Area Forecast Discussion
Issued by NWS Flagstaff, AZ

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

FXUS65 KFGZ 160428

Area Forecast Discussion
National Weather Service Flagstaff AZ
928 PM MST Thu Jun 15 2017

.SYNOPSIS...A strong warming trend will continue into the weekend
and next week with record high temperatures likely during this
period. An Excessive Heat Warning is in effect for the lower
elevations of Yavapai, Coconino and northern Gila counties from
Saturday through Wednesday of next week. A Heat Advisory is in
effect for the mountains of Yavapai County from Sunday through


.DISCUSSION...Previous forecast remains on track. As has been the
case over the past several days, clear skies and light winds have
led to rapidly falling temperatures after a warm afternoon.
Expect afternoon high temperatures to be a few degrees warmer
Friday as thicknesses continue to rise across the area. This trend
of rising thicknesses and warmer temperatures with each
successive day will continue into this weekend and next week as
a ridge of high pressure strengthens over the southwest. The
result will be a dangerous, prolonged heat wave over much of the
southwest. The hot weather looks to continue through a good
portion of next week.


.PREV DISCUSSION /242 PM MST/...Temperatures are over 100 degrees
in the Verde Valley and other low elevation locations of N.
Arizona this afternoon. Much hotter temperatures are forecast
over the next week as the unusually strong high pressure
continues to strengthen over the southwest. It will become
dangerously hot over the lower terrain - and Excessive Heat
Warnings and a Heat Advisory are in place this weekend into next

What makes this heat wave different from other June events we`ve
recorded is the forecast duration of the heat. We`re currently
forecasting 5 days in a row with temps over 100 in Prescott, and 5
consecutive days over 90 in Flagstaff. This is highly unusual,
and will adversely impact those living in the valley locations,
without air conditioning, or working outside. The heat wave will
also continue to dry out the forests and significantly increase
the risk of fire and fire growth.

There are a few complicating factors, however. Most significantly,
we`re continuing to see the models wrap mid-level moisture into
the ridge over AZ late on Sunday and Monday. We will likely see an
increase in mid-level clouds over NE AZ late on Sunday, and more
clouds over the high terrain on Monday into early next week. While
little in the way of precipitation is expected, it could serve to
temper the heat in the high terrain a bit and limit the extreme
temperatures. At this time there is little relief in site, as the
hot ridge is expected to persist over AZ through next week.


.AVIATION...For the 06Z package...VFR conditions will prevail across
northern Arizona over the next 24 hours. Light and variable winds
will persist overnight. Southwesterly wind gusts up to 15 knots are
forecast for KGCN-KFLG-KSEZ Friday afternoon. Furthermore, smoke
from area fires may affect flight paths. Aviation discussion not
updated for TAF amendments.


.FIRE WEATHER....Warmer temperatures are forecast Friday and
Saturday along with very low humidity. Winds will be mainly terrain
driven and 10 mph or less for most areas.

Sunday through Tuesday...The hottest temperatures of the year are
forecast with Haines Indices between 5 and 6. There is a slight
chance of high-based thunderstorms over the higher terrain of
eastern Arizona Monday and Tuesday. While wetting rains are
unlikely, gusty and erratic winds will accompany storms that develop.


.FGZ WATCHES/WARNINGS/ADVISORIES...Excessive Heat Warning from 10
AM Saturday to 8 PM MST Wednesday FOR AZZ005-006-018-037-038.

Heat Advisory from 10 AM Sunday to 8 PM MST Wednesday FOR AZZ008.




For Northern Arizona weather information visit is the U.S. government's official web portal to all federal, state and local government web resources and services.