Area Forecast Discussion
Issued by NWS Reno, NV
Issued by NWS Reno, NV
982 FXUS65 KREV 162039 AFDREV Area Forecast Discussion National Weather Service Reno NV 139 PM PDT Thu May 16 2024 .SYNOPSIS... Unseasonably warm temperatures will persist through Saturday with afternoon breezes. Other than low chances of showers and thunderstorms in the eastern Sierra and far western NV south of Highway 50 on Saturday, conditions will stay dry. Low pressure will keep the breezes around for next week with temperatures remaining seasonally mild. && .DISCUSSION... * Unseasonably warm temperatures through Saturday with highs remaining about 10 degrees above normal. * Afternoon breezes (typical of early summer) continue into the weekend. Nothing crazy, but locally choppy lake waters and impacts to activities more sensitive to wind. * 10% chance of thunder along the Mono County crest late this afternoon and a 15-30% chance of showers and thunderstorms south of Hwy 50 Saturday afternoon. Otherwise, dry conditions will prevail through the weekend. THROUGH SATURDAY: Warmest temperatures will be this afternoon with temperatures atop Slide Mt in the mid 50s as of 1 pm, 6 degrees warmer from 24 hours ago. So it will be close whether we can hit 90 degrees at the airport. Winds were also beginning to pick up on the ridges and should mix down into the lower terrain by late this afternoon. These breezy conditions will persist across midslopes and ridges overnight as a weak front moves into the northern Great Basin and turns our flow more N-NE for Friday and cools us down a few degrees Friday afternoon. An isolated storm or two cannot be ruled out along the Sierra crest south of Markleeville Friday afternoon as a few ensemble members show some light QPF. Given the light flow and very warm temperatures, we maintained a 10% chance. For Saturday, westerly breezes will pick up again ahead of a trough moving through the PacNW. lake waters. Strongest winds will be north of Hwy 50 where gusts to 30-35 mph may be sufficient for some localized choppy lake waters. Farther south across Mono-Mineral-S Lyon counties, ECS/GEFS continue to indicate the potential for isold-scattered showers/storms (15-30% chance). Instability is marginal, but a few stronger cells could produce some small hail, wind gusts to 40 mph, lightning and brief heavy rain. Temperatures will be similar to Friday, still about 10 degrees above normal. SUNDAY AND BEYOND: Ensemble clusters show a trough with afternoon breezes and temperatures cooling back to near or slightly above normal levels. There is still a lot of spread in the temperature field which indicates lower confidence in the details regarding depth and track of upper level features. Blended guidance has trended drier overall with lower chances for showers. This overall trend of troughiness and seasonal temperatures may persist through the rest of May. Hohmann && .AVIATION... * 30-HR Operating Period (through 18/06Z): VFR. W-NW winds 10-15 kts shifting to the N-NE after 15Z Friday as a front works through the Great Basin. Gusts 20-25 kts through 03Z this evening. There is a 10-15% chance of showers/thunder near the Sierra crest after 21Z Friday vicinity KBAN-KMMH. * This Weekend: A trough will drop southward into the Great Basin with breezy daytime W-NW winds, gusts 20-30 kts at times. There remains a 15-30% chance of showers/thunderstorms eastern Sierra Saturday afternoon, potentially impacting KMMH-KBAN-KHTH. A few model scenarios indicate a 10% chance of a storm drifting as far north as KTVL/KMEV. Hohmann && .HYDROLOGY... Unseasonably warm daytime temperatures and mild nights, combined with higher solar angles, longer days, and limited cloud cover, will continue to increase snowmelt rates late week. Even the higher elevation deeper snow areas have begun to melt in earnest. This rapid melt will lead to elevated flows with rivers and streams running cold and fast, most notably in areas draining significant terrain over ~7500 feet from Lake Tahoe south through Mono County. Rivers and streams in this area will remain high through the weekend, with the highest flows likely Thursday into Saturday. Cooler temperatures and a depleting snow-covered contributing area will help reduce flows somewhat Sunday into early next week. While these high and cold flows can be hazardous to recreationalists, flooding is very unlikely. Remember the highest flows are significantly lagged from the heat of the day and can often occur at night. More steady high flows will also continue along the Lower Humboldt, with additional rises likely in very late May or early June. Please use extra caution around local rivers and streams which will be running fast and cold and can be very hazardous. TB && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$