Marine Weather and Tide Forecast for South Lake Tahoe, CA

DISCUSSION

While the remainder of this week will remain dry with daytime highs warming to the upper 60s-mid 70s on Friday, winds will be the primary weather feature through Friday night. East winds have increased over the Sierra crest with gusts up to 60 mph this morning while for the Carson Range, gusts on Slide Mtn have ranged from 35-40 mph. Lake Tahoe buoys reported conditions nearing lake wind advisory thresholds--sustained 15-20 mph with gusts 25-30 mph and observed choppy conditions (estimated wave heights up to 2 feet) from west shore web cameras. These winds are projected to peak this evening and late tonight which align with Tahoe's current Lake Wind Advisory. Elsewhere, east to northeast wind gusts of 15-20 mph with occasional gusts to 25 mph are expected through early this evening.

By Friday, the Sierra ridge winds diminish, but a surface gradient remains over lower elevations with winds shifting to the southeast. Gusts of 15-25 mph are expected for much of the region, with pockets of enhanced 30-35 mph gusts in parts of Mineral County and northeast CA/far northwest NV which could elevate fire weather concerns in these areas--see the Fire Weather section below for more details. Higher resolution guidance holds on to a small area of enhanced southeast to south winds (sustained 15-25 mph with gusts 30-40 mph) across Mineral and southeast Churchill counties Friday night. This includes Walker Lake which could become choppy overnight, but these conditions will ease by Saturday morning as winds diminish.

Lighter winds then prevail through the remainder of Saturday, then more typical zephyr-type southwest/west breezes (gusts up to 25 mph) return Sunday afternoon. Temperatures this weekend will rise into the mid-upper 70s for lower elevations and near 70 degrees in the Sierra.

An approaching upper-level trough breaks down the ridge early next week. Monday brings the start of a cooling trend with increasing potential for wind gusts 30-40 mph and renewed fire weather concerns (also detailed in the Fire Weather section below).

Cooler temperatures in the 50s to lower 60s follow Tuesday through Thursday as low pressure drops southward off the CA coast. While some scenarios were still showing a farther offshore track, there's a bit more confidence this low will be close enough to bring showers into the Sierra as soon as Tuesday morning, then spread into parts of western NV Tuesday afternoon or evening.
Precip chances have increased to 40-60% near and south of I-80, with 25-40% chances north of I-80 from Tuesday night through Wednesday night, with 15-35% shower chances lingering through Thursday, as the most likely scenario favors a slow eastward progression of this low across the Great Basin or southwest US as it moves inland. Precip and mountain snow amounts (mainly above 8000 ft) have also trended upward compared to yesterday's forecast, although this will continue to fluctuate depending on the storm's eventual track. MJD

AVIATION

* VFR conditions prevail through this weekend under clear skies or patchy cirrus. East/southeast gusts up to 15-20 kts this afternoon through Friday, then lighter winds Saturday. Stronger FL100/ridge top east winds (40-50 kts) through Friday morning may trigger mountain wave turbulence and LLWS west of the Sierra and Carson Ranges. MJD

FIRE WEATHER

* A short period of elevated fire weather conditions may occur Friday afternoon over isolated portions of northern Washoe County, the Surprise Valley, northeast Lassen County and parts of Mineral County where southeast wind gusts could reach 30-35 mph, with minimum humidity between 12-18%.

* The next period to watch for elevated fire weather concerns is Monday afternoon, as southwest winds return with potential gusts 30-40 mph from the Sierra Front/Tahoe basin northward to northeast CA/northwest NV. Humidity looks more marginal with minimums mainly 15-20% in lower elevations and 20-30% for Sierra locations, but most of these areas have seen little to no rainfall for the past few weeks. MJD

REV Watches/Warnings/Advisories
NV...Lake Wind Advisory from 7 PM this evening to 2 AM PDT Friday NVZ002.

CA...Lake Wind Advisory from 7 PM this evening to 2 AM PDT Friday CAZ072.