textproduct: Reno

KEY MESSAGES

* Warm and overall dry conditions prevail through tomorrow with typical afternoon breezes returning Monday afternoon.

* Gusty winds and low humidity bring elevated to critical fire weather conditions for northeast CA and parts of western NV Tuesday.

* Cooler and breezy conditions are expected through the remainder of this week, with rain shower chances mainly in northeast CA and northwest NV Thursday and Friday.

DISCUSSION

Overall tranquil weather prevails through the remainder of August with a brief warmup to near 90 degrees for lower elevations and near 80 for Sierra communities to close out the month on Monday. Winds today will be on the lighter side (gusts 20 mph or less), then typical zephyr-type breezes with gusts near 25 mph return Monday afternoon. A weak area of low pressure near the central CA coast may produce a few short lived showers (10% chance) near the Sierra crest in Mono County later this afternoon. Then as this low moves inland, a similar low-end 10% chance of showers/thunder shifts to Mineral and far eastern Churchill counties for Monday.

As September begins on Tuesday, a low pressure trough approaching the northern CA coast will become the primary weather feature, bringing a more significant increase in winds from around midday through the evening. Precipitation chances are minimal as moisture is limited with this system, leading to fire weather concerns as detailed in the Fire Weather section below, along with aviation and lake recreation impacts.

This trough is then projected to eject inland Tuesday night- Wednesday, leaving cooler conditions and continued breezy-gusty winds (gusts up to 35 mph) for Wednesday. A larger area of low pressure than reaches the Pacific NW coast for the late portion of this week, continuing breezy to windy periods, along with 15-30% chances for rain showers favoring northeast CA-northwest NV. Temperatures remain below average through the remainder of this week with highs mainly in the upper 70s-lower 80s for western NV valleys, and upper 60s-mid 70s for Sierra communities and far northeast CA-northwest NV.

An early look ahead to Labor Day weekend favors a mainly dry start with decreasing winds, but a potential for increasing shower chances late Sunday through Monday. Confidence is lower due to varied locations of weather systems near or off the west coast, and potentially an additional push of moisture provided by an eastern Pacific tropical system by that time. MJD

AVIATION

VFR conditions prevail at the main terminals through at least Tuesday with less than 10% chance for brief patchy FG at KTRK early Monday morning.

Winds will be lighter this afternoon with gusts below 20 kts at the main terminals, then typical afternoon gusts around 20 kts return Monday. For Tuesday, gusts increase to 30-35 kts with increased mountain wave turbulence and periods of LLWS as a low pressure approaches the region. MJD

FIRE WEATHER

Periods of elevated to critical fire weather conditions return early this week. On Monday, after a night of more limited humidity recovery, afternoon humidity reaches its lowest levels this week with minimum values dropping to near 10% across areas of northeast CA and northwest NV. SW-W Winds return to near typical speeds with gusts near 25 mph by mid-afternoon, but a few sites could see gusts near 30 mph for an hour or two.

Tuesday continues to have the greatest concerns as Fire Weather Watches were issued for parts of northeast CA, northwest NV and extending southward to the northern Sierra Front (including Reno- Carson vicinity). Southwest wind gusts increase to 30-40 mph around the midday hours and continue through much of the evening, In addition, many of these areas north of Reno have received little or no rainfall through mid-late August, resulting in dry vegetation receptive to carrying fire if ignitions occur.

By Wednesday, winds only diminish slightly (gusts to 25-35 mph) but minimum RH continues to increase. A few sites near/east of US-95 could see an hour or two of overlapping near-critical wind/RH conditions Wednesday afternoon. Breezy to windy conditions likely persist each day through Friday, but a cooler air mass with rising humidity, along with rain shower chances mainly north of Susanville-Gerlach will further decrease the risk of fire weather concerns. MJD

REV Watches/Warnings/Advisories

NV...Fire Weather Watch from Tuesday morning through Tuesday evening NVZ420-458.

CA...Fire Weather Watch from Tuesday morning through Tuesday evening CAZ270-278.