Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 13, NWS Flagstaff, AZ

July 19, 1998Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 19, 1998, 5:40 PM MST for Coconino County, Arizona. It was in force for 50 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
Jul 19, 1998, 5:40 PM MST (00:40 UTC)
Expired
Jul 19, 1998, 6:30 PM MST
In force
50 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 00:43 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 00:00Z, 0.7 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 00:00Z on 1998-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1975 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 00:00Z on 1998-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 square meters per square second.1939Sfc1 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
1975 J/kg
Mixed-layer CIN
-60 J/kg
Mixed-layer LCL
1530 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
138 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.

000 
TTAA00 KFLG 200041
SVRFLG
AZC005-200130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
540 PM MST SUN JUL 19 1998

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A

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

* UNTIL 630 PM MST

* AT 538 PM MST...  NATIONAL WEATHER SERVICE DOPPLER RADAR
  INDICATED A SEVERE THUNDERSTORM 21 MILES WEST OF HEBER OR 14
  MILES NORTHWEST OF FOREST LAKES MOVING WEST AT 5 MPH.

* THE SEVERE THUNDERSTORM WARNING IS AN EXTENSION OF THE
  PREVIOUS SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN COCONINO
  COUNTY.

THIS IS A VERY DANGEROUS STORM.  IF YOU ARE IN THE WARNING A8REA...
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 Jul 19, 2:00 PM MST, 3 hours 40 minutes earlier.

Area forecast discussion, Jul 19, 2:00 PM MST, 3 hours 40 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
200 PM MST SUN JUL 19 1998

SYNOPSIS...AN AREA OF HIGH PRESSURE NORTH OF THE STATE WILL CONTINUE
A GENERAL EASTERLY FLOW OVER ARIZONA. THIS WILL BRING SOME MOISTURE
INTO THE REGION FROM NEW MEXICO AND TEXAS...RESULTING IN ISOLATED
AFTERNOON AND EVENING THUNDERSTORMS ACROSS THE NORTHLAND FOR THE NEXT
FEW DAYS.

DISCUSSION...MID LEVEL DISTURBANCE MOVING THROUGH SE AZ AT THIS TIME.
CONVECTION OVER MOGOLLON RIM DEVELOPED A BIT LATER THAN FCSTED...BUT
HAS DEVELOPED QUITE RAPIDLY. NEAR THE BORDER...STORMS HAVE BEEN
ENHANCED BY S/W WHICH IS IN THE AREA.

LOW LEVEL MOISTURE TO REMAIN IN PLACE...AS THEIR WILL BE LITTLE
CHANGE IN THE OVERAL PATTERN THE NEXT FEW DAYS. MODELS ALL SEEM TO BE
HANDLING LARGER SCALE FAIRLY WELL...BUT ARE SHOWING CONSIDERABLE
DIFFERENCES WITH FINER SCALE FEATURES. STANDARD MONSOON SEASON
WEATHER WILL BE THE RULE THE NEXT FEW DAYS.
MCGRATVH
FLG 312  INW 111
FLG...NONE.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 5:20 PM MSTSevere Thunderstorm WarningFGZGila45 min
Jul 19, 5:59 PM MSTSevere Thunderstorm WarningFGZYavapai46 min
Jul 19, 6:07 PM MSTSevere Thunderstorm WarningFGZGila48 min
Jul 19, 6:48 PM MSTSevere Thunderstorm WarningFGZYavapai62 min

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.