Alert archive / Arizona / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 7, NWS Flagstaff, AZ

July 21, 2000Gila County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 21, 2000, 4:55 PM MST for Gila County, Arizona. It was in force for 35 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued: Jul 21, 2000, 4:55 PM MST (23:55 UTC)
Expired: Jul 21, 2000, 5:30 PM MST
In force: 35 min
Issued by: NWS Flagstaff, AZ
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Gila County, AZ

The radar

The Flagstaff radar (KFSX), 45 km from the middle of the area, began a volume at 23:58 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, 11.9 hours before the alert went out and 129 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 3022 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -53 m²/s²
0-3 km storm-relative helicity: 14 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.

571 
WUUS55 KFGZ 212356
SVRFLG
AZC007-220030-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
455 PM MST FRI JUL 21 2000

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A

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

* UNTIL 530 PM MST

* AT 454 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER NORTHWESTERN GILA COUNTY...OR ABOUT 6
  MILES SOUTHEAST OF PAYSON.  THE STORM WAS NEARLY STATIONARY.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  TONTO BASIN AT 510 PM MST

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

LAT...LON 3418 11136 3410 11129 3413 11107 3420 11111
          3425 11118

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 21, 2:30 PM MST, 2 hours 25 minutes earlier.

Area forecast discussion, Jul 21, 2:30 PM MST, 2 hours 25 minutes before

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST FRI JUL 21 2000

SYNOPSIS...A STRONG HIGH PRESSURE CELL WILL REMAIN CENTERED OVER
ARIZONA THIS WEEKEND. THE CLOCKWISE CIRCULATION AROUND THE HIGH WILL
CONTINUE TO BRING IN MAINLY MID LEVEL MOISTURE TO THE WESTERN HALF
OF ARIZONA ON SATURDAY. THIS MID LEVEL MOISTURE IS EXPECTED TO
SPREAD EASTWARD INTO THE NAVAJO NATION SATURDAY NIGHT AND SUNDAY.
THE MID LEVEL MOISTURE WILL ALLOW A SLIGHT CHANCE OF HIGH BASED
THUNDERSTORMS BOTH SATURDAY AND SUNDAY AFTERNOON. ON MONDAY... A DRY
SOUTHWEST FLOW ALOFT IS EXPECTED TO RETURN TO THE STATE...LASTING
THROUGH MID WEEK.

DISCUSSION...ON THE LARGE SCALE... THE WARM WARM HIGH PRESSURE
SYSTEM EXPECTED TO SIT OVER ARIZONA THIS WEEKEND. THE FORECASTS WERE
BASED ON THE ETA...ALTHOUGH NGM SIMILAR WITH LARGE SCALE FEATURES.
WHAT WE HAVE NOW IS AN EAST TO WEST H5 RIDGE AXIS STRETCHING FROM
NEW MEXICO INTO SOUTHEASTERN CAL. THE GULF SURGE INTO THE COLORADO
RIVER VALLEY ALSO CONTINUES THIS AFTERNOON...WITH THE REMNANTS OF AN
EASTERLY WAVE HEADED TOWARD PALM SPRINGS. A LINE OF CONVECTION HAS
DEVELOPED ALONG THE MOGOLLON RIM THIS AFTERNOON AND WILL LIKELY
SWEEP SOUTHWARD LATER TODAY. POPS TONIGHT WILL BE ADJUSTED
ACCORDINGLY.

ON SATURDAY...MID LEVEL MOISTURE (H5 TO H3) ON THE WESTERN PORTION
OF THE RIDGE AXIS EXPECTED TO MOVE NORTHWARD TOWARDS UTAH. THIS DUE
THE RIDGE AXIS BECOMING ALIGNED MORE NORTH TO SOUTH...AND MID LEVEL
WINDS BECOMING SOUTHERLY. AREAL EXTENT OF THE LOW LEVEL MOISTURE
STILL A WILD CARD. WE DO FEEL THAT THE FAR WESTERN PORTIONS OF THE
CWA HAVE SHOT AT SOME LIQUID HITTING THE GROUND SATURDAY. ELSEWHERE
ITS HIGH BASED CONVECTION. IT LOOKS LIKE ANOTHER HOT ONE IN THE
NORTHEAST WITH LITTLE CLOUD COVER.

SATURDAY NIGHT AND SUNDAY THE MID LEVEL WINDS BECOMING SOUTHWESTERLY
WITH TIME AND EXPAND THE MID LEVEL MOISTURE INTO NORTHEAST ARIZONA.
THUS ALL AREAS WILL HAVE AT LEAST A SLIGHT CHANCE OF AFTERNOON
THUNDER.

IN THE EXTENDED... EXTENDED PROGS IN SIMILAR AGREEMENT AS THEY KEEP
A H5 HIGH CENTERED OVER NEW MEXICO AND DRY SOUTHWEST FLOW ALOFT OVER
THE NORTHERN PORTIONS OF AZ. SO IT LOOKS DRY WITH A SLOW WARMING
TREND THROUGH MID WEEK.

.FGZ...NONE.

JDL

Nearby

Severe Thunderstorm Warnings in Arizona, 2000 Every severe thunderstorm warning in 2000

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.