Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 49, NWS Flagstaff, AZ

September 5, 1998Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Sep 5, 1998, 11:33 AM MST for Coconino County, Arizona. It was in force for 47 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 5, 1998, 11:33 AM MST (18:33 UTC)
Expired
Sep 5, 1998, 12:20 PM MST
In force
47 min
Issued by
NWS Flagstaff, AZ
Area
Whole counties

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 150 km from the middle of the area, began a volume at 18:34 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 68 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 1998-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 71 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 1998-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 214 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
71 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
984 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
214 m²/s²
0-3 km storm-relative helicity
225 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.

226 
WUUS1 KFLG 051835 RRA
SVRFLG
AZC005-051920-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1133 AM MST SAT SEP 5 1998

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN COCONINO COUNTY IN NORTH CENTRAL ARIZONA

* UNTIL 1220 PM MST

* AT 1130 AM MST...  NATIONAL WEATHER SERVICE DOPPLER RADAR
  INDICATED A SEVERE THUNDERSTORM 13 MILES SOUTH OF METEOR CITY
  MOVING NORTH AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  METEOR CITY AT 1155 AM MST
  SUNSHINE AT 1155 AM MST
  TWO GUNS AT NOON MST

IF YOU ARE IN THE WARNING AREA... SEEK SAFETY IN AN INTERIOR ROOM
AWAY FROM WINDOWS. IF YOU ARE CAUGHT OUTSIDE... TRY TO FIND
SHELTER IN A WELL PROTECTED AREA. SEVERE THUNDERSTORMS PRODUCE
DAMAGING WIND AND HAIL ALONG WITH VERY HEAVY RAIN AND FREQUENT
LIGHTNING.

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 5, 10:25 AM MST, 1 hour 8 minutes earlier.

Area forecast discussion, Sep 5, 10:25 AM MST, 1 hour 8 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1025 AM MST SAT SEP 5 1998

SYNOPSIS...ALTHOUGH DEEPER MOISTURE ASSOCIATED WITH THE REMNANTS OF
ISIS HAS MOVED NORTH OF THE REGION...WIDESPREAD SHOWERS AND
THUNDERSTORMS WILL REMAIN OVER ARIZONA THROUGH THE WEEKEND AS
ABUNDANT LOW-LEVEL MOISTURE OVER THE REGION INTERACTS WITH AN UPPER
LEVEL WEATHER DISTURBANCE OVER EXTREME WESTERN ARIZONA.  THICK CLOUD
COVER WILL ALSO GIVE WAY TO MORE BREAKS OF SUN SO EXPECT TEMPERATURES
TO BE A LITTLE WARMER TODAY AS WELL.

DISCUSSION...SATELLITE SHOWING VIGOROUS UPPER LOW SPINNING OVER
SOUTHERN CALIFORNIA...AND DRIFT APPEARS TO BE MAINLY TO THE NORTH
THIS MORNING. RUN THROUGH OF THE 12Z MODELS SHOWS ETA MAY BE EJECTING
LOW TOO QUICKLY TO THE NE...NGM LOOKS BETTER. TSTORMS ALREADY MOVING
THROUGH CENTRAL PORTIONS OF THE CWFA TRUCKING ALONG AT 20 TO 30 MPH.
IF MODEL COOLING AT 500MB IS REALIZED...MODIFIED FGZ SOUNDING YIELDS
A CAPE VALUE OF 300-500 J/KG...ENOUGH FOR SOME DECENT SIZE HAIL
ESPECIALLY IN THE NORTHWEST THIS AFTERNOON. STORMS WILL ALSO DUMP A
LOT OF RAIN...BUT QUICK MOVEMENT SHOULD KEEP DOWNPOURS FAIRLY BRIEF.

FLG...NONE.

In the hours before

Special weather statement, Sep 5, 9:10 AM MST, 2 hours 23 minutes before
AZZ004>018-051900-

AREA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
910 AM MST SAT SEP 5 1998

...STRONG THUNDERSTORMS PRODUCING HAIL...GUSTY WINDS AND HEAVY RAIN
POSSIBLE TODAY...

SPOTTER REPORTS OF SIGNIFICANT WEATHER ARE REQUESTED.

AN UPPER LEVEL LOW PRESSURE SYSTEM WILL LIFT NORTHEAST OUT OF
CALIFORNIA TODAY THROUGH NORTHWESTERN ARIZONA. THIS SYSTEM WILL ACT
ON ABUNDANT LOW LEVEL MOISTURE TO PRODUCE STRONG THUNDERSTORMS OVER
THE NORTHLAND. THUNDERSTORMS THAT DO FORM WILL MOVE RATHER QUICKLY TO
THE NORTH AT 20 TO 30 MPH. THE GREATEST THREAT TODAY WILL BE
HAIL...POSSIBLY EXCEEDING AN INCH IN DIAMETER WITH THE STRONGEST
THUNDERSTORMS.

Nearby

Severe Thunderstorm Warnings in Arizona, 1998Every severe thunderstorm warning in 1998

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.