Alert archive / Arizona / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 50, NWS Tucson, AZ

August 19, 2001Santa Cruz County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Aug 19, 2001, 1:35 PM MST for Santa Cruz County, Arizona. It was in force for 40 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 19, 2001, 1:35 PM MST (20:35 UTC)
Expired
Aug 19, 2001, 2:15 PM MST
In force
40 min
Issued by
NWS Tucson, AZ
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Santa Cruz County, AZ

The nearest sounding before it

Tuscon, AZ (KTUS), launched 12:00Z, 8.6 hours before the alert went out and 61 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 2001-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 763 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 2001-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 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
763 J/kg
Mixed-layer CIN
-182 J/kg
Mixed-layer LCL
1715 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
93 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.

502 
WUUS55 KTWC 192035
SVRTUS
AZC023-192115-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
135 PM MST SUN AUG 19 2001

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN SANTA CRUZ COUNTY IN ARIZONA

* UNTIL 215 PM MST

* AT 130 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER EXTREME NORTHEASTERN SANTA CRUZ COUNTY...
  JUST EAST OF SONOITA...MOVING NORTHWEST AROUND 5 MPH. THIS STORM
  WILL AFFECT THE TOWN SONOITA THROUGH 200 PM.

HAIL...HEAVY RAIN AND STRONG DAMAGING WINDS ARE LIKELY WITH THIS
STORM. TAKE COVER IN A SUBSTANTIAL SHELTER UNTIL THE STORM PASSES.

REMEMBER...A SEVERE THUNDERSTORM CAN PRODUCE LARGE HAIL...DAMAGING
WINDS IN EXCESS OF 60 MPH...DEADLY LIGHTNING...AND HEAVY RAIN.

LAT...LON 3168 11070 3162 11060 3171 11055 3174 11069

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 Tucson, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 19, 9:30 AM MST, 4 hours 5 minutes earlier.

Area forecast discussion, Aug 19, 9:30 AM MST, 4 hours 5 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
930 AM MST SUN AUG 19 2001

.SYNOPSIS...AN INCREASE IN MOISTURE IS EXPECTED THE NEXT FEW DAYS AS
HIGH PRESSURE ALLOWS A MORE SOUTHEAST WIND FLOW. THIS WILL INCREASE
THE THUNDERSTORM ACTIVITY ACROSS SOUTHEAST ARIZONA THROUGH MONDAY.
THEN A TROUGH OFF THE WEST COAST WILL BRING SOME DRY AIR INTO THE
STATE WITH A DECREASE IN THE THUNDERSTORM ACTIVITY BY MIDWEEK.

.DISCUSSION...THE INITIAL BAND OF CLOUDINESS THAT WAS SPREADING
NORTHWARD AHEAD OF THE BAJA LOW CONTINUED TO THIN AND MOVE OUT OF
THE AREA THIS MORNING. NOT MUCH IN THE WAY OF SHOWER OR THUNDERSTORM
ACTIVITY YET AS PREVIOUSLY EXPECTED. HOWEVER...THE CLEARING THIS
MORNING WILL PROVIDE SOUTHERN ARIZONA WITH MORE INSOLATION THAN
YESTERDAY. THIS WILL HELP GET STORMS GOING THIS AFTERNOON...WITH AN
EARLIER START IN THE MOUNTAINS ANTICIPATED TODAY COMPARED TO THE
PAST SEVERAL DAYS. THE UPWARD VERTICAL MOTION FIELD ASSOCIATED WITH
THE BAJA SYSTEM BECOMES MORE FAVORABLE THIS EVENING INTO MONDAY AS
THE LOW LIFTS NORTH AND TRACKS WEST ACROSS THE STATE. AT ANY
RATE...THIS AFTERNOON AND TONIGHT LOOKS VERY ACTIVE THUNDERSTORM
WISE AS MANY OF THE NEEDED INGREDIENTS ARE COMING TOGETHER. CURRENT
FORECAST LOOKS ON TRACK...SO NO UPDATES THIS MORNING.

.TWC...NONE.

In the hours before

Special weather statement, Aug 19, 12:03 PM MST, 1 hour 32 minutes before
AZZ019-029>035-200700-

SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
12 NOON MST SUN AUG 19 2001

.SYNOPSIS...THE COMBINATION OF INCREASED SUNSHINE...A MOIST
ATMOSPHERE...AND DYNAMICS ASSOCIATED WITH AN UPPER LOW OFF THE BAJA
COAST WILL LEAD TO AN INCREASE IN THUNDERSTORM ACTIVITY LATER THIS
AFTERNOON AND THIS EVENING. A FEW STORMS MAY LINGER ON OVERNIGHT.

.DISCUSSION...A LOT MORE SUNSHINE THIS MORNING THAN THE PREVIOUS
MORNINGS WHICH WILL ALLOW THE LOWER PART OF THE ATMOSPHERE TO WARM
UP TO ITS POTENTIAL THIS AFTERNOON. AS OF 12 NOON...TEMPERATURES
WERE RUNNING 3 TO 6 DEGREES ABOVE SATURDAY READINGS. PRECIPITABLE
WATER VALUES ARE STILL A LITTLE ABOVE NORMAL AND RANGE FROM JUST
OVER AN INCH IN PARTS OF GRAHAM AND COCHISE COUNTIES TO OVER 1.50
WEST OF TUCSON.

UPPER AIR ANALYSIS AND SATELLITE IMAGERY THIS MORNING SHOWED AN
ELONGATED UPPER LOW EXTENDING FROM OFF THE BAJA COAST NORTHEAST INTO
SOUTHWEST ARIZONA. UPPER LEVEL HIGH PRESSURE EXTENDS FROM NORTHERN
ARIZONA SOUTHEAST INTO CHIHUAHUA MEXICO. SOUTHERN ARIZONA LIES IN
DIVERGENCE AREA BETWEEN THESE TWO FEATURES. MORNING MODELS SLOWLY
MOVE THE BAJA LOW SLOWLY TO THE NORTH-NORTHEAST AND INCREASE UPWARD
VERTICAL MOTION FIELDS TONIGHT.

WITH THE INCREASED SUNSHINE THIS MORNING...TOWERING CUMULUS CLOUDS
ARE ALREADY DEVELOPING OVER THE HIGHER TERRAIN. THUNDERSTORMS THAT
DEVELOP EARLY THIS AFTERNOON WILL WILL NOT MOVE OFF THEM UNTIL LATER
THIS AFTERNOON. STORMS THAT DEVELOP LATER THIS AFTERNOON AND THIS
EVENING WILL HAVE THE POTENTIAL FOR STRONG DOWNBURST WINDS...
ESPECIALLY FROM TUCSON WEST...AS AFTERNOON SOUNDINGS WILL LIKELY
HAVE AN INVERTED-V LOOK TO THEM. THUS WILL GO ABOVE CLIMATOLOGY FROM
TUCSON WEST. ALTHOUGH THE STORMS WILL BE MOVING AROUND 15 TO 20 MPH
WHICH WILL REDUCE THE RISK FOR FLASH FLOODING...SOME OF THE STORMS
MAY BE BIG ENOUGH TO PRODUCE HEAVY RAINFALL. WILL SLIGHTLY GO ABOVE
CLIMATOLOGY FROM TUCSON WEST.

STORM MOVEMENT WILL BE GENERALLY TO THE WEST AT 15 TO 20 MPH.
Special weather statement, Aug 19, 12:05 PM MST, 1 hour 30 minutes before
AZZ019-029>035-200700-

SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK...CORRECTION
NATIONAL WEATHER SERVICE TUCSON AZ
1205 PM MST SUN AUG 19 2001

.SYNOPSIS...THE COMBINATION OF INCREASED SUNSHINE...A MOIST
ATMOSPHERE...AND DYNAMICS ASSOCIATED WITH AN UPPER LOW OFF THE BAJA
COAST WILL LEAD TO AN INCREASE IN THUNDERSTORM ACTIVITY LATER THIS
AFTERNOON AND THIS EVENING. A FEW STORMS MAY LINGER ON OVERNIGHT.

.DISCUSSION...A LOT MORE SUNSHINE THIS MORNING THAN THE PREVIOUS
MORNINGS WHICH WILL ALLOW THE LOWER PART OF THE ATMOSPHERE TO WARM
UP TO ITS POTENTIAL THIS AFTERNOON. AS OF 12 NOON...TEMPERATURES
WERE RUNNING 3 TO 6 DEGREES ABOVE SATURDAY READINGS. PRECIPITABLE
WATER VALUES ARE STILL A LITTLE ABOVE NORMAL AND RANGE FROM JUST
OVER AN INCH IN PARTS OF GRAHAM AND COCHISE COUNTIES TO OVER 1.50
WEST OF TUCSON.

UPPER AIR ANALYSIS AND SATELLITE IMAGERY THIS MORNING SHOWED AN
ELONGATED UPPER LOW EXTENDING FROM OFF THE BAJA COAST NORTHEAST INTO
SOUTHWEST ARIZONA. UPPER LEVEL HIGH PRESSURE EXTENDS FROM NORTHERN
ARIZONA SOUTHEAST INTO CHIHUAHUA MEXICO. SOUTHERN ARIZONA LIES IN
DIVERGENCE AREA BETWEEN THESE TWO FEATURES. MORNING MODELS SLOWLY
MOVE THE BAJA LOW SLOWLY TO THE NORTH-NORTHEAST AND INCREASE UPWARD
VERTICAL MOTION FIELDS TONIGHT.

WITH THE INCREASED SUNSHINE THIS MORNING...TOWERING CUMULUS CLOUDS
ARE ALREADY DEVELOPING OVER THE HIGHER TERRAIN. THUNDERSTORMS THAT
DEVELOP EARLY THIS AFTERNOON WILL NOT MOVE OFF THE HIGHER TERRAIN
UNTIL LATER THIS AFTERNOON. STORMS THAT DEVELOP LATER THIS AFTERNOON
AND THIS EVENING WILL HAVE THE POTENTIAL FOR STRONG DOWNBURST
WINDS...ESPECIALLY FROM TUCSON WEST...AS AFTERNOON SOUNDINGS WILL
LIKELY HAVE AN INVERTED-V LOOK TO THEM. THUS WILL GO ABOVE
CLIMATOLOGY FROM TUCSON WEST. ALTHOUGH THE STORMS WILL BE MOVING
AROUND 15 TO 20 MPH WHICH WILL REDUCE THE RISK FOR FLASH
FLOODING...SOME OF THE STORMS MAY BE BIG ENOUGH TO PRODUCE HEAVY
RAINFALL. WILL SLIGHTLY GO ABOVE CLIMATOLOGY FROM TUCSON WEST.

STORM MOVEMENT WILL BE GENERALLY TO THE WEST AT 15 TO 20 MPH.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 2:06 PM MSTSevere Thunderstorm WarningTWCCochise24 min
Aug 19, 3:28 PM MSTSevere Thunderstorm WarningTWCSanta Cruz47 min
Aug 19, 3:55 PM MSTFlash Flood WarningTWCSanta Cruz35 min
Aug 19, 4:28 PM MSTSevere Thunderstorm WarningTWCPinal32 min
Aug 19, 4:32 PM MSTSevere Thunderstorm WarningTWCPima, Santa Cruz28 min
Aug 19, 4:54 PM MSTFlash Flood WarningTWCPinal21 min

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.