Alert archive / Arizona / Flash Flood Warnings in 2019

Flash Flood Warning 27, NWS Tucson, AZ

August 28, 2019Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 28, 2019, 7:15 PM MST for Pima County, Arizona. It was in force for 90 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 28, 2019, 7:15 PM MST (02:15 UTC)
Expired: Aug 28, 2019, 8:45 PM MST
In force: 90 min
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Flood severity: None

County Pima County, AZ

The radar

The Tucson radar (KEMX), 111 km from the middle of the area, began a volume at 02:18 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Tuscon, AZ (KTUS), launched 00:00Z, 2.3 hours before the alert went out and 87 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1255 J/kg
Mixed-layer CIN: -57 J/kg
Mixed-layer LCL: 2593 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 68 m²/s²
0-3 km storm-relative helicity: 49 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

851 
WGUS55 KTWC 290215
FFWTWC
AZC019-290345-
/O.NEW.KTWC.FF.W.0027.190829T0215Z-190829T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
715 PM MST Wed Aug 28 2019

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  Central Pima County in southeastern Arizona...

* Until 845 PM MST.

* At 715 PM MST, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding is expected to
  begin shortly.

* Some locations that will experience flooding include...
  Sells, San Isidro, Fresnal, No:ligk, Comobabi, South Comobabi,
  Cababi and Rincon.

This includes Route 86 between mile markers 101 and 112, and between
mile markers 120 and 130.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3205 11163 3193 11168 3193 11205 3214 11202

$$
Zell

2 follow-up statements

663 
WGUS75 KTWC 290254
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
754 PM MST Wed Aug 28 2019

AZC019-290345-
/O.CON.KTWC.FF.W.0027.000000T0000Z-190829T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima-
754 PM MST Wed Aug 28 2019

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM MST FOR
CENTRAL PIMA COUNTY...

At 751 PM MST, Doppler radar continued to indicate thunderstorms 
producing heavy rain across the warned area. Radar precipitation 
estimates from north of Sells in the warning area are between 2 and 
3 inches of rainfall.

Some locations that will experience flooding include...
Sells, San Isidro, Fresnal, No:ligk, Comobabi, South Comobabi, Cababi
and Rincon.

This includes Route 86 between mile markers 101 and 112, and between
mile markers 120 and 130.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 3205 11163 3193 11168 3193 11205 3214 11202

$$
Zell

036 
WGUS75 KTWC 290346
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
846 PM MST Wed Aug 28 2019

AZC019-290356-
/O.EXP.KTWC.FF.W.0027.000000T0000Z-190829T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima-
846 PM MST Wed Aug 28 2019

...THE FLASH FLOOD WARNING FOR CENTRAL PIMA COUNTY HAS EXPIRED...

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

LAT...LON 3205 11163 3193 11168 3193 11205 3214 11202

$$
Zell

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Tucson, AZ wrote its last area forecast discussion before this flash flood warning went out at Aug 28, 2:40 PM MST, 4 hours 35 minutes earlier.

Area forecast discussion, Aug 28, 2:40 PM MST, 4 hours 35 minutes before

Area Forecast Discussion
National Weather Service Tucson AZ
240 PM MST Wed Aug 28 2019

.SYNOPSIS...Adequate moisture combined with a favorable flow will
potentially produce an active period of showers and thunderstorms,
especially especially this evening. Brief strong gusty winds and
locally rainfall may occur. Otherwise, scattered mainly afternoon
and evening thunderstorms can be expected Thursday into early next
week.

&&

.DISCUSSION...Isolated to scattered showers were developing this
afternoon in the mountains of southeast Arizona and along the
Mogollon Rim into the White Mountains. The upper high was situated
over southwest Arizona with a north to northeast steering flow over
the area today. An MCV spinning over Sonora, Mexico was showing up
nicely in visible satellite imagery early this afternoon. This
feature might aid in the development of thunderstorms near the
International Border this afternoon and evening. Otherwise, storms
forming in the mountains should eventually track west and southwest
into the lower deserts this evening. Areas of blowing dust will be
possible across Pinal county as outflow from thunderstorms become
organized and travel north toward Phoenix down the Santa Cruz River
Valley. Models continued to suggest a more active weather pattern
for daily thunderstorms compared to the past several days. Models
were in agreement with the upper high over southwest Arizona
transitioning to a position over the Four Corners region this coming
weekend. This position of the upper high will also favor daily
thunderstorm activity over the weekend into early next week. Given
the increasing rain chances, daytime temperatures will also begin to
moderate some through the weekend.

&&

.AVIATION...Valid through 30/00Z.
Scattered -TSRA/-SHRA across much of southeast Arizona this evening.
Brief wind gusts approaching 50 kts and MVFR vsbys/cigs with the
strongest TSRA. Isolated to scattered -TSRA/-SHRA continuing late
tonight and Thursday.

Otherwise, cloud decks mainly 10k-15k ft MSL through Thursday. Aside
from thunderstorm gusts, surface wind variable in direction and
mainly under 12 kts. The exception is vicinity KSAD with nwly
surface wind 12-20 kts and gusts near 25 kts late this afternoon.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Scattered to perhaps numerous thunderstorms this
evening and tonight. Thereafter, a favorable flow regime combined
with adequate moisture will provide the daily cycle of mainly
afternoon and evening thunderstorms Thursday into next Tuesday.
Expect gusty and erratic winds with the stronger thunderstorms.
Otherwise, 20-foot winds will be terrain driven mainly under 15 mph.

&&

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

&&

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

In the hours before

Special weather statement, Aug 28, 3:58 PM MST, 3 hours 17 minutes before

Special Weather Statement
National Weather Service Tucson AZ
358 PM MST Wed Aug 28 2019

AZZ504-507-514-282345-
Santa Catalina and Rincon Mountains including Mount
Lemmon/Summerhaven-Upper San Pedro River Valley including Sierra
Vista/Benson-Tucson Metro Area including Tucson/Green
Valley/Marana/Vail-
358 PM MST Wed Aug 28 2019

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL PIMA COUNTY UNTIL
445 PM MST...

At 358 PM MST, Doppler radar was tracking a strong thunderstorm near
Saguaro National Park East, or 12 miles east of Davis-Monthan Air
Force Base, moving southwest at 5 mph.

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

Locations impacted include...
Tucson, Tanque Verde, Vail, Saguaro National Park East and Rita
Ranch.

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.

&&

LAT...LON 3227 11077 3227 11054 3193 11046 3204 11083
TIME...MOT...LOC 2258Z 036DEG 5KT 3215 11067

Zell

Special weather statement, Aug 28, 4:40 PM MST, 2 hours 35 minutes before

Special Weather Statement
National Weather Service Tucson AZ
440 PM MST Wed Aug 28 2019

AZZ502-504-290015-
Tohono O'odham Nation including Sells-Tucson Metro Area including
Tucson/Green Valley/Marana/Vail-
440 PM MST Wed Aug 28 2019

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN PIMA COUNTY UNTIL
515 PM MST...

At 439 PM MST, Doppler radar was tracking a strong thunderstorm near
Tucson Estates, or 11 miles south of Marana, moving southwest at 5
mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Tucson, Drexel Heights, Saguaro National Park West, Valencia West,
Tucson Estates, Picture Rocks and Ryan AirField.

LAT...LON 3235 11114 3220 11102 3208 11120 3229 11134
TIME...MOT...LOC 2339Z 057DEG 5KT 3224 11116

RH

Special weather statement, Aug 28, 4:43 PM MST, 2 hours 32 minutes before

Special Weather Statement
National Weather Service Tucson AZ
443 PM MST Wed Aug 28 2019

AZZ509>511-290030-
Upper Gila River and Aravaipa Valleys including Clifton/Safford-White
Mountains of Graham and Greenlee Counties including Hannagan
Meadow-Galiuro and Pinaleno Mountains including Mount Graham-
443 PM MST Wed Aug 28 2019

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

At 443 PM MST, Doppler radar was tracking a strong thunderstorm 26
miles east of San Carlos, or 37 miles northwest of Safford, moving
south at 10 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Bylas, Fort Thomas, Calva and San Carlos Reservoir.

LAT...LON 3337 10988 3296 10990 3315 11043 3319 11043
      3320 11040 3322 11042 3340 11040 3340 11037
      3341 11035
TIME...MOT...LOC 2343Z 020DEG 7KT 3331 11002

AH

Special weather statement, Aug 28, 5:52 PM MST, 1 hour 23 minutes before

Special Weather Statement
National Weather Service Tucson AZ
552 PM MST Wed Aug 28 2019

AZZ503-504-513-290145-
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-
552 PM MST Wed Aug 28 2019

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN PIMA AND
NORTHWESTERN SANTA CRUZ COUNTIES UNTIL 645 PM MST...

At 552 PM MST, Doppler radar was tracking a strong thunderstorm over
Tubac, moving west at 15 mph.

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

Locations impacted include...
Tubac, Tumacacori, Amado and Arivaca Junction.

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.

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 3174 11091 3156 11089 3148 11121 3175 11126
TIME...MOT...LOC 0052Z 085DEG 11KT 3165 11103

Carpenter

Special weather statement, Aug 28, 6:37 PM MST, 38 minutes before

Special Weather Statement
National Weather Service Tucson AZ
637 PM MST Wed Aug 28 2019

AZZ502-504-505-290215-
Tohono O'odham Nation including Sells-Tucson Metro Area including
Tucson/Green Valley/Marana/Vail-South Central Pinal County including
Eloy/Picacho Peak State Park-
637 PM MST Wed Aug 28 2019

...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL PIMA AND
SOUTHWESTERN PINAL COUNTIES UNTIL 715 PM MST...

At 636 PM MST, Doppler radar was tracking strong thunderstorms 15
miles west of Chui-Chu, moving southeast at 15 mph.

Winds in excess of 40 mph and blowing dust will be possible with
these storms.

Locations impacted include...
Cockleburr, North Komelik, Kohatk and Jack Rabbit.

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 3251 11222 3255 11220 3268 11220 3268 11216
      3272 11215 3273 11213 3272 11205 3277 11204
      3277 11198 3252 11172 3237 11222
TIME...MOT...LOC 0136Z 332DEG 14KT 3269 11206

Carpenter

Special weather statement, Aug 28, 7:01 PM MST, 14 minutes before

Special Weather Statement
National Weather Service Tucson AZ
701 PM MST Wed Aug 28 2019

AZZ502-290245-
Tohono O'odham Nation including Sells-
701 PM MST Wed Aug 28 2019

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL PIMA COUNTY UNTIL 745 PM
MST...

At 700 PM MST, Doppler radar was tracking a strong thunderstorm near
Sells, moving west at 10 mph.

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

Locations impacted include...
Sells, San Isidro, Ali Chukson, Gu Oidak, Fresnal, Comobabi, South
Comobabi, Cababi, Artesia, Rincon and Ali Molina.

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.

&&

LAT...LON 3216 11205 3205 11165 3186 11182 3191 11211
TIME...MOT...LOC 0200Z 083DEG 9KT 3201 11190

Zell

The office that day

Everything else NWS Tucson, AZ issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 28, 5:05 PM MST	Flash Flood Warning	TWC	Pima	115 min
Aug 28, 5:09 PM MST	Severe Thunderstorm Warning	TWC	Graham, Pinal	51 min
Aug 28, 5:13 PM MST	Areal Flood Advisory	TWC	Pima	2 hr
Aug 28, 5:40 PM MST	Dust Storm Advisory	TWC	Pima, Pinal	95 min
Aug 28, 5:41 PM MST	Areal Flood Advisory	TWC	Cochise	2 hr
Aug 28, 5:44 PM MST	Severe Thunderstorm Warning	TWC	Pima	46 min
Aug 28, 5:52 PM MST	Special Weather Statement	TWC	Santa Cruz	53 min
Aug 28, 6:37 PM MST	Special Weather Statement	TWC	Pima	38 min
Aug 28, 6:51 PM MST	Dust Storm Advisory	TWC	Pima, Pinal	54 min
Aug 28, 7:01 PM MST	Special Weather Statement	TWC	Pima	44 min
Aug 28, 7:36 PM MST	Special Weather Statement	TWC	Pima	39 min
Aug 28, 7:52 PM MST	Areal Flood Advisory	TWC	Pima, Pinal	113 min
Aug 28, 10:13 PM MST	Areal Flood Advisory	TWC	Pima, Pinal	92 min

Nearby

Flash Flood Warnings in Arizona, 2019 Every flash flood warning in 2019

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.