Alert archive / Arkansas / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 405, NWS Tulsa, OK

August 18, 1998Washington County, Arkansas

NWS Tulsa, OK issued this severe thunderstorm warning at Aug 18, 1998, 4:47 PM CDT for Washington County, Arkansas. It was in force for 43 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 18, 1998, 4:47 PM CDT (21:47 UTC)
Expired
Aug 18, 1998, 5:30 PM CDT
In force
43 min
Issued by
NWS Tulsa, OK
Area
Whole counties

County Washington County, AR

The radar

The Western Arkansas radar (KSRX), 78 km from the middle of the area, began a volume at 21:51 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

Springfield, MO (KSGF), launched 12:00Z, 9.8 hours before the alert went out and 109 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, Springfield, MO at 12:00Z on 1998-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1016 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, Springfield, MO at 12:00Z on 1998-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 115 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
1016 J/kg
Mixed-layer CIN
-221 J/kg
Mixed-layer LCL
1469 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
115 m²/s²
0-3 km storm-relative helicity
142 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

302 
WUUS54 KTSA 182149 RRA
SVRTUL
ARC143-182230-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TULSA OK
447 PM CDT TUE AUG 18 1998

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...

  WASHINGTON COUNTY IN NORTHWESTERN ARKANSAS

* UNTIL 530 PM CDT

* AT 446 PM...RADAR DETECTED A SEVERE THUNDERSTORM 3 MILES NORTH OF
  FAYETTEVILLE...DRIFTING SLOWLY NORTHWEST.

* SOME LOCATIONS AFFECTED INCLUDE...
  SPRINGDALE
  FAYETTEVILLE

  HAIL TO THE SIZE OF DIMES AND WIND GUSTS TO 60 MPH CAN BE EXPECTED
  IN THE WARNED AREA.

BE ALERT TO RAPIDLY CHANGING WEATHER CONDITIONS AS STORMS APPROACH.

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 Aug 18, 3:50 PM CDT, 57 minutes earlier.

Area forecast discussion, Aug 18, 3:50 PM CDT, 57 minutes before
EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
350 PM CDT TUE AUG 18 1998

PATTERN LOOKING FAIRLY SIMILAR THROUGH THE SHORT RANGE FORECAST.
SYSTEMS WILL MOVE ALONG IN THE EASTERLY FLOW GENERALLY TO THE SOUTH
OF THE FORECAST AREA. THUS BELIEVE THAT MOST IF NOT ALL PRECIPITATION
WILL BE DIURNAL IN SOUTHERN AND EASTERN ZONES. WILL CONTINUE TO
MENTION ISOLATED AFTERNOON AND EVENING THUNDERSTORMS IN THESE AREAS.
ELSEWHERE IT SHOULD REMAIN DRY. LOW LEVEL FLOW GRADUALLY BECOMES MORE
EASTERLY. MAXIMUM TEMPERATURES LOOK NEARLY AS WARM ON WEDNESDAY
COMPARED TO TODAY BUT THEN DROPPED THEM JUST A LITTLE BIT BY
THURSDAY.

MEDIUM RANGE MODELS SHOW THE UPPER RIDGE ONCE AGAIN RETROGRADING INTO
THE ROCKIES DURING THE WEEKEND. THIS WILL RESULT IN WEAK NORTHWEST
FLOW DEVELOPING ACROSS EASTERN OKLAHOMA AND NORTHWEST ARKANSAS.
BELIEVE THE MEDIUM RANGE FORECAST MODEL IS OVERDONE WITH A SHORTWAVE
COMING ACROSS THE PLAINS AND SO FOR NOW WILL KEEP THE STATUS QUO WITH
A DRY FORECAST IN THE EXTENDED PERIODS.

TUL   76  97  75  95 /   0   0   0   0
FSM   71  97  70  94 /  10  10  10  10
MLC   74  98  73  95 /   0   0   0   0
BVO   72  99  71  96 /   0   0   0   0
FYV   69  94  68  92 /  10  10  10  10
IDB   70  98  69  95 /  10  10  10  10
BYV   67  94  66  91 /  10  10  10  10
MIO   72  94  71  93 /   0   0   0  10
MKO   72  97  71  95 /   0   0   0  10
F10   74  98  73  95 /   0   0
0   0
HHW   73  99  72  96 /  10  10  10  10

.TUL...
OK...NONE.
AR...NONE.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 4:56 PM CDTSevere Thunderstorm WarningTSABenton34 min
Aug 18, 5:53 PM CDTSevere Thunderstorm WarningTSABenton52 min
Aug 18, 6:00 PM CDTFlash Flood WarningTSABenton90 min

Nearby

Severe Thunderstorm Warnings in Arkansas, 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.