textproduct: NWS Flagstaff

SYNOPSIS

Gusty winds are expected today ahead of a cold front, along with areas of critical fire weather conditions. Chances for rain and high elevation snow showers increase later tonight and into Monday morning, mainly across far northern Arizona. Cooler and breezy conditions remain on Monday, before gradually warmer and less windy conditions return for the remainder of the week.

DISCUSSION...Today

Southwesterly winds will begin to increase later this morning ahead of an approaching cold front. For most of the area, winds are expected to be stronger than we saw yesterday, and as such a Wind Advisory is in effect for much of northern Arizona today. Gusts upwards of 40-50 mph are expected across the higher terrain today, with some locally higher gusts possible just downwind of terrain features. Winds will likely peak later this afternoon into the early evening, as the upper-level jet max moves overhead. Winds may remain elevated past sunset set as a result, as model soundings do not show the boundary layer decoupling right away.

With the strong winds and dry conditions, widespread critical fire weather conditions are also expected across far northern and eastern Arizona. A Red Flag Warning is in effect through this evening for these locations. Elsewhere, while the expected winds and fuels met criteria, a subtle uptick in moisture south and west of the Mogollon Rim looks to keep RH values above the 15% threshold this afternoon. Thus, while some localized areas of critical fire weather conditions will remain possible in these areas, the threat does not appear widespread enough to support headlines.

Tonight and Monday...As the aforementioned front moves through the region later tonight, a brief period of showers looks to develop from west to east, primarily across far northern Arizona. Given that surface moisture will remain fairly minimal, much of the activity is expected to be either virga or light in nature. The best shot at measurable precip looks to mainly be across the Kaibab Plateau, an potentially Black Mesa and the Chuska Mountains as well. 00Z HREF guidance appears to be a bit bullish with precipitation chances, brining them as far south of as the Mogollon Rim. However, model soundings don't really support this outside of a subtle increase in low-level moisture early Monday morning. Nevertheless, PoP chances were maintained in the Flagstaff area for the potential for a couple isolated showers. Colder air aloft does move in with the front, so a few snow flakes may mix in at times above 7000-7500 feet. However any potential for measurable snow looks to remain above 7500-8000 feet and primarily near the Kaibab Plateau.

Tuesday through Saturday...Zonal flow sets in behind the low earlier in the week. Warming temperatures and dry conditions look to ensue as a result, with a return to near-normal highs by the middle to end of next week. Weak troughing will keep winds fairly light each day, with mainly only the typical afternoon breezes expected.

AVIATION...Sunday 17/12Z through Monday 18/12Z

Mainly VFR conditions. Brief periods of MVFR possible in -SHRA/-SHSN mainly north of a KGCN-KRQE line after 04Z Monday. MVFR CIGS possible INVOF KFLG after 08Z. Winds S/SW 15-25 kts with gusts 35-45 kts after 16Z, subsiding to 10-20 kts after 06Z.

OUTLOOK...Monday 18/12Z through Wednesday 20/12Z...Mainly VFR conditions. Brief MVFR conditions possible in ISO -SHRA/-TSRA east of a KPGA-KRQE line before 18Z Monday. MVFR CIGS possible INVOF KFLG/KSEZ before 15Z Monday. Winds W/SW 10-20 kts with gusts 25-35 kts on Monday, becoming VRB 5-10 kts on Tuesday.

FIRE WEATHER...Today and Monday

Red Flag Warning in effect for far northern and eastern Arizona today. Slight chance for light rain/snow showers later tonight into early Monday morning across far northern Arizona, otherwise dry and cooler. Wetting precipitation is not expected. Winds southwest 20-30 mph with gusts 40-50 mph today, becoming west 10-20 mph with gusts 25-35 mph on Monday. Minimum afternoon RH 10-25% each day.

Tuesday through Thursday....Dry conditions with gradually warming temperatures. Winds west/southwest 5-15 mph each day, along with minimum afternoon RH 5-15%.

FGZ WATCHES/WARNINGS/ADVISORIES

Red Flag Warning from 11 AM MST /noon MDT/ this morning to 8 PM MST /9 PM MDT/ this evening for AZZ104>106-109>114-116-117-139- 140.

Wind Advisory from 11 AM MST /noon MDT/ this morning to 8 PM MST /9 PM MDT/ this evening for AZZ004-006>009-011>017-038>040.