textproduct: NWS Flagstaff

SYNOPSIS

Isolated showers/storms forecast to continue today and tomorrow, before a gradual increase in coverage returns Friday onward. Expect breezy winds through the end of the week, along with below normal daytime highs.

DISCUSSION

A few showers/storms have begun firing up across the northern portion of our CWA. With storm motion being 20-30 kts, flash flooding concerns are lower, but can't completely rule it out if we start to see storms back-building. This more isolated storm coverage looks to continue through tomorrow afternoon, but then we'll gradually see greater precipitation coverage heading into the weekend and early next week.

This moisture surge will primarily be due to Tropical Storm Marie building south of the California Baja coast. Between this tropical system and a large trough descending from the Pacific Northwest, the synoptic pattern will favor a more saturated southwesterly flow aloft. Simultaneously, high pressure looks to strengthen across the Midwest and also push some additional moisture into the state. Due to a few different factors contributing to the potential active weekend/early next week, our confidence is still moderate at this time. Certainly higher confidence in the increase in storm/shower potential, but the timing and specific locations are still up in the air. For now, the greatest chances for activity look to be across the higher terrain, especially across the Kaibab Plateau and White Mountains.

Daily chances for activity look to stay in the forecast for the foreseeable future. As Tropical Storm Marie moves further westward in the Pacific (by early to mid next week), the high pressure previously mentioned is projected to shift westward. Where models start to diverge is where the high eventually settles. There's still time to see how things shake out in the long-range forecast, but for now expect additional showers/storms Friday onward.

Other than precipitation, expect breezy winds through the end of the week, along with daytime high temperatures generally below normal for this time of year.

AVIATION...Thursday 03/00Z through Friday 04/00Z

Mainly VFR conditions expected. SW 10-20 kts gusting 25-30 kts will decrease after 03Z, becoming light and VRB or terrain driven through 16Z. ISOLD SHRA/TSRA possible along higher terrain again starting around 18Z, with best potential near the White Mountains. Gusty/erratic winds possible near storms. Winds are SW 10-20 kts gusting 25-30 kts after 16Z.

OUTLOOK...Friday 04/00Z through Sunday 06/00Z...VFR conditions expected, with brief MVFR conditions near SHRA/TSRA. Winds are SW 10-20 kts gusting 25-30 kts each afternoon, and light and VRB or terrain driven each night. ISO-SCT SHRA/TSRA each day, with the highest chances along the White Mountains. Storms may continue Thursday evening into Friday morning over the Eastern Mogollon Rim and the White Mountains, and in Yavapai County Friday evening into Saturday morning.

FIRE WEATHER...This afternoon through Friday

Drier and breezy conditions continue through Thursday, with mostly isolated shower and thunderstorm chances each afternoon/evening. Today the highest potential is over the Rim near Flagstaff and the Little Colorado River, and over the White Mountains Thursday afternoon. Starting Friday, moisture will start to increase, but the higher potential and coverage of showers and thunderstorms are expected to remain over and just west and east of the White Mountains. Winds are southwest 10-20 mph with gusts up to 25-30 mph, strongest in northwest AZ. Daytime highs slightly below normal. Minimum RH is 30- 50% each day.

Saturday through Monday...Increasing moisture will cause shower and thunderstorm coverage to increase Saturday through Monday. Best chances will be seen near the White Mountains each day, with elevated potentials along other areas of higher terrain. Winds are expected to decrease slightly, becoming south through southwest 5-15 mph through Monday. Light and variable or terrain driven winds overnight. Max daytime temps are expected to remain near or just below normal, but will depend on storm and cloud coverage during the day.

FGZ WATCHES/WARNINGS/ADVISORIES

None.