Alert archive / California / Flash Flood Warnings in 2021

Flash Flood Warning 3, NWS Medford, OR

October 22, 2021Siskiyou County, California

NWS Medford, OR issued this flash flood warning at Oct 22, 2021, 4:25 AM PDT for Siskiyou County, California. It was in force for 2 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
Oct 22, 2021, 4:25 AM PDT (11:25 UTC)
Expired
Oct 22, 2021, 6:50 AM PDT
In force
2 hr
Issued by
NWS Medford, OR
Area
Storm-based polygon
Flood severity
Moderate

County Siskiyou County, CA

The radar

The Medford radar (KMAX), 71 km from the middle of the area, began a volume at 11:25 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

Medford/Jackson, OR (KMFR), launched 00:00Z, 11.4 hours before the alert went out and 103 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, Medford/Jackson, OR at 00:00Z on 2021-10-22Temperature 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, Medford/Jackson, OR at 00:00Z on 2021-10-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 square meters per square second.1939587897Sfc1 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
1770 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
201 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

439 
WGUS56 KMFR 221125
FFWMFR
CAC093-221415-
/O.NEW.KMFR.FF.W.0003.211022T1125Z-211022T1415Z/
/00000.2.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Medford OR
425 AM PDT Fri Oct 22 2021

The National Weather Service in Medford has issued a

* Flash Flood Warning for...
  Rain and Snowmelt in...
  Southeastern Siskiyou County in northern California...

* Until 715 AM PDT.

* At 425 AM PDT, local law enforcement reported debris flow and 
  flooding on roadway from excessive runoff.

  HAZARD...Flash flooding from rain and snowmelt.

  SOURCE...Law enforcement reported.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Highway 97 near Whitney Creek. 

This includes the following streams and drainages...
Flooding is occurring along the Whitney Creek beginning at Highway 
97.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Be aware of your surroundings and do not drive on flooded roads.

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

&&

LAT...LON 4154 12226 4152 12225 4151 12228 4152 12231
      4154 12230

FLASH FLOOD...OBSERVED

$$

Petrucelli
1 follow-up statement
203 
WGUS76 KMFR 221350
FFSMFR

Flash Flood Statement
National Weather Service Medford OR
650 AM PDT Fri Oct 22 2021

CAC093-221400-
/O.CAN.KMFR.FF.W.0003.000000T0000Z-211022T1415Z/
/00000.2.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Siskiyou CA-
650 AM PDT Fri Oct 22 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHEASTERN SISKIYOU 
COUNTY...

Flood waters have receded.

LAT...LON 4154 12226 4152 12225 4151 12228 4152 12231
      4154 12230

$$

Petrucelli

The office that day

Everything else NWS Medford, OR issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 22, 12:05 PM PDTFlash Flood WatchMFRSiskiyou59 hr
Oct 22, 2:59 PM PDTHigh Wind WarningMFRModoc, Siskiyou56 hr
Oct 22, 2:59 PM PDTWind AdvisoryMFRModoc56 hr

Nearby

Flash Flood Warnings in California, 2021Every 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.