textproduct: NWS Flagstaff

SYNOPSIS

Dry and windy conditions will continue through this evening with areas of critical fire weather. Winds begin to diminish by midweek, and daytime temperatures become above normal. Slight chances for a few showers or thunderstorms return by the weekend.

DISCUSSION

A longwave trough stationed over the western states is expected to remain in place through this evening before shifting eastward on Wednesday. The result has been more of the same for warm and dry conditions today, with southwest winds at 15-25 mph gusting up to 35-40 mph downslope of the Mogollon Rim in particular. Dry and warm conditions will continue on Wednesday, but with the trough shifting eastward a bit lighter winds are in store, becoming more southwest to west at 10-20 mph gusting to 30 mph. The gusty winds and dry conditions are combining to produce critical fire weather conditions today with a Red Flag Warning in effect for much of northern Arizona until 8 PM this evening. In addition, winds will be strong enough this afternoon for portions of the area from Flagstaff eastward for a Wind Advisory where a few wind gusts over 40 mph are anticipated. Elevated fire weather conditions will continue on Wednesday with humidity as low as 5%, but the lighter winds will fall below Red Flag Warning criteria.

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

From Friday onward..Models continue to show a weak high pressure system developing over northwest Mexico and the southwest United States. As a result, the general low-level flow looks to favor some moisture moving across Arizona from over the Gulf of California. Moisture amounts continue to look limited, but likely enough for isolated thunderstorms at least through the weekend. Confidence is moderate (30-50%) Saturday afternoon over the White Mountains for measurable rain and thunder. The moisture increase will probably be short- lived as drier air is expected to move over our area early next week as a series of dry shortwave troughs from the north brush Arizona.

AVIATION...Tuesday 09/18Z through Wednesday 10/18Z

OUTLOOK...Wednesday 10/18Z through Friday 12/18Z...

FIRE WEATHER...Today through Thursday

Dry and windy today, a Red Flag Warning remains in effect for most of northern Arizona through this evening. Warm and dry with lighter winds on Wednesday and Thursday. Winds are southwest 15-25 mph with gusts 30-40 mph today, becoming southwest to west 10-15 mph gusting 20-30 mph on Wednesday, then diminishing to 5-15 mph on Thursday. Minimum RH is 5-15% each day.

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

FGZ WATCHES/WARNINGS/ADVISORIES

Red Flag Warning until 8 PM MST /9 PM MDT/ this evening for AZZ104>107-109>117-139-140.

Wind Advisory until 8 PM MST /9 PM MDT/ this evening for AZZ010>015-039-040.