Alert archive / Oregon / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 39, NWS Medford, OR
NWS Medford, OR issued this severe thunderstorm warning at Aug 10, 1999, 4:18 PM PDT for Jackson County, Josephine County, Oregon. It was in force for 62 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 10, 1999, 4:18 PM PDT (23:18 UTC)
- Expired
- Aug 10, 1999, 5:20 PM PDT
- In force
- 62 min
- Issued by
- NWS Medford, OR
- Area
- Whole counties
Counties Jackson County, OR, Josephine County, OR
The nearest sounding before it
Medford/Jackson, OR (KMFR), launched 12:00Z, 11.3 hours before the alert went out and 28 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
- 948 J/kg
- Mixed-layer CIN
- -183 J/kg
- Mixed-layer LCL
- 924 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- 19 m²/s²
- 0-3 km storm-relative helicity
- 16 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 KMFR 102321 RRA SVRMFR ORC029-033-110020- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE MEDFORD OR 418 PM PDT TUE AUG 10 1999 THE NATIONAL WEATHER SERVICE IN MEDFORD HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... NORTHEASTERN AND SOUTHEASTERN JOSEPHINE COUNTY IN SOUTHWESTERN OREGON WEST CENTRAL AND SOUTHWESTERN JACKSON COUNTY IN SOUTHWESTERN OREGON * UNTIL 520 PM PDT * AT 417 PM PDT... MEDFORD DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 20 MILES SOUTHWEST OF CENTRAL POINT OR 4 MILES SOUTHWEST OF APPLEGATE... MOVING EAST AT 10 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... PROVOLT AT 433 PM PDT APPLEGATE AT 450 PM PDT DAMAGING WINDS...vHEAVY DOWNPOUR AND LARGE HAIL ARE LIKELY. GO INSIDE A STURDY BUILDING AND STAY AWAY FROM WINDOWS! FB
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 Medford, OR wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 10, 2:30 PM PDT, 1 hour 48 minutes earlier.
Area forecast discussion, Aug 10, 2:30 PM PDT, 1 hour 48 minutes before
SOUTHWEST OREGON/NORTHERN CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 230 PM PDT TUE AUG 10 1999 12Z NGM/ETA/AVN IN. THE MAIN FORECAST PROBLEM IS SEVERE CONVECTION NOW IN PROGRESS. UPPER LEVEL CUTOFF LOW NOW CENTERED OVER CENTRAL CALIFORNIA AND IS IN THE PROCESS OF LIFTING BACK INTO THE WESTERLIES. MODEL SOLUTIONS APPEAR TO HAVE A GOOD GRIP ON THIS FEATURE...AND BOTH BRING THE UPPER LOW TO NEAR THE NEVADA/CALIFORNIA/OREGON TRIPLE POINT AROUND MIDNIGHT TONIGHT. THE LOW WILL WEAKEN AND MOVE ON TO THE EAST WEDNESDAY MORNING. ANALYSIS OF THE 12Z SOUNDING SHOWS LOTS MORE AVAILABLE MOISTURE TODAY AND COOLING ALOFT AS WELL. AFTERNOON TEMPERATURES HAVE GENERATED PLENTY OF LIFT WITH LOTS OF CAPE. SO...SEVERE THUNDERSTORMS HAVE DEVELOPED AND WILL CONTINUE UNTIL THE WEE HOURS OF WEDNESDAY. WINDS ALOFT ARE WEAK SO SLOW MOVING THUNDERSTORMS WILL GENERATE LOCALLY HEAVY RAINS. CONDITIONS WILL STABILIZE RAPIDLY EARLY WEDNESDAY AS THE LOW MOVES EAST AND IS REPLACED BY A WEAK UPPER TROUGH. AT LOW LEVELS...ONCE THE LOW EXITS TONIGHT A MORE TYPICAL SUMMER PATTERN WILL DEVELOP OVER THE AREA WITH ONSHORE FLOW DIURNALLY PEAKING IN THE EVENING HOURS AND TROUGHING IN THE MORNING. SOME WEAK OFFSHORE FLOW MAY DEVELOP OVER THE SOUTH COAST WEDNESDAY NIGHT. THE TROUGH ALOFT SHOULD ASSIST IN INCREASING THE DEPTH OF THE MARINE LAYER...SO LOOK FOR LOTS MORE LOW CLOUDS AND FOG IN THE UMPQUA BASIN...DONT THINK IT WILL MAKE IT TO THE ROGUE BASIN DURING THE NEXT FEW NIGHTS. ON THURSDAY...A FAIRLY STRONG SHORT WAVE WILL AMPLIFY THE COASTAL TROUGH AND MAY BRING SOME SHOWERS TO SISKIYOU/MODOC COUNTY THURSDAY EVENING. MOST OF THE ENERGY WILL BE TO THE SOUTH. FOR NOW...WILL JUST GO FOR PARTLY CLOUDY SKIES IN THE CALIFORNIA ZONES THURSDAY AFTERNOON. STOCKTON .MFR...NONE. MFR UU 060/085 057/083 058 157000 LMT UU 052/080 047/077 049 158000 RBG BB 058/078 057/077 057 153000 4BK CC 055/064 054/064 054 151110 OTH CC 056/067 055/067 055 151110 YKA UU 046/086 040/085 042 158000 MHS UU 054/080 048/077 050 158000 AAT UU 049/082 049/079 047 158000
In the hours before
Local storm report, Aug 10, 3:48 PM PDT, 30 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OREGON
348 PM PDT TUE AUG 10 1999
TIME(PDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0346 PM SELMA OR .88 INCH HAIL
08/10/99 JOSEPHINE SPOTTER J038 REPORTS DIME
TO NICKEL SIZED HAIL.The office that day
Everything else NWS Medford, OR issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 9, 8:57 PM PDT | Severe Thunderstorm Warning | MFR | Jackson | 33 min |
| Aug 10, 1:25 PM PDT | Severe Thunderstorm Warning | MFR | Jackson | 30 min |
| Aug 10, 2:22 PM PDT | Severe Thunderstorm Warning | MFR | Jackson | 63 min |
| Aug 10, 3:29 PM PDT | Severe Thunderstorm Warning | MFR | Josephine | 61 min |
| Aug 10, 3:58 PM PDT | Severe Thunderstorm Warning | MFR | Jackson | 92 min |
| Aug 10, 4:41 PM PDT | Severe Thunderstorm Warning | MFR | Josephine | 59 min |
Nearby
Severe Thunderstorm Warnings in Oregon, 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.