Alert archive / Arizona / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 21, NWS Flagstaff, AZ

July 31, 2012Navajo County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 31, 2012, 12:38 PM MDT for Navajo County, Arizona. It was in force for 22 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
Jul 31, 2012, 12:38 PM MDT (18:38 UTC)
Expired
Jul 31, 2012, 1:00 PM MDT
In force
22 min
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon

County Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 62 km from the middle of the area, began a volume at 18:39 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

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 6.6 hours before the alert went out and 143 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, Flgstf/Belemont, AZ at 12:00Z on 2012-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 209 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2012-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -17 square meters per square second.193958Sfc1 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
209 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
818 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
121 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

973 
WUUS55 KFGZ 311838
SVRFGZ
AZC017-311900-
/O.NEW.KFGZ.SV.W.0021.120731T1838Z-120731T1900Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1138 AM MST TUE JUL 31 2012

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTH CENTRAL NAVAJO COUNTY IN NORTHEAST ARIZONA...

* UNTIL NOON MST

* AT 1134 AM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  ARIPINE...OR 17 MILES EAST OF FOREST LAKES...AND MOVING NORTHWEST  
  AT 15 MPH. ANOTHER SEVERE THUNDERSTORM CAPABLE OF PRODUCING        
  QUARTER SIZE HAIL WAS LOCATED 1 MILE EAST OF                       
  HEBER-OVERGAARD...ALSO MOVING NORTHWEST AT 15 MPH.

* THE SEVERE THUNDERSTORMS WILL BE NEAR...
  HEBER-OVERGAARD CURRENTLY
  RURAL SOUTHWESTERN NAVAJO COUNTY

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

&&

LAT...LON 3457 11075 3471 11047 3425 11030 3420 11043
TIME...MOT...LOC 1836Z 153DEG 14KT 3443 11053

$$
2 follow-up statements
161 
WWUS55 KFGZ 311853
SVSFGZ

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1153 AM MST TUE JUL 31 2012

AZC017-311900-
/O.CON.KFGZ.SV.W.0021.000000T0000Z-120731T1900Z/
NAVAJO AZ-
1153 AM MST TUE JUL 31 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL NOON MST FOR
SOUTH CENTRAL NAVAJO COUNTY...

AT 1148 AM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS 
LOCATED 2 MILES NORTHEAST OF HEBER-OVERGAARD...MOVING NORTHWEST AT 
15 MPH.

LAT...LON 3425 11047 3457 11075 3471 11047 3432 11032
TIME...MOT...LOC 1853Z 148DEG 13KT 3448 11051

$$
999 
WWUS55 KFGZ 311900
SVSFGZ

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1200 PM MST TUE JUL 31 2012

AZC017-311909-
/O.EXP.KFGZ.SV.W.0021.000000T0000Z-120731T1900Z/
NAVAJO AZ-
1200 PM MST TUE JUL 31 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL NAVAJO COUNTY
WILL EXPIRE AT NOON MST...

HAIL TO THE SIZE OF NICKELS WILL CONTINUE TO BE POSSIBLE EAST AND 
NORTHEAST OF HEBER-OVERGAARD...ALONG WITH HEAVY RAIN.

LAT...LON 3425 11047 3457 11075 3471 11047 3432 11032
TIME...MOT...LOC 1859Z 148DEG 13KT 3450 11052

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 6:51 PM MDTSevere Thunderstorm WarningFGZApache24 min
Jul 30, 6:54 PM MDTSevere Thunderstorm WarningFGZCoconino, Navajo36 min
Jul 30, 7:03 PM MDTSevere Thunderstorm WarningFGZApache, Navajo27 min
Jul 30, 7:43 PM MDTSevere Thunderstorm WarningFGZCoconino32 min
Jul 30, 8:01 PM MDTAreal Flood AdvisoryFGZApache119 min
Jul 31, 1:15 AM MDTAreal Flood AdvisoryFGZApache2 hr
Jul 31, 11:55 AM MDTSpecial Weather StatementFGZ20 min
Jul 31, 12:04 PM MDTSpecial Weather StatementFGZ26 min
Jul 31, 1:07 PM MDTAreal Flood AdvisoryFGZNavajo3 hr
Jul 31, 1:22 PM MDTSevere Thunderstorm WarningFGZApache19 min
Jul 31, 1:26 PM MDTSpecial Weather StatementFGZ34 min
Jul 31, 1:57 PM MDTSpecial Weather StatementFGZApache33 min
Jul 31, 2:14 PM MDTSpecial Weather StatementFGZ31 min
Jul 31, 2:39 PM MDTSpecial Weather StatementFGZ36 min
Jul 31, 3:04 PM MDTSpecial Weather StatementFGZApache26 min
Jul 31, 3:21 PM MDTSpecial Weather StatementFGZ24 min
Jul 31, 4:00 PM MDTSpecial Weather StatementFGZ30 min
Jul 31, 4:16 PM MDTSpecial Weather StatementFGZ29 min
Jul 31, 4:55 PM MDTSpecial Weather StatementFGZ35 min
Jul 31, 5:14 PM MDTSpecial Weather StatementFGZ31 min
Jul 31, 5:48 PM MDTAreal Flood AdvisoryFGZCoconino, Yavapai3 hr

Nearby

Severe Thunderstorm Warnings in Arizona, 2012Every severe thunderstorm warning in 2012

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.