textproduct: Las Vegas

KEY MESSAGES

* Dangerous heat will remain the primary weather concern through Saturday, with widespread Moderate to Major HeatRisk expected.

* Monsoon moisture will slowly begin to return late in the week, with isolated thunderstorms first returning to northwest Arizona before spreading into southern Nevada over the weekend.

DISCUSSION

through Monday.

A 595dm high pressure ridge remains focused over Arizona/New Mexico this afternoon with widespread hot conditions once again this afternoon. While it remains very hot, regional temperatures are hovering 1-3 degrees cooler than this time Monday thanks to a very subtle decrease in heights across the region. This high pressure ridge will gradually strengthen the remainder of the week with temperatures slowly ticking back upwards. In addition, a modest amount of monsoonal moisture will push into our southern zones, with increasing humidity adding to the oppressiveness of the heat and elevating overnight low temperatures. The ongoing heat headlines remain in good shape through Saturday evening.

Meanwhile, the monsoon remains active across southern Arizona but this moisture has failed to translate westward into the Mojave through most of the season. Anticipating a modest moisture increase late in the week and over the weekend as the high pressure ridge builds into eastern NV/UT and southeasterly flow beneath the ridge advects richer moisture into the region. This will result in increasing thunderstorm potential Thu/Friday across Northwest Arizona, with chances spreading westward into the Mojave Desert and southern Great Basin over the weekend and into early next week.

AVIATION...For Harry Reid

For the 18Z Forecast Package...Much like the previous few days, southeast winds early in the afternoon will transition to the southwest between 20Z-22Z. Winds over 10KT are likely through the afternoon with gusts 15-20KT with the southeast winds, increasing to gusts 20-25KT with the southwest winds. Winds will diminish around sunset as gusts end and southwest winds at 8-10KT in the evening become southwest at 8KT or less overnight. This pattern repeats on Wednesday as elevated southeast winds become breezy out of the southwest in the afternoon. VFR mostly clear skies through the period. Temperatures will exceed 100 degrees through 05Z tonight, then again Wednesday between 18Z to 05Z.

For the rest of southern Nevada, northwest Arizona and southeast California...For the 18Z Forecast Package...South to southwest winds gusting 15-25KT can be expected across the region outside of the KDAG area where light winds will begin gusting out of the west around 00Z. Winds will diminish this evening in most locations with typical wind patterns expected overnight. The exception is in the Colorado River Valley where a south to southeast outflow may push north out of southern Arizona overnight. Low confidence in this occuring and what it would look like, captured the potential elevated south-southeast winds in the current TAF, but higher wind speeds with gusts over 20KT are possible if this outflow occurs. VFR skies and dry conditions expected area-wide through the TAF period.

CLIMATE

Numerous climate locations have a forecast high temperature and/or forecast warm low temperature within 3 degrees of the daily record.

The table below shows the daily record maximum temperature and the year the record was last set. An asterisk (*) denotes which records are in jeopardy (within 3 degrees of the forecast).

MAX TUE, AUG 4 WED, AUG 5 THU, AUG 6 Record(Yr) Record(Yr) Record(Yr) Las Vegas 114(1979)* 113(2024)* 114(2024)* Bishop 105(2020)* 105(2024)* 106(2024)* Needles 121(2021) 119(2019) 118(2018) Daggett 114(2021)* 114(1998)* 114(1997) Kingman 107(2021) 107(2019) 109(1920) Desert Rock 109(2021)* 108(2024)* 109(2024)* Death Valley 126(2021) 125(1936)* 127(2017)

The table below shows the daily record warm minimum temperature and the year the record was last set. An asterisk (*) denotes which records are in jeopardy (within 3 degrees of the forecast).

WARM MIN TUE, AUG 4 WED, AUG 5 THU, AUG 6 Record(Yr) Record(Yr) Record(Yr) Las Vegas 89(2024)* 89(2024)* 91(2024)* Bishop 75(1961) 68(1971) 69(1979) Needles 94(1908) 94(2024) 94(2021) Daggett 82(1974)* 83(1998)* 84(1983)* Kingman 78(2024)* 78(2024)* 79(2019)* Desert Rock 79(2018)* 81(2015)* 82(1994)* Death Valley 100(1925) 100(1915)* 99(2024)*

SPOTTER INFORMATION STATEMENT

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