textproduct: Reno

KEY MESSAGES

* Seasonably warm and dry today with typical afternoon zephyr breezes prevailing.

* A dry cold front will produce gusty winds and low humidity Tuesday with critical fire weather concerns for northeast CA and parts of western NV.

* Cooler and breezy conditions are expected through the remainder of the week along with rain shower chances for northeast CA and northwest NV Thursday and Friday.

DISCUSSION

After a quiet start to the week with typical temperatures and breezes, we will transition to a more active pattern with breezy conditions resulting in recreation and fire concerns, as well as some chances for precipitation later this week. For details on the fire concerns, see the Fire Discussion below.

Windy Week: An approaching trough and cold front will result in increased winds on Tuesday. Sierra ridgetops will respond first this evening with gusts near 50 mph overnight increasing to near 70 mph by Tuesday evening. The increased winds along the ridges will result in choppy aviation conditions starting late tonight and persisting into tomorrow. The strong upper level winds will begin to mix down into the lower valleys by Tuesday afternoon and evening with gusts approaching 30 to 40 mph, particularly north of Highway 50. The strong winds will produce mountain wave turbulence and wind shear for aviation, hazardous boating conditions on area lakes, crosswind hazards for high-profile vehicles, and locally reduced visibility from blowing dust on the desert playas.

Cool and Breezy: Cooler conditions persevere behind the front with the coolest temperatures of the week on Wednesday. High temperatures will plummet 10-15 degrees from what we will experience today. Western Nevada areas will be feeling more fall-like with highs in the mid-70s and low to mid-60s in Sierra valleys. For the colder Sierra valleys, overnight low temperatures will be dipping down near and below freezing each morning from Wednesday onward. Breezes will remain through the rest of the week, but fire concerns will be mitigated by higher humidities with the cooler temperatures. On a wetter note, chances for showers increase Thursday and Friday across northeastern California. While the highest chances are focused over western Lassen and far northern Washoe counties (20-50%), there are 10-20% chances extending into the Tahoe Basin and Sierra Front foothills as well from Thursday into Friday.

More Rain?: The better potential for precipitation favors Sunday into early next week. Ensemble guidance continues to show a possibility that moisture from a tropical system may sweep north into the Sierra and western Nevada. Confidence remains very low at this time, but this will be a feature to watch over the next week.

-Edan

AVIATION

* VFR conditions persist today with typical afternoon wind gusts of around 20 kts expected for Sierra and W.Nevada terminals.

* Plan on increased areas of mountain wave turbulence with N.Sierra ridgetops winds (FL100) gusting near 40-45 kts after 06z this evening as a dry cold front approaches.

* For Tuesday, ridgetop gusts increase near 70 kts late afternoon, with Sierra and W.Nevada terminal gusts around 30-35 kts. Expect increased mountain wave turbulence and periods of LLWS.

* Areas of reduced visibility from blowing dust may impact KLOL, KNFL, KHTH and aviation operations on the Black Rock desert on Tuesday afternoon/evening. Fuentes/Edan

FIRE WEATHER

* Elevated to critical fire weather conditions return early this week with Tuesday being the main concern with a dry cold frontal passage expected to provide gusty winds and dry conditions.

* For today, plan on very low humidity near 10% in parts of northeast California and northwest Nevada with southwest to west wind gusts around 25 mph and isolated gusts near 30 mph.

* Tuesday poses the greatest fire weather threat. Red Flag Warnings are in place for parts of NE California, NW Nevada, and the N.Sierra Front, including Reno and Carson City. Southwest gusts may reach 30 to 40 mph from midday into the evening.

* Winds will remain gusty Wednesday, around 25 to 35 mph, but improved humidity should limit fire concerns for most areas. Brief near-critical conditions are possible near and east of US-95. Breezy to windy weather continues through Friday, but cooler temperatures, higher humidity, and possible showers mainly north of Susanville to Gerlach should reduce fire weather concerns. Fuentes/Edan

REV Watches/Warnings/Advisories

NV...Red Flag Warning from 11 AM to 11 PM PDT Tuesday NVZ458.

Red Flag Warning from 11 AM to 11 PM PDT Tuesday NVZ420.

Lake Wind Advisory from 11 AM to 8 PM PDT Tuesday NVZ002>004.

CA...Red Flag Warning from 11 AM to 11 PM PDT Tuesday CAZ270-278.

Lake Wind Advisory from 11 AM to 8 PM PDT Tuesday CAZ071-072.