Special Weather Statement, NWS Tucson, AZ

Area Forecast Discussion
National Weather Service Tucson AZ
327 PM MST Tue Jul 13 2021

.SYNOPSIS...An active period of daily scattered showers and
thunderstorms during the next 7 days. High temperatures will be
near normal today then be below normal levels through the
remainder of the week into the weekend.

&&

.DISCUSSION...Starting to destabilize this afternoon with
a decent cu field developing over terrain. A few of the more robust
updrafts have been able to sustain and develop into thunderstorms,
with isolated to scattered convection occuring across both Santa
Cruz and Cochise Counties, as well as portions of Graham and far
northern Greenlee Counties. Plenty of moisture to tap into with PWAT
from Tucson westward in excess of 1.25" via satellite estimates, and
surface dewpoints holding steady in the upper 50s to lower 60s. This
is helping generate 1000-1500 J/kg of SBCAPE. Storm motions are
expected to be a little slower compared to Monday, generally around
10 to 20 mph. The focus for stronger storms today is generally west
of a line from about Safford to Nogales where the best moisture is
located. Various CAM solutions including the HREF and U of A WRFs
generally seem to agree with this scenario, so we have moderate to
high confidence that coverage will continue to increase into this
evening and potentially last into a portion of the overnight hours.
With the potential for slow moving/wet storms, the Flash Flood Watch
is now in effect and continues through Wednesday evening.

Speaking of Wednesday, things could get fairly interesting depending
on how things progress today. We'll watch a weak shortwave move
through the Four Corners and displace the upper ridge south and
slightly west, allowing the steering flow to become briefly more
westerly, and potentially enhancing upper level support for
convection if it sags far enough south into our area. We still look
to have plenty of deep moisture in place, so the flash flooding
threat will continue with any storms which develop.

High pressure reconsolidates over southern CA Thu/Fri with steering
flow adjusting to be mainly out of the north. Deeper moisture will
then be positioned east of Tucson toward the AZ/NM border, with
another round of scattered afternoon and evening showers and
thunderstorms on tap. WPC continues a slight risk of Excessive
Rainfall for these areas on Thursday.

As is generally the case, conditions can change daily depending upon
the previous day's activity. What we can confidently say, is that a
favorable monsoon regime remains in place this weekend with high
pressure moving back toward northern AZ. This brings deeper easterly
flow back to the area with another uptick in storminess over the
weekend which may then continue into early next week.

In terms of temperatures, expect daily highs generally below normal
for the remainder of the week through the weekend.

&&

.AVIATION...Valid through 16/00Z.
SCT-BKN clouds at 10k-14k ft MSL and BKN-OVC clouds AOA 20k ft MSL.
ISOLD-SCT SHRA/TSRA are expected to continue thru the forecast
period. Wind gusts to 45 kts possible near any TSRA. Otherwise,
surface winds 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 through the weekend and into next week. Gusty
outflow winds will be the primary concern with the daily storms. Min
RH values will generally be in the 20-30 percent range, with higher
values in the mountains. Surface winds will be light and follow
normal daily trends when not influenced by thunderstorms.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 Flash Flood Watch through Wednesday evening for AZZ501>507-509-511-
513>515.

&&

Carpenter/Lader

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Special Weather Statement
National Weather Service Tucson AZ
257 PM MST Tue Jul 13 2021

AZZ503-504-507-513-132230-
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-
257 PM MST Tue Jul 13 2021

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL PIMA...WEST CENTRAL
COCHISE AND NORTHEASTERN SANTA CRUZ COUNTIES UNTIL 330 PM MST...

At 257 PM MST, Doppler radar was tracking a strong thunderstorm 8
miles north of Elgin, or 17 miles southwest of Benson, moving west at
15 mph.

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

Locations impacted include...
Sonoita, Elgin, Corona De Tucson and Fort Huachuca.

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.

&&

LAT...LON 3192 11041 3160 11040 3156 11077 3195 11078
TIME...MOT...LOC 2157Z 087DEG 12KT 3177 11052

RH

Special Weather Statement
National Weather Service Tucson AZ
345 PM MST Tue Jul 13 2021

AZZ503-504-507-513-132330-
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-
345 PM MST Tue Jul 13 2021

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL PIMA...WESTERN
COCHISE AND NORTH CENTRAL SANTA CRUZ COUNTIES UNTIL 430 PM MST...

At 344 PM MST, Doppler radar was tracking a strong thunderstorm 7
miles southeast of Corona De Tucson, or 16 miles east of Sahuarita,
moving northwest at 20 mph.

Wind gusts up to 50 mph will be possible with this storm.

Locations impacted include...
Sahuarita, Vail, East Sahuarita, Sonoita, Corona De Tucson 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 3187 11045 3159 11075 3181 11099 3200 11090
      3211 11071
TIME...MOT...LOC 2244Z 120DEG 15KT 3185 11072

Cerniglia

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
406 PM MST TUE JUL 13 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0330 PM     TSTM WND GST     18 NNE PATAGONIA        31.78N 110.64W
07/13/2021  M63 MPH          PIMA               AZ   MESONET

            EMPIRE RAWS MEASURED A 63 MPH WIND GUST.

&&

KG

Special Weather Statement
National Weather Service Tucson AZ
415 PM MST Tue Jul 13 2021

AZZ503-513-140000-
Dragoon/Mule/Huachuca and Santa Rita Mountains including
Bisbee/Canelo Hills/Madera Canyon-Upper Santa Cruz River and Altar
Valleys including Nogales-
415 PM MST Tue Jul 13 2021

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL SANTA CRUZ COUNTY...

At 414 PM MST, a strong thunderstorm was located near Rio Rico, or 9
miles southeast of Tubac, moving southwest at 10 mph.

Wind gusts up to 50 mph are possible with this storm.

Locations impacted include...
Nogales, Rio Rico, Patagonia, Nogales International Airport,
Patagonia Lake State Park, Tumacacori and Pena Blanca Lake.

This includes the following highways...
 Interstate 19 between mile markers 1 and 19.
 Route 82 between mile markers 1 and 22.

Torrential rainfall is also occurring with this storm, and may cause
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 3134 11111 3152 11114 3171 11086 3154 11070
      3133 11086 3133 11108
TIME...MOT...LOC 2314Z 050DEG 9KT 3154 11093

TRIPOLI

Special Weather Statement
National Weather Service Tucson AZ
420 PM MST Tue Jul 13 2021

AZZ504-506-507-514-132345-
Santa Catalina and Rincon Mountains including Mount
Lemmon/Summerhaven-Upper San Pedro River Valley including Sierra
Vista/Benson-Southeast Pinal County including
Kearny/Mammoth/Oracle-Tucson Metro Area including Tucson/Green
Valley/Marana/Vail-
420 PM MST Tue Jul 13 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN PIMA AND
SOUTHEASTERN PINAL COUNTIES UNTIL 445 PM MST...

At 419 PM MST, Doppler radar was tracking a strong thunderstorm over
Mount Lemmon/Summerhaven, or 10 miles east of Catalina, moving
southwest at 10 mph. This is part of a series of storms over the
mountain.

Periods of heavy rain and winds in excess of 40 mph will be possible
with this storm.

Locations impacted include...
Catalina, San Manuel, Mount Lemmon/Summerhaven, Campo Bonito and
Redington.

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 3263 11070 3255 11057 3239 11047 3230 11067
      3244 11092
TIME...MOT...LOC 2319Z 054DEG 15KT 3244 11072

Cerniglia

Special Weather Statement
National Weather Service Tucson AZ
444 PM MST Tue Jul 13 2021

AZZ507-508-511-513-140030-
Upper San Pedro River Valley including Sierra
Vista/Benson-Dragoon/Mule/Huachuca and Santa Rita Mountains including
Bisbee/Canelo Hills/Madera Canyon-Eastern Cochise County Below 5000
Feet including Douglas/Willcox-Galiuro and Pinaleno Mountains
including Mount Graham-
444 PM MST Tue Jul 13 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN COCHISE COUNTY UNTIL
530 PM MST...

At 444 PM MST, Doppler radar was tracking a strong thunderstorm 15
miles north of Dragoon, or 15 miles west of Willcox, moving southwest
at 15 mph.

Wind gusts of 50 mph and blowing dust will be possible with this
storm.

This storm will remain over mainly remote areas of northwestern
Cochise County.

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 3237 11007 3220 10993 3201 11019 3226 11037
TIME...MOT...LOC 2344Z 058DEG 14KT 3224 11011

Cerniglia