textproduct: NWS Flagstaff

SYNOPSIS

Look for warm, dry and breezy weather through Thursday before increasing moisture delivers chances for a few showers or thunderstorms by the weekend.

DISCUSSION

The recent longwave trough over the western states was heading to the east during the early morning. Dry and warm conditions will continue during the day today but lighter winds are anticipated as pressure gradients weaken. Look for southwest to west winds at 10-20 mph gusting to 25-30 mph. Near-critical fire weather conditions will continue but the lighter winds will fall below Red Flag Warning criteria.

On Thursday...A weak high pressure system begins to build over the southwest United States. Dry conditions will continue but winds will turn even lighter, southwest to west 5-15 mph gusting to around 20 mph with a much reduced fire weather threat. Daytime temperatures will turn slightly warmer with mild overnight temperatures.

For Friday and the weekend..Models continue to show a weak high pressure system developing over northwest Mexico and the southwest United States from Friday into early Saturday. As a result, the general low-level flow looks to favor some moisture moving into Arizona from over the Gulf of California. Moisture amounts will gradually increase on Friday leading to a slight chance of showers and thunderstorms with daytime heating, mainly from the Mogollon Rim southward. From Saturday into Sunday moisture will increase further and interact with a shortwave trough brushing Arizona from the north. Cooler temperatures aloft associated with the trough will combine with daytime heating to produce a fair amount of instability. As a result, look for a decent chance for showers and thunderstorms later on Saturday into Sunday. One thing we will be keeping an eye on, when it comes to moisture from the south, thunderstorm activity over Mexico could juice-up those chances. We'll let you know.

From Monday onward...Isolated showers and thunderstorms could linger into Monday but the forecast models are set on a drier west to northwest flow aloft setting up over Arizona as high pressure builds from the west. The forecast is for a return to the usual daytime breezes and dry weather with a bit above seasonal average temperatures continuing.

AVIATION...Wednesday 10/12Z through Thursday 11/12Z

VFR conditions. Winds becoming SW to W 10-15 kts gusting 20-30 kts after 15Z, then variable at 5-10 kts after 03Z.

OUTLOOK...Thursday 11/12Z through Saturday 13/12Z...VFR conditions. Daytime winds SW to W 5-15 kts on Thursday and Friday, generally subsiding to 5-10 kts each night. A stray shower or thunderstorm possible Friday afternoon.

FIRE WEATHER...Today and Thursday

Expect warm, dry and breezy weather. Winds southwest to west 10-20 mph gusting 25-30 mph today, then diminishing to 5-15 mph gusting 20 mph on Thursday. Minimum afternoon RH of 5-15% is predicted for both days.

Friday through Sunday...Warm with increasing moisture. Chances for showers and thunderstorms each day, highest on Saturday. Winds forecast to be southwest to west 5-15 mph on Friday, increasing to 10-20 mph on Saturday and Sunday. Look for minimum RH to be 10-20% on Friday, increasing to 15-25% on Saturday and Sunday.

FGZ WATCHES/WARNINGS/ADVISORIES

None.