Alert archive / Arizona / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 21, NWS Flagstaff, AZ
NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 16, 1999, 2:36 PM MST for Coconino County, Arizona. It was in force for 29 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
- Aug 16, 1999, 2:36 PM MST (21:36 UTC)
- Expired
- Aug 16, 1999, 3:05 PM MST
- In force
- 29 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 21:35 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.
The nearest sounding before it
Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 9.6 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.
- Mixed-layer CAPE
- 228 J/kg
- Mixed-layer CIN
- -64 J/kg
- Mixed-layer LCL
- 1220 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 18 m²/s²
- 0-3 km storm-relative helicity
- 49 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KFLG 162139 RRA SVRFLG AZC005-162210- - BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE FLAGSTAFF AZ 236 PM MST MON AUG 16 1999 THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHEASTERN COCONINO COUNTY IN NORTH CENTRAL ARIZONA * UNTIL 305 PM MST * AT 232 PM MST... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 22 MILES NORTHWEST OF HEBER OR 22 MILES NORTH OF FOREST LAKES... MOVING NORTHEAST AT 10 MPH. *THE SEVERE THUNDERSTORM WILL BE NEAR... HIGHWAY 99 NEAR CHEVLON BUTTE AT 245. DAMAGING WINDS AND LARGE HAIL ARE LIKELY. GO INSIDE A STURDY BUILDING AND STAY AWAY FROM WINDOWS! j TW
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, 2:30 PM MST, 6 minutes earlier.
Area forecast discussion, Aug 16, 2:30 PM MST, 6 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FLAGSTAFF AZ 230 PM MST MON AUG 16 1999 SYNOPSIS...SLIGHTLY DRIER AIR WILL MOVE INTO ARIZONA ON TUESDAY WITH FEWER SHOWERS AND THUNDERSTORMS. A STRENGTHENING HIGH PRESSURE SYSTEM WILL MOVE BACK OVER THE FOUR CORNERS BY WEDNESDAY WITH AN INCREASE IN MOISTURE AND RAIN FALL POTENTIAL THROUGH THE END OF THE WEEK. DISCUSSION...ACTIVE THIS AFTERNOON OVER THE WESTERN RIM TO THE NORTH AND WEST ACROSS THE CANYON AND INTO THE NORTH KAIBAB. STEERING WIND WILL PUSH THE STORMS OFF THE RIM AND TO THE NORTHEAST THIS EVENING. FOUR CORNER HIGH PRESSURE WILL ELONGATE AND MOVE WEST SOME ON TUESDAY AND DRIER AIR WILL MOVE OVER THE NORTHERN PART OF THE STATE. WILL STILL LEAVE IN SLIGHT CHANCE DURING THE DAY ON TUESDAY AND END SHOWER AND THUNDERSTORM ACTIVITY EARLY TUESDAY EVENING. HIGH PRESSURE RE-CENTERS OVER FOUR CORNERS ON WEDNESDAY AND WILL CIRCULATE MORE MOISTURE INTO THE STATE AND WILL INCREASE CHANCE OF PRECIPITATION. EASTERLY WAVE SEEN ON WATER VAPOR IMAGERY JUST OFF THE SOUTHERN TIP OF TEXAS IS PROGED BY THE AVN TO REACH SOUTHERN AZ BY WEDNESDAY MORNING. THIS WILL ALSO HELP INCREASE MOISTURE OVER N AZ. EXTENDED...THE MRF KEEPS THE HIGH PRESSURE CENTERED OVER THE FOUR CORNERS AREA FOR A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE PERIOD. MAS .FLG...NONE.
In the hours before
Special weather statement, Aug 16, 9:30 AM MST, 5 hours 6 minutes before
AZZ004>018-037>040-162000- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE FLAGSTAFF AZ 930 AM MST MON AUG 16 1999 ...SHOWERS AND THUNDERSTORMS EXPECTED OVER MOST OF NORTHERN ARIZONA TODAY... ...SPOTTER REPORTS REQUESTED FOR HEAVY RAIN... DISCUSSION...MOISTURE STILL REMAINS ACROSS THE STATE TODAY AND SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP BY LATE MORNING. THE HIGHEST CONCENTRATION OF MOISTURE IS OVER THE LITTLE COLORADO RIVER VALLEY AND NORTHERN APACHE AND NAVAJO COUNTIES. BECAUSE OF THIS...MORE SHOWERS ARE EXPECTED HERE AND THUNDERSTORMS WHICH DO DEVELOP WILL MOSTLY CONTAIN HEAVY RAIN. EXPECT CONVECTION TO DEVELOP FIRST OVER THE RIM COUNTRY...INCLUDING THE KAIBAB PLATEAU AND THEN MOVE NORTHEAST OVER THE VALLEYS AND DESERTS. THE STRONGER AND MORE ORGANIZED STORMS ARE MOST LIKELY TO DEVELOP OVER THE LITTLE COLORADO RIVER VALLEY AND MOVE NORTHEAST. STORM ACTIVITY SHOULD START DEVELOPING BY 11 AM MST TO 12 PM MST THIS MORNING. MAS
Special weather statement, Aug 16, 9:30 AM MST, 5 hours 6 minutes before
AZZ004>018-037>040-162000- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE FLAGSTAFF AZ 930 AM MST MON AUG 16 1999 ...SHOWERS AND THUNDERSTORMS EXPECTED OVER MOST OF NORTHERN ARIZONA TODAY... ...SPOTTER REPORTS REQUESTED FOR HEAVY RAIN... DISCUSSION...MOISTURE STILL REMAINS ACROSS THE STATE TODAY AND SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP BY LATE MORNING. THE HIGHEST CONCENTRATION OF MOISTURE IS OVER THE LITTLE COLORADO RIVER VALLEY AND NORTHERN APACHE AND NAVAJO COUNTIES. BECAUSE OF THIS...MORE SHOWERS ARE EXPECTED HERE AND THUNDERSTORMS WHICH DO DEVELOP WILL MOSTLY CONTAIN HEAVY RAIN. EXPECT CONVECTION TO DEVELOP FIRST OVER THE RIM COUNTRY...INCLUDING THE KAIBAB PLATEAU AND THEN MOVE NORTHEAST OVER THE VALLEYS AND DESERTS. THE STRONGER AND MORE ORGANIZED STORMS ARE MOST LIKELY TO DEVELOP OVER THE LITTLE COLORADO RIVER VALLEY AND MOVE NORTHEAST. STORM ACTIVITY SHOULD START DEVELOPING BY 11 AM MST TO 12 PM MST THIS MORNING. MAS
The office that day
Everything else NWS Flagstaff, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 16, 12:44 PM MST | Severe Thunderstorm Warning | FGZ | Coconino | 31 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.