Severe Thunderstorm Warning 62, NWS Tucson, AZ

277 
WWUS55 KTWC 220010
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
510 PM MST Fri Aug 21 2020

AZC009-011-220019-
/O.EXP.KTWC.SV.W.0062.000000T0000Z-200822T0015Z/
Graham-Greenlee-
510 PM MST Fri Aug 21 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN GRAHAM AND
SOUTHEASTERN GREENLEE COUNTIES WILL EXPIRE AT 515 PM MST...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire. However gusty 
winds are still possible with this thunderstorm.

LAT...LON 3296 10932 3294 10911 3272 10912 3276 10937
TIME...MOT...LOC 0009Z 005DEG 17KT 3275 10924 

$$

Area Forecast Discussion
National Weather Service Tucson AZ
215 PM MST Fri Aug 21 2020

.SYNOPSIS...A better chance of thunderstorms through the weekend,
with temperatures closer to average for late August. High pressure
building back through Arizona will tend to limit thunderstorm
coverage and push temperatures back up next week.

&&

.DISCUSSION...The much cooler temperatures across much of southeast
Arizona compared to 24 hours ago are quite noticeable as
temperatures are struggling rising through the 90's in Tucson,
albeit with higher dewpoints which makes it a bit more
uncomfortable. With temperatures struggling, there is increasing
likelihood that it will be the first day all month with a high
temperature below 100 degrees in Tucson. If not today, there will be
another opportunity on Saturday.

Latest visible satellite shows mostly clear to partly cloudy skies
across the region. There is still some residual cloudiness to the
west of Tucson on the backside of the MCV which has now pushed west
into Yuma County. The atmosphere remains quite worked over after the
convection last night with considerable CIN which will limit surface
based convection. A few showers and thunderstorms have developed
across the White Mountains with generally dry conditions elsewhere
with the exception for perhaps a few sprinkles from the mid level
cloud cover west of Tucson. Latest CAMs are all in pretty good
agreement keeping activity to a minimum today. A few showers and
thunderstorms will try to move off the Mogollon Rim/White Mountains
but tend to struggle as they do so. It's noted that a couple of CAM
solutions are trying to initiate some showers late tonight to the
north to northeast of Tucson with outflow moving in from the Gila
region of New Mexico but confidence on this is low.

Heading into the weekend, the flow regime will remain fairly
favorable with easterly flow as the high pressure aloft is centered
across northern Arizona into the Four Corners region. There still
might be some CIN to contend with especially from Tucson westward
Saturday with better chances for storms on Saturday east of Tucson
across Graham, Greenlee and Cochise County. Sunday is more likely to
be the up day of the weekend with more widespread thunderstorm
potential across the CWA.

East to northeast flow aloft will continue through much of next week
as well above normal temperatures region with high pressure aloft
just to our north and east. Still some uncertainty on just how much
moisture we'll have, with only a low grade monsoon pattern
anticipated much of next week. High temperatures will be borderline
for excessive heat headlines, therefore given the marginal
temperatures we're gonna hold off on any headlines and see how the
forecast evolves.

&&

.AVIATION...Valid through 23/00Z.
FEW-SKC for KTUS this afternoon with FEW-SCT for KOLS between 10-14k
ft MSL. Expect a little more clouds later this evening with isolated
TSRA/SHRA from late this afternoon into the evening. KOLS will see
the best chance for activity. SFC winds generally less than 10kts.
Strong wind gusts over 40kt possible in and around TS. Expect a more
active day tomorrow for all TAF locations with scattered TSRA/SHRA,
some +TSRA will be possible with brief reductions in CIGS/VIS and
MTN obscurations. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Moisture remains in place with isolated to scattered
afternoon and evening showers and thunderstorms through Sunday.
Greatest coverage appears to be Sunday. Min Rh 25-30 percent across
the valleys and 30-45 percent in the mountains through Sunday along
with good/excellent overnight RH recoveries. 20-foot winds generally
remain less than 15 mph outside of any thunderstorm gusts which
could reach 40+ mph. Drier conditions and hotter temperatures next
week slightly reduces shower/thunderstorm coverage and humidity
values by 5 to 10 percent each afternoon.

&&

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

&&

Public...Lader
Aviation...Michael
Fire Weather....Michael

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Special Weather Statement
National Weather Service Tucson AZ
342 PM MST Fri Aug 21 2020

AZZ509-510-212330-
Upper Gila River and Aravaipa Valleys including Clifton/Safford-White
Mountains of Graham and Greenlee Counties including Hannagan Meadow-
342 PM MST Fri Aug 21 2020

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL GRAHAM AND CENTRAL
GREENLEE COUNTIES UNTIL 430 PM MST...

At 341 PM MST, Doppler radar was tracking a strong thunderstorm over
Morenci, or over Clifton, moving south at 20 mph.

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

Locations impacted include...
Clifton, Morenci, Three Way and Guthrie.

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 3314 10940 3314 10918 3294 10916 3294 10943
TIME...MOT...LOC 2241Z 359DEG 16KT 3307 10929