Alert archive / Arizona / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 29, NWS Tucson, AZ

July 19, 2009Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Jul 19, 2009, 4:28 PM MST for Pima County, Arizona. It was in force for 47 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 19, 2009, 4:28 PM MST (23:28 UTC)
Expired
Jul 19, 2009, 5:15 PM MST
In force
47 min
Issued by
NWS Tucson, AZ
Area
Storm-based polygon

County Pima County, AZ

The radar

The Tucson radar (KEMX), 32 km from the middle of the area, began a volume at 23:28 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Tuscon, AZ (KTUS), launched 12:00Z, 11.5 hours before the alert went out and 37 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 2009-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 61 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 2009-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -11 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
61 J/kg
Mixed-layer CIN
-512 J/kg
Mixed-layer LCL
3180 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-11 m²/s²
0-3 km storm-relative helicity
17 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 
WUUS55 KTWC 192328
SVRTWC
AZC019-200015-
/O.NEW.KTWC.SV.W.0029.090719T2328Z-090720T0015Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
428 PM MST SUN JUL 19 2009

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN PIMA COUNTY IN SOUTH CENTRAL ARIZONA...
  THIS INCLUDES THE CITY OF GREEN VALLEY...

* UNTIL 515 PM MST

* AT 427 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DESTRUCTIVE WINDS IN
  EXCESS OF 70 MPH.  THIS STORM WAS LOCATED 6 MILES EAST OF GREEN
  VALLEY...AND MOVING NORTHWEST AT 5 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  SAHUARITA

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXPECT DAMAGING WINDS IN EXCESS OF 60 MPH...LARGE HAIL...FREQUENT
LIGHTNING...AND HEAVY RAIN WITH THIS STORM.

&&

LAT...LON 3178 11111 3200 11101 3190 11076 3175 11082
TIME...MOT...LOC 2328Z 138DEG 5KT 3183 11090

$$
2 follow-up statements
000 
WWUS55 KTWC 192344
SVSTWC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
444 PM MST SUN JUL 19 2009

AZC019-200015-
/O.CON.KTWC.SV.W.0029.000000T0000Z-090720T0015Z/
PIMA AZ-
444 PM MST SUN JUL 19 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM MST 
FOR SOUTHEASTERN PIMA COUNTY...INCLUDING GREEN VALLEY AND 
SAHUARITA...

AT 441 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT THE STORM EAST OF GREEN VALLEY WAS DIMINISHING IN 
INTENSITY...BUT ANOTHER STORM WAS STRENGTHENING NEAR SAHUARITA WHICH 
WILL LIKELY PRODUCE DAMAGING WINDS AS WELL. THEREFORE...THE WARNING 
WILL REMAIN IN EFFECT UNTIL 515 PM MST. 

LAT...LON 3178 11111 3200 11101 3190 11076 3175 11082
TIME...MOT...LOC 2341Z 138DEG 5KT 3184 11091

$$
000 
WWUS55 KTWC 200010
SVSTWC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
510 PM MST SUN JUL 19 2009

AZC019-200018-
/O.EXP.KTWC.SV.W.0029.000000T0000Z-090720T0015Z/
PIMA AZ-
510 PM MST SUN JUL 19 2009

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN PIMA COUNTY 
INCLUDING GREEN VALLEY AND SAHUARITA WILL EXPIRE AT 515 PM MST...

THE THUNDERSTORMS THAT PROMPTED THE WARNING FOR THE GREEN VALLEY AND 
SAHUARITA AREAS HAD DIMINISHED IN INTENSITY AND WERE NO LONGER 
EXPECTED TO PRODUCE WINDS IN EXCESS OF 60 MPH. 

HOWEVER...ANOTHER SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR 
MUCH OF THE GREATER TUCSON AREA UNTIL 600 PM MST. THE MAIN THREAT 
FROM THESE STORMS WILL BE LOCALLY DAMAGING WINDS. 

LAT...LON 3178 11111 3200 11101 3190 11076 3175 11082
TIME...MOT...LOC 0008Z 138DEG 5KT 3187 11094

$$

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 Jul 19, 1:31 PM MST, 2 hours 57 minutes earlier.

Area forecast discussion, Jul 19, 1:31 PM MST, 2 hours 57 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
130 PM MST SUN JULY 19 2009

.SYNOPSIS...STRONG HIGH PRESSURE ALOFT WILL BRING HOT CONDITIONS TO
SOUTHEAST ARIZONA THROUGH AT LEAST THE MIDDLE OF THE WEEK. MOISTURE
WILL ALSO BE SUFFICIENT FOR THE DAILY CYCLE OF SCATTERED MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.

&&

.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 35-55 DBZ CELLS NEAR
THE CATALINA MOUNTAINS AS WELL AS FAR SRN PIMA COUNTY AND WRN SANTA
CRUZ COUNTY AT 2025Z. OTHER CELLS WERE JUST NE OF HANNAGAN MEADOW.
VISIBLE SATELLITE IMAGERY INDICATED CUMULOFORM CLOUDS DEVELOPING
ACROSS THE HIGHER TERRAIN OF THE FORECAST AREA. HAVE OPTED TO
MAINTAIN THE SCENARIO OF ISOLATED-SCATTERED SHOWERS AND TSTMS THE
REST OF THIS AFTERNOON AND INTO THIS EVENING. THE CONCERN WITH ANY
THUNDERSTORMS WILL BE THE POTENTIAL FOR LOCALIZED STRONG/GUSTY WINDS
PARTICULARLY GIVEN THE FAIRLY DRY SURFACE ENVIRONMENT. FOR INSTANCE
KTUS DEWPOINT WAS 45 F AT 2020Z. BULK OF ACTIVITY EXPECTED TO END
AROUND MIDNIGHT OR SO.

SYNOPTIC-SCALE PATTERN PROGGED TO EXHIBIT ONLY VERY MINOR CHANGES
THIS WEEK AS HIGH PRESSURE ALOFT TO REMAIN CENTERED OVER THE SWRN
CONUS. THUS MONSOON MOISTURE TO CONTINUE ACROSS THE AREA. BASED ON
19/12Z GFS/ECMWF SOLUTIONS...DIFFICULT TO DISCERN FEATURES WITHIN
THE FLOW THAT WOULD SIGNIFY A MORE-PRONOUNCED CONVECTIVELY-ACTIVE
DAY FROM ANOTHER. SO WILL CONTINUE TO DEPICT EITHER A SLIGHT CHANCE
OR LOW-END CHANCE-CATEGORY POPS DURING THE AFTERNOON AND EVENING
PERIODS. DAYTIME HIGH TEMPS DURING MUCH OF THIS FORECAST PERIOD TO
BE ABOUT 5-10 DEGS ABOVE NORMAL.

&&

.AVIATION...EXPECT ISOLATED TO SCATTERED TSRA/SHRA THE REST OF THIS
AFTERNOON AND EVENING. THE STRONGEST TSRA WILL BE ACCOMPANIED WITH
WIND GUSTS OF 40-45 KTS. OTHERWISE...SCATTERED TO BROKEN CUMULOFORM
CLOUDS WITH BASES 11-13K FT AGL. TSRA/SHRA TO DECREASE IN COVERAGE
AFTER 04Z AND ANY CONVECTIVE CLOUD DEBRIS TO DISSIPATE LATE TONIGHT.
SURFACE WINDS SWLY/WLY 5-15 KTS THRU 06Z THEN SLY/SELY 5-15 KTS LATE
TONIGHT AND INTO MONDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.

&&

.FIRE WEATHER...ISOLATED TO SCATTERED THUNDERSTORMS WILL OCCUR THIS
WEEK...WITH THE BULK OF ACTIVITY DURING THE AFTERNOON AND EARLY
NIGHTTIME HOURS. SURFACE WINDS GENERALLY FROM THE SOUTHWEST AND WEST
THE REST OF THIS AFTERNOON AND THIS EVENING...THEN A DIURNALLY
DRIVEN WIND REGIME ON TAP MONDAY INTO WEDNESDAY.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

BF

WEATHER.GOV/TUCSON
Hazardous weather outlook, Jul 19, 9:30 AM MST, 6 hours 58 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
930 AM MST SUN JUL 19 2009

AZZ019-030-034-035-201200-
NORTHERN GREENLEE COUNTY-UPPER GILA RIVER VALLEY-
SANTA CRUZ COUNTY-COCHISE COUNTY-
930 AM MST SUN JUL 19 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST
ARIZONA.

.DAY ONE...TODAY AND TONIGHT

EXPECT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE
AREA INTO THIS EVENING. THE STRONGEST STORMS MAY PRODUCE BRIEF
HEAVY RAIN AND WIND GUSTS UP TO 45 MPH. THE BULK OF THE ACTIVITY
IS FORECAST TO END BY AROUND MIDNIGHT.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THE DAILY CYCLE OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
IS EXPECTED MONDAY THROUGH SATURDAY...MAINLY DURING THE AFTERNOON
AND EARLY NIGHTTIME HOURS.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

AZZ029-031>033-201200-
SOUTHEAST PINAL COUNTY-WESTERN PIMA COUNTY-TOHONO OODHAM NATION-
TUCSON METRO/MARANA/GREEN VALLEY-
930 AM MST SUN JUL 19 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
ARIZONA AND SOUTHEAST ARIZONA.

.DAY ONE...TODAY AND TONIGHT

EXPECT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE
AREA INTO THIS EVENING. THE STRONGEST STORMS MAY PRODUCE BRIEF
HEAVY RAIN...WIND GUSTS UP TO 45 MPH...AND REDUCED VISIBILITIES
DUE TO BLOWING DUST. THE BULK OF THE ACTIVITY IS FORECAST TO END
BY AROUND MIDNIGHT. ALSO...NEAR RECORD HIGH TEMPERATURES ARE ON
TAP THIS AFTERNOON FOR SOUTHEAST PINAL AND PIMA COUNTIES.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THE DAILY CYCLE OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
IS EXPECTED MONDAY THROUGH SATURDAY...MAINLY DURING THE AFTERNOON
AND EARLY NIGHTTIME HOURS.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

WEATHER.GOV/TUCSON

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 4:55 PM MSTSevere Thunderstorm WarningTWCPima65 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2009Every severe thunderstorm warning in 2009

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.