National Weather Service Raw Text Product

651 
FXUS65 KREV 210928
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
228 AM PDT Sun Jul 21 2024

.SYNOPSIS...

* Heat continues into Tuesday with triple digit highs expected 
  for western Nevada valleys. 

* Increased storm chances this afternoon across the E. Sierra.
  Heavy rain with isolated flash flood potential mainly across area 
  burn scars south of US-50. 

* Daily thunderstorm chances continue through Thursday. Elevated 
  fire weather concerns possible across far NE CA and NW NV this 
  afternoon.

&&

.DISCUSSION...

Hot – Hot – Hot: 

* High pressure dominating the western US will continue to bring
  unseasonably warmer temperatures to the region. Temperatures in
  some western Nevada valleys will be up to 8 degrees above mid to
  late July averages through Tuesday. Therefore, most daytime
  highs across western Nevada valleys will will either push into
  the upper 90s or more likely into the 100-105 degree range. The
  heat advisory was extended into Tuesday for northwest and west
  central NV as highs remain nearly steady through that time
  frame. Sierra communities will see mostly upper 80s with a few
  exceptions rising into the lower 90s. The heat will also be felt
  during the overnight hours as lows remain on the mild side, some
  10-15 degrees above July normals through Tuesday. Most western
  Nevada valleys will only cool into the upper 60s to lower 70s,
  which will result in areas of moderate to major HeatRisk. So
  it’s advised to take on all those necessary precautions to beat
  the heat. 

Thunderstorms Continue Into Next Week: 

* In this category the only change to the status quo will be
  thunderstorm areal coverage, and general storm organization. Hi-
  Resolution ensemble simulations show mean PWAT values across the
  Sierra and western Nevada rising to 0.8 inches through midday,
  and then increasing further to a full inch across many areas in
  far western Nevada west of US-95. Rapid late morning and
  afternoon surface heating, along with modestly moistened mid-
  levels, and sufficient surface CAPE (150-500 j/kg) will initiate
  scattered shower and storm formation across the eastern Sierra
  south of Highway 50 by early afternoon. Storms will once again
  push into western Nevada, and become more isolated up to and
  beyond I-80, continuing into northern Washoe County and 
  northeast CA late in the afternoon and evening. Storm cells that
  do develop in the somewhat drier environment will be high based
  with an extended dry sud-cloud region. This notion coupled with
  some storm motions exceeding 20 kts will enhance the threat of 
  isolated dry lightning strikes and new fire ignitions today and 
  Monday.

Heat and Storm Relief By Weeks End: 

* Some relief from the current heat wave will come in the form of
  an upper level longwave trough pattern sagging south into the
  region late in the upcoming week. This pattern will allow for a
  more southern trajectory of incoming upper shortwaves that 
  bring an increased southwest upper flow to the region by 
  Thursday onward. This pattern will not only bring drier 
  conditions that suppress showers and storms across the region, 
  but also restrain temperatures to more seasonal July averages. 
  Daily afternoon breezes will return in earnest with the cooler 
  temperatures and increasing southwest flow over the region as 
  well. - Amanda

&&

.AVIATION...

* Prevailing VFR conditions in the morning will once give way to
  increased afternoon shower and thunderstorm chances for western
  NV and Sierra main terminals after 21z. A 25-40% chance for
  showers and thunderstorms includes not only Sierra terminals
  (KTRK-KTVL), but also far western NV terminals (KRNO-KCXP-KMEV)
  and the eastern Sierra/Mono County (KMMH). Elsewhere, terminals
  across the region will see shower and thunderstorm chances that
  hover around 15-25%.

* Storms in close proximity to regional terminals will still be
  capable of brief periods of MVFR/IFR conditions in brief heavy
  rainfall, small hail, and frequent lightning. Look for another
  round of strong-gusty storm outflow winds that bring a potential
  for wind gusts to 45 kt across basin and range terminals (KLOL,
  KNFL, KHTH). Also be prepared this afternoon for rapid 
  reductions to visibility in blowing dust in and near desert 
  sinks and dry lake beds. 

* Daily afternoon shower/storm chances will continue into the
  first half of this week with the best potential existing south
  of US-50. Drier air will then move into the region later in the
  week that includes a much lesser chance for storms, but
  increased afternoon SW-W breezes. -Amanda

&&

.REV Watches/Warnings/Advisories...
NV...Heat Advisory until 8 PM PDT Tuesday NVZ004-005.

CA...None.
&&

$$