Alert archive / Arizona / Flash Flood Warnings in 2018

Flash Flood Warning 45, NWS Tucson, AZ

October 21, 2018Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Oct 21, 2018, 6:30 PM MST for Pima County, Arizona. It was in force for 88 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
Oct 21, 2018, 6:30 PM MST (01:30 UTC)
Expired
Oct 21, 2018, 7:58 PM MST
In force
88 min
Issued by
NWS Tucson, AZ
Area
Storm-based polygon
Flood severity
None

County Pima County, AZ

The radar

The Tucson radar (KEMX), 31 km from the middle of the area, began a volume at 01:32 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

Tuscon, AZ (KDMA), launched 00:00Z, 1.5 hours before the alert went out and 19 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, Tuscon, AZ at 00:00Z on 2018-10-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 63 joules per kilogram.LCLLFCEL10008507005003002001001 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, Tuscon, AZ at 00:00Z on 2018-10-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
63 J/kg
Mixed-layer CIN
-147 J/kg
Mixed-layer LCL
2148 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
50 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

208 
WGUS55 KTWC 220130
FFWTWC
AZC019-220330-
/O.NEW.KTWC.FF.W.0045.181022T0130Z-181022T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
630 PM MST SUN OCT 21 2018

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  East central Pima County in southeastern Arizona...

* Until 830 PM MST.

* At 626 PM MST, Doppler radar indicated that thunderstorms earlier 
  this evening have produced between 2 and 4 inches of rainfall 
  across portions of east central Pima County near Sahuarita, with 
  light to moderate rainfall continuing. This warning extends the 
  Flash Flood Warning for this area. 

* Some locations that will experience flooding include...
  Green Valley, Sahuarita, East Sahuarita, Summit and Corona De
  Tucson.

This includes Interstate 19 between mile markers 37 and 54.
 
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 3208 11083 3205 11077 3196 11078 3178 11106
      3198 11117 3206 11108

$$
Zell
1 follow-up statement
173 
WGUS75 KTWC 220258
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
758 PM MST SUN OCT 21 2018

AZC019-220306-
/O.CAN.KTWC.FF.W.0045.000000T0000Z-181022T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima-
758 PM MST SUN OCT 21 2018

...THE FLASH FLOOD WARNING FOR EAST CENTRAL PIMA COUNTY IS
CANCELLED...

The heavy rainfall has ended. Flash flooding is no longer expected 
to pose a threat. However, ponding of water in low spots and dips 
can be expected, as well as flow in normally dry washes. Please 
continue to heed any remaining road closures.

LAT...LON 3208 11083 3205 11077 3196 11078 3178 11106
      3198 11117 3206 11108

$$
Zell

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 21, 6:10 PM MSTFlash Flood WarningTWCCochise3 hr
Oct 21, 6:14 PM MSTSpecial Weather StatementTWCPinal46 min
Oct 21, 6:18 PM MSTAreal Flood AdvisoryTWCCochise117 min
Oct 22, 3:00 AM MSTSpecial Weather StatementTWCPinal30 min
Oct 22, 3:35 AM MSTSpecial Weather StatementTWCPinal40 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.