Alert archive / Arizona / Flash Flood Watches in 2018

Flash Flood Watch 5, NWS Tucson, AZ

August 24, 20186 counties in Arizona

NWS Tucson, AZ issued this flash flood watch at Aug 24, 2018, 3:37 AM MST for 6 counties in Arizona. It took effect at Aug 24, 2018, 11:00 AM MST. It was in force for 13 hr.

The area

The counties it named.

The facts

Issued
Aug 24, 2018, 3:37 AM MST (10:37 UTC)
In effect from
Aug 24, 2018, 11:00 AM MST
Expired
Aug 25, 2018, 12:00 AM MST
In force
13 hr
Issued by
NWS Tucson, AZ
Flood severity
None

Counties Cochise County, AZ, Graham County, AZ, Greenlee County, AZ, Pima County, AZ, Pinal County, AZ, Santa Cruz County, AZ

The radar

The Tucson radar (KEMX), 61 km from the middle of the area, began a volume at 10:38 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 00:00Z, 10.6 hours before the alert went out and 179 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 2018-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1001 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 00:00Z on 2018-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.1939Sfc1 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
1001 J/kg
Mixed-layer CIN
-36 J/kg
Mixed-layer LCL
1988 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
76 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 Tucson, AZ wrote its last area forecast discussion before this flash flood watch went out at Aug 23, 9:08 PM MST, 6 hours 29 minutes earlier.

Area forecast discussion, Aug 23, 9:08 PM MST, 6 hours 29 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Aug 24, 2:10 PM MSTAreal Flood AdvisoryTWCGraham, Greenlee3 hr
Aug 24, 4:00 PM MSTSpecial Weather StatementTWCCochise45 min
Aug 24, 4:25 PM MSTFlash Flood WarningTWCCochise3 hr
Aug 24, 4:33 PM MSTAreal Flood AdvisoryTWCCochise117 min
Aug 24, 4:42 PM MSTAreal Flood AdvisoryTWCCochise, Graham, Pima, Pinal2 hr
Aug 24, 4:48 PM MSTAreal Flood AdvisoryTWCGraham, Pinal117 min

Nearby

Flash Flood Watches in Arizona, 2018Every flash flood watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.