424
FXUS65 KFGZ 300538
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
1038 PM MST Sun Sep 29 2024

.SYNOPSIS...Above average temperatures and light winds continue
through the week. Isolated afternoon showers through Wednesday.

&&

.UPDATE...Will update forecast for more clouds this evening and isolated
light to very light showers that are persisting over northern
Arizona north of Interstate 40.

&&

.PREV DISCUSSION /434 PM MST/...High pressure in place across northern
Arizona will lead to a continuation of abnormally warm
temperatures through the week. Highs are forecast to range from
10-15 degrees above normal each afternoon, challenging records.
For example, On Tuesday (Oct 1), Flagstaff is forecast to reach 85
degrees which would tie 1980 for the latest occurrence of 85+
degrees.

Despite the low-levels of the atmosphere being very warm and dry,
there is enough moisture around for mid-level cumulus development
each day, primarily over mountainous regions. On Monday, HiRes
model guidance shows the most well-developed cumulus field, likely
resulting in a round of virga, which is rainfall that evaporates
before reaching the ground. While winds are expected to be light
on Monday, erratic surface wind gusts to 25 mph are possible in
the vicinity of any virga showers that do develop. In addition,
the forecast was updated to include a 10-15% chances of light
rain showers over high terrain on Monday. It`s unlikely, but
there may be a few showers briefly capable of producing very light
rainfall at the surface.

&&

.AVIATION...Monday 30/06Z through Tuesday 01/06Z...VFR
conditions under scattered clouds over 10,000 feet MSL. Isolated
-SHRA 18Z-00Z. Light winds through 16Z will become south to west
 at 10-20 kts.

OUTLOOK...Tuesday 01/06Z through Thursday 03/06Z...VFR conditions
will continue under scattered mid-level cloudiness. ISOLD -shra
18Z-00Z each day. North to northeast winds at 5-15 kts for
Tuesday and south to west winds on Wednesday.

&&

.FIRE WEATHER...Monday and Tuesday...Hot with near record heat.
Cumulus clouds will develop over higher terrain each afternoon with
isolated showers. Expect erratic winds in the vicinity of showers.
Afternoon humidity will range from 10-20%. Winds north to northwest
5-15 mph on Monday, becoming more easterly on Tuesday.


Wednesday through Friday...Daytime temperatures remain around 10
degrees above average. Afternoon cloud buildups and showers
over higher terrain again on Wednesday. Min RH values
10-20%. Light winds continue, averaging from the west, but
heavily influenced by terrain.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...None.

&&

$$

PUBLIC...MAS/RR
AVIATION...MAS
FIRE WEATHER...MAS

For Northern Arizona weather information visit
weather.gov/flagstaff