Flash Flood Warning 43, NWS Tucson, AZ

473 
WGUS75 KTWC 272129
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
229 PM MST Sat Jul 27 2024

AZC003-023-272245-
/O.CON.KTWC.FF.W.0043.000000T0000Z-240727T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cochise AZ-Santa Cruz AZ-
229 PM MST Sat Jul 27 2024

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 345 PM MST THIS 
AFTERNOON FOR SOUTHWESTERN COCHISE AND SOUTHEASTERN SANTA CRUZ 
COUNTIES...

At 229 PM MST, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 1 
and 2 inches of rain have fallen. Flash flooding is ongoing or 
expected to begin shortly.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar and automated gauges.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Parker Canyon Lake.

This includes Route 83 between mile markers 3 and 8.

This includes the following streams and drainages...
  Santa Cruz River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Remain alert for flooding even in locations not receiving rain. 
Washes, streams, and rivers can become raging killer currents in a 
matter of minutes, even from distant rainfall.

Flooding is occurring or is imminent. It is important to know where 
you are relative to streams, rivers, or creeks which can become 
killers in heavy rains. Campers and hikers should avoid streams or 
creeks.

&&

LAT...LON 3135 11059 3143 11063 3147 11054 3148 11048
      3148 11041 3145 11038 3141 11042 3139 11044
      3134 11053

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

KJS

852 
WGUS75 KTWC 272236
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
336 PM MST Sat Jul 27 2024

AZC003-023-272246-
/O.EXP.KTWC.FF.W.0043.000000T0000Z-240727T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cochise AZ-Santa Cruz AZ-
336 PM MST Sat Jul 27 2024

...FLASH FLOOD WARNING WILL EXPIRE AT 345 PM MST THIS AFTERNOON FOR 
SOUTHWESTERN COCHISE AND SOUTHEASTERN SANTA CRUZ COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

&&

LAT...LON 3135 11059 3143 11063 3147 11054 3148 11048
      3148 11041 3145 11038 3141 11042 3139 11044
      3134 11053

$$

KJS

Area Forecast Discussion
National Weather Service Tucson AZ
947 AM MST Sat Jul 27 2024

.SYNOPSIS...Daily chances for showers and thunderstorms this
weekend and into next week with the main threats being strong
gusty winds and heavy rainfall leading to localized flash
flooding.

&&

.UPDATE...Latest visible satellite imagery shows diminishing
cloud cover across much of southeast AZ with some lingering
cloud cover particularly focused across west of Tucson associated
with early morning showers that have dried up. The 12Z KTWC
sounding shows an increase in precipitable water from yesterday
with 1.84 inches of precipitable water, which is up from 1.37
inches at this same time yesterday. Latest GOES precipitable water
imagery shows 1.2 to 1.6 inches across southeast AZ with values
around an inch across the White Mountains in northern Greenlee
county.

According to the SPC Sounding Climatology page, 1.67 inches is the
climatological 90th percentile for 12Z soundings on this date, which
was exceeded by nearly a quarter inch in this morning's sounding.
Thus, adequate moisture for heavy rainfall is present throughout the
atmospheric column today. The warm cloud layer depth calculated from
this morning's sounding was around 7800 ft, which is a decent layer
for warm cloud processes to dominate any convection helping the
heavy rainfall potential. Additionally, the mean flow is incredibly
weak overhead, enhancing the potential for any storm to dump a
substantial amount of rain over a given point.

Wind risk seems to be on the lower end today with DCAPE only sitting
at about 725 J/kg overhead. That being said, a strong to severe wind
gust or two should not be ruled out with any of the stronger storms.
CAMs are tending to focus on areas south and east of Tucson this
afternoon. While this is where there was slightly less precipitable
water this morning, HREF is showing locally a slight chance (around
20 percent) of seeing up to 2 inches in a 6-hour period this
afternoon and evening in portions of Cochise and Santa Cruz counties.

Overall, looking at more of a flash flood threat today focusing on
areas to the south and east of Tucson.

&&

.DISCUSSION...Relatively tame Friday evening perked up before
midnight with scattered showers and thunderstorms occurring this
morning across Pinal, Pima and Santa Cruz county. Gusty winds and
brief heavy rain associated with the strongest storms. These storms
likely continuing past sunrise. Later today expect scattered
afternoon and evening showers and thunderstorms. With the upper high
nearly overhead, storms will be slow movers, thus increasing the
chances for flash flooding. Upper high moves into New Mexico late
tonight into Sunday, turning the mid-level flow out of the south-
southeast that will continue into much of next week. Daily chances
for afternoon and evening showers and thunderstorms. Temperatures
will be about 2 to 6 degrees above normal through the forecast
period.

&&

.AVIATION...Valid through 28/12Z.
SCT-BKN clouds AOA 7-11k ft AGL with scattered SHRA/TSRA mainly
west and south of KTUS through 27/16Z, then across most of
southeast Arizona after 27/20z. Strong winds to 45 kts possible
near the strongest TSRA with MVFR conditions. Outside of TSRA,
surface winds will generally be easterly/southeasterly and remain
under 10 kts. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Scattered afternoon and evening showers and
thunderstorms with day to day variability on which areas will see
the best chance of rainfall. The best chances will typically be
from Tucson south and eastward through much of the forecast
period. Each day has the threat of heavy rain, localized flash
flooding and strong gusty winds. Minimum relative humidities will
be 20 to 30 percent in most lower elevation locations and 25 to 40
percent in mountain areas. Away from thunderstorms, 20-foot winds
will generally be 15 mph or less, with afternoon/early evening
gusts to 20-25 mph and light winds overnight.

&&

&&

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

&&

DVS

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