Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 4, NWS Flagstaff, AZ

July 17, 1998Gila County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 17, 1998, 3:49 PM MST for Gila County, Arizona. It was in force for 46 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 17, 1998, 3:49 PM MST (22:49 UTC)
Expired
Jul 17, 1998, 4:35 PM MST
In force
46 min
Issued by
NWS Flagstaff, AZ
Area
Whole counties

County Gila County, AZ

The radar

The Flagstaff radar (KFSX), 93 km from the middle of the area, began a volume at 22:53 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

Tuscon, AZ (KTUS), launched 12:00Z, 10.8 hours before the alert went out and 181 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, Tuscon, AZ at 12:00Z on 1998-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 39 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tuscon, AZ at 12:00Z on 1998-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -50 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
39 J/kg
Mixed-layer CIN
-292 J/kg
Mixed-layer LCL
2735 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
-50 m²/s²
0-3 km storm-relative helicity
60 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFLG 172249 RRA
SVRFLG
AZC007-172335-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
349 PM MST FRI JUL 17 1998

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN GILA COUNTY IN CENTRAL ARIZONA

* UNTIL 435 PM MST

* AT 345 PM MST...  NATIONAL WEATHER SERVICE DOPPLER RADAR
  INDICATED A SEVERE THUNDERSTORM 19 MILES SOUTHEAST OF PAYSON OR
  5 MILES SOUTHWEST OF FULTON MOVING SOUTHWEST AT 10 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  THE RURAL SIERRA ANCHAS MOUNTAINS AT 350 PM 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.

CUOCO

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 17, 3:15 PM MST, 34 minutes earlier.

Area forecast discussion, Jul 17, 3:15 PM MST, 34 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST FRI JUL 17 1998

SYNOPSIS...NORTHEASTERLY WIND FLOW AROUND AN AREA OF HIGH PRESSURE
WILL CONTINUE TO BRING INCREASING MOISTURE FROM THE NORTH.  THIS WILL
LEAD TO INCREASING CLOUDS AND A CHANCE OF AFTERNOON AND EVENING
THUNDERSTORMS ACROSS MOST OF THE AREA THIS WEEKEND.

DISCUSSION...SATELLITE/88D SHOWS CONVECTION OCCURRING MAINLY ALONG
SOUTHERN EDGE OF RIM AND OFF OF THE MESAS OF THE NORTHEAST.  THIS
ACTIVITY IS SPREADING TO THE SOUTH DUE TO THE NORTHEASTERLY FLOW
ALOFT.  WITH DRY AIR IN PLACE IN THE LOW-LEVELS...GUSTY WINDS MAIN
PROBLEM.  EXPECT MOST OF THE ACTIVITY IN THE NORTH TO DIE AWAY SOON
AFTER SUNSET...WITH ACTIVITY TO THE SOUTH LINGERING LONGER AS IT
MOVES OUT OF CWFA.  TOMORROW SHOULD BE REPEAT OF TODAY...WITH JUST A
TAD MORE MOISTURE THAN TODAY.  UPPER VORT MAX...APPARENT IN 250 MB
VORT FIELD...WILL SPIN TOWARD SOUTHERN AZ TONIGHT AND CONTINUE
WESTWARD TOMORROW.  THUS...THINK INCREASE IN MOISTURE WILL BE OFFSET
BY LESS DYNAMICS FOR PRETTY SIMILAR DAY TOMORROW.  STORMS SHOULD MOVE
LESS QUICKLY TOMORROW DUE TO LESS WINDS ALOFT AS WELL...HOWEVER
MICROBURST POTENTIAL REMAINS.  TEMPERATURES HAVE BEEN MOVED DOWN A
FEW DEGREES DUE TO STRUGGLING TEMPS TODAY AND MORE CLOUDS EXPECTED
TOMORROW.  THIS TREND OF AFTERNOON SHOWERS AND THUNDERSTORMS WITH
TEMPERATURES RETURNING TOWARD NORMAL WILL CONTINUE THROUGH THE
EXTENDED PERIOD.

FLG 1222  INW -111
STAUDENMAIER
FLG...NONE.

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.