Alert archive / California / Flash Flood Warnings in 2019

Flash Flood Warning 9, NWS Sacramento, CA

May 24, 2019Butte County, California

NWS Sacramento, CA issued this flash flood warning at May 24, 2019, 9:50 PM PDT for Butte County, California. It was in force for 115 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, 9:50 PM PDT (04:50 UTC)
Expired
May 24, 2019, 11:45 PM PDT
In force
115 min
Issued by
NWS Sacramento, CA
Area
Storm-based polygon
Flood severity
None

County Butte County, CA

The radar

The Beale AFB radar (KBBX), 19 km from the middle of the area, began a volume at 04:51 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

Medford/Jackson, OR (KMFR), launched 00:00Z, 4.8 hours before the alert went out and 317 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, Medford/Jackson, OR at 00:00Z on 2019-05-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 178 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, Medford/Jackson, OR at 00:00Z on 2019-05-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 square meters per square second.19395878Sfc1 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
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

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood 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 flash flood warning went out at May 24, 1:54 PM PDT, 7 hours 56 minutes earlier.

Area forecast discussion, May 24, 1:54 PM PDT, 7 hours 56 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

Local storm report, May 24, 7:57 PM PDT, 1 hour 53 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SACRAMENTO CA
757 PM PDT FRI MAY 24 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0752 PM     HAIL             1 N PINE GROVE          40.68N 122.35W
05/24/2019  E1.75 INCH       SHASTA             CA   PUBLIC

            GOLF BALL SIZE HAIL REPORTED IN SHASTA LAKE
            CITY. PICTURE SENT VIA TWITTER.

&&

CM
Special weather statement, May 24, 8:05 PM PDT, 1 hour 45 minutes before
Special Weather Statement
National Weather Service Sacramento CA
805 PM PDT Fri May 24 2019

CAZ015-016-250345-
Northern Sacramento Valley-Central Sacramento Valley-
805 PM PDT Fri May 24 2019

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT SOUTH CENTRAL TEHAMA...
NORTHWESTERN BUTTE AND NORTHEASTERN GLENN COUNTIES...

At 804 PM PDT, radar indicated strong thunderstorms were located
along a line extending from near Orland to 7 miles southwest of
Corning. Movement was southeast at 20 mph.

Half inch hail is possible with these storms.

Locations impacted include...
Chico, Orland, Nord, Black Butte Dam, Hamilton City, Black Butte
Summit and Black Butte Lake.

LAT...LON 3977 12185 3960 12232 3990 12238 3987 12210
TIME...MOT...LOC 0304Z 316DEG 19KT 3978 12213 3983 12225

cs
Local storm report, May 24, 8:24 PM PDT, 1 hour 26 minutes before
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Local storm report, May 24, 8:31 PM PDT, 1 hour 19 minutes before
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Special weather statement, May 24, 9:14 PM PDT, 36 minutes before
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Local storm report, May 24, 9:34 PM PDT, 16 minutes before
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The office that day

Everything else NWS Sacramento, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 24, 5:17 PM PDTSpecial Weather StatementSTOLake58 min
May 24, 6:03 PM PDTSpecial Weather StatementSTOShasta57 min
May 24, 6:39 PM PDTSpecial Weather StatementSTOShasta66 min
May 24, 6:46 PM PDTSevere Thunderstorm WarningSTOShasta44 min
May 24, 7:28 PM PDTSpecial Weather StatementSTOShasta47 min
May 24, 7:45 PM PDTSevere Thunderstorm WarningSTOShasta45 min
May 24, 8:05 PM PDTSpecial Weather StatementSTOGlenn40 min
May 24, 8:16 PM PDTTornado WarningSTOShasta44 min
May 24, 9:14 PM PDTSpecial Weather StatementSTOShasta46 min
May 24, 9:43 PM PDTSevere Thunderstorm WarningSTOButte, Plumas47 min
May 24, 10:29 PM PDTSevere Thunderstorm WarningSTOButte, Sierra, Yuba40 min
May 25, 1:51 AM PDTSpecial Weather StatementSTOTehama39 min
May 25, 2:45 AM PDTSevere Thunderstorm WarningSTOTehama45 min
May 25, 3:35 AM PDTSpecial Weather StatementSTOButte25 min
May 25, 10:55 AM PDTWinter Weather AdvisorySTO33 hr

Nearby

Flash Flood Warnings in California, 2019Every flash flood 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.