textproduct: Reno

KEY MESSAGES

* Slight chance (10-15%) of showers and isolated thunderstorms across NE California and NW Nevada this afternoon, with similar chances in the Sierra of Mono County Monday.

* Fog development for fog-prone Sierra valleys again tonight through tomorrow morning.

* Above normal temperatures through mid-week, with a pattern change arriving by the weekend.

DISCUSSION

Similar precip chances (10-15%) again today for NE CA and the Sierra Front south of I-80. Like we've seen all weekend, we'll get those cumulus buildups along the higher terrain which will then push eastward due to the zephyr kicking in. Shower chances (10%) shift to the Sierra of Mono county on Monday. Confidence remains low on any substantial impacts from any showers that develop.

Fog potential renews for Sierra valleys again tonight through tomorrow morning. Fog development will be more localized to Truckee and the Martis Valley as the weak upper level low exits the region and ridging fills back in, bringing drier conditions. High temps reach the upper 80s (valleys) and upper 70s (Sierra) by mid-week. Moderate HeatRisk is introduced to the lower valleys of the Basin and Range Wednesday and Friday. Make sure to drink plenty of water!

There's a slight shortwave in the upper level pattern Wednesday, which will bring increased afternoon zephyr winds. There's a 30-60% chance for wind gusts over 30 mph Wednesday. With the warm conditions and low RH values, isolated areas of 2-4 hours of critical fire weather conditions are likely, especially where already dry fuels reside.

Long range guidance agrees on a pattern change this weekend, with the arrival of an upper level trough. However, models are having difficulty pinpointing the location and timing of the low. Precip chances will be restricted to far N Washoe county along the OR border, with the main concern areawide being gusty winds. 700 mb winds are increasing in response to the low so, at the very least, expect localized impacts to air travel with bumpy flights. Additional impacts include choppy lake waters and fire weather concerns with 3-7 hours of critical fire weather conditions.

-Giralte

AVIATION

Fog is expected to redevelop overnight at KTRK/the Martis Valley, lowering CIGS/VIS to IFR/LIFR conditions at times between 10Z and 16Z. Elsewhere, VFR conditions and light winds prevail through the morning.

An increasing cumulus field should develop along higher terrain this afternoon, possibly obscuring mountaintops. Otherwise, expect another day of widespread VFR conditions and breezy W/NW winds in the afternoon.

-Salas

REV Watches/Warnings/Advisories

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