Flash Flood Warning 94, NWS Tucson, AZ

348 
WGUS75 KTWC 222314
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
414 PM MST Thu Aug 22 2024

AZC019-222324-
/O.EXP.KTWC.FF.W.0094.000000T0000Z-240822T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
414 PM MST Thu Aug 22 2024

...FLASH FLOOD WARNING WILL EXPIRE AT 415 PM MST THIS AFTERNOON FOR 
EAST CENTRAL PIMA COUNTY...

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

&&

LAT...LON 3205 11069 3199 11071 3190 11070 3190 11081
      3196 11087 3202 11083 3206 11078

$$

GLZ

Area Forecast Discussion
National Weather Service Tucson AZ
921 AM MST Thu Aug 22 2024

.SYNOPSIS...Scattered thunderstorms this afternoon and evening,
mainly east of Sells. Heavy rain, strong wind gusts, and small hail
will be possible with any thunderstorm. Thunderstorm chances become
more isolated and shift east of Tucson Friday through the weekend.
High temperatures near to slightly above normal through the forecast
period.

&&

.UPDATE...
Moving in from the south, an MCV makes its way through Cochise
county heading to the northeast. Unlike yesterday, this MCV is
not bringing with it storms and showers, just a blanket of
clouds. West of Cochise county, skies are mostly clear other than
some high clouds that are generally dissipating. Moisture
continues to stick around today with PWATs around 1.5-1.6 inches
west of Tucson and 1-1.5 inches east of Tucson. There will be a
fair bit of instability today with CAPE values around 2000 J/kg
and DCAPE around 900-1200 J/kg. There will not be as much shear
today as observed yesterday but still 15-25 knots from surface to
6 kilometers. Convection will be focused from Kitt Peak eastward
and will begin developing around 1-2 PM MST starting out scattered
becoming more widespread as the afternoon progresses. Storms will
taper off around 6-7 PM MST. Storms and showers will generally be
moving to the north northeast at 5-15 MPH. The main concerns
associated with storm and showers today will be strong to severe
winds and locally heavy rainfall that may lead to flash flooding.
Hail and blowing dust are secondary concerns. Temperatures will be
warmer today than yesterday with highs around 95-103 degrees.

&&

.PREV DISCUSSION... /issued 326 AM MST Thu Aug 22 2024/

.DISCUSSION...The upper air pattern this morning was characterized
by the subtropical high centered over far southeast New Mexico and
noticeable troughiness over the Pacific Northwest. To the south, a
mesoscale convective complex was rapidly decaying as it drifted to
the north and west over Sonora Mexico.

After yesterday's thunderstorm activity across southeast Arizona,
the thunderstorm potential this afternoon becomes dependent upon
multiple considerations including moisture, sunshine, and mesoscale
features.

Plenty of moisture resides over central and eastern portions of the
forecast area with latest GOES precipitable water readings of 1.25
inches in southern Cochise County to around 1.5 inches across
western Pima County. However, areas west of Tucson will begin drying
out as the mean flow becomes southwesterly through the day. Unlike
yesterday, morning convection and associated cloud cover will not be
quite as favorable resulting in stronger daytime heating by mid to
late morning. 0-6 km shear of 15-20 kts and sufficient CAPE will be
supportive of scattered afternoon thunderstorms, a few of which
could be strong to severe. Areas that were not worked over yesterday
appear to be favored today with the CAMs highlighting areas to the
east of Sells. The 22/00Z HREF depicted a 10 percent chance of winds
exceeding 50 kts (58 mph) within 25 miles of a point specifically
over Pinal County this afternoon and again on Friday afternoon for
areas east of Tucson.

Friday and Saturday the best chances for afternoon thunderstorms
will be shunted further south and east of Tucson and will also be
dependent upon convective activity this afternoon. Dry southwesterly
flow will continue to dominate the Desert Southwest as a strong
trough hangs around the upper Great Basin and Pacific Northwest.
Friday may be an interesting transition day with the drier air
surging a bit further east and increased dynamic support. Looking
ahead into next week, ensembles show ridging building back in place
over the Desert Southwest allowing additional moisture to return to
the area along with daily chances for afternoon thunderstorms.
However, there are differences in the timing and placement of the
upper high which may impact how quickly storm chances return.

Overall, looking like another average Monsoon day generally to the
east of Sells. A few storms may be strong to severe with gusty
winds, heavy rain, and small hail being the primary concerns.

&&

.AVIATION...Valid through 23/12Z.
Scattered showers and thunderstorms this afternoon and evening at
all terminals. Visibility reductions, wind gusts up to 50 kts, heavy
rain, and mountain obscurations possible with any thunderstorm.
Outside of thunderstorm wind gusts, winds 12 kts or less with a
southwest to northwesterly direction. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...Mainly afternoon and evening showers and
thunderstorms can be expected across southeast Arizona today, with a
drying trend Friday through the weekend resulting in a reduction in
thunderstorm activity. High temperatures will be near to slightly
above normal through the forecast period. Min RH values will be in
the 25-35 percent range in most valleys locations today, lowering to
around 18-28 percent Friday through the weekend as drier air
overspreads the area. Outside of any thunderstorm outflow winds, 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.
&&

Update...Malarkey
Previous...DVS

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