Heat in Arizona, June 10, 2021

Area Forecast Discussion
National Weather Service Tucson AZ
333 AM MST Thu Jun 10 2021

.SYNOPSIS...Strong high pressure will heat things up late in the
week into next week, with temperatures around 10 to 15 degrees
hotter than average Sunday through much of the week. We may see
enough of a moisture increase during the week for clouds and
thunderstorm chances to knock the heat back a bit in southern and
eastern areas by Wednesday.

&&

.DISCUSSION...Satellite imagery showed scattered high clouds
moving across the area under southwest flow aloft. One more day
of near normal high temperatures before the heat cranks up.

Strong high pressure over northern Mexico will expand across the
desert southwest through early next week bringing record or near
record high temperatures starting Saturday through much of next
week. Much of the lower deserts will be highs in the 110-115
range. Excessive Heat Warnings for portions of the forecast area
starts Sunday and continues into next week.

We start picking up an easterly component to the mid-level flow on
Monday which will bring an increase in moisture across the area
starting as early as Monday where we may see a few mainly dry
thunderstorms across the White mountains both Monday and Tuesday.
At this time Wednesday has the potential to be an active early
monsoon day with modest moisture in place as possible weak
inverted trof passes through. Confidence at this time is low but
something to watch as we kick off Monsoon 2021.

The bottom line is that the atmosphere will likely support record
heat through the entire week. However, some moisture increase is
very likely next week. It may be sufficient to create enough cloud
cover and thunderstorm chances to mitigate some of the heat,
mainly the second half of the week.

&&

.AVIATION...Valid through 11/12Z.
VFR conditions with FEW-SCT clouds above 20k ft MSL. SFC winds light
and variable this morning, becoming WLY/NWLY 10-15 kts with gusts to
around 25 kts aft 10/18Z. Sfc winds then diminish to light and
variable once again aft 11/03Z. Aviation discussion not updated for
TAF amendments. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Dry and hot weather is expected into next week as
temperatures climb to well above normal levels. Some mid level
moisture increase is expected starting Monday, continuing to
increase Tuesday and Wednesday. Isolated mainly dry thunderstorms
are possible as early as Monday afternoon across the higher terrain
to the east of Tucson. The thunderstorm threat expands westward
Tuesday and Wednesday with perhaps enough moisture for a mix of
isolated dry and wet thunderstorms, though confidence is still low
on the details. Typical afternoon breezes with gusts to around 20-25
mph are expected each day into next week due to strong daytime
heating. Minimum humidities will generally be in the single digits
in the valleys and 6-12% in the mountains with poor overnight
recoveries through Monday. A slight improvement is expected
thereafter especially in the mountains and with improving overnight
recoveries areawide.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 Excessive Heat Warning from 10 AM Sunday to 8 PM MST Wednesday
  for AZZ503-504-509.

 Excessive Heat Watch from Wednesday evening through Friday
  evening for AZZ503-504-509.

 Excessive Heat Warning from 10 AM Sunday to 9 PM MST Friday for
  AZZ501-502-505-506.

&&

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