Alert archive / California / Severe Thunderstorm Warnings in 2019
Severe Thunderstorm Warning 4, NWS Sacramento, CA
NWS Sacramento, CA issued this severe thunderstorm warning at May 24, 2019, 6:46 PM PDT for Shasta County, California. It was in force for 44 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 24, 2019, 6:46 PM PDT (01:46 UTC)
- Expired
- May 24, 2019, 7:30 PM PDT
- In force
- 44 min
- Issued by
- NWS Sacramento, CA
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 50.0 mph
County Shasta County, CA
The radar
The Beale AFB radar (KBBX), 145 km from the middle of the area, began a volume at 01:48 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
Medford/Jackson, OR (KMFR), launched 00:00Z, 1.8 hours before the alert went out and 189 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
- 178 J/kg
- Mixed-layer CIN
- -36 J/kg
- Mixed-layer LCL
- 2118 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 11 m²/s²
- 0-3 km storm-relative helicity
- 167 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
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 Sacramento, CA wrote its last area forecast discussion before this severe thunderstorm warning went out at May 24, 1:54 PM PDT, 4 hours 52 minutes earlier.
Area forecast discussion, May 24, 1:54 PM PDT, 4 hours 52 minutes before
Area Forecast Discussion National Weather Service Sacramento CA 154 PM PDT Fri May 24 2019 .SYNOPSIS... Scattered rain showers and thunderstorms mainly mountains and foothills today and Saturday as one low pressure system moves east and another drops in to take its place. Locally heavy rain possible. More widespread showers or thunderstorms on Sunday and Sunday night with snow for the higher Sierra elevations. Afternoon mountain showers continuing through mid week. && .DISCUSSION... Showers and a few isolated thunderstorms have popped up over the Sierra early this afternoon, thanks to a upper level disturbance moving through the area. Favorable conditions for shower and tstorm activity will likely continue into the early evening hours, with most of the precip staying confined to the terrain. However, some shower activity may slip into the Sacramento valley this evening as the upper low drops farther southward. Overall precipitation amounts are expected to remain light but some embedded heavier showers/thunderstorms could bring locally heavier precipitation. Looking to Saturday a Pacific Northwest trough will drop southward through Northern California and will mostly be an inside slider type of system. Therefore, the biggest chance of showers or thunderstorms will be over the eastern half of the forecast area. Once again precip amounts overall will be light but heavier showers will be possible. The passage of the trough will also bring cooler air into the north state, putting our high temperatures to a few to several degrees below normal. Come Sunday, a stronger low pressure system is forecast to arrive in northern California. Showers and thunderstorms will remain in the forecast but over the entire CWA this time. This system will usher in even cooler air which will drop snow levels and put our daytime highs down to 10-15 degrees below normal. Snow levels will likely drop to below pass levels, which will likely bring travel impacts to the Sierra. The greatest threat for snowfall and potential accumulation will be Sunday - Monday morning, so travelers should take note of the road conditions and forecast before heading out. This storm system will shift eastward into the Great Basin on Monday, placing the shower threat on our eastern mountains. By the afternoon, snow levels should be above pass levels with daytime highs climbing a bit although remaining below normal. && .EXTENDED DISCUSSION (Tuesday THROUGH Friday) Unsettled pattern continues through the period as ensembles support troughing across the area through the week. Chances for showers or thunderstorms expected over higher terrain throughout the week, mainly in the afternoon and early evening hours. Elsewhere, dry conditions are expected. Temperatures will be on the rise through the period with Valley highs in the upper 70s to low 80s Tuesday, reaching into the mid and upper 80s by late next week. && .AVIATION... Mainly VFR conditions at TAF sites next 24 hours. Local MVFR/IFR conditions in showers and thunderstorms mainly over the foothills/mountains and the N Sac Valley through the overnite hrs obscuring higher terrain Sustained winds less than 15 kts at TAF sites with local gusts to 20 kts. After sunrise Sat morning, marine cloudiness spreading inland into the Srn Sac Vly with MVFR CIGS 015-025 expected. && .STO WATCHES/WARNINGS/ADVISORIES... None. &&
In the hours before
Special weather statement, May 24, 4:16 PM PDT, 2 hours 30 minutes before
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html>Special weather statement, May 24, 5:17 PM PDT, 1 hour 29 minutes before
Special Weather Statement National Weather Service Sacramento CA 517 PM PDT Fri May 24 2019 CAZ063-064-250115- Clear Lake/Southern Lake County-Mountains Southwestern Shasta County to Northern Lake County- 517 PM PDT Fri May 24 2019 ...A LINE OF STRONG THUNDERSTORMS WILL AFFECT WEST CENTRAL COLUSA AND CENTRAL LAKE COUNTIES... At 516 PM PDT, radar indicated strong thunderstorms located over northern Lake county along a line extending from 9 miles west of Fouts Springs to to Barkerville. Movement was south at 20 mph. Half inch hail is possible with these storms. Locations impacted include... Lakeport, Upper Lake, Clearlake, Barkerville, Mount Konocti, Glenhaven, Soda Bay, Hough Springs, North Lakeport, Konocti Bay, Finley, Hidden Valley Lake, Kelseyville, Buckingham Park, Indian Valley Reservoir, Lower Lake, Clearlake Oaks, Nice, Clearlake Park and Lucerne. Torrential rainfall is also occurring with these storms, and may cause localized flooding. Do not drive your vehicle through flooded roadways. Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. LAT...LON 3901 12292 3878 12244 3927 12253 3942 12297 TIME...MOT...LOC 0016Z 344DEG 25KT 3932 12284 3921 12266 3914 12258 cs
Special weather statement, May 24, 6:03 PM PDT, 43 minutes before
Special Weather Statement National Weather Service Sacramento CA 603 PM PDT Fri May 24 2019 CAZ013-250200- Shasta Lake Area / Northern Shasta County- 603 PM PDT Fri May 24 2019 ...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL SHASTA COUNTY... At 603 PM PDT, a strong thunderstorm was located over Fisher, or 20 miles south of Mount Shasta, moving southeast at 10 mph. Dime size hail is possible with this storm. Locations impacted include... Lakehead, Fisher, O'brien, Sims, Pollard Flat, Castle Crag and Lakehead-Lakeshore. Torrential rainfall is also occurring with this storm, and may cause localized flooding. Do not drive your vehicle through flooded roadways. Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. LAT...LON 4103 12251 4115 12235 4095 12200 4077 12229 TIME...MOT...LOC 0103Z 315DEG 8KT 4103 12235 cs
Special weather statement, May 24, 6:39 PM PDT, 7 minutes before
Special Weather Statement
National Weather Service Sacramento CA
639 PM PDT Fri May 24 2019
CAZ013-250245-
Shasta Lake Area / Northern Shasta County-
639 PM PDT Fri May 24 2019
...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL SHASTA COUNTY...
At 639 PM PDT, a strong thunderstorm was located near Pollard Flat,
or 21 miles south of Mount Shasta, moving southeast at 15 mph.
Dime size hail is possible with this storm.
Locations impacted include...
Lakehead, Sugarloaf, Fisher, O'brien, Lakehead-Lakeshore, Vollmers,
Sims and Pollard Flat.
Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
LAT...LON 4100 12211 4078 12234 4098 12258 4101 12255
4101 12253 4106 12252 4107 12254 4109 12251
4110 12246 4114 12244
TIME...MOT...LOC 0139Z 308DEG 12KT 4103 12246
csThe office that day
Everything else NWS Sacramento, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 24, 5:17 PM PDT | Special Weather Statement | STO | Lake | 58 min |
| May 24, 6:03 PM PDT | Special Weather Statement | STO | Shasta | 57 min |
| May 24, 6:39 PM PDT | Special Weather Statement | STO | Shasta | 66 min |
| May 24, 7:28 PM PDT | Special Weather Statement | STO | Shasta | 47 min |
| May 24, 7:45 PM PDT | Severe Thunderstorm Warning | STO | Shasta | 45 min |
| May 24, 8:05 PM PDT | Special Weather Statement | STO | Glenn | 40 min |
| May 24, 8:16 PM PDT | Tornado Warning | STO | Shasta | 44 min |
| May 24, 9:14 PM PDT | Special Weather Statement | STO | Shasta | 46 min |
| May 24, 9:43 PM PDT | Severe Thunderstorm Warning | STO | Butte, Plumas | 47 min |
| May 24, 9:50 PM PDT | Flash Flood Warning | STO | Butte | 115 min |
| May 24, 10:29 PM PDT | Severe Thunderstorm Warning | STO | Butte, Sierra, Yuba | 40 min |
| May 25, 1:51 AM PDT | Special Weather Statement | STO | Tehama | 39 min |
| May 25, 2:45 AM PDT | Severe Thunderstorm Warning | STO | Tehama | 45 min |
| May 25, 3:35 AM PDT | Special Weather Statement | STO | Butte | 25 min |
| May 25, 10:55 AM PDT | Winter Weather Advisory | STO | 33 hr |
Nearby
Severe Thunderstorm Warnings in California, 2019Every severe thunderstorm warning in 2019
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.