509
FXUS65 KFGZ 191734
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
1034 AM MST Thu Sep 19 2024

.SYNOPSIS...Seasonably cool temperatures remain through Saturday,
before warmer temperatures return next week. A cold front will
bring a chance for showers and possibly thunderstorms to the area
late Friday into Saturday, with otherwise dry conditions expected.

&&

.UPDATE...The mild and breezy weather pattern will continue for
northern Arizona today. A few clouds to speak of this morning with
a band of high clouds across southeast Arizona and a scattered
cumulus field across far western Arizona. The band of high clouds
will gradually expand and spread northwest across the area through
this afternoon. Otherwise, similar conditions to yesterday with
temperatures near to slightly below normal and winds gusting
around 25-30 mph. A few tweaks made to the sky cover forecast with
no other updates needed at this time.

&&

.PREV DISCUSSION /429 AM MST/...Today...Arizona is sandwiched
between a strengthening trough to the west just off the
Califorina Coast and high pressure to the east over Texas and
northern Mexico. With the increased pressure gradient, southerly
flow looks to increase over Arizona, keeping breezy conditions
around. However, winds should remain largely in the 20-30 mph
range. Temperatures should also be a bit warmer this afternoon,
but still remaining slightly below normal.

Friday through Saturday...The aforementioned low ejects off the
Pacific and moves into southern California. As this occurs, the
increased southerly flow should be enough to advect some moisture
northward into northern Arizona. To what extent is still
uncertain, but latest guidance has trended towards an increase in
precipitation chances over the past 24 hours.

As the low continues to move eastward, an area of frontogenetic
forcing should allow for a period of banded showers moving across
northern Arizona starting Friday evening and into Saturday morning.
The only question is how much moisture this forcing will have to
work with.

700 mb temperatures look to dip down to around +2C in the core of
the low, so snow levels look to be high enough for all rain across
much of the area. However, snow levels may dip down enough for the
first snow across the mountains tops above 10,000 feet.

Sunday through Wednesday...Heights rise behind the departing trough,
and high pressure largely builds over Arizona. Rising temperatures
and dry conditions follow suit into the start of next week. Model
guidance does have a shortwave trough dropping southward through the
Rockies sometime next week, but given the track, the system will be
fairly moisture starved and any sensible impacts will be limited to
some breezier northeasterly winds and slightly cooler
temperatures.

&&

.AVIATION...Thursday 19/18Z through Friday 20/18Z...VFR conditions
persist through the period with variable cloud cover. Expect
south-southwest winds 15-25 kts through 01Z, becoming variable
under 10 kts thereafter.

OUTLOOK...Friday 20/18Z through Sunday 22/18Z...Cloud cover
increases from west to east on Friday with chances for -SHRA and
an isolated -TSRA late Friday through Saturday morning. Greatest
chances will be along and west of a KPRC-KFLG-KPGA line. Showers
cloud linger throughout the day on Saturday near the AZ/UT border.
Widespread VFR conditions with SKC returns on Sunday. Anticipate
south-southwest winds 15-30 kts on Friday, followed by west-
northwest winds 15-25 kts on Saturday.

&&

.FIRE WEATHER...Today and Friday...Dry weather continues today with
seasonable temperatures and afternoon southwest wind 15 to 25 mph. A
chance of showers will develop over western Coconino and Yavapai
counties late Friday morning with southerly winds 15 to 25 mph. The
chance for showers will spreads eastward through Friday night.

Saturday through Monday...Cooler with a chance of showers lingering
north of I-40 Saturday. Northwest winds 10 to 20 mph Saturday
afternoon. West to north winds on Sunday and Monday as a warming and
drying trend develops.

&&

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

&&

$$

PUBLIC...MCT/Humphreys
AVIATION...LaGuardia
FIRE WEATHER...LaGuardia

For Northern Arizona weather information visit
weather.gov/flagstaff