Areal Flood Advisory 45, NWS Tucson, AZ

Area Forecast Discussion
National Weather Service Tucson AZ
927 AM MST Fri Jul 16 2021

.SYNOPSIS...An active monsoon period of daily scattered showers
and thunderstorms will continue during the next seven days. High
temperatures will remain below normal into next week as well.

&&

.UPDATE...Morning activity has been focused across southern Pinal
County and central Pima County this morning with isolated embedded
lightning strikes. Everything has remained fairly tame at this point
with no current warnings in effect. Going into today, we are
expecting another busy day with potential for at least a couple of
rounds of showers and storms for southeast Arizona.  Moisture
remains in abundance as indicated on this mornings 12z sounding with
a PWAT of 1.92 inches. Additional forcing will be provided by a wave
passing across the area as it rotates around the southern periphery
of the ridge today into tomorrow which will help facilitate storm
activity. Current consensus amongst the hi-res models shows this
morning's precipitation continuing to transition southward towards
the international border before afternoon activity gets going across
eastern Pima, Santa Cruz, and western Cochise counties as early as
12 PM. This area looks to be the focus for afternoon activity with
more isolated shower and storm activity possible across the
remainder of the area. As we get later into the day, a shot of
convection moving off the Mogollon Rim from northeast to southwest
through he area looks like a possibility into tonight. Slow storm
motion and short duration heavy rain leading to flash flooding
continue to be the primary threat today with a more localized strong
wind threat. Flash Flood Watch remains in effect through this
evening which will be reassessed for extension early this afternoon.

&&
.DISCUSSION...The shower and thunderstorm activity was rather
limited so far early this morning compared to the past few mornings.
However, high resolution models showed another round of scattered
showers and thunderstorms developing across the area today. A weak
shortwave passing through central AZ should turn south around the
upper high before tracking back toward the west as an inverted
trough later today. This feature will likely play a role in the
development of showers and thunderstorms this afternoon and evening.
The potential for locally heavy rainfall will be a concern again
today as the air mass over the area remained very moist. This heavy
rainfall potential in combination with the saturated ground in spots
could led to more flash flooding. Thus, a flash flood watch remains
in effect through this evening.

The latest ensemble means supported an active weather pattern across
the Desert Southwest as the upper high amplifies and becomes
centered over the four corners region this weekend. Otherwise, high
temperatures will remain a few degrees below normal.

&&

.AVIATION...Valid through 17/12Z.
FEW-SCT clouds at 11k-15k ft MSL and BKN-OVC clouds AOA 20k ft MSL
thru 16/18Z, then SCT-BKN clouds at 8k-12k ft MSL til 17/04Z. Slowly
diminishing clouds aft 17/04Z. Slight chance of -SHRA/-TSRA thru
16/19Z, then scattered to numerous SHRA/TSRA developing and
persisting through the evening hours tonight before diminishing.
Wind gusts to 45 kts possible near any TSRA along with MVFR
conditions and mountain obscurations. Otherwise, SFC wind generally
less than 12 kts. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...There will be a good chance of showers and
thunderstorms across southeast Arizona the next week. Gusty outflow
winds will be the primary concern with the daily storms. Min RH
values will be in the 25-35 percent range at the lower elevations,
with higher values in the mountains. 20-foot winds will generally be
less than 15 mph and follow normal diurnal trends when not
influenced by thunderstorms.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 Flash Flood Watch through this evening for AZZ503>515.

&&

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

Special Weather Statement
National Weather Service Tucson AZ
1021 AM MST Fri Jul 16 2021

AZZ503-504-507-513-161800-
Upper San Pedro River Valley including Sierra
Vista/Benson-Dragoon/Mule/Huachuca and Santa Rita Mountains including
Bisbee/Canelo Hills/Madera Canyon-Upper Santa Cruz River and Altar
Valleys including Nogales-Tucson Metro Area including Tucson/Green
Valley/Marana/Vail-
1021 AM MST Fri Jul 16 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN PIMA AND EASTERN
SANTA CRUZ COUNTIES UNTIL 1100 AM MST...

At 1020 AM MST, Doppler radar was tracking a strong thunderstorm 8
miles northwest of Patagonia, or 13 miles east of Tubac, moving
southwest at 20 mph.

Winds in excess of 40 mph will be possible with this storm.

Locations impacted include...
Tubac, Rio Rico, Patagonia, Sonoita, Elgin, Patagonia Lake State
Park, Tumacacori, Amado and Madera Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Heavy rainfall is also occurring with this storm, and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3181 11064 3160 11052 3146 11076 3142 11102
      3167 11115 3177 11091
TIME...MOT...LOC 1720Z 067DEG 17KT 3165 11083

Cerniglia