textproduct: Reno

KEY MESSAGES

* Warmer conditions return for the remainder of the week and this weekend.

* Increased east to southeast breezes Thursday into Friday with stronger ridge top winds peaking Thursday night.

* Cooler temperatures return next week with increased winds followed by chances for rain and mountain snow showers.

DISCUSSION

As a high pressure ridge off the CA coast builds inland across the northern Great Basin during the next few days, an area of low pressure forms over southern CA. This pattern will bring east to northeast breezes across much of the region Thursday afternoon with gusts 15-25 mph. However, for higher elevations these east winds will be notably stronger, with ridge top gusts increasing to 40-50 mph Thursday morning and peak gusts near 60 mph Thursday night. Some of these winds may mix down to Lake Tahoe Thursday night, producing a short period of choppy conditions along western shores.

By Friday, the ridge top winds ease as the low drops farther south, but the surface gradient remains with the wind direction shifting to the southeast. While afternoon gusts again look to range between 15-25 mph, parts of Mineral County and areas near the OR border may see gusts increase to 30 mph. In these areas with the enhanced gusts, a short period of elevated fire weather concerns could arise as afternoon humidity drops to the 15-20% range.

These winds are expected to diminish by Saturday, then more typical zephyr-type SW-W breezes return Sunday afternoon. Temperatures will continue a steady climb, with highs this weekend into the mid-upper 70s for lower elevations and near 70 degrees for Sierra communities.

By next week, the ridge pattern breaks down in response to an upper level trough approaching the west coast. The first effect of this system will be increasing winds Monday afternoon, with potential for 30-40 mph gusts across most lower elevations. Fire weather concerns could increase again, although temperatures will also start trending downward with humidity not as low compared to this weekend.

Then from Tuesday-Wednesday, further cooling is expected with highs dipping into below-average territory, mainly in the 50s to lower 60s. There are more indications that the trough digs farther offshore from the CA coast which could delay the onset of showers until Tuesday night and Wednesday, and also shift the better chances (30-50%) to areas south of US-50 with lesser 15-30% probabilities elsewhere. These "shoulder season" storms when involving closed upper lows tend to have a larger spread of outcomes (resulting in lower confidence) and this system is no exception. Current liquid precip and mountain snow projections are not that impressive from Tuesday-Wednesday (up to 0.25" with locally up to 0.50" mainly south of US-50, and snowfall up to 3" above 8000 feet in Mono County), although some of the wetter scenarios could produce additional amounts beyond Wednesday. MJD

AVIATION

* VFR flight conditions prevail through this weekend with little to no cloud cover.

* Light winds (gusts 15 kt or less) at the main terminals today. East winds increase Thursday between 20-02Z with gusts 15-20 kt for most main terminals. Similar speeds with mainly east to southeast winds return Friday afternoon. Stronger FL100 east wind gusts of 40-50 kt from Thursday morning through early Friday, leading to areas of mountain wave turbulence near and west of the Sierra and Carson Range. MJD

REV Watches/Warnings/Advisories

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