Alert archive / Arizona / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 46, NWS Flagstaff, AZ

September 7, 2002Yavapai County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Sep 7, 2002, 3:35 PM MST for Yavapai 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 as issued.

The facts

Issued: Sep 7, 2002, 3:35 PM MST (22:35 UTC)
Expired: Sep 7, 2002, 4:10 PM MST
In force: 35 min
Issued by: NWS Flagstaff, AZ
Area: Counties, with a storm outline in the text

County Yavapai County, AZ

The radar

The Phoenix radar (KIWA), 174 km from the middle of the area, began a volume at 22:35 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

Phoenix, AZ (KPSR), launched 12:00Z, 10.6 hours before the alert went out and 143 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: 146 J/kg
Mixed-layer CIN: -210 J/kg
Mixed-layer LCL: 1553 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 38 m²/s²
0-3 km storm-relative helicity: 62 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

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

050 
WUUS55 KFGZ 072235
SVRFGZ
AZC025-072310-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
334 PM MST SAT SEP 7 2002

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN YAVAPAI COUNTY IN WEST CENTRAL ARIZONA

* UNTIL 410 PM MST

* AT 334 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER SOUTHWESTERN YAVAPAI COUNTY...OR ABOUT 26
  MILES WEST OF YARNELL...MOVING NORTHEAST AT 25 MPH.

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM MST
SATURDAY EVENING FOR NORTHEASTERN ARIZONA.

LAT...LON 3425 11331 3412 11317 3426 11284 3447 11307

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 Sep 7, 2:55 PM MST, 40 minutes earlier.

Area forecast discussion, Sep 7, 2:55 PM MST, 40 minutes before

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
255 PM MST SAT SEP 07 2002

.SYNOPSIS...DEEP MOISTURE WILL CONTINUE TO AFFECT THE STATE WELL
INTO THE COMING WEEK. EXPECT WIDESPREAD SHOWERS AND THUNDERSTORMS TO
CONTINUE INTO TUESDAY...BEFORE BECOMING MORE SCATTERED LATER IN THE
WEEK. SOME STORMS MAY CONTAIN VERY HEAVY RAIN OVER THE NEXT FEW
DAYS. TEMPERATURES WILL BE BELOW NORMAL.

.DISCUSSION...FIRST WELL ORGANIZED BAND OF CONVECTION ASSOCIATED
WITH THIS MORNINGS JET ENTRANCE REGION IS MOVING NORTHEAST AND WILL
EVENTUALLY EXIT THE STATE. A SMALL REGION OF SUBSIDENCE TRAILING
THIS CONVECTIVE MASS IS NOW QUICKLY FILLING IN OVER SOUTHERN
ARIZONA. THIS IS IN RESPONSE TO ANOTHER WELL-DEFINED JET STREAK
MOVING TOWARDS THE SOUTHERN CALIFORNIA COASTLINE. THIS STREAK WILL
BRING A PROLONGED PERIOD OF UPPER LEVEL DIV TO THE FORECAST AREA
INTO MONDAY. MOISTURE IS SO DEEP ACROSS THE AREA...THAT ANY FURTHER
INCREASE IS NOT LIKELY...OR NECESSARY. EXPECT CONVECTION TO DEVELOP
AGAIN OVER YAVAPAI COUNTY AND POINTS SOUTH...ADVECTING BACK INTO THE
FORECAST AREA THIS AFTERNOON AND EVENING. THIS WILL CONTINUE INTO
SUNDAY AND MONDAY...WITH SEVERAL AREAS OF ORGANIZED CONVECTION
LIKELY. WILL CONTINUE THE FLASH FLOOD WATCH UNTIL MIDNIGHT AND THE
SEVERE THUNDERSTORM WATCH LOOKS GOOD INTO THE EVENING HOURS. PAST
MONDAY...MOISTURE BEGINS TO MOVE VERY SLOWLY EAST OF THE AREA. WILL
CARRY SCATTERED POPS EVERYWHERE INTO THURSDAY...BUT THEN JUST OVER
THE RIM AND THE WHITES FRIDAY AND SATURDAY. WILL HAVE TO WATCH THE
REMAINS OF T.D. 11 AS WELL AS T.D. FAY FOR ANY MOISTURE INTRUSIONS
FOR THE NEXT SEVERALS DAYS. THIS COULD EASILY PROLONG OUR MOIST
PERIOD PAST CURRENT MODEL FORECASTS. PETERSON.

.FGZ...SEVERE THUNDERSTORM WATCH UNTIL 8 PM MST.
       FFA UNTIL MIDNIGHT FOR AZZ004>009-012-015-016-018-037-038.

.CODED TEMPERATURES/POPS FOR SELECTED CITIES IN NORTHERN ARIZONA

CITY             TEMPERATURES HI/LO           PROBABILITY OF PRECIP
                 TDY TON   SUN     MON        TDY TON   SUN   MON
FLAGSTAFF        070/049 070/048 071/047      080 080 070 050 060 050
WINSLOW          081/060 080/058 081/057      070 080 060 040 050 050
PRESCOTT         079/058 079/057 080/056      080 080 060 040 050 050
PAGE             076/062 077/061 080/060      080 080 060 040 050 050
WINDOW ROCK      079/052 078/051 079/050      070 080 060 050 060 050
CANYON DE CHELLY 085/059 084/058 085/057      050 050 050 060 050 050
COTTONWOOD       090/066 090/065 091/064      060 070 060 050 040 040
GRAND CANYON     071/050 071/049 072/048      070 080 060 060 040 050
GREER            067/048 067/047 068/046      050 070 060 060 040 050
HEBER            075/052 075/051 076/050      060 080 060 060 040 050
JACOB LAKE       067/049 067/048 068/047      060 070 050 050 040 040
NAVAJO N.M.      077/058 076/057 077/056      050 050 050 060 050 050
PAYSON           083/058 083/057 084/056      050 060 050 050 040 050
SEDONA           087/065 087/064 088/063      060 070 060 050 040 040
SELIGMAN         082/051 082/050 083/049      070 080 060 060 040 050
SHOW LOW         076/058 076/057 077/056      050 070 060 060 040 050
ST. JOHNS        077/056 076/054 077/053      040 060 050 050 040 040
WUPATKI N.M.     083/062 082/060 083/059      050 060 050 050 040 040

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 6, 9:15 PM MST	Flash Flood Warning	FGZ	Coconino, Gila, Navajo, Yavapai	9 hr
Sep 7, 10:16 AM MST	Severe Thunderstorm Warning	FGZ	Yavapai	29 min
Sep 7, 11:13 AM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	32 min
Sep 7, 11:42 AM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	33 min
Sep 7, 12:13 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	47 min
Sep 7, 12:20 PM MST	Flash Flood Warning	FGZ	Coconino	115 min
Sep 7, 12:21 PM MST	Flash Flood Warning	FGZ	Coconino	3 hr
Sep 7, 12:41 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	34 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2002 Every severe thunderstorm warning in 2002

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.