Alert archive / Arizona / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 70, NWS Flagstaff, AZ

August 16, 2001Gila County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 16, 2001, 5:37 PM MST for Gila County, Arizona. It was in force for 33 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
Aug 16, 2001, 5:37 PM MST (00:37 UTC)
Expired
Aug 16, 2001, 6:10 PM MST
In force
33 min
Issued by
NWS Flagstaff, AZ
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Gila County, AZ

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 0.6 hours before the alert went out and 151 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 2001-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 233 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 2001-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 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
233 J/kg
Mixed-layer CIN
-103 J/kg
Mixed-layer LCL
2513 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
78 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.

366 
WUUS55 KFGZ 170041
SVRFLG
AZC007-170110-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
537 PM MST THU AUG 16 2001

THE NATIONAL WEATHER SERVICE HAS ISSUED A

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

* UNTIL 610 PM MST

* AT 537 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER CENTRAL GILA COUNTY...OR ABOUT 5 MILES
  SOUTHWEST OF YOUNG...MOVING WEST AT 15 MPH.

* THE SEVERE THUNDERSTORM WILL AFFECT OR PASS CLOSE TO...
BREAD PAN MOUNTAIN AND SHEEP BASIN MOUNTAIN IN RURAL WESTERN GILA 
COUNTY AT 550 PM MST

THIS STORM LIKELY CONTAINS STRONG WIND AND LARGE HAIL.

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

LAT...LON 3396 11093 3414 11096 3411 11127 3391 11123

MAS

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 Aug 16, 3:00 PM MST, 2 hours 37 minutes earlier.

Area forecast discussion, Aug 16, 3:00 PM MST, 2 hours 37 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
300 PM MST THU AUG 16 2001

.SYNOPSIS...THE AIR MASS OVER NORTHERN ARIZONA WILL SLOWLY DRY OVER
THE NEXT FEW DAYS. HOWEVER...ENOUGH MOISTURE WILL REMAIN FOR
ISOLATED STORMS EACH DAY. OVER THE WEEKEND AND INTO NEXT WEEK
MONSOON MOISTURE WILL GRADUALLY INCREASE WITH THE DAILY THREAT OF
THUNDERSTORMS CONTINUING. OTHERWISE...TEMPERATURES WILL REMAIN NEAR
SEASONABLE LEVELS WITH LIGHT WINDS.

.DISCUSSION...LARGE ANTICYCLONE REMAINS OVER THE EPAC WITH
SUBSIDENCE AND DRYING EVIDENT IN THE WV IMAGERY. STRONGEST DRYING
OVER NORTHERN ARIZONA REMAINS IN THE MID AND UPPER TROPOSPHERE. LOW
LEVELS HAVE BEEN SLOWER TO DRY...MAINLY THROUGH VERTICAL MIXING.
KFGZ 1200 UTC SOUNDING NOW SHOWS DRYING EXTENDING INTO THE LOWER
LEVELS SUCH THAT SURFACE DEWPOINTS COULD PLUMMET INTO THE LOW 40S
ONCE THE CONVECTIVE BOUNDARY LAYER BECOMES WELL MIXED. SURFACE
DEWPOINTS ACROSS THE REGION ARE DOWN A FEW DEGREES FROM 24 HOURS AGO
AND THIS CORRESPONDS WELL WITH THE MOISTURE PROFILE IN THE SOUNDING.
LAPSE RATES CONTINUE TO STEEPEN THROUGH A DEEPER LAYER SO THAT
INSTABILITY IS STILL PRESENT. SHOWERS HAVE BEGUN TO DEVELOP OVER THE
HIGHER TERRAIN EARLY THIS AFTERNOON AND ARE SLOWLY MOVING TO THE
SOUTHEAST. RAINFALL AMOUNTS HAVE BEEN ONLY LIGHT TO MODERATE WITH
THESE STORMS. AS THESE STORMS MOVE OFF THE HIGH TERRAIN INTO THE
VALLEYS AND DESERTS EXPECT SOME STRENGTHENING SINCE THERE IS MORE
LOW LEVEL MOISTURE AVAILABLE.

EXPECT MORE OF THE SAME FOR FRIDAY AND SATURDAY. MOSTLY SUNNY SKIES
EACH MORNING WILL GIVE WAY TO PARTLY CLOUDY SKIES IN THE AFTERNOON
WITH ONLY A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN ALL ZONES.
WITH FAIRLY DRY MOISTURE PROFILES AND PW ABOUT 60% OF NORMAL...
SHOWERS SHOULD BE LIGHT TO MODERATE IN INTENSITY.

.EXTENDED...AS ANTICYCLONE MIGRATES TO THE EAST THE FLOW WILL VEER
TO THE SOUTHEAST AND MOISTURE WILL BEGIN TO RETURN TO THE REGION.
SOME DIFFERENCES ARISE BETWEEN THE ECMWF AND MRF IN THE LATTER
PORTIONS OF THE EXTENDED. THE MRF DRIVES A STRONG WAVE ACROSS THE
WEST COAST WHILE THE ECMWF MAINTAINS A CLOSED LOW IN THE EASTERN
PACIFIC. BOTH SITUATIONS WILL INCREASE POPS ACROSS THE AREA BUT THE
MRF SCENARIO WOULD HAVE AN ABRUPT SHUTOFF OF THE MONSOON FLOW WITH
DRY SOUTHWESTERLY FLOW DEVELOPING AND COOLER TEMPS. FOR NOW...THERE
DOES NOT APPEAR TO BE ANY WAY TO DETERMINE WHICH MODEL IS THE MORE
CORRECT SOLUTION. WILL SIMPLY KEEP A CHANCE OF SHOWERS EACH DAY IN
THE EXTENDED UNTIL SOME CONSENSUS DEVELOPS.  DB

.FGZ...NONE.

Nearby

Severe Thunderstorm Warnings in Arizona, 2001Every severe thunderstorm warning in 2001

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.