textproduct: Reno

KEY MESSAGES

* A mild cold front will pass through the region today, bringing light rain and mountain snow chances areawide along with gusty winds, strongest across the Western Nevada Basin and Range and eastern Sierra.

* A brief cooldown and breezy winds are expected on Thursday.

* Dry conditions and above average temperatures are forecast this weekend through the first half of next week.

DISCUSSION

For today, forecast guidance shows a PacNW trough crossing through the Western CONUS. With this pattern aloft, a cold front will move through the region causing valley rain, mountain snow, and gusty winds today. The latest run of the HREF shows the light precipitation chances moving into the NE CA portion of the CWA by 7 AM and spreading into NW NV a few hours later. The areas with the best chances (>75%) expect to be those closer to the OR border (Modoc, Lassen, N. Washoe, and Pershing Counties) as this front moves through in a NW to SE fashion. Around 12 PM, shower chances (20-40%) look to reach down into the Tahoe Basin followed by the region generally seeing a 15-25% chance going into the evening. Going through the night, remaining chances (15-25%) for isolated light showers look to stay mostly confined to the southern portion of the CWA (Alpine, Mono, Douglas, Lyon, and Mineral Counties). Snow levels this morning look to be 6-7 kft and steadily drop to below valley floor level as the front moves southeast across the region. The latest QPF values look to range between a trace and around 0.25 inches (higher end amounts closer to the OR border with the better PoPs). As for accumulating snow with these showers today, little to no accumulation is expected for most of the region that see snow. The Sierra Passes in the Tahoe Region as well as portions of N. Washoe County currently have a 10-20% NBM probability for 1+ inches of snow by Thursday morning. The NE CA mountain peaks in the region also may see up to a few inches of snow.

Gusty winds expect to be the main hazard with the cold front passage today. Wind Advisories are in effect today for the W NV Basin & Range along with Mono, S. Lyon, and Mineral Counties. A Lake Wind Advisory is also in effect for Lake Tahoe. Widespread gusts up to around 40 mph are expected in the region with gusts up to around 55-65 mph in wind-prone areas along US-95 and US-395 this afternoon and evening. Sierra ridgetop winds may gust up to around 70-80 mph. Please be prepared for these winds today especially if you are traveling on N/S oriented roads where the crosswinds may cause hazardous driving conditions. It is also worth mentioning that there may be blowing dust downwind of desert sinks and playas within the region today.

The upper trough will move eastward on Thursday, taking the wintry precipitation chances with it and leaving behind generally dry conditions in the region for a good portion of the day. Following today's cold front passage, daytime high temperatures on Thursday will cool to between the upper 40s to lower 50s in NE CA and W NV valleys while Sierra communities will be between the upper 30s and lower 40s. Breezy winds generally out of the north are expected during the afternoon as well with gusts up to 25-35 mph.

On Friday, temperatures begin a warming trend that will continue into next week with a ridge starting to building over the Western CONUS. Models are still showing quicker winds aloft moving through the jet over the region courtesy of an upper low well south of the CWA. This may allow for some increased Sierra ridgetop winds out of the E/NE on Friday with a 40-50% probability of 60+ mph gusts. For this weekend into next week, dry conditions look to be on tap with portions of W NV currently seeing a 60-90% chance of 70+ degree high temperatures on Monday. -078

AVIATION

A cold front moves through the region NW to SE today allowing for gusty winds with light rain and mountain snow chances. Area TAF sites will experience west-southwest winds gusting up to around 30-35 kts today beginning around 04/17-19Z. KTVL will be the lone exception to this statement with southerly winds. KTRK and KTVL will see some rain showers between 04/20-24Z which will bring about MVFR conditions. FL100 winds in the Sierra increase to around 45-50 kts this afternoon which will cause some some LLWS for Sierra terminals. -078

AVALANCHE

A cold front bringing gusty winds with light rain and snow shower chances (20-40%) is expected across the Sierra Wednesday between noon and 10PM. Tahoe will get the precipitation chances first, then as the front moves south, Mono County will finally see some light showers later on in the evening.

* Snow levels and amounts: Snow levels look to be 6-7 kft this morning then drop to <6 kft in the afternoon from north to south. Minimal snowfall accumulation is expected (10-20% chance of 1+ inches in the Tahoe Basin above 7 kft, 10-15% chance 0.5+ inches in Mono County above 8 kft).

* SLR and SWE: SLRs 7-10:1 at the start of the snow, then increasing to 12-14:1 as the front pushes south of Tahoe. SWE expected to be less than 0.20 inches along the highest peaks.

* Wind gusts: Southwest-west ridgetop wind gusts up to 70-80 mph in the afternoon.

* Lightning: Thunderstorm chances generally <10%, some areas around Tahoe could reach 10-15% in more convective showers between 1-6 PM. -Justin/078

REV Watches/Warnings/Advisories

NV...Lake Wind Advisory from 7 AM this morning to 10 PM PST this evening NVZ002.

Wind Advisory from 1 PM this afternoon to 10 PM PST this evening NVZ001-004.

CA...Lake Wind Advisory from 7 AM this morning to 10 PM PST this evening CAZ072.

Wind Advisory from 10 AM this morning to 10 PM PST this evening CAZ073.