Area Forecast Discussion

KEY MESSAGES

* Gusty southwest winds and increased fire danger expected through mid-week.

DISCUSSION

through Friday.

Latest water vapor imagery shows that troughing has begun to take hold over the western US, and models indicate it will linger through mid-week. The height falls associated with this system bring temperatures back to seasonable values for several days, with highs of 80-95 degrees in the southern Great Basin and 90-105 across most of the Mojave Desert. PoPs remain scant (less than 10%) in our forecast area due to meager moisture. The main story with this trough continues to be the gusty southwest winds and increased fire danger. The fire aspect is discussed below in the Fire Weather section, but outside of that, wind impacts will likely be confined to the local lakes (mainly Mead and Mohave). A Lake Wind Advisory is in effect today due to winds 20-25 mph and gust up to 40 mph causing waves of 2-4 feet. Monday and Tuesday present the next best odds (40- 50% chances) of boating impacts. As we get into the 2nd half of next week, ensemble guidance shows the trough lifting to our northeast, allowing winds to relax, temperatures to rise, and dry conditions to persist.

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

Expecting widespread southwest winds of 15-25 mph with gusts up to 40 mph today. Combined with minimum RH values of 5-15% and fuels approaching critical, Red Flag Warnings cover all of southern NV and northwestern AZ except for Nevada Zone 460. The warning continues on Sunday for northwestern AZ and the NV side of the Colorado River Valley. Near to critical fire weather conditions look likely to persist into early next week as the trough reloads and produces similar winds. Winds are forecast be most widespread on Monday, becoming confined to far southeastern NV and northwestern AZ on Tuesday. A Fire Weather Watch remains in effect for all of our AZ zones and most of our NV zones on Monday and Tuesday.

SPOTTER INFORMATION STATEMENT

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