307
FXUS65 KFGZ 181119
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
419 AM MST Thu Jul 18 2024

.SYNOPSIS...Scattered showers and thunderstorms are expected each
day through the next week. Temperatures will remain above average
through the weekend with typical afternoon winds.

&&

.DISCUSSION...Today...High pressure remains situated over Arizona
today, keeping monsoonal moisture flowing into the state. Another
round of showers and thunderstorms look to develop later this
afternoon as a result.

Storm activity looks to initially develop over the higher terrain
across much of northern and central Arizona late this morning into
early part of the afternoon. As storms mature and outflows begin to
develop, storm activity should beginning to increase across the lower
elevations from about mid-afternoon through the evening hours.

Instability looks to be maximized largely south of I-40 with HREF
guidance showing around 1000 J/Kg of SBCAPE. So the greatest
coverage for today will continue to mainly be over the central
portions of the state, with more isolated coverage over the north.
PWATs across the vast majority of the area will be above 0.80
inches with upwards of 1.2 inches across the far southern portions
of the CWA. Storm motions continue to be minimal (~5 kts or less)
with weak flow in the 0-6 km layer, thus flash flooding will
continue to be the primary concern. With the instability, a few
stronger storms will be possible, with gusty outflow winds and
small hail being a potential threat.

Friday through Wednesday...The high continues to shift westward
through the end of the week and into next week. Moisture looks to
remain in place, however guidance seems to vary on the exact details
of the amount. The overall trend from ensemble guidance members from
the GEFS shows a slight upward tick on Friday and Saturday, followed
by a slight downward trend to start out next week. While the EPS and
CMCE seem to be a bit less optimistic about any real noticeable
changes.

Nevertheless, enough monsoonal moisture does look to remain in place
to warrant continued daily chances for showers and thunderstorms
across much of the area. The day to day trends will be largely
dependent upon any remnant debris clouds from earlier convection
and the extract positioning of the high for steering the storms.

Outside of precipitation chances, warmer temperatures look to ensue
over the region with the rising heights. The warmest temperatures
look to occur on Saturday, with the lower desert locations nearing
the threshold for excessive heat headlines. However, increasing
cloud cover will likely limit the overall heating potential, so
confidence isn`t very to go out with any heat headlines at this
time.

&&

.AVIATION...Thursday 18/12Z through Friday 19/12Z...VFR conditions will
prevail through the early morning hours with some isolated shower
activity mainly east of a KGCN-KPAN line. Expect scattered to
widespread showers/thunderstorms from 18Z through 06Z, developing
first over the higher terrain and moving into lower elevation
areas by mid afternoon and evening. Heavy rain, small hail, and
gusty/erratic outflow winds will be the primary hazards. Outside
of thunderstorm driven winds, look for W winds 5-15 kts.

OUTLOOK...Friday 19/12Z through Sunday 21/12Z...Expect daily
SHRA/TSRA chances mostly in the afternoon/evening hours. Gusty and
erratic winds likely from storm development, with W-NW winds
generally less than 15 kts otherwise. VFR conditions will persist
outside of MVFR conditions from showers/storms.

&&

.FIRE WEATHER...Today and Friday...Isolated to scattered showers and
storms (most numerous over the higher terrain) are expected each
afternoon and evening. Gusty and erratic outflow winds, small hail,
and heavy rainfall remain the main hazards. Daytime Winds generally
southwest to northwest 5 to 15 mph outside of storms, along with
slightly above normal temperatures.

Saturday through Monday...Scattered to widespread showers and storms
each afternoon and evening. Gusty and erratic outflow winds, small
hail, and heavy rainfall remain the main hazards. Winds generally
variable 5 to 15 mph outside of storms, along with slightly above
normal temperatures.

&&

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

&&

$$

PUBLIC...Humphreys
AVIATION...JJ
FIRE WEATHER...JJ

For Northern Arizona weather information visit
weather.gov/flagstaff