512
FXUS65 KFGZ 191551
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
851 AM MST Wed Jun 19 2024

.SYNOPSIS...Another dry day with seasonal temperatures is in store
today. Increasing moisture will bring daily chances for showers
and thunderstorms from Thursday through the early part of next
week. Warming temperatures are expected from Thursday onward.

&&

.UPDATE...No forecast updates this morning. Still looking at
increasing precip chances tomorrow and into the weekend. The POPs
tomorrow look good and match pretty well with what the local U of
A WRF has with more robust convection developing near and north
of 40 in Apache/Navajo counties. Meanwhile, more isolated
convection develops during the afternoon in Gila County and drifts
northward with the southerly flow and added terrain lift.

&&

.PREV DISCUSSION /330 AM MST/...Another dry and mild day is in
store today before a pattern change unfolds for later in the week.
A broad trough positioned across the western U.S. will continue
to bring a dry southwesterly flow to the area today. Temperatures
will run very close to normal with typical afternoon breezy winds
gusting up to about 25 mph.

The pattern change begins tonight as a moist southeast flow
develops in advance of a tropical system moving through northern
Mexico/southern TX. Moisture will increase and spread west across
Arizona tonight through Thursday. Both operational and ensemble
model guidance have continued an upward trend in moisture and
resulting precipitation chances from Thursday through the weekend.
Precipitable water (PW) values are forecast to be in the 0.75 to
1.00" range, which is about 2 to 3 standard deviations above
normal for this time of year. The increasing moisture trend is
leading to a greater threat for measurable rain, and less of a
threat for dry lightning. Some storms are expected to produce
moderate rainfall amounts and some small hail. Temperatures will
be warmer than they have been during this period due to rising
heights and high pressure building westward, but the increased
moisture and shower activity will keep them from rising too much.

Subtropical high pressure is forecast to build over the southwest
and center near the AZ/NM border by late in the weekend. The
moisture stays in place under the building high through the early
part of next week, but it looks like it begins to wane from
Tuesday onward as drier southwesterly flow develops again. The
higher heights and thinning moisture will lead to rising
temperatures, and we could be looking at nearing excessive heat
criteria by Tuesday/Wednesday of next week in the lower valley
locations.

&&

.AVIATION...Wednesday 19/12Z through Thursday 20/12Z...VFR
conditions with S/SW winds 10-15 kts, gusting 20-25 kts. Winds
becoming light and variable after 03Z.

OUTLOOK...Thursday 20/12Z through Saturday 22/12Z...Daily chances
for SHRA/TSRA with localized MVFR and gusty, erratic outflow
winds possible. VFR conditions are otherwise expected, with winds
S 15-20 kts and gusts 20-30 kts each day.

&&

.FIRE WEATHER...Today and Thursday...Dry and breezy conditions for
today, with southwest winds gusting 20-30 mph. Warmer temperatures
and chances for showers and thunderstorms return on Thursday. South
winds gusting 25-35 mph on Thursday.

Friday through Sunday...Warm temperatures with daily chances for
showers and thunderstorms. South/southwest winds 15-25 mph, with
gusts up to 30 mph on Friday, becoming light for the weekend.

&&

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

&&

$$

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

For Northern Arizona weather information visit
weather.gov/flagstaff