Alert archive / Arizona / Flash Flood Warnings in 2018

Flash Flood Warning 101, NWS Phoenix, AZ

October 7, 2018Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Oct 7, 2018, 3:49 AM MST for Maricopa County, Arizona. It was in force for 3 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Oct 7, 2018, 3:49 AM MST (10:49 UTC)
Expired
Oct 7, 2018, 6:45 AM MST
In force
3 hr
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Flood severity
None

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 49 km from the middle of the area, began a volume at 10:51 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.

What was reported inside it

TimeReportWhereRemark
Oct 7, 6:10 AM MSTFLASH FLOOD6 N Deer Valley, AZ**DELAYED REPORT** NORTHERN VALLEY PARKWAY LOW WATER CROSSING CLOSED DUE TO FLASH FLOODING. DATA FROM MARICOPA COUNTY FLOOD CONTROL STREAM GAGE LOCATED ALONG SONORAN WASH LOCATED UPSTREAM OF THE IMPACTED ROADWAY. TIMING BASED ON STREAM GAGE RECORD.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 10.8 hours before the alert went out and 28 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-pSkew-T log-p diagram, Phoenix, AZ at 00:00Z on 2018-10-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 00:00Z on 2018-10-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
2153 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
141 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

268 
WGUS55 KPSR 071049
FFWPSR
AZC013-071345-
/O.NEW.KPSR.FF.W.0101.181007T1049Z-181007T1345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
349 AM MST SUN OCT 7 2018

The National Weather Service in Phoenix has issued a

* Flash Flood Warning for...
  Maricopa County in south central Arizona...

* Until 645 AM MST.

* At 349 AM MST, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to one inch of rain has
  already fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Phoenix, Glendale, Scottsdale, Tempe, Paradise Valley, New River,
  Cave Creek, Carefree, Papago Park, Piestewa Peak Park, Deer Valley
  Airport, North Mountain Park, Downtown Scottsdale, Metro Center and
  Desert Mountain.

* This includes the following highways...
  AZ Interstate 17 between mile markers 203 and 222.
  AZ Route 51 between mile markers 1 and 15.
  US Highway 60 between mile markers 155 and 157.

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 3390 11176 3364 11183 3344 11191 3344 11195
      3352 11219 3391 11210

$$

CK
1 follow-up statement
585 
WGUS75 KPSR 071146
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
446 AM MST SUN OCT 7 2018

AZC013-071345-
/O.CON.KPSR.FF.W.0101.000000T0000Z-181007T1345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
446 AM MST SUN OCT 7 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 AM MST FOR
MARICOPA COUNTY...

At 445 AM MST, Doppler radar and automated rain gauges indicated 
thunderstorms produced heavy rain over the warned area with moderate 
rain still ongoing. Over one inch of rain has already fallen. Flash 
flooding is expected to begin shortly.

Some locations that will experience flooding include...
Phoenix, Glendale, Scottsdale, Tempe, Paradise Valley, New River,
Cave Creek, Carefree, Papago Park, Piestewa Peak Park, Deer Valley
Airport, North Mountain Park, Downtown Scottsdale, Metro Center and
Desert Mountain.

This includes the following highways...
AZ Interstate 17 between mile markers 203 and 222.
AZ Route 51 between mile markers 1 and 15.
US Highway 60 between mile markers 155 and 157.

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.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

&&

LAT...LON 3390 11176 3364 11183 3344 11191 3344 11195
      3352 11219 3391 11210

$$

CK

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 6, 10:34 PM MSTSpecial Weather StatementPSR26 min
Oct 6, 10:38 PM MSTAreal Flood AdvisoryPSRLa Paz3 hr
Oct 6, 10:52 PM MSTSpecial Weather StatementPSR38 min
Oct 6, 11:50 PM MSTSpecial Weather StatementPSR25 min
Oct 7, 12:08 AM MSTSpecial Weather StatementPSR22 min
Oct 7, 12:31 AM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Oct 7, 12:36 AM MSTAreal Flood AdvisoryPSRLa Paz3 hr
Oct 7, 1:13 AM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Oct 7, 1:29 AM MSTSpecial Weather StatementPSRMaricopa31 min
Oct 7, 1:49 AM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Oct 7, 2:08 AM MSTSpecial Weather StatementPSRMaricopa37 min
Oct 7, 2:11 AM MSTSpecial Weather StatementPSRMaricopa34 min
Oct 7, 2:29 AM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Oct 7, 2:37 AM MSTSpecial Weather StatementPSR38 min
Oct 7, 2:42 AM MSTSpecial Weather StatementPSRMaricopa33 min
Oct 7, 2:47 AM MSTFlash Flood WarningPSRMaricopa3 hr
Oct 7, 2:50 AM MSTAreal Flood AdvisoryPSRMaricopa, Pinal3 hr
Oct 7, 3:09 AM MSTSpecial Weather StatementPSR36 min
Oct 7, 3:22 AM MSTSpecial Weather StatementPSRMaricopa23 min
Oct 7, 3:24 AM MSTSpecial Weather StatementPSRMaricopa36 min
Oct 7, 3:43 AM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Oct 7, 4:13 AM MSTFlash Flood WarningPSRMaricopa3 hr
Oct 7, 4:26 AM MSTFlash Flood WarningPSRMaricopa4 hr
Oct 7, 5:56 AM MSTAreal Flood AdvisoryPSRGila, Maricopa, Pinal3 hr
Oct 7, 6:40 AM MSTFlash Flood WarningPSRMaricopa3 hr
Oct 7, 6:47 AM MSTAreal Flood WarningPSRMaricopa6 hr
Oct 7, 7:04 AM MSTAreal Flood WarningPSRMaricopa3 hr
Oct 7, 7:11 AM MSTAreal Flood AdvisoryPSRMaricopa, Pinal2 hr
Oct 7, 7:28 AM MSTAreal Flood AdvisoryPSRMaricopa, Pinal2 hr
Oct 7, 7:59 AM MSTAreal Flood WarningPSRMaricopa, Pinal3 hr
Oct 7, 9:21 AM MSTAreal Flood AdvisoryPSRGila3 hr
Oct 7, 9:43 AM MSTSpecial Weather StatementPSRPinal32 min
Oct 7, 10:53 AM MSTAreal Flood WarningPSRMaricopa3 hr
Oct 7, 1:10 PM MSTSpecial Weather StatementPSR35 min
Oct 7, 2:03 PM MSTSpecial Weather StatementPSR42 min
Oct 7, 2:39 PM MSTSpecial Weather StatementPSR51 min
Oct 7, 2:47 PM MSTSpecial Weather StatementPSR43 min
Oct 7, 2:57 PM MSTSpecial Weather StatementPSRMaricopa48 min
Oct 7, 3:34 PM MSTSpecial Weather StatementPSR41 min
Oct 7, 4:00 PM MSTSpecial Weather StatementPSRMaricopa45 min
Oct 7, 4:32 PM MSTSpecial Weather StatementPSRMaricopa43 min
Oct 7, 4:33 PM MSTSpecial Weather StatementPSR42 min
Oct 7, 4:43 PM MSTAreal Flood AdvisoryPSRMaricopa2 hr
Oct 7, 4:55 PM MSTSpecial Weather StatementPSRMaricopa50 min

Nearby

Flash Flood Warnings in Arizona, 2018Every flash flood warning in 2018

Sources

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