textproduct: NWS Flagstaff

SYNOPSIS

Breezy winds and chances for high-based showers today with cooler and unsettled weather returning through the middle of the week.

DISCUSSION...Today

A deep low pressure system currently located off the off the coast of California is slowly propagating inland. A subtle shortwave is swinging ahead of the low today, and bringing a southerly surge of higher PW and dewpoints. Showers are firing along and downwind the higher terrain this afternoon as a result. Showers have remained fairly high based. Some measurable precipitation will reach the ground, but will stay in the range of a few hundredths. Away from gusty outflow winds, expect breezy south to southwest winds gusting up to 30 mph as the gradient aloft begins to tighten.

Monday...The California low continues its approach. We begin to see a cooling trend as temperatures drop 5-10 degrees compared to Sunday. Breezy southwesterly winds continue as the gradient aloft tightens, however the magnitude of gusts generally peak in the 30-40 mph range due to cloud cover and shallow mixing. Localized gusts over 40 mph will be possible, especially Monday evening downwind of the San Francisco Peaks, Mogollon Rim, and White Mountains. Mostly dry conditions are expected throughout the day on Monday, but some showers may arrive to the White Mountains region by the evening.

Tuesday and Wednesday...The low finally reaches northern AZ, bringing moisture, lift, and cold air aloft. The current forecast calls for a 40-60% chance of rain on Tuesday mostly Mogollon Rim and northward. Added afternoon instability will bring some thunderstorms as well. Temperatures will be coldest on Tuesday, with daytime highs 5-15 degrees below normal. Into Wednesday, expect warming temperatures with just some isolated showers as the low weakens and the trough axis moves past our area. Gusts 30-40 mph are possible in far eastern AZ on Tuesday, then lighter northwest winds are expected Wednesday.

Thursday onward...Drier conditions are expected under predominantly northwest flow, and temperatures return to above normal as heights aloft recover.

AVIATION...Monday 04/00Z through Tuesday 05/00Z

Expect VFR conditions. ISOLD-SCT -SHRA/-TSRA north of the I-40 corridor will dissipate north of the Utah border by 02Z-04Z. Gusty S-SSW sfc winds from 15-25g30kts will decrease to less than 10-15kts overnight. Sfc winds S-SW15-25g30-035kts redevelop AFT 18Z Monday.

OUTLOOK...Tuesday 05/00Z through Thursday 07/00Z...Expect mainly VFR conditions. SCT -SHRA/ISOLD -TSRA late Monday night through Tuesday afternoon, especially east of the I-17 corridor and toward the Four Corners. Some stronger showers may produce brief MVFR conditions. All other periods dry. Sfc winds SW15-25g30-035kts continuing on Tuesday, becoming NW10-20kts on Wednesday.

FIRE WEATHER...Monday and Tuesday

Dry conditions expected on Monday with scattered showers on Tuesday. South to southwest winds at 15-25 mph with gusts 30-40 mph on Monday, decreasing slightly on Tuesday. Minimum RH between 15-30% on Monday, increasing to 25-50% on Tuesday.

Wednesday through Friday...Isolated to scattered showers on Wednesday, then dry conditions return for Thursday and Friday. West to northwest winds at 5-15 mph on Wednesday, becoming variable on Thursday, then west to northwest 5-15 mph on Friday. Minimum RH between 15-25% on Wednesday, decreasing to 10-20% for Thursday and Friday.

FGZ WATCHES/WARNINGS/ADVISORIES

None.