Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 133, NWS Flagstaff, AZ

July 30, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 30, 2021, 1:47 PM MST for Yavapai County, Arizona. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 30, 2021, 1:47 PM MST (20:47 UTC)
Expired: Jul 30, 2021, 4:45 PM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 156 km from the middle of the area, began a volume at 20:48 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.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 8.8 hours before the alert went out and 130 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1217 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 21 m²/s²
0-3 km storm-relative helicity: 39 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

983 
WGUS55 KFGZ 302047
FFWFGZ
AZC025-302345-
/O.NEW.KFGZ.FF.W.0133.210730T2047Z-210730T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
147 PM MST Fri Jul 30 2021

The National Weather Service in Flagstaff has issued a

* Flash Flood Warning for...
  Yavapai County in west central Arizona...

* Until 445 PM MST.

* At 147 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 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.

  IMPACT...Life-threatening flash flooding of low-water
           crossings, creeks, normally dry washes and roads.

* Some locations that will experience flash flooding include...
  Yava.

This includes the following highways...
	State Route 96 between mile markers 17 and 21.

This includes the following streams and drainages...
Sycamore Creek, Tank Wash, Ally Wash, Alkali Wash, Waterman Creek, 
Bland Creek, Kirkland Creek and Eastwood Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly or mountainous terrain, there are many low water crossings 
which will become dangerous in heavy rain. Do not attempt to cross 
flooded roads. Find an alternate route.

&&

LAT...LON 3455 11292 3454 11286 3452 11285 3447 11282
      3445 11277 3439 11276 3439 11283 3441 11296
      3446 11300 3451 11300 3454 11300 3454 11299

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

$$

ET

2 follow-up statements

723 
WGUS75 KFGZ 302122
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
222 PM MST Fri Jul 30 2021

AZC025-302345-
/O.CON.KFGZ.FF.W.0133.000000T0000Z-210730T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
222 PM MST Fri Jul 30 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 PM MST THIS 
AFTERNOON FOR YAVAPAI COUNTY...

At 221 PM MST, heavy rain has ended across the warned area. Between 
1 and 3.50 inches of rain have fallen. Flash flooding will continue 
to be possible near the warned area.

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

SOURCE...Radar.

IMPACT...Life-threatening flash flooding of low-water crossings,
         creeks, normally dry washes and roads.

Some locations that will experience flash flooding include...
  Yava.

This includes the following highways...
	State Route 96 between mile markers 17 and 21.

This includes the following streams and drainages...
  Santa Maria River, Sycamore Creek, Tank Wash, Alkali Wash, 
  Waterman Creek, Bland Creek, Kirkland Creek and Eastwood Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly or mountainous terrain, there are many low water crossings 
which will become dangerous in heavy rain. Do not attempt to cross 
flooded roads. Find an alternate route.

&&

LAT...LON 3455 11292 3454 11286 3452 11285 3447 11282
      3445 11277 3439 11276 3439 11283 3441 11296
      3446 11300 3451 11300 3454 11300 3454 11299

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

$$

ET

176 
WGUS75 KFGZ 302344
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
444 PM MST Fri Jul 30 2021

AZC025-302354-
/O.EXP.KFGZ.FF.W.0133.000000T0000Z-210730T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
444 PM MST Fri Jul 30 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 445 PM MST THIS AFTERNOON FOR 
YAVAPAI COUNTY...

At 440 PM MST, National Weather Service Flagstaff Doppler radar 
indicated that rainfall was no longer occurring near Yava and 
Hillside. As much as 3.5 inches of rain fell in the area earlier 
today and area washes, streams and creeks are likely still running 
high.
 
The Flood Advisory will expire at 445 PM MST. Please continue to 
heed remaining road closures.

A Flash Flood Watch remains in effect until 1100 PM MST Friday for 
portions of north central Arizona and west central Arizona.

LAT...LON 3455 11292 3454 11286 3452 11285 3447 11282
      3445 11277 3439 11276 3439 11283 3441 11296
      3446 11300 3451 11300 3454 11300 3454 11299

$$

Peterson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 29, 5:05 PM MST	Special Weather Statement	FGZ	Coconino	40 min
Jul 29, 5:35 PM MST	Special Weather Statement	FGZ		25 min
Jul 29, 5:38 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	112 min
Jul 29, 6:45 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 29, 6:56 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 29, 8:12 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	5 hr
Jul 30, 5:58 AM MST	Areal Flood Warning	FGZ	Coconino	5 hr
Jul 30, 11:34 AM MST	Areal Flood Advisory	FGZ	Navajo	2 hr
Jul 30, 12:44 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	2 hr
Jul 30, 1:15 PM MST	Areal Flood Advisory	FGZ	Coconino	3 hr
Jul 30, 2:01 PM MST	Special Weather Statement	FGZ		29 min
Jul 30, 2:18 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	27 min
Jul 30, 4:09 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Gila	2 hr

Nearby

Flash Flood Warnings in Arizona, 2021 Every flash flood warning in 2021

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.