Heat in Arizona, May 6, 2021

Area Forecast Discussion
National Weather Service Tucson AZ
318 AM MST Thu May 6 2021

.SYNOPSIS...Rather warm early May day with normal afternoon
breeziness. An approaching storm system well north of the region
will bring cooler conditions to the area along with another round
of gusty winds for the weekend into early next week.

&&

.DISCUSSION...The sky was clear across the area this morning under
high pressure aloft. Rather warm early May day with high
temperatures running 8 to 12 degrees above normal. Big forecast
challenge of the day surrounds the possibility of the first 100
degree high day of the year at the Tucson Intl airport. I've been
mostly using NBM high temperature guidance since late last week
and its been running a cool bias, around 1.5 degrees, for the
today part of the forecast. With the said I've added 2 degrees to
the inherited forecast, thus going with 99 for a high at TIA. If
it does hit 100, it'll be brief, like less than 5 minutes. But you
only need one 5 minute average. Otherwise for today there will be
an increase in limited moisture moving out of western Chihuahua
MX north along the AZ/NM border and east into southern NM with any
shower/T-storms occuring over SW NM. Some cumulus clouds eastern
areas. Early this evening will see gusty outflow winds move into
the far eastern areas.

For the remainder of the forecast, there will be a series of
upper level trofs passing by to our north, one on Friday and the
other early next week. Cooler tomorrow then highs hovering around
normal this weekend into early next week. Breezy conditions Friday
into early next week.

&&

.AVIATION...Valid through 07/12Z.
SKC-FEW clouds AOA 25k ft MSL this morning, then FEW-SCT clouds
developing this afternoon at 12-16k ft MSL and continuing through
about 07/04Z. Thereafter, skies generally SKC into Friday morning.
SFC wind E/SE 10 kts or less this morning, becoming SW/W 8-14 kts
this afternoon/evening. Winds diminish and become E/SE less than 8
kts aft 07/06Z. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Hot and dry conditions continue today with terrain
driven winds mainly under 15 mph. A few build-ups are expected along
the AZ/NM border Thursday in the higher terrain of the White
Mountains and Chiricahua Mountains. Otherwise, increased breezes
return Friday and this weekend with brief localized critical fire
weather conditions possible along the AZ/NM border and southeast
Cochise County Friday through Monday. Expect wind speeds 15 to 20
mph with higher gusts during this period. Minimum RH values will be
5 to 15 percent through the forecast period with generally poor
overnight recoveries.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...None.

&&

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