Alert archive / Tennessee / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 201, NWS Morristown, TN
NWS Morristown, TN issued this severe thunderstorm warning at May 20, 1998, 6:58 PM EDT for Johnson County, Tennessee. It was in force for 32 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
- May 20, 1998, 6:58 PM EDT (22:58 UTC)
- Expired
- May 20, 1998, 7:30 PM EDT
- In force
- 32 min
- Issued by
- NWS Morristown, TN
- Area
- Whole counties
County Johnson County, TN
The nearest sounding before it
Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 11.0 hours before the alert went out and 180 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
- 68 J/kg
- Mixed-layer CIN
- -336 J/kg
- Mixed-layer LCL
- 1739 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 198 m²/s²
- 0-3 km storm-relative helicity
- 246 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
028 WUUS01 KMRX 202257 RRA SVRMRX TNC091-202330- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE KNOXVILLE/TRI-CITIES TN 658 PM EDT WED MAY 20 1998 THE NATIONAL WEATHER SERVICE IN KNOXVILLE/TRI-CITIES HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... JOHNSON COUNTY IN EASTERN TENNESSEE * UNTIL 730 PM EDT * AT 658 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 8 MILES NORTHEAST OF MOUNTAIN CITY... MOVING SOUTHEAST AT 10 MPH. DAMAGING WINDS AND LARGE HAIL ARE LIKELY. GO INSIDE A STURDY BUILDING AND STAY AWAY FROM WINDOWS
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 Morristown, TN wrote its last area forecast discussion before this severe thunderstorm warning went out at May 20, 2:50 PM EDT, 4 hours 8 minutes earlier.
Area forecast discussion, May 20, 2:50 PM EDT, 4 hours 8 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KNOXVILLE/TRI-CITIES TN 250 PM EDT WED MAY 20 1998 NO SATELLITE PICS AVAILABLE SO AM WATCHING KOHX 1.1 NM RES RADAR IMAGERY AND KEEPING AN EYE ON LDS CHART WHICH SHOWS MCS SHIFTING E THRU LWR OH VLY. CONVECTION SEEMS TO BE HOLDING A LITTLE CLOSER TO AND JUST S OF FNTL BOUNDARY DRAPED ACRS N MO/CNTRL IL/CNTRL IN AND BELIEVE THIS WL GENERALLY BE THE CASE THRU MUCH OF 1ST PD ALTHOUGH FNT WL GRADUALLY DROP S TWD SW VA/NRN TN BORDER REGION OVRNITE AND SO CONVECTION (PROBABLY WEAKENING TO SHRA OVRNITE) WL OCCUR FARTHER S AFFECTING SW VA/NE TN AND CUMBERLAND PLATEAU ZONES PRIMARILY TONITE WHERE 30-40% POPS DECENT WITH SLGT CHC VARIETY OVR CNTRL VLY ZONE. FWC TEMPS LOOK GOOD FOR TONITE. MODELS (ETA FASTEST) DROP FNT ACRS FA ON THU BUT PREFER SLGTLY SLOWER SWD PUSH DEPICTED BY NGM AS LOW LVL FLO DOESNT LOOK APPRECIABLEY STRONG AND TERRAIN MUST BE OVERCOME. WITH FNT PUSHING S THRU SW VA/NE TN TWD CNTRL VLY ZONE BY 00Z WOULD USE 40% FOR THESE NRN ZONES INCLUDING PLATEAU AND 30% FOR CNTRL VLY AND KEEP SLGT CHC FOR SRN VLY/SRN MTNS AS CONVECTION WL HAVE FOCUS ON FNT. FAN TEMPS PROBABLY BEST FOR THU EXCEPT CHA CLOSER TO 90 WELL S OF FNTL BNDRY. FNT DROPS TWD SRN VLY /SRN MTNS OVRNITE THU AND WOULD KEEP SMALL CHC POPS FOR CNTRL/SRN VLY/SRN MTNS AND DROP POPS FARTHER N. FRI RIDGING BUILDS BACK TWD THE FA AND UPR DYNAMICS NON-EXISTANT SO ONLY POSSIBLE THREAT FOR CONVECTION WL BE ACRS SRN VLY/SRN MTNS AS FNT SLIPS ONLY SLOLY S INTO DIXIE. GUIDANCE SIMILAR LAST TWO PERIODS AND ACCEPTED.
Nearby
Severe Thunderstorm Warnings in Tennessee, 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.