Alert archive / Oklahoma / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 93, NWS Tulsa, OK

April 5, 1999Okfuskee County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Apr 5, 1999, 7:30 AM CDT for Okfuskee County, Oklahoma. It was in force for 45 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Apr 5, 1999, 7:30 AM CDT (12:30 UTC)
Expired
Apr 5, 1999, 8:15 AM CDT
In force
45 min
Issued by
NWS Tulsa, OK
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Okfuskee County, OK

The radar

The Norman radar (KTLX), 88 km from the middle of the area, began a volume at 12:33 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.

What was reported inside it

TimeReportWhereRemark
Apr 5, 8:10 AM CDTThunderstorm Wind 57Weleetka, OK

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Lamont, OK (KLMN), launched 12:00Z, 0.5 hours before the alert went out and 165 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, Lamont, OK at 12:00Z on 1999-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1211 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, Lamont, OK at 12:00Z on 1999-04-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1513 square meters per square second.1939587897117136156175Sfc1 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
1211 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
593 m above ground
0-6 km bulk shear
139 kt
0-1 km storm-relative helicity
1513 m²/s²
0-3 km storm-relative helicity
1962 m²/s²
Significant tornado parameter
14.2
Supercell composite
52.4

Open this sounding in Storm Lab

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 Tulsa, OK wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 5, 5:00 AM CDT, 2 hours 30 minutes earlier.

Area forecast discussion, Apr 5, 5:00 AM CDT, 2 hours 30 minutes before
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In the hours before

Special weather statement, Apr 5, 6:05 AM CDT, 1 hour 25 minutes before
ARZ001-002-010-011-019-020-029-OKZ049-053>076-061200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
605 AM CDT MON APR 5 1999

...A FEW SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS EASTERN OKLAHOMA AND
NORTHWEST ARKANSAS THIS MORNING AND AFTERNOON...

.SYNOPSIS...
A STRONG UPPER LEVEL LOW PRESSURE SYSTEM OVER NORTHERN NEW MEXICO EARLY
THIS MORNING WILL LIFT INTO WESTERN KANSAS BY THIS AFTERNOON.
MEANWHILE...SURFACE LOW PRESSURE ACROSS NORTHWEST OKLAHOMA WILL MOVE
INTO NORTHEASTERN KANSAS...WITH A DRYLINE PUSHING INTO FAR EASTERN
OKLAHOMA THIS AFTERNOON.

.DISCUSSION...
THE AIRMASS ACROSS EASTERN OKLAHOMA REMAINS VERY MOIST AND UNSTABLE THIS
MORNING...WITH SURFACE DEWPOINTS IN THE LOWER TO MID 60S.  STRONG
SOUTHERLY TO SOUTHEASTERLY LOW-LEVEL WINDS WILL RESULT IN CONTINUED
STRONG LIFT ACROSS THE REGION.  AN INITIAL BAND OF SHOWERS AND A FEW
THUNDERSTORMS WILL MOVE ACROSS EASTERN OKLAHOMA EARLY THIS MORNING
BETWEEN 6 AM AND 9 AM....BUT THIS ACTIVITY SHOULD REMAIN BELOW SEVERE
LIMITS.

MEANWHILE...A SECONDARY LINE OF THUNDERSTORMS OVER SOUTH CENTRAL
OKLAHOMA EARLY THIS MORNING WILL CONTINUE TO MOVE QUICKLY NORTHEAST.
THESE THUNDERSTORMS SHOULD REMAIN STRONG TO SEVERE AS THE DRYLINE
PUNCHES INTO CENTRAL OKLAHOMA AND COOLER TEMPERATURES ALOFT SPREAD EAST.
THIS ACTIVITY SHOULD EVENTUALLY FORM INTO A BROKEN SQUALL LINE...AND
MOVE THROUGH EASTERN OKLAHOMA AFTER 9 AM AND EVENTUALLY REACH NORTHWEST
ARKANSAS AROUND 11 AM.  STRONG STRAIGHT-LINE WINDS WILL BE THE PRIMARY
SEVERE WEATHER THREAT.

THE SEVERE WEATHER THREAT SHOULD DIMINISH AFTER 2 TO 3 PM AS THE LINE OF
THUNDERSTORMS MOVES FARTHER EAST INTO ARKANSAS.

.EMERGENCY AGENCY AND SPOTTER ACTIVATION...
STORM SPOTTER ACTIVATION MAY BE NEEDED THIS MORNING ACROSS EASTERN
OKLAHOMA AND NORTHWEST ARKANSAS.

AN UPDATED HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED AROUND 1 PM.
Special weather statement, Apr 5, 6:05 AM CDT, 1 hour 25 minutes before
ARZ001-002-010-011-019-020-029-OKZ049-053>076-061200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
605 AM CDT MON APR 5 1999

...A FEW SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS EASTERN OKLAHOMA AND
NORTHWEST ARKANSAS THIS MORNING AND AFTERNOON...

.SYNOPSIS...
A STRONG UPPER LEVEL LOW PRESSURE SYSTEM OVER NORTHERN NEW MEXICO EARLY
THIS MORNING WILL LIFT INTO WESTERN KANSAS BY THIS AFTERNOON.
MEANWHILE...SURFACE LOW PRESSURE ACROSS NORTHWEST OKLAHOMA WILL MOVE
INTO NORTHEASTERN KANSAS...WITH A DRYLINE PUSHING INTO FAR EASTERN
OKLAHOMA THIS AFTERNOON.

.DISCUSSION...
THE AIRMASS ACROSS EASTERN OKLAHOMA REMAINS VERY MOIST AND UNSTABLE THIS
MORNING...WITH SURFACE DEWPOINTS IN THE LOWER TO MID 60S.  STRONG
SOUTHERLY TO SOUTHEASTERLY LOW-LEVEL WINDS WILL RESULT IN CONTINUED
STRONG LIFT ACROSS THE REGION.  AN INITIAL BAND OF SHOWERS AND A FEW
THUNDERSTORMS WILL MOVE ACROSS EASTERN OKLAHOMA EARLY THIS MORNING
BETWEEN 6 AM AND 9 AM....BUT THIS ACTIVITY SHOULD REMAIN BELOW SEVERE
LIMITS.

MEANWHILE...A SECONDARY LINE OF THUNDERSTORMS OVER SOUTH CENTRAL
OKLAHOMA EARLY THIS MORNING WILL CONTINUE TO MOVE QUICKLY NORTHEAST.
THESE THUNDERSTORMS SHOULD REMAIN STRONG TO SEVERE AS THE DRYLINE
PUNCHES INTO CENTRAL OKLAHOMA AND COOLER TEMPERATURES ALOFT SPREAD EAST.
THIS ACTIVITY SHOULD EVENTUALLY FORM INTO A BROKEN SQUALL LINE...AND
MOVE THROUGH EASTERN OKLAHOMA AFTER 9 AM AND EVENTUALLY REACH NORTHWEST
ARKANSAS AROUND 11 AM.  STRONG STRAIGHT-LINE WINDS WILL BE THE PRIMARY
SEVERE WEATHER THREAT.

THE SEVERE WEATHER THREAT SHOULD DIMINISH AFTER 2 TO 3 PM AS THE LINE OF
THUNDERSTORMS MOVES FARTHER EAST INTO ARKANSAS.

.EMERGENCY AGENCY AND SPOTTER ACTIVATION...
STORM SPOTTER ACTIVATION MAY BE NEEDED THIS MORNING ACROSS EASTERN
OKLAHOMA AND NORTHWEST ARKANSAS.

AN UPDATED HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED AROUND 1 PM.

The office that day

Everything else NWS Tulsa, OK issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 4, 7:10 PM CDTSevere Thunderstorm WarningTSAAdair, Sequoyah35 min
Apr 4, 7:42 PM CDTSevere Thunderstorm WarningTSAAdair33 min
Apr 5, 8:01 AM CDTSevere Thunderstorm WarningTSAMcIntosh, Okmulgee44 min
Apr 5, 10:51 AM CDTSevere Thunderstorm WarningTSAAdair, Sequoyah39 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.