Alert archive / Arizona / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 13, NWS Flagstaff, AZ

July 26, 1999Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 26, 1999, 6:06 PM MST for Coconino County, Arizona. It was in force for 44 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 26, 1999, 6:06 PM MST (01:06 UTC)
Expired
Jul 26, 1999, 6:50 PM MST
In force
44 min
Issued by
NWS Flagstaff, AZ
Area
Whole counties

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 150 km from the middle of the area, began a volume at 01:09 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 00:00Z, 1.1 hours before the alert went out and 68 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 1999-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 178 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 1999-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 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
178 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
1539 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
34 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFLG 270111
SVRFLG
AZC005-270150-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
606 PM MST MON JUL 26 1999

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN COCONINO COUNTY IN NORTH CENTRAL ARIZONA

* UNTIL 650 PM MST

* AT 554 PM MST...  NATIONAL WEATHER SERVICE DOPPLER RADAR
  INDICATED A SEVERE THUNDERSTORM 64 MILES SOUTHEAST OF FLAGSTAFF
  OR 12 MILES NORTH OF FOREST LAKES... MOVING NORTHWEST AT 10 MPH.


* THE SEVERE THUNDERSTORM WILL BE NEAR...
  CHEVELON CANYON CAMPGROUND IN BY 610 PM MST
  FOREST SERVICE ROAD 169 NEAR DIP ROAD BY 625 PM MST
  WALLACE ROAD AT OR NEAR FOREST ROAfD 211 BY 645 PM MST

DAMAGING WINDS AND HEAVY RAIN ARE LIKELY. GO INSIDE A STURDY
BUILDING AND STAY AWAY FROM WINDOWS!

JD

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 26, 2:30 PM MST, 3 hours 36 minutes earlier.

Area forecast discussion, Jul 26, 2:30 PM MST, 3 hours 36 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST MON JUL 26 1999

SYNOPSIS...A MOIST AIR MASS WILL REMAIN ACROSS NORTHERN ARIZONA
WITH WIDESPREAD AFTERNOON SHOWERS AND THUNDERSTORMS OCCURRING
THROUGH MOST OF THE COMING WEEK. DAYTIME TEMPERATURES WILL
REMAIN NEAR SEASONAL NORMALS.

DISCUSSION...THE AIR MASS OVER CENTRAL AND WESTERN PORTIONS OF
ARIZONA WILL REMAIN MOIST THE NEXT COUPLE OF DAYS. THE GOES
SOUNDER PRECIPITABLE WATER PRODUCT WAS SHOWING VALUES IN THE 1.5 TO
2.0 INCH RANGE FROM YAVAPAI COUNTY SOUTHWARD INTO MEXICO DURING THE
AFTERNOON. THE 12Z ETA IS CONTINUING THIS TREND OVER THE NEXT 48-
HOUR PERIOD. WITH THIS MUCH MOISTURE IMPINGING ON THE TERRAIN OF
NORTHERN ARIZONA THUNDERSTORMS ARE SURE TO DEVELOP EACH DAY. THE
SUBTROPICAL RIDGE WILL CONTINUE TO PROPAGATE WESTWARD TOWARDS THE
FOUR-CORNERS REGION AND IN RESPONSE THE GREAT BASIN THERMAL LOW IS
CERTAIN TO INTENSIFY. AS A RESULT CAN SEE NO END IN
SIGHT TO THE NORTHWARD STREAM OF MOISTURE FROM MEXICO. THE SHEAR
ALOFT ON TUESDAY WILL BE SOMEWHAT BETTER FOR HEAVY RAIN PRODUCING
STORMS WITH 5 TO 10 KT SOUTH WINDS BELOW 500 MB AND 10 TO 20 KT
FLOW ABOVE 400 MB. CELLS THAT FORM WILL BE LESS TILTED AND SLOWER
MOVING WITH TRAINING BEHAVIOR ONCE AGAIN LIKELY. ALSO...AS AN
INVERTED TROUGH...CURRENTLY OVER BIG BEND COUNTRY IN TEXAS...MOVES
INTO ARIZONA FROM THE SOUTHEAST ON TUESDAY EXPECT ABSOLUTE
VORTICITY ABOVE 300 MB TO LOWER AGAIN WITH WEAK INERTIAL STABILITY
POSSIBLY DEVELOPING ALONG WITH LARGER SCALE ORGANIZATION (MODELS
ARE TO BE INTERPRETED WITH GREAT CAUTION OUT PAST 18 HOURS THIS
TIME OF YEAR). IN ANY CASE THERE PROBABLY WILL BE AN UPSWING IN THE
COVERAGE OF HEAVY RAINFALL ON TUESDAY. STORMS WILL REMAIN NUMEROUS
ALONG THE MOGOLLON RIM INTO YAVAPAI AND COCONINO COUNTIES AND
ISOLATED ALONG THE UTAH BORDER AND NORTHEAST. OTHERWISE...NO
CHANGES TO THE CURRENT POP..TEMPERATURE AND WIND FORECAST TRENDS.

IN THE EX8TENDED...MID TO UPPER HIGH PRESSURE WILL GRADUALLY
PROPAGATE WESTWARD ACROSS THE FOUR CORNERS AREA AND INTO SOUTHERN
UTAH. AS A RESULT AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO CONTINUE.

MCCOLLUM

.FLG...NONE.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 11:45 AM MSTSevere Thunderstorm WarningFGZYavapai45 min

Nearby

Severe Thunderstorm Warnings in Arizona, 1999Every severe thunderstorm warning in 1999

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.