Area Forecast Discussion

KEY MESSAGES

* Dry and seasonable conditions through the weekend.

* Precipitation chances return Monday and Tuesday

* Slight warming and low precipitation chances late in the work week.

DISCUSSION

through Friday.

Morning satellite imagery clearly depicts a closed low spinning over southern ID. Westerly flow has ushered in much drier air, with observed PWAT values dropping over 2/3 of an inch when comparing this morning's sounding to yesterday morning's. The surface dewpoint has also dropped ~25F, giving the air that crisp, fall-like feeling. Most of the Mojave Desert fell into the 50s and 60s this morning, with the southern Great Basin reaching into the 40s and even upper 30s! Highs today will rebound to within a few degrees of climatology, with similar conditions on Sunday. Temperatures top out in the 90s to low 100s in the Mojave Desert, and upper-70s to upper- 80s in the southern Great Basin.

Early in the upcoming work week, ensemble guidance remains in good agreement on an upper-level low drifting across central CA and into our region. There will be some modest moisture return ahead of this feature as ensemble mean PWAT values increase to 2/3 - 1". The combination of upper-level dynamics, colder air aloft, and anomalous moisture should be enough to spark scattered showers and maybe even isolated thunderstorms. Best chances (30-60%) appear to be Monday afternoon through Tuesday afternoon northwest of I-15. Given the modest moisture, expecting rainfall amounts to be on the light to moderate side. However, would not rule out some gusty outflow winds nor some small hail/graupel (if enough instability can materialize).

After a subtle cooldown on Monday and Tuesday, temperatures rebound during the 2nd half of the week thanks to 500mb height rises and clearer skies. Ensemble guidance also has the mid-level flow turning more southerly late in the week, allowing some late-season monsoon moisture to creep up towards the I-15 corridor. Still a ways out, but this is enough to support at least low PoPs (10-30%) across the southeastern half of the CWA on Friday.

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

Winds will remain relatively light over the next 30 hours, with sustained speeds remaining 10 knots or less and generally following typical daily directional trends. There is a low chance (10 percent) of a gust to around 15 knots this afternoon during peak heating, but any gusts should be short lived. VFR conditions will prevail through the TAF period with mainly clear skies into tonight, then increasing high cloud cover on Sunday.

For the rest of southern Nevada, northwest Arizona and southeast California...For the 18Z Forecast Package...Winds across the region will remain relatively light this afternoon into Sunday, with sustained speeds of 12 knots or less. Directions will favor typical daily directional trends in most locations. VFR conditions will prevail through the TAF period with high clouds increasing from west to east overnight and Sunday.

SPOTTER INFORMATION STATEMENT

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