Alert archive / Arizona / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 1, NWS Flagstaff, AZ

April 7, 2002Apache County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Apr 7, 2002, 6:16 PM MST for Apache County, Arizona. It was in force for 29 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: Apr 7, 2002, 6:16 PM MST (01:16 UTC)
Expired: Apr 7, 2002, 6:45 PM MST
In force: 29 min
Issued by: NWS Flagstaff, AZ
Area: Counties, with a storm outline in the text

County Apache County, AZ

The radar

The Flagstaff radar (KFSX), 166 km from the middle of the area, began a volume at 01:24 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 1.3 hours before the alert went out and 240 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: 70 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 1694 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 167 m²/s²
0-3 km storm-relative helicity: 206 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

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

000 
WUUS55 KFGZ 080116
SVRFLG
AZC001-080145-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
612 PM MST SUN APR 7 2002

THE NATIONAL WEATHER SERVICE HAS ISSUED A

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

* UNTIL 645 PM MST

* AT 612 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 11 MILES NORTHWEST OF LYMAN LAKE STATE PARK...
  OR ABOUT 5 MILES EAST OF CONCHO...MOVING SOUTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL AFFECT OR PASS CLOSE TO...
  OVER SPRINGERVILLE AT 640 PM MST
  OVER EAGAR AT 645 PM MST

IF SEVERE WEATHER APPROACHES YOUR AREA...GO INSIDE A STURDY SHELTER
AWAY FROM CREEK BEDS AND OTHER FLOOD-PRONE AREAS. REMEMBER...A SEVERE
THUNDERSTORM CAN PRODUCE LARGE DAMAGING HAIL...DAMAGING WINDS IN
EXCESS OF 58 MPH...DEADLY LIGHTNING...AND VERY HEAVY RAIN.

VERY LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE
IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A
SUBSTANTIAL SHELTER.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE.

LAT...LON 3453 10945 3444 10963 3401 10941 3415 10912

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 Apr 7, 2:45 PM MST, 3 hours 31 minutes earlier.

Area forecast discussion, Apr 7, 2:45 PM MST, 3 hours 31 minutes before

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
245 PM MST SUN APR 07 2002

.SYNOPSIS...THE STORM SYSTEM THAT BROUGHT RAIN AND SNOW TO ARIZONA
YESTERDAY HAS MOVED INTO NEW MEXICO. FOR TONIGHT...EXPECT A FEW
EARLY EVENING SHOWERS FOLLOWED BY CLEARING SKIES OVERNIGHT. ALONG
THE EASTERN BORDER...SHOWERS WILL LAST LONGER INTO THE EVENING
BEFORE DIMINISHING. ON MONDAY...HIGH PRESSURE WILL BRING PARTLY
CLOUDY SKIES AND A WARMING TREND TO THE NORTHLAND. FOR THE REMAINDER
OF THE WEEK...A SERIES OF WEAK WEATHER DISTURBANCES WILL BRING
MOSTLY CLOUDY SKIES AND A CHANCE OF SHOWERS TO NORTHERN ARIZONA ON
WEDNESDAY AND AGAIN OVER THE WEEKEND.

.DISCUSSION...COLD CORE UPPER LOW WAS CENTERED OVER NEW MEXICO THIS
AFTERNOON AND MOVING EAST. SKIES WERE MOSTLY CLEAR OVER THE WESTERN
HALF OF THE STATE THIS MORNING BUT CUMULUS BUILDUPS AND SHOWERS HAVE
OCCURRED OVER MOST OF THE HIGHER TERRAIN AND EVEN SOME OF THE LOWER
DESERTS THIS AFTERNOON. EXPECT MOST OF THIS TO DIMINISH QUICKLY AFTER
SUNSET AS THE BOUNDARY LAYER STABILIZES. FARTHER EAST...SKIES ARE
MOSTLY CLOUDY AND SHOWERS SHOULD CONTINUE LATER INTO THE EVENING
BEFORE DIMINISHING. FOR MONDAY AND TUESDAY...A WEAK RIDGE TRANSITS
THE AREA BRINGING SOME WARMING AND PARTLY CLOUDY SKIES. NEXT S/WV
TROUGH APPROACHES THE AREA ON WEDNESDAY AND THERE IS A CHANCE OF
SHOWERS OVER MOST OF THE CWFA...WITH CHANCES DIMINISHING TO THE
SOUTH.

.EXTENDED...MRF AND ECMWF SHOW SIMILAR PATTERNS FOR THURSDAY AND
FRIDAY AND BRING PARTLY CLOUDY SKIES WITH SEASONABLE TEMPERATURES TO
THE REGION. MODEL SOLUTIONS BEGIN TO DIVERGE FOR THE WEEKEND WITH
THE ECMWF SOLUTION SHOWING A MUCH COLDER...DEEPER...AND FASTER
TROUGH THAN THE MRF. WILL GO WITH A PARTLY CLOUDY FORECAST FOR THE
FIRST HALF OF THE EXTENDED...AND MOSTLY CLOUDY WITH A CHANCE OF
SHOWERS FOR THE SECOND HALF. ENOUGH DIFFERENCES EXIST BETWEEN THE
MODELS THAT THE TIMING AND AMPLITUDE OF THE FEATURES IS DIFFICULT TO
ASSESS. DB

.FGZ...NONE.

.CODED TEMPERATURES/POPS FOR SELECTED CITIES IN NORTHERN ARIZONA

CITY             TEMPERATURES LO/HI           PROBABILITY OF PRECIP
                 TON MON   TUE     WED        TON MON   TUE     WED
FLAGSTAFF        031/058 030/060 032/055      020 000 000 000 000 040
WINSLOW          040/070 040/072 041/071      020 000 000 000 000 020
PRESCOTT         038/068 042/070 042/066      000 000 000 000 000 030
PAGE             048/069 050/072 050/068      020 000 000 000 000 040
WINDOW ROCK      026/060 031/062 032/062      030 000 000 000 000 040
CANYON DE CHELLY 036/064 041/066 042/066      020 000 000 000 000 040
COTTONWOOD       045/076 049/078 049/074      000 000 000 000 000 030
GRAND CANYON     033/062 032/064 034/059      020 000 000 000 000 030
GREER            030/058 029/060 031/055      030 000 000 000 000 030
HEBER            032/066 031/068 033/063      030 000 000 000 000 020
JACOB LAKE       031/053 030/055 032/050      020 000 000 000 000 030
NAVAJO N.M.      030/058 035/060 036/060      020 000 000 000 000 040
PAYSON           038/071 042/073 042/069      000 000 000 000 000 030
SEDONA           044/075 048/077 048/073      000 000 000 000 000 030
SELIGMAN         030/070 034/072 034/068      000 000 000 000 000 020
SHOW LOW         039/068 038/070 040/065      030 000 000 000 000 030
ST. JOHNS        037/068 037/070 038/069      030 000 000 000 000 020
WUPATKI N.M.     045/070 045/072 046/071      020 000 000 000 000 020

Nearby

Severe Thunderstorm Warnings in Arizona, 2002 Every severe thunderstorm warning in 2002

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.