Alert archive / Arizona / Flash Flood Watches in 2017

Flash Flood Watch 4, NWS Phoenix, AZ

July 18, 20174 counties in Arizona

NWS Phoenix, AZ issued this flash flood watch at Jul 18, 2017, 9:58 AM MST for 4 counties in Arizona. It took effect at Jul 18, 2017, 1:00 PM MST. It was in force for 13 hr.

The area

The counties it named.

The facts

Issued: Jul 18, 2017, 9:58 AM MST (16:58 UTC)
In effect from: Jul 18, 2017, 1:00 PM MST
Expired: Jul 19, 2017, 1:56 AM MST
In force: 13 hr
Issued by: NWS Phoenix, AZ
Flood severity: None

Counties Gila County, AZ, La Paz County, AZ, Maricopa County, AZ, Pinal County, AZ

The radar

The Phoenix radar (KIWA), 48 km from the middle of the area, began a volume at 16:59 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

Phoenix, AZ (KPSR), launched 12:00Z, 5.0 hours before the alert went out and 17 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: 172 J/kg
Mixed-layer CIN: -284 J/kg
Mixed-layer LCL: 1310 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 0 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

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

NWS Phoenix, AZ wrote its last area forecast discussion before this flash flood watch went out at Jul 18, 5:13 AM MST, 4 hours 45 minutes earlier.

Area forecast discussion, Jul 18, 5:13 AM MST, 4 hours 45 minutes before

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In the hours before

Local storm report, Jul 18, 9:22 AM MST, 36 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
922 AM MST TUE JUL 18 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1100 PM     TSTM WND DMG     1 SE GLOBE              33.38N 110.77W
07/17/2017                   GILA               AZ   LAW ENFORCEMENT

            TREES KNOCKED DOWN.

&&

MP

Local storm report, Jul 18, 9:35 AM MST, 23 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
935 AM MST TUE JUL 18 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1100 PM     FLASH FLOOD      4 SSW GLOBE             33.34N 110.80W
07/17/2017                   GILA               AZ   LAW ENFORCEMENT

            HEAVY DEBRIS AND WATER WASHING OVER BRIDGE
            IN UPPER ICE HOUSE CANYON NEAR 9758 ICE
            HOUSE CANYON ROAD. DELAYED REPORT.

&&

MS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 5:52 PM MST	Special Weather Statement	PSR	Gila	38 min
Jul 17, 6:29 PM MST	Special Weather Statement	PSR	La Paz	46 min
Jul 17, 6:30 PM MST	Special Weather Statement	PSR		45 min
Jul 17, 6:58 PM MST	Special Weather Statement	PSR		47 min
Jul 17, 7:26 PM MST	Special Weather Statement	PSR	La Paz	49 min
Jul 17, 7:35 PM MST	Severe Thunderstorm Warning	PSR	La Paz	55 min
Jul 17, 8:18 PM MST	Special Weather Statement	PSR		42 min
Jul 17, 8:20 PM MST	Special Weather Statement	PSR	La Paz	40 min
Jul 17, 9:00 PM MST	Special Weather Statement	PSR	La Paz	45 min
Jul 17, 9:23 PM MST	Special Weather Statement	PSR	Gila	52 min
Jul 17, 9:41 PM MST	Special Weather Statement	PSR	La Paz	49 min
Jul 17, 9:51 PM MST	Special Weather Statement	PSR		39 min
Jul 17, 10:31 PM MST	Special Weather Statement	PSR		44 min
Jul 17, 10:37 PM MST	Severe Thunderstorm Warning	PSR	Gila	23 min
Jul 17, 11:04 PM MST	Flash Flood Warning	PSR	Gila	3 hr
Jul 17, 11:27 PM MST	Special Weather Statement	PSR	Pinal	48 min
Jul 18, 12:11 AM MST	Areal Flood Advisory	PSR	Pinal	3 hr
Jul 18, 12:30 AM MST	Special Weather Statement	PSR	Pinal	45 min
Jul 18, 12:51 AM MST	Special Weather Statement	PSR	Pinal	39 min
Jul 18, 2:24 PM MST	Special Weather Statement	PSR	Gila	51 min
Jul 18, 3:06 PM MST	Severe Thunderstorm Warning	PSR	Gila, Maricopa	24 min
Jul 18, 3:42 PM MST	Areal Flood Advisory	PSR	Gila, Maricopa, Pinal	3 hr
Jul 18, 3:55 PM MST	Special Weather Statement	PSR	Gila	50 min
Jul 18, 4:06 PM MST	Flash Flood Warning	PSR	Gila	3 hr
Jul 18, 4:34 PM MST	Special Weather Statement	PSR	Maricopa	41 min

Nearby

Flash Flood Watches in Arizona, 2017 Every flash flood watch in 2017

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.