Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/20/18

Area Forecast Discussion
National Weather Service Las Vegas NV
800 PM PDT Thu Apr 19 2018 .SYNOPSIS...A cold low pressure system over the region will slowly move away toward the Four Corners on Friday. Gusty winds will decrease somewhat late this evening but north breezes will persist through Friday. Scattered showers will diminish overnight then linger near the southwest Utah border Friday. Dry and warmer weather will return Saturday and hold much of next week. && .UPDATE...Scattered light showers and isolated thunderstorms continue this evening in response to a closed low and cold temperatures aloft passing through the region. Dozens of lightning strikes occured earlier in the afternoon across Southern Inyo County, most concentrated in the southern reaches of Death Valley NP south of Telescope Peak. Lightning has since diminished but pockets of light showers and sprinkles persist across Southern Nevada and Northwest Arizona. Suspect these showers will diminish in the coming hours with the loss of daytime heating but widespread mid level cloud cover will persist overnight. Winds continue to gust across our western zones and I plan to maintain the current wind advisories through their expiration at 11 pm. A few minor adjustments to the grids will be sent out shortly mainly to account for current trends, but otherwise most everything is in good shape. -Outler- .AVIATION...For McCarran...Breezy northwest winds have pushed into the valley this evening with gusts to 25 knots. These winds will continue through 05z before weakening. Another reinforcing shot of northwest winds are expected tomorrow morning and by afternoon winds are forecast to be between 010-030 deg with speeds 7-10 kts. A few showers around the valley this will dissipate this evening with mainly sct-bkn clouds around 8k feet overnight. Skies will remain mostly clear on Friday. For the rest of southern Nevada, northwest Arizona and southeast California...Gusty northwest to north winds will be seen across Inyo, Esmeralda, and central Nye Counties with speeds between 20-35 kts these winds will diminish slightly overnight, but overall will remain gusty overnight and Friday. A few showers and isolated thunderstorms will be seen this evening, mainly north of I-40. Showers and storms will diminish through the evening hours. Cigs down to 5-6k feet are possible with lower cigs down to 3k feet in heavier showers. && .SHORT TERM...through Saturday night. Scattered light showers were apparent from radar returns around southern Nevada and southeast California. A few lightning strikes were detected over southern Inyo County and between Bicycle Lake and Baker, but thunderstorms have been scarce over south central Nevada. Widespread gusts over 40 mph were primarily observed where Wind Advisories were in effect over the Western Mojave Desert and west central Nevada. Brief bursts of wind over 40 mph have been observed from Indian Springs down into the northwest Las Vegas Valley associated with the showers, but these are expected to be short lived. However, gusts in the 30s will continue through early evening before winds begin to decrease. Showers will diminish after sunset but the HRRR indicates Lincoln County should see redeveloping showers over night as a disturbance rotates down the back side of the exiting closed low. Eastern Lincoln and northern Mohave counties will see lingering showers Friday while the rest of the region is under a dry northwest flow with high temperatures climbing 10-15 degrees. Some north breezes will remain Friday night for areas prone to north winds but speeds should generally be less than 15 mph. Saturday will see temperatures climb an additional 3-5 degrees with light winds most everywhere except maybe 10-15 mph along the lower Colorado River Valley. .LONG TERM...Sunday through Wednesday. Confidence is still high on dry, breezy and warm conditions as we head into next week. Operational runs of GFS and ECMWF continue to show a shortwave trough moving across the Pacific Northwest on Sunday then across northern Nevada Sunday into Monday. As the wave passes to the north, breezy winds should develop Sunday and Monday in response to surface pressure falls north of the region. Any precip should be north of the forecast area. During the Tuesday and Wednesday period the GFS and ECMWF solutions show considerable differences in the synoptic evolution of a shortwave trough. The GFS supports a progressive wave which quickly dives south across California Tuesday and shifts to the east into Arizona Wednesday. Whereas, the ECMWF suggests prolonged ridging through at least Wednesday before a cutoff low off of the California coast slowly tracks inland late next week. These patterns would yield very different weather conditions: windy and cool under the GFS solution and continued quiet weather and above normal temperatures under the Euro. The extend forecast is favoring the Euro due to run-to-run consistency, but forecast confidence after Monday is very low. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather according to standard operating procedures. && $$ SHORT TERM...Adair LONG TERM...Boothe AVIATION...Gorelow For more forecast information...see us on our webpage: or follow us on Facebook and Twitter