Alert archive / Arizona / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 24, NWS Flagstaff, AZ
NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 31, 1998, 3:29 PM MDT for Navajo County, Arizona. It was in force for 46 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 31, 1998, 3:29 PM MDT (21:29 UTC)
- Expired
- Jul 31, 1998, 4:15 PM MDT
- In force
- 46 min
- Issued by
- NWS Flagstaff, AZ
- Area
- Whole counties
County Navajo County, AZ
The radar
The Flagstaff radar (KFSX), 122 km from the middle of the area, began a volume at 21:32 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, 9.5 hours before the alert went out and 136 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1625 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 39 m²/s²
- 0-3 km storm-relative helicity
- 53 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
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 31, 3:07 PM MDT, 22 minutes earlier.
Area forecast discussion, Jul 31, 3:07 PM MDT, 22 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FLAGSTAFF AZ 207 PM MST FRI JUL 31 1998 SYNOPSIS...SOME LOW LEVEL MOISTURE REMAINING OVER EASTERN ARIZONA WILL CONTINUE TO CAUSE SOME AFTERNOON SHOWERS AND THUNDERSTORMS TO DEVELOP THROUGH SATURDAY IN THE EAST CENTRAL MOUNTAINS. OVER THE REMAINDER OF NORTHERN ARIZONA...SUNNY MORNINGS...WITH A FEW CLOUDS DEVELOPING OVER THE HIGHER TERRAIN WILL BE THE RULE. DISCUSSION...LOW TO MID LEVEL RH OVER THE EASTERN HALF OF CWA...WITH A DECENT MOISTURE GRADIENT CUTTING N-S THROUGH THE AREA. SOME EFFICIENT PRECIP PRODUCING STORMS HAVE DEVELOPED ALONG THE SOUTHERN EDGE OF THIS BOUNDARY IN GILA COUNTY. FURTHER N...ATMOSPHERE A BIT MORE STABLE...AND ALTHOUGH SOME CONVECTION HAS OCCURRED...IT HAS NOT BEEN QUITE AS STRONG OVER THE NE. THIS COULD CHANGE A CAP ERODES THIS AFTERNOON. 12Z ETA CONTINUING THE TREND OF DRYING CWA OUT...AND IS MORE AGGRESSIVE WITH THIS THAN THE AVN-NGM. PREFER NGM THE BEST AS IT KEEPS RH HANGING AROUND FOR A WHILE. AS TROUGH OVER S NV-UT LIFTS OUT...WE SHOULD SEE HEIGHTS AND THICKNESS REBOUND SOME WHICH WILL BRING A DEGREE OR TWO OF WARMING INTO THE AREA. OTHERWISE WILL KEEP DRY CONDITIONS IN THE WEST...WITH ISOLD TO SCT POPS OVER THE EASTERN PORTIONS OF THE CWA. IN THE EXTENDED...WITH DECENT NORTHWESTERLY FLOW CONTINUING MONDAY...IT SHOULD REMAIN DRY. THE 5H RIDGE BUILDS BACK IN...AND SUSPECT THAT MONSOONAL FLOW WILL TAKE OVER ONCE AGAIN...ALLOWING FOR THE DEVELOPMENT OF AFTERNOON SHOWERS AND THUNDERTORMS FOR DAY 4 AND 5 OF THE PERIOD. MCGRATH FLG 0000 INW 21-- FLG...NONE.
In the hours before
Special weather statement, Jul 31, 10:05 AM MDT, 5 hours 24 minutes before
AZZ004>018-311900- AREA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE FLAGSTAFF AZ 905 AM MST FRI JUL 31 1998 ...ISOLATED THUNDERSTORMS EXPECTED OVER THE MOUNTAINS OF EAST CENTRAL ARIZONA TODAY... SPOTTER ACTIVATION SHOULD NOT BE REQUIRED TODAY. DISCUSSION...DRYER AIR WILL CONTINUE TO SETTLE IN OVER MOST OF NORTHERN ARIZONA TODAY...AS A DISTURBANCE PASSES TO OUR NORTH. THIS DISTURBANCE WILL INCREASE DRY SOUTHWEST FLOW AT THE MID LEVELS. NEAR THE SURFACE...SOME MOISTURE REMAINS...BUT NOT QUITE ENOUGH TO CAUSE THUNDERSTORM DEVELOPMENT OVER MOST OF NORTHERN ARIZONA. HOWEVER... AREAS SUCH AS THE WHITE MOUNTAINS AND ALONG THE MOGOLLON RIM EAST OF FLAGSTAFF WILL SEE SOME ISOLATED SHOWERS AND THUNDERSTORMS BY EARLY THIS AFTERNOON. THESE THUNDERSTORMS ARE NOT EXPECTED TO REACH SEVERE LIMITS. MCGRATH
The office that day
Everything else NWS Flagstaff, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 31, 1:54 PM MDT | Flash Flood Warning | FGZ | Gila | 2 hr |
| Jul 31, 3:29 PM MDT | Severe Thunderstorm Warning | FGZ | Apache | 46 min |
| Jul 31, 4:27 PM MDT | Flash Flood Warning | FGZ | Navajo | 2 hr |
Nearby
Severe Thunderstorm Warnings in Arizona, 1998Every severe thunderstorm warning in 1998
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.