Area Forecast Discussion
Issued by NWS Reno, NV
Issued by NWS Reno, NV
055 FXUS65 KREV 012042 AFDREV Area Forecast Discussion National Weather Service Reno NV 142 PM PDT Mon Jul 1 2024 .SYNOPSIS... * High pressure will bring a significant warmup this week with a prolonged heatwave setting up over the 4th of July weekend. * Heat risk levels will rise to moderate Wednesday through Friday, increasing to major across western NV over the weekend. A few records will be broken. * It will remain very dry with low afternoon humidity and poor overnight recovery. && .DISCUSSION... * CHANGES: Excessive Heat Watch issued Saturday to Tuesday morning. Blended guidance was significantly warmer this morning. * Strong high pressure will build across CA-NV this week with temperatures rising to 10-15 degrees above average by the weekend and overnight lows only cooling briefly early each day. While we are heading into our climatologically hottest time of the summer, blended guidance is impressive as it pushes strongly against climatology, as much as 15 degrees above normal over the extended holiday weekend. This pushes the HeatRisk into the major impact category across all of western NV Sat-Mon, while July 4th and Friday will be miserable and not far behind as the HeatRisk moves into the Moderate category. It is not only going to be unusually hot with record highs expected, but this is going to be an extended period of heat. Many of the long term ensemble members keep us in a heat wave until the middle of next week with a better than 50/50 chance of staying over 100 degrees. Even Sierra communities will reach or exceed 90 degrees and advisory headlines may be warranted at some point. * Conditions will remain very dry with little chance for convection. Then again, it would not take much to get a storm or two by late in the weekend or early next week after several days of intense heat. While the forecast contains no mention of storms, keep it in the back of your mind that there is a 5-15% chance for a few high-based buildups/showers/storms over the weekend and early next week, especially in the typical convergence zones east of Lassen Peak and along the eastern Sierra south of Lake Tahoe. * A period of locally breezy north winds with gusts generally 20-25 mph is expected through this evening across western NV and lower elevations of northeast CA. Winds turn east tonight with breezy ridge winds into early Tue AM and maybe a bit of east wind on Lake Tahoe as a front swings through the area. Otherwise, just some typical late day winds through the weekend. Hohmann && .AVIATION... * No big changes. VFR conditions with main concern being heat as temperatures warm to well above average through the July 4th holiday weekend. No significant wind with chances for storms very low (less than 10%). * Afternoon highs will approach 100 degrees for lower elevation terminals Wed-Fri. Highs warm further over the weekend with 90+ degrees at Sierra terminals and 105+ degrees across lower elevation airports, further increasing potential density altitude impacts. Hohmann && .FIRE WEATHER... * Locally breezy north winds (gusts 25-30 mph) and low humidity (10-15%) may result in a short period of near critical fire weather through mid evening, mainly across northwest NV where there were a few lightning strikes late Sunday. * Dry and hot weather will persist the rest of the week and into next weekend with poor overnight recovery and temperatures climbing to near record levels by the weekend. While no significant winds are forecast, the very dry conditions and deep mixing will be capable of promoting fire growth. Hohmann && .REV Watches/Warnings/Advisories... NV...Excessive Heat Watch from Saturday morning through Tuesday morning NVZ001-003>005. CA...None. && $$