Area Forecast Discussion
Issued by NWS Reno, NV
Issued by NWS Reno, NV
027 FXUS65 KREV 150929 AFDREV Area Forecast Discussion National Weather Service Reno NV 229 AM PDT Sat Jun 15 2024 .SYNOPSIS... Temperatures cooling to seasonal averages are expected this weekend. Afternoon breezes today will be followed by another increase in winds late Sunday and Sunday night due to a secondary cold front passage, with a few showers possible near the Oregon border. Monday will be the coolest day of the week, before slow warming and dry conditions settle in for the rest of next week. && .DISCUSSION... Key Points: * Temperatures cooling to near mid-June averages this weekend. * The next cold front passage for Sunday night will bring increased winds and possible isolated fire weather concerns. * Monday will be the coolest day with highs around 10 degrees below average, followed by steady warming through next week. A reprieve from the heat is in store for Father`s Day weekend as the 10-day streak of 90+ degrees for most western NV valleys ends today. For Sierra communities, highs will be mainly in the lower-mid 70s today and Sunday. We`ll continue to see breezy conditions today, but Sunday afternoon-evening presents the best opportunity for more impactful winds in regard to recreation and fire weather. With the main cold front passage most likely occurring Sunday night, most areas won`t have the most optimal setup for peak wind gusts occurring at the warmest and driest part of the day, but isolated fire weather concerns will be present after the recent period of hot and dry conditions. Behind this cold front, northwest-north winds will bring in the coolest air mass of the month with temperatures only reaching the lower 70s for western NV valleys and 60s elsewhere Monday. The potential for showers continues to decrease, with latest guidance only brushing 10-15% chances for very light showers north of Cedarville to the OR border early Monday morning. Winds will decrease across most areas during the day Monday, but the US-95 and US-6 corridors of Mineral/southern Mono counties that respond more readily to north winds will likely see enhanced gusts of 30+ mph through the afternoon. Monday night will be on the chilly side with lows in the 40s for most western NV communities, but some rural/outlying valleys could dip into the 30s. The typically colder Sierra valleys have a good potential of lows below freezing, so it would be a good idea to protect any cold-sensitive garden vegetation in these areas Monday night. A general dry trough pattern remains near the west coast for next week, with a slow rise in 500 mb heights allowing for a steady warmup from Tuesday onward. By late next week, highs could push above 90 in lower elevations, although the higher potential for more substantial warming is projected for the June 22-23 weekend. By that time, the ensemble guidance favors rebuilding a high pressure ridge over the southwest US, expanding into much of the central-eastern Great Basin. MJD && .AVIATION... * Widespread VFR conditions will continue today with typical afternoon breezes to 20-25kt after 19Z-21Z. Breezes will gradually taper off after sundown, then transition to overnight diurnally terrain driven flows. Temperatures trending cooler this weekend will dampen afternoon density altitude concerns for warmer western NV terminals. General aviation and helicopter OPS should still check density altitudes for their respective areas. * Look once more for return of enhanced W-SW breezes Sunday with wind gusts to 25-30 kts for main terminal sites. Also, FL100 winds will increase to 30-35 kts Sunday evening after 00-03Z that heighten chances (15-20%) for LLWS and moderate turbulence over Sierra terminals (KSVE/KTRK/KTVL/KMMH) through Sunday night. LLWS and turbulence look to subside after 12-15Z Monday. -Amanda && .FIRE WEATHER... Typical afternoon breezes, prevailing dry conditions, and receptive fine fuels will bring elevated to locally critical fire weather conditions for much of the region through Sunday. Overnight RH recoveries this weekend, as projected by higher confidence blended guidance, will remain poor to marginal for the valley floors and mid-slope areas of western Nevada, with early morning RH across the region expected to struggle only into the low 40% each night. Marginal improvements to RH recoveries, however, are projected across the Sierra Front overnight Sunday into Monday morning as early morning maximum RHs of 50-70% respond to the cooler early morning temperatures. A weak upper trough will induce a wind shift from W to NW/N tonight, which may impact any new or existing ignitions across western Nevada. Enhanced Sunday afternoon breezes coupled with minimum RHs ranging between 10-15% ahead of another cold frontal passage will feature the potential for periods of isolated critical fire weather conditions once again for western Nevada. Overall, however, expect elevated fire weather conditions regionwide through Sunday. -Amanda && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$