Scientific Forecaster Discussion
fxus65 kfgz 192202
Area forecast discussion
National Weather Service Flagstaff Arizona
302 PM MST Thu Sep 19 2019
Synopsis...windy condtions will continue through around sunset
before decreasing. Dry conditions and near normal temperatures
are forecast Friday through the weekend, with thunderstorm chances
returning to northern Arizona Monday and Tuesday of next week.
Discussion...breezy southwest winds have developed this
afternoon as advertised. Most gusts have been in the 30 - 40 mph
range with the highest gusts near 45 mph from Two Guns northwest
through the Grand Canyon region. This is in response to a deep trough
centered over Nevada and Idaho. Mostly dry conditions are being
observed, with the exception of a few isolated showers or storms
over central Apache County. Wind speeds will decrease around
sunset when the Wind Advisory expires, but they will remain
breezier than usual overnight due to tighter pressure gradients
from the trough.
The passing trough will continue to affect our weather on Friday
with continued breezy afternoon winds and a slight decrease in
daytime temperatures. The trough heads northeast through the
remainder of the weekend. Expect lighter winds and near average
temperatures Saturday and Sunday. Some higher elevations near and
above 7,000 ft will drop near or below freezing over the weekend.
Confidence is increasing in a rain event across Arizona early next
week as a weakening tropical system pushes moisture northward and
interacts with a deepening trough moving into the southwest.
Consistency has been increasing among operational and ensemble
mean solutions. There continues to be a great deal of spread among
possible rainfall amounts, but our current forecast suggests 1-2"
is certainly possible. At this point, areas from Flagstaff
southward look to be favored. Keep an eye on the forecast over the
weekend as the details of this event unfold.
Aviation...for the 00z package...expect mainly VFR conditions
through the 24 hour taf period. The exception being isold shra/-tsra
along the New Mexico border through 01z. Sfc winds sw15-25g35-40kts
through 02z becoming sw5-10g15 after 02z. Aviation discussion not
updated for taf amendments.
Fire weather...expect breezy southwest winds to continue
Friday. Lighter winds return Saturday with dry conditions for all
of northern Arizona through this period.
Sunday through Tuesday...dry and seasonable weather and light
southwest winds will continue through Sunday. Moisture increasing
from the south on Monday will bring cooler weather, with areas of
showers and thunderstorms possible on Monday and Tuesday.
Fgz watches/warnings/advisories...Wind Advisory until 8 PM MST
this evening for azz004-006-007-012-015.
Red flag warning until 8 PM MST this evening for azz106-107.