Alert archive / Arizona / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 89, NWS Flagstaff, AZ

September 10, 2008Navajo County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Sep 10, 2008, 1:11 PM MDT for Navajo County, Arizona. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Sep 10, 2008, 1:11 PM MDT (19:11 UTC)
Expired: Sep 10, 2008, 1:45 PM MDT
In force: 34 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon

County Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 122 km from the middle of the area, began a volume at 19:13 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, 7.2 hours before the alert went out and 266 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: 755 J/kg
Mixed-layer CIN: -80 J/kg
Mixed-layer LCL: 1658 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 6 m²/s²
0-3 km storm-relative helicity: 76 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.8

Open this sounding in Storm Lab

What forecasters said that day

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

NWS Flagstaff, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 10, 1:05 PM MDT, 6 minutes earlier.

Area forecast discussion, Sep 10, 1:05 PM MDT, 6 minutes before

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Hazardous weather outlook, Sep 10, 12:56 PM MDT, 15 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1156 AM MST WED SEP 10 2008

AZZ004>018-037>040-110300-
KAIBAB PLATEAU-MARBLE AND GLEN CANYONS-GRAND CANYON COUNTRY-
COCONINO PLATEAU-YAVAPAI COUNTY MOUNTAINS-
NORTHEAST PLATEAUS AND MESAS HWY 264 NORTHWARD-CHINLE VALLEY-
CHUSKA MOUNTAINS AND DEFIANCE PLATEAU-
LITTLE COLORADO RIVER VALLEY IN COCONINO COUNTY-
LITTLE COLORADO RIVER VALLEY IN NAVAJO COUNTY-
LITTLE COLORADO RIVER VALLEY IN APACHE COUNTY-
WESTERN MOGOLLON RIM-EASTERN MOGOLLON RIM-WHITE MOUNTAINS-
NORTHERN GILA COUNTY-YAVAPAI COUNTY VALLEYS AND BASINS-
OAK CREEK AND SYCAMORE CANYONS-BLACK MESA AREA-
NORTHEAST PLATEAUS AND MESAS SOUTH OF HWY 264-
1156 AM MST WED SEP 10 2008

...UPDATE...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL
ARIZONA...NORTH CENTRAL ARIZONA...NORTHEAST ARIZONA AND WEST
CENTRAL ARIZONA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR YAVAPAI COUNTY
UNTIL 7 PM MST...AS WEATHER CONDITIONS ARE FAVORABLE FOR
ORGANIZED SEVERE THUNDERSTORM ACTIVITY TODAY.

EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS
MUCH OF NORTHERN ARIZONA TODAY. BULK SHEAR AND MOST UNSTABLE CAPE
VALUES INDICATE THE POTENTIAL EXISTS FOR A FEW ORGANIZED SEVERE
STORMS TO DEVELOP DURING THE DAY...MAINLY ACROSS YAVAPAI COUNTY
AND SOUTHERN COCONINO COUNTY. STORM MOTION WILL BE FROM WEST TO
EAST AROUND 15 TO 20 MPH. THE PRIMARY THREAT TODAY WILL BE FROM
LARGE HAIL...LOCALLY HEAVY RAINFALL AND STRONG GUSTY DOWNDRAFT
WINDS 40 TO 60 MPH. ISOLATED TO WIDELY SCATTERED SHOWER AND
THUNDERSTORM ACTIVITY WILL LIKELY CONTINUE INTO THE OVERNIGHT
HOURS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

SCATTERED THUNDERSTORM ACTIVITY WILL CONTINUE ON THURSDAY WITH
ISOLATED SEVERE ACTIVITY STILL POSSIBLE. A DRYING TREND WILL
DEVELOP BY FRIDAY...INTO THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 9, 7:42 PM MDT	Severe Thunderstorm Warning	FGZ	Yavapai	33 min
Sep 9, 8:18 PM MDT	Severe Thunderstorm Warning	FGZ	Yavapai	27 min
Sep 10, 12:54 PM MDT	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	36 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2008 Every severe thunderstorm warning in 2008

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.