO SHRA/TSRA between 18Z-02Z, mainly across the higher terrain. Brief MVFR conditions and gusty/erratic winds to 40 kts possible in heavier SHRA/TSRA. Outside of storms, expect S-SW winds 5-15 kts, becoming variable or terrain driven winds overnight.

OUTLOOK...Wednesday 26/12Z through Friday 28/12Z...Mainly VFR conditions. ISO SHRA/TSRA between 18Z-02Z each day, mainly over the higher terrain. Brief MVFR conditions and gusty/erratic winds to 40 kts possible in heavier SHRA/TSRA. Outside of storms, expect SW-W winds 5-15 kts, becoming variable or terrain driven winds overnight.

FIRE WEATHER...Today through Wednesday

Warmer and drier conditions expected. Isolated to scattered showers and thunderstorms along the higher terrain each afternoon/evening. Outside of gusty and erratic storm driven winds, expect southwest to west winds around 5-15 mph during the day, becoming variable at night.

Thursday through Saturday...Hot temperatures continue. Isolated showers and thunderstorms mainly across the higher terrain through Friday, increasing in coverage on Saturday. Outside of storms, expect southwest to west winds around 5-15 mph each afternoon, becoming variable at night.

FGZ WATCHES/WARNINGS/ADVISORIES

Extreme Heat Warning from 10 AM Wednesday to 8 PM MST Friday for AZZ006-037.