Area Forecast Discussion
Issued by NWS Reno, NV
Issued by NWS Reno, NV
631 FXUS65 KREV 190816 AFDREV Area Forecast Discussion National Weather Service Reno NV 116 AM PDT Wed Jun 19 2024 .SYNOPSIS... * Light winds with afternoon temperatures warming 5 or so degrees each day through Friday. Cannot rule out a stray storm or two late this afternoon and again Thursday afternoon near the Sierra. * Temperatures peak this weekend with moderate heat risk. Afternoon temperatures will approach 100 degrees for hotter western NV valleys with daytime west to southwest breezes returning. * A trough anchors over the Pacific Northwest next week, keeping it dry with breezy afternoon winds. Temperatures may cool a few degrees, but they will remain 5 to 10 degrees above average. && .DISCUSSION... Through Friday: * A weak trough will meander slowly across the Sierra and Great Basin through Friday with temperatures warming each day. This morning`s temperatures were already 5-10 degrees warmer than 24 hours prior. Near average highs today will warm to around 10 degrees above normal by Friday. It will remain quite dry with limited RH recoveries, especially for mid slopes. * The wind pattern is very light along and ahead of the trough which will allow for some instability to slowly build along the Sierra. For today, temperatures near average and PWATs rising to around 0.40" may bring just enough instability for a 5-10% chance of high-based showers/storms late this afternoon/early evening. By Thursday afternoon, additional heating and PWATs near 0.50" will result in a bit more CAPE (300-500 J/KG) and a better chance of seeing a few storms (10-20% chance). This Weekend: * Temperatures are expected to peak this weekend as the ridge builds northward into CA-NV, 500 MB heights rise to around 590 DAM and 700 MB temperatures push 16-17C. Ensemble spreads are quite low, so confidence is high for another round of hot temperatures close to 15 degrees above average Sat-Sun when highs will approach 100 degrees across western NV and 85-90 degrees in Sierra communities. This puts the HeatRisk back into the moderate category which is a level that impacts most individuals who are sensitive to the heat. * Otherwise, things look capped and dry with storm potential very low despite the heat (5% or less). Late day zephyr breezes will return with gusts 20-30 mph from late afternoon into the evening. Next Week: Ensemble spread increases a bit as shortwaves moving eastward through the PacNW and northern Rockies try to flatten the ridge. With the ridge axis remaining south across the Desert Southwest and northern Baja region, the most likely scenario is for a dry westerly flow aloft to dominate with temperatures dropping back a few degrees but remaining 5-10 degrees above average. Afternoon and evening breezes would persist as well. Hohmann && .AVIATION... VFR and light winds will be the prevailing features through Friday. The only caveat will be a 5-10% chance for showers/storms along the Sierra late this afternoon (22-02Z) with a slightly better 10-20% chance late Thursday afternoon. Any cells will be high-based and capable of gusty outflow winds to 35-40 kts, but easily circumnavigable while en-route. Hohmann && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$