Area Forecast Discussion
Issued by NWS Flagstaff, AZ
Issued by NWS Flagstaff, AZ
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050 FXUS65 KFGZ 191030 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 330 AM MST Wed Jun 19 2024 .SYNOPSIS...Another dry day with seasonal temperatures is in store today. Increasing moisture will bring daily chances for showers and thunderstorms from Thursday through the early part of next week. Warming temperatures are expected from Thursday onward. && .DISCUSSION...Another dry and mild day is in store today before a pattern change unfolds for later in the week. A broad trough positioned across the western U.S. will continue to bring a dry southwesterly flow to the area today. Temperatures will run very close to normal with typical afternoon breezy winds gusting up to about 25 mph. The pattern change begins tonight as a moist southeast flow develops in advance of a tropical system moving through northern Mexico/southern TX. Moisture will increase and spread west across Arizona tonight through Thursday. Both operational and ensemble model guidance have continued an upward trend in moisture and resulting precipitation chances from Thursday through the weekend. Precipitable water (PW) values are forecast to be in the 0.75 to 1.00" range, which is about 2 to 3 standard deviations above normal for this time of year. The increasing moisture trend is leading to a greater threat for measurable rain, and less of a threat for dry lightning. Some storms are expected to produce moderate rainfall amounts and some small hail. Temperatures will be warmer than they have been during this period due to rising heights and high pressure building westward, but the increased moisture and shower activity will keep them from rising too much. Subtropical high pressure is forecast to build over the southwest and center near the AZ/NM border by late in the weekend. The moisture stays in place under the building high through the early part of next week, but it looks like it begins to wane from Tuesday onward as drier southwesterly flow develops again. The higher heights and thinning moisture will lead to rising temperatures, and we could be looking at nearing excessive heat criteria by Tuesday/Wednesday of next week in the lower valley locations. && .AVIATION...Wednesday 19/12Z through Thursday 20/12Z...VFR conditions with S/SW winds 10-15 kts, gusting 20-25 kts. Winds becoming light and variable after 03Z. OUTLOOK...Thursday 20/12Z through Saturday 22/12Z...Daily chances for SHRA/TSRA with localized MVFR and gusty, erratic outflow winds possible. VFR conditions are otherwise expected, with winds S 15-20 kts and gusts 20-30 kts each day. && .FIRE WEATHER...Today and Thursday...Dry and breezy conditions for today, with southwest winds gusting 20-30 mph. Warmer temperatures and chances for showers and thunderstorms return on Thursday. South winds gusting 25-35 mph on Thursday. Friday through Sunday...Warm temperatures with daily chances for showers and thunderstorms. South/southwest winds 15-25 mph, with gusts up to 30 mph on Friday, becoming light for the weekend. && .FGZ WATCHES/WARNINGS/ADVISORIES...None. && $$ PUBLIC...MCT AVIATION...Humphreys FIRE WEATHER...Humphreys For Northern Arizona weather information visit weather.gov/flagstaff