Area Forecast Discussion

KEY MESSAGES

* Expect increasing southwest winds and cooling temperatures this weekend and into next week.

DISCUSSION

through Friday.

A persistent trough will be the main driver of weather through the weekend and next week. First, temperatures will fall back to near normal values by Sunday, which means highs in the upper 90s to low 100s across much of the Mojave Desert. HeatRisk decreases from Moderate(Level 2 of 4) to Minor (Level 1 of 4) for most locations as a result. Highs should remain within a few degrees of normal throughout the week. The position of the trough will allow for an increase in southerly to southwesterly winds across much of the area. The strongest gusts should generally remain in the 30 to 40 mph range today, which will create rough waters and waves between 2 and 4 feet on Lake Mead and Lake Mohave. Gusty winds combined with dry conditions also raise elevated to critical fire weather concerns - see the FIRE WEATHER discussion below for more details. Winds may weaken a bit on Sunday, but are expected to strengthen again on Monday and Tuesday as the trough becomes reestablished. Additional periods of breezy winds are possible later in the week depending on the strength and position of the trough, but confidence in this setup is lower at this time.

AVIATION...For Harry Reid...For the 18Z Forecast Package

Winds will remain southwesterly through Sunday afternoon. Speeds will remain elevated into tonight, with occasional gusts of 25 to 33 knots into the early evening. Gusts will decrease after that, although gusts to around 25 knots will remain possible through sunrise. A brief lull in the winds is possible Sunday morning, but southwest gusts will redevelop by Sunday afternoon. VFR conditions will prevail into Sunday with SCT to BKN clouds with bases AOA 15kft AGL moving across the region this evening through Sunday morning. Temperatures are expected to exceed 100 degrees from 19Z to 02Z, topping out around 102 degrees. Temperatures on Sunday should top out in the upper 90s.

For the rest of southern Nevada, northwest Arizona and southeast California...For the 18Z Forecast Package...Southerly to southwesterly winds will continue to increase through the afternoon, with occasional gusts of 20 to 30 knots expected to continue into the evening. One exception will be across the western Mojave Desert, including KDAG, where winds will favor a more westerly direction and gusts will be in the 25 to 35 knot range. Another exception is the northern Owens Valley, including KBIH, where winds will remain light and favor typical diurnal directional trends until gusty westerly winds develop by mid-afternoon. VFR conditions will persist through the TAF period with SCT to BKN clouds with bases AOA 15kft AGL moving across the area this evening through Sunday morning.

FIRE WEATHER

A combination of widespread southwesterly winds of 15 to 25 mph gusting between 30 and 40 mph, minimum RH values between 5 and 15 percent, and dry fuels bring critical fire weather conditions to much of the area today. Red Flag Warnings cover all of southern Nevada and northwestern Arizona except for Nevada Zone 460. This warning continues into Sunday for northwestern Arizona, where gusty winds will persist as the trough moves east. Another round of gusty winds and dry conditions is expected on Monday and Tuesday as the trough strengthens again, and a Fire Weather Watch has been issued for all of northwestern Arizona and most of southern Nevada for this time as well.

SPOTTER INFORMATION STATEMENT

Spotters are encouraged to report any significant weather or impacts according to standard operating procedures.