textproduct: Reno

KEY MESSAGES

* Widespread showers and thunderstorms today with a focus on heavy rain and localized flooding potential.

* Convective activity becomes isolated and shifts south and east Wednesday through Friday as dry, breezy and hot air moves into the region.

* Monsoonal moisture returns this weekend, bringing renewed chances for showers and thunderstorms.

DISCUSSION

We had a decent soaking last night and early this morning, leading to fog and low-level stratus clouds seen all across the region this morning. The overnight 12z sounding revealed the PWAT climbed to 1.1 inches, which explains the humid air we are all feeling. This moisture will play a starring role in today's showers and thunderstorms, as the main concern for today will be heavy rain that could lead to localized flash flooding. After yesterday's rains, it is a good idea to get out and check the storm drains for debris, and make sure they are cleared. Showers and storms are already starting to develop over northern Washoe County as of 11 AM, and we anticipate an early start to today's convection. Showers should start to develop in earnest by noon to 1 PM, first firing over Lassen County, but soon to be joined by storms over Mono and Mineral counties. Storm motions will be a tad slower than yesterday's, but still around 35 to 40 mph to the northeast. CAMs have shown some storm training behavior this afternoon, which increases concerns for flooding, if heavy rain continues from storm after storm repeatedly going over the same area. While the expected QPF shows only a few hundredths up to 0.25 inches, with all the available moisture and the possibility to see training showers, we could see amounts in excess of 0.5 inches up to an inch.

The difference from today as opposed to yesterday's storms, they don't look to hang on into the overnight hours. A trough is dropping in, bringing along a bit of dry air that will help to move storms off to the east and south, as the high pressure also slides eastward into the evening. This will signal the change in airmass that by Wednesday brings in warmer, drier and breezier conditions. Showers and storms will still be found over the Basin and Range Wednesday through Friday (10-20% chances), with a few model solutions hinting showers and storms may be found as far west as Mono and Mineral counties, but chances are only 10-15% at this time. For now, the breeziest day looks to land on Thursday, with afternoon gusts over western Nevada valleys 20-25 mph and ridges gusting 35-40 mph.

The weekend is trending back to the wetter side as a ridge of high pressure rebuilds over the Four Corners region. This set up is favored for returning monsoonal flow to our vicinity. HRICH

AVIATION

* Showers and thunderstorms this afternoon with the greatest chances near KBAN(60-80%) and KRNO(55-65%), however all local terminals have chances today. The focus is on the 20z-03z time frame, with storms moving north after forming. Wind gusts near the storms may reach up to 35 kts, with heavy rain, small accumulating hail and lightning as the main threats today. After 06z most showers will be moving out or tapering off. HRICH

FIRE WEATHER

* The main area of interest today for fire risk will be in northern Washoe and Lassen counties, where little to no rainfall fell yesterday. There will be showers and thunderstorms over that area, renewing concerns for dry lightning strikes, and gusty outflow winds up to 40 mph that could drive flames, should a spark ignite. Elsewhere, heavy rains may work to help fire efforts for the Elephant Fire, however too much rain could create difficulty in moving personnel and equipment if roads become inundated with flood waters. Additionally, the morning fog that was found over the Sierra Valley may return tomorrow morning, which could impact visibility.

* Wednesday through Friday brings a drier, warmer and breezier airmass, reintroducing elevated to critical fire weather concerns over NE California and far NW Nevada. Gust speeds will be around 20-25 mph in valleys, with ridgelines gusting 35-40 mph. HRICH

REV Watches/Warnings/Advisories

NV...None. CA...None.