textproduct: Reno

KEY MESSAGES

* Hotter, breezier, and drier weather is forecast through the weekend, with only isolated storm chances remaining across the southern Basin and Range through Friday.

* A Fire Weather Watch is in effect Friday afternoon through Saturday evening for critical fire weather conditions across northeast California and far northwest Nevada.

* The hot and dry pattern will persist through at least the middle of next week.

DISCUSSION

For today and going through the weekend, forecast guidance shows the CWA with generally a southwesterly flow aloft being between a Pacific trough to the west and a high pressure ridge to the east. The GFS does show a shortwave disturbance moving through central NV during the afternoon hours of both today and tomorrow, which will allow for 15-25% chances for isolated showers in Mineral, Churchill, and Mono Counties. The latest HRRR shows around 200-500 J/kg of MUCAPE with some isolated pockets of higher amounts in these areas on both afternoons allowing for a few isolated thunderstorms to develop with these showers. The HRRR forecast soundings show an inverted-V shape, which signals that storms will have high cloud bases and capable of gusty and erratic outflow winds. Forecast PW values look to be generally around 0.6-0.8 inches, so storms may be able to produce brief periods of heavy rain. However, there is quite the dry layer at the surface that may absorb a good amount of moisture on both days. The remainder of the area looks to stay dry on Thursday and Friday with the entire CWA having very low chances for precipitation over the weekend. The high temperature forecast for today through Saturday look to be in the upper 90s to the lower 100s in the W NV valleys with Sunday's highs dropping a few degrees to where the lower limit is in the middle 90s. Sierra communities should see high temperatures in the 80s through Sunday.

Forecast models are also projecting winds increasing going into the weekend with afternoon/evening gusts up to around 25-35 mph starting on Friday. This looks to due to a stronger upper jet moving over the NW CONUS that could mix down within some portions of the CWA. With these increased winds and the expected drier conditions with the aforementioned summer heat, critical fire weather conditions are currently forecast on Friday and Saturday for several hours in portions of NE CA and far NW NV, where there is the best confidence that the joint criteria of higher winds and lower minimum RH will be met for a longer duration. Please refer to the Fire Weather Watch in effect on both days and the Fire Weather discussion below for more information. Avoid any activities that could generate sparks and cause new wildfires. Will be monitoring the wind forecast in these areas on Sunday as well as these increased winds could possibly linger for a third day. The remaining portions of the area may see elevated fire weather concerns through the weekend as well.

Beyond Sunday and into the middle of the week, forecast guidance continues showing the CWA sandwiched between the upper trough and ridge. But the models do project the increased upper jet to have departed the region by Monday. As such, typical afternoon zephyr breezes are expected to return to the CWA next week. Also, very low chances for precipitation are seen through at least midweek. Daytime high temperatures start to climb slightly back by Tuesday in the W NV valleys to where they will be in the upper 90s to lower 100s again by Wednesday. The Sierra communities are currently forecast to stay in the 80s. -078

AVIATION

Morning fog near KTRK expects to reduce flight conditions to LIFR through around 23/14Z. After this, VFR conditions are expected at all area TAF sites today and tonight with winds gusting up to 20-25 kts between 23/22Z-24/04Z. While mostly dry weather prevails across the region, there is a 15-25% chance for isolated showers and thunderstorms in S. Mono, Mineral, and SE. Churchill Counties between 23/21Z-24/05Z. Portions of Mono County may also have slightly reduced visibilities due to smoke from the Rock Fire in Inyo County through the day as well. Not anticipating KMMH to see sub-VFR visibilities, but will monitor in case this changes. High temperatures around seasonal normals for late July are also in the forecast which may allow for density altitude concerns going through this weekend. -078

FIRE WEATHER

A drying and warming trend begins today, although a 15-25% chance of storms in Mono, Mineral, and Churchill Counties continues through Friday. Friday and Saturday will be the two main days of concern this weekend. Increased winds gusting to 35 mph and afternoon minimum RHs ranging from 5-10% will overlap each afternoon across northeast California and far northwest Nevada, yielding 3-8 hours of critical fire-weather conditions. For this reason, and due to the proximity of these conditions to the Biscar Fire, a Fire Weather Watch remains in effect for these areas from 1 PM Friday through 9 PM Saturday. Will be monitoring winds on Sunday to see if the increased winds linger and critical fire weather conditions persist for a third day. -Justin/078

REV Watches/Warnings/Advisories

NV...Fire Weather Watch from Friday afternoon through Saturday evening NVZ458.

CA...Fire Weather Watch from Friday afternoon through Saturday evening CAZ270-278.