S. on the 24th and persisted through the 26th.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS REV wrote it up.
A broad area of upper level low pressure moved into the western part of the U.S. on the 24th and persisted through the 26th. This low brought greater forcing for showers and thunderstorms which occurred each afternoon the 24th through the 26th. The backside of this low brought rain and snow to the Sierra Nevada the morning of the 26th.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Reno, NV wrote its last area forecast discussion before the first event at May 25, 2:16 AM PST, 5 hours 29 minutes earlier.
Area Forecast Discussion
National Weather Service Reno NV
316 AM PDT Sat May 25 2019
.SYNOPSIS...
Cool, showery weather, with periods of steadier precipitation,
mountain snow, and a few thunderstorms, will continue through the
Memorial Day weekend. Snow could impact travel over Sierra passes
late Saturday night through Sunday night. Showers and
thunderstorms are still expected next week, but with decreasing
coverage as we move through the week.
&&
.SHORT TERM...
Main change to the forecast overnight was to issue Winter Weather
Advisories for the Sierra from late Saturday night into Sunday
night as an unusually potent low pressure (for late May) brings
widespread rain and high elevation snow back to the region.
Weak area of low pressure currently moving into northern
Nevada/California brought enough forcing to sustain thunderstorms
overnight. Storms have weakened this morning with only a few
isolated cells remaining in west central Nevada and along the
Shasta/Lassen county line.
Another round of thunderstorms is expected to develop early this
afternoon. The synoptic pattern for today is a bit messy and
complicated as the trough currently over the Sierra is forecast to
continue weakening and another low pressure currently over
British Colombia is forecast to drop rapidly down the Pacific
Northwest Coast and begin asserting it's influence over our
region. Best estimate is for storms to form early today in the
Sierra and extreme western Nevada with less intensity and coverage
in the late afternoon and early evening as the incoming low
pressure draws warmer air aloft into the area from the south
helping to cap the convection.
Now for the main course of the weekend, a potent low pressure
that is forecast to slide down the west coast making it's way
into central California by Sunday. Long range global models and
ensembles have done an amazing job forecasting that a low pressure
was going to be over the region as much as 7 to 10 days ago.
However, with the system now around 24 hours out, it appears to
be a bit more potent then previously advertised.
The cold core of the low pressure has a decent sized area of
700mb temps of -8C, and while most of that cold air is forecast
to stay on the western slope of the Sierra, enough cold air is
expected to move into the Sierra to drive snow levels down to
around 6500 feet at times. The area of heaviest snowfall is
expected to be in Alpine and northern Mono County where the higher
elevations could easily see another coating of 6 to 10 inches of
snow.
For the lower elevation passes like Donner pass and Echo Summit
the most likely periods of possible snow accumulations on the
roads will remain during the overnight hours Saturday, when they
could see an inch or two, and to a slightly lesser extent on
Sunday night. For higher passes, like Mt. Rose and Carson pass,
the temperatures will be cold enough that snow could stick to the
roadway, even during the day Sunday. Along the 395 corridor in
Mono County, snow will begin early Sunday morning and could
accumulate a few inches on the road during the day on Sunday and
especially Sunday evening.
For the rest of the region, it's going to be one of those cold
rainy Memorial Day Sundays with widespread moderate rain during
the day and a few embedded thunderstorms with periods of heavier
rain possible at times. Temperatures are going to struggle to
reach the mid 50s in western Nevada with low to mid 40s at best
in the Sierra. So if you plan on being outside, be prepared.
Temperatures will be 5 to 10 degrees warmer on Monday with most
areas seeing just a few light showers. Heavier precipitation with
few thunderstorms will still be possible, but the best chances
will be in west-central Nevada be Monday. -Zach
.LONG TERM...End of May and start of June...
No big changes in the large scale pattern for the end of the May.
Trough will remain over California and Nevada with daily chances for
showers and a few afternoon thunderstorms. The air mass will start
to moderate as the ridge over the eastern Pacific moves over British
Columbia and cuts off any reinforcing shots of cooler air from the
north. By the time June arrives a zonal flow across the Pacific with
the jet stream set up near 50N should allow the region into the 70s
and low 80s. Precipitation potential looks rather minimal, but some
ensembles maintain some troughing along the west coast which could
bring a day or two of shower activity. Brong
&&
.AVIATION...
Fog around KTRK and some northern Sierra valleys will burn off by
mid morning.
Active and wet holiday weekend on tap with periods of MVFR ceilings,
showers and thunderstorms. Thunderstorms today will be able to
produce some moderate to heavy rain, small hail and gusty outflow
winds to 40 kts.
Sunday looks to be the wettest day as low pressure drops into the
region with a period of mountain wave turbulence and bumpy
approaches/departures. Rain/snow line could dip to 6000-7000
feet, which may bring some snow to TRK, TVL and MMH. Brong
&&
.REV Watches/Warnings/Advisories...
NV...Winter Weather Advisory from 5 AM Sunday to 5 AM PDT Monday
NVZ002.
CA...Winter Weather Advisory from 5 AM Sunday to 5 AM PDT Monday
CAZ072-073.
&&
For more information from the National Weather Service visit...
http://weather.gov/renoThe national radar mosaic for the moment the first event began.
1 heavy rain, 1 winter weather. Local standard time, as filed.
Trained weather spotter 1 mile north-northwest of Homewood reported 1.86 inches of rainfall in a 24 hour period from 25 May 0745PST to 26 May 0745PST. Much of this rain was due to showers passing overhead the afternoon and evening of the 25th. Spotter elevation 6230 feet MSL.
Snowfall totals were generally 4 inches or less in the Sierra Nevada above 6500 feet, with up to 2 inches at a few sites in the Lake Tahoe Basin during the morning of the 26th.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2019Every state in 2019This day in weather historyWarnings in California, May 2019
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 831970, 831981.