textproduct: NWS Flagstaff

SYNOPSIS

Above normal temperatures will stick around due to a strong area of high pressure across much of the Southwest. Daily chances for showers/storms will remain as well, primarily focused across the higher terrain. Heat products remain in place for lower elevation locations through at least Wednesday.

DISCUSSION

A strong area of high pressure remains over the region, bringing daytime highs 5-15 degrees above normal and isolated showers/storms. This synoptic pattern looks to mostly stay in place through the forecast period, but beginning as early as Wednesday, the high looks to push northward, which would allow for an increase in moisture across our CWA. Before diving more into what's to come this week/weekend, let's discuss the heat and precipitation chances for today (Tuesday). An Extreme Heat Warning remains in place for the lower elevations of the Grand Canyon and Glen/Marble Canyons, plus a Heat Advisory is in effect for much of northeastern AZ. Both the U of A WRF and the SPC HREF suggest pretty minimal convective activity this afternoon, but a few stray showers/storms are possible.

The Extreme Heat Warning for the Grand Canyon and Glen/Marble Canyons goes through Wednesday evening, but there is still potential for this to be extended. Hot temperatures don't look to go away anytime soon, but with the projected movement of the area of high pressure, precipitation chances could limit how warm temperatures get. Regardless, daytime highs will land 5-15 degrees above normal through the end of the week and into the weekend, so stay hydrated and try to limit activity during the hottest part of the day. Outside of the heat, shower and thunderstorm coverage looks to expand westward rather than being solely focused across the Rim and White Mountains for Wednesday and Thursday. Storms will be capable of producing localized heavy rain, small hail, frequent lightning, and gusty/erratic winds.

Model guidance doesn't suggest the strong area of high pressure moving out anytime soon, so continue to expect hot daytime highs and isolated to scattered chances for precipitation for the foreseeable future.

AVIATION...Tuesday 04/06Z through Wednesday 05/06Z

Mainly VFR expected. ISO SHRA/TSRA along the higher terrain from 19Z-02Z, mostly along and south of KPAN-KSJN line. West light and variable overnight, west at 10-20 kts daytime. Gusty/erratic winds possible near showers/storms.

OUTLOOK...Wednesday 05/06Z through Friday 07/06Z...Mainly VFR expected. ISO-SCT SHRA/TSRA between 18Z-03Z each day. West winds 10-20 kts each afternoon, becoming light and variable overnight. Gusty/erratic winds possible near showers/storms.

FIRE WEATHER...Tuesday and Wednesday

Above normal temperatures forecast to continue, along with daily chances for showers/storms. Precipitation chances looks to be focused across the higher terrain each afternoon/early evening. Westerly winds 10-20 mph expected each afternoon, with light/terrain driven winds overnight. Minimum RH values between 5-15% along and north of the Little Colorado River Valley, with 20-40% elsewhere.

Thursday through Saturday...Daytime highs 5-15 degrees above normal will persist through the weekend, along with daily chances for showers/storms. Coverage will primarily remain focused across the higher terrain. Look for westerly winds 5-15 mph each afternoon, becoming light/terrain driven during the overnight periods. Minimum RH values between 5-15% along and north of the Little Colorado River Valley, with 20-40% elsewhere.

FGZ WATCHES/WARNINGS/ADVISORIES

Extreme Heat Warning until 8 PM MST /9 PM MDT/ Wednesday for AZZ005-006.

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