Wildfire in Arizona, May 1 to 7, 2018

Area Forecast Discussion
National Weather Service Tucson AZ
923 PM MST Mon Apr 30 2018

.SYNOPSIS...Breezy to windy conditions will continue the next
couple of days with cooling temperatures. There will be a chance
for showers and thunderstorms to go along with cool temperatures
Tuesday evening through Wednesday as a storm system moves across
the area. Snow levels could briefly drop below 7000 ft Wednesday.
Friday into the weekend will be dry with a rapid heating trend.

&&

.DISCUSSION...Winds continued to slowly increase today ahead of a
strong weather system digging into the region from the northwest.
The gradient tightens even more tomorrow with a wind advisory over
southern areas and a Red Flag warning for a significant portion of
the area. A shallow but strong increase in surface moisture as the
southwesterly flow gets stronger will bring higher surface dew
points tomorrow, mainly west of Tucson. This will tend to put a
damper on afternoon temperatures out west, so we lowered forecast
highs for our lower desert locations west and northwest of Tucson.
Otherwise, no updates. Please see sections below for additional
details.

&&

.AVIATION...Valid through 02/06Z.
BKN-OVC clouds above 20ft. SFC winds SWLY 12-20 kts gusting to 30
kts, gradually decreasing this evening to SLY 8-12 kts. Winds
strengthen further on Tuesday SWLY 22-28 kts with higher gusts
during the late morning into the early evening. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...The trend of breezy to windy days continues, with
the greatest wind speeds and areal extent likely occurring
Tuesday afternoon. 20-foot winds reach 20-30 mph and some
localized areas of Cochise and Santa Cruz Counties could
experience even stronger winds, especially over exposed and
elevated terrain. Showers with a slight chance of thunderstorm
development pushes through Tuesday night into Wednesday. The
highest probabilities occur north of Tucson keying in on the
higher elevations.

Breezy to windy conditions conditions continue southeast of Tucson
in Cochise County on Wednesday, finally settling down late in the
week, with gusty upslope winds at times in the afternoon due to
strong surface heating. Dry and hotter Friday into the weekend.

&&

.PREV DISCUSSION...Gusty westerly winds area wide today along
with cooler temperatures with an upper level trof axis over the
state. High level cloud cover has been on the increase this
afternoon associated with a weak vort max which was over central
California this afternoon. So expect mostly cloudy conditions this
evening then becoming partly cloudy overnight before increasing
yet again on Tuesday.

Further upstream off the Oregon coast is an upper level low which
will dive SE along the west coast over the next 24 hours with a
new upper level low developing between Vegas and LA. This feature
will gradually move east across Arizona through Thursday morning.
Surface cold front to push across the area Tuesday night, bringing
isolated to scattered showers/high elevation snow showers and a
few thunderstorms to the area. Rainfall amounts, for those areas
that see rain, will be less than two-tenths with localized higher
amounts in the higher terrain. Snow levels lowering to around 7500
feet with 1-4 inches possible above 8000 feet. Convective nature
of showers and possible thunderstorms makes it difficult to
determine which mountain range from Tucson northeast into the
White mountains will see the greater snow amounts. At this time
going with the Whites. Blowing dust a concern tomorrow also
especially across Cochise county and NW of Tucson in advance of
approaching cold front. Cooling trend to continue into Wednesday
with highs 8-12 degrees below normal for early May. Cool overnight
lows in wake of system Wednesday night into Thursday morning with
localized near freezing temperatures for an hour or two in the
usual colder valleys east of Tucson.

After this system leaves the area, its time to warm up again with
the warmest temperatures of 2018 for so on tap for this weekend
with Tucson flirting with triple digits for the first time this
year on Sunday.

Models hinting at some moisture moving up from the south across
the AZ/NM state border area Sunday into Monday. Confidence low at
this time with the scenario.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 AM to 7 PM MST Tuesday for AZZ151-152.

Fire Weather Watch Wednesday afternoon for AZZ151-152.

Wind Advisory from noon to 7 PM MST Tuesday for AZZ503-507-508.

&&

Meyer/JG

Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson