Area Forecast Discussion
Issued by NWS Las Vegas, NV
Issued by NWS Las Vegas, NV
806 FXUS65 KVEF 140135 AAA AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 635 PM PDT Thu Jun 13 2024 .SYNOPSIS...A weak low pressure system brings slightly cooler temperatures to the area as well as potential for precipitation in the Sierra and northwest Arizona today. Temperatures rise on Friday and Saturday but start to fall next week as a broad trough moves into the western United States. && .UPDATE...Narrow line of cumulus over far eastern San Bernardino County near Essex, just ahead of the the upper low becoming better developed with weak returns now being detected by radar. Likely there is not the instability present to support thunderstorms so only looking at light showers/virga. However, due to dry low levels there could be some higher gusts up to 35 mph possible. Did a quick update to increase POPs say between Nipton and Essex for the next few hours. Otherwise, no changes. && .PREV DISCUSSION...1229 PM PDT Thu Jun 13 2024 .SHORT TERM...Tonight through Sunday The low pressure system moving through southern California and Arizona today advects moisture northward and brings isolated precipitation chances to northwest Arizona this afternoon and early evening. Convection should taper off after sundown as surface heating ends. Limited CAPE means lightning is unlikely but a few strikes cannot be ruled out. The main concern is strong outflow winds that are usually associated with high based storms and dry air near the surface. Convection may also occur over the Sierra crest in northern Inyo County, but these should be low impact and limited in range to the mountains. POPs are in the 10 to 30 percent range and precipitation totals should be light. The low moves east and ridging resumes starting Friday. Temperatures continue to be around 5 to 10 degrees above normal through the end of the week. By Saturday, HeatRisk Level 2 (Moderate) will spread across the area with patches of Level 3 (Major) near Las Vegas, the Colorado River Valley, and southern San Bernardino County. There is a 75 percent chance of a high of at least 110 degrees in Las Vegas on Saturday. This level of heat is dangerous to those without adequate cooling or hydration. Be sure to plan ahead if spending time outside this weekend. Surface temperatures should start to decrease again on Sunday as a trough moves into the western United States and heights aloft fall. Because of the limited spatial and temporal extent of the heat, especially compared to the previous two extreme heat events this summer, there will be no headlines issued for the heat this weekend at this point. A westerly low level jet develops ahead of the trough, bringing gusty surface winds to the Sierra and western San Bernardino County. The current NBM run shows the strongest winds limited to high terrain on Saturday, but coverage spreads to lower elevations of western San Bernardino County on Sunday. Will continue to monitor these winds to determine the necessity of a headline. .LONG TERM...Monday through next Thursday A cooler weather patten is likely for the beginning of next week as a trough digs into the Western US. ECMWF EFIs highlights this well with a increasing signal for below normal max and min temperatures Tuesday and Wednesday. There remains some uncertainty still in exact temperatures models continue try to resolve how strong and deep the trough will dig, but a trough of some flavor is being highlighted on all long range model camps so cooler temperatures are expected. Winds are the other concern with the trough. While exact wind impacts will depend on the exact setup of the upper level trough, increasing winds possible early next week. Fire weather will also be a concern as it will remain dry with the increasing winds. Pinning down exact wind strength and the time period for the strongest winds is still uncertain, though there is a decent signal in probabilities for win gusts over 40 MPH in the Barstow area and western Mojave Desert. Stay tuned! && .AVIATION...For Harry Reid...Winds between 180-200 degrees with occasional gusts of 15-20 knots are expected through the afternoon and early evening. Wind speeds will diminish to less than 10 knots after sunset and become light and variable by tomorrow morning. Northeast winds (040-070) are possible tomorrow morning after 16Z, but speeds are expected to remain 8 knots or less. Southeast to south winds will redevelop tomorrow afternoon. No significant cloud cover is forecast through the TAF period. For the rest of southern Nevada, northwest Arizona and southeast California...South to southwest winds are expected across most of the region through the afternoon and early evening, with occasional gusts of 20 -25 knots common. Isolated showers will develop over northwest Arizona after 20Z and showers and a few embedded thundershowers are expected along the Sierra after 21Z. Winds will diminish in most areas overnight, and lighter winds following similar directional trends are forecast for Friday. VFR conditions will prevail at all regional TAF sites through the period. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ UPDATE...Pierce SHORT TERM...Meltzer LONG TERM...Nickerson AVIATION...Planz For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter