226
FXUS65 KFGZ 122039
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
139 PM MST Wed Jun 12 2024

.SYNOPSIS...Hot temperatures, even for June, are in the forecast
the next couple of days. Some relief from the heat arrives Thursday
evening into Friday along with a chance for light rain showers
and a few thunderstorms. Precipitation amounts will be minimal
with dry lightning possible. Dry, warm, and breezy conditions
return by the weekend, with a slight cooling trend early next week.

&&

.DISCUSSION...Hot temperatures continue today with strong high
pressure in place (500mb height 593-595 dam). Highs today are
going to top out at 10-15 degrees above mid-June averages. An
Excessive Heat Warning is in effect below 4000 feet in Coconino
and Yavapai counties. A closed low centered off the coast of San
Diego is moving slowly eastward. Pressure gradients between these
2 systems are tightening, and breezy southwest winds are the
result. Gusts in the 20-30 mph range are being observed at 1 PM.

Thursday and Friday - the closed low will move into southern
California by Thursday afternoon and western Arizona by sunrise
Friday. The low will open up and move into Colorado by Friday
afternoon. We will see some increasing mid and high level
cloudiness as early as sunrise Thursday, continuing to increase
through the day. There will be a chance of virga/sprinkles from
around Flagstaff westward through the afternoon, but forecast CAPE
values are very low so the risk of thunderstorms should be
minimal until the low pressure center moves closer to the area.
The extra clouds could knock temperatures down a bit and allow for
an early end to the Excessive Heat Warning, but will make that
call tomorrow. The best lift and slightly deeper moisture move up
across Yavapai/Coconino counties Thursday night with precip
chances 30-40%. Only very light amounts of less than 0.10" are
anticipated. Lightning chances go up slightly due to cooling
aloft, but without daytime heating the instability and lightning
risk remain low overnight. On Friday - the higher rain chances
(30-60%) shift into northeast Arizona. With daytime heating, the
chance of lightning goes up which poses a threat of new wildfire
starts, again mainly in northeast Arizona. Rain chances end Friday
evening near the four corners.

Saturday through Tuesday - temperatures rebound briefly on
Saturday as the low departs eastward. Highs will be 7-12 degrees
above normal. From Sunday onward, models are in agreement that a
large trough will set up over the northwest US, pushing the ridge
well south of our area. This will bring a gradual cooling trend to
the region, with highs possibly even a few degrees cooler than
normal by early next week. Unfortunately, we will be on the windy
southern end of the trough with gusts in the 30-40 mph range in
the forecast Sunday and Monday - possibly leading to a period of
critical fire weather so stay tuned.

&&

.AVIATION...Wednesday 12/18Z through Thursday 13/18Z...VFR
conditions expected to continue through the TAF period. Look for
SW winds 10-20 kts, gusting near 25 kts this afternoon. Overnight
winds look to become light and variable.

OUTLOOK...Thursday 13/18Z through Saturday 15/18Z...VFR conditions
will mostly prevail, but areas of brief MVFR conditions possible
due to -SHRA/TSRA between 18Z Thursday and 06Z Saturday. Coverage
of showers/storms will move west to east throughout the timeframe.
Gusty and erratic winds will be likely near storm development.
Otherwise, look for SW winds 10-20 kts Thursday afternoon and W-NW
winds 10-20 kts Friday afternoon. Overnight winds expected to
become light and variable.

&&

.FIRE WEATHER...Thursday and Friday...Hot temperatures will
continue Thursday before slightly cooling off on Friday. Look for
rain/storm potential to begin Thursday afternoon across Yavapai &
Coconino Counties, becoming more focused in NE Arizona on Friday.
Dry lightning and gusty/erratic possible throughout the period.
Outside of storm-driven winds, look for southwest winds 15-25 mph
on Thursday and west winds 10-20 mph on Friday.

Saturday through Monday...Above normal temperature will continue
through Sunday, with cooler conditions returning by Monday. Expect
mostly dry conditions (minimum RH values 5-15%) and gusty southwest
winds. Near critical fire weather conditions likely over the
weekend/into next week.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
Excessive Heat Warning until 8 PM MST /9 PM MDT/ Thursday for
AZZ005-006-037.

&&

$$

PUBLIC...JJ
AVIATION...Konieczny
FIRE WEATHER...Konieczny

For Northern Arizona weather information visit
weather.gov/flagstaff