Area Forecast Discussion
Issued by NWS Reno, NV
Issued by NWS Reno, NV
533 FXUS65 KREV 030914 AFDREV Area Forecast Discussion National Weather Service Reno NV 214 AM PDT Mon Jun 3 2024 .SYNOPSIS... An area of low pressure will bring light showers, increased cloud cover, cooler temperatures, and increased breezes through this evening. A significant warmup occurs mid to late this week, with highs nearing the century mark in lower western Nevada valleys. Afternoon thunderstorms will also be possible from Wednesday through next weekend. && .DISCUSSION... Current GOES-18 infrared and water vapor satellite imagery show a vigorous upper low moving ashore over northwestern Washington and southwest British Columbia this morning. Increased moisture along the southern fringe of the polar front jet will overspread our region this morning. The upper-level shortwave trough and the attendant cold front associated with this weather system will push south across the region today, cooling temperatures into the upper-70s to low-80s across western Nevada and upper-60s to low-70s in the Sierra. Light showers will also be possible into the early afternoon mainly north of US-50, as the pre-frontal trough swings through northern Nevada. Westerly winds will also increase this afternoon and evening with sustained speeds of 15-25 mph and gusts to 35 mph expected across lower elevations and 55-65 mph gusts this morning across Sierra ridges. Lake Wind Advisories are in effect for Sierra and western Nevada lakes through this evening. Increased relative humidities will hinder most fire weather concerns associated with the increased wind speeds. Tuesday into at least Saturday, a moderately anomalous upper-level ridge will build over the Great Basin and Pacific Northwest, heating our region, with highs topping out in the mid-to-upper 90s for lower elevations and 80s for the Sierra. NBM probabilistic guidance has a 25-35% chance of lower valley locations in Pershing and Churchill counties hitting the century mark Thursday. Heat risks will be moderate, so limit outdoor activities if you can. Streams will continue to run fast and cold, so take precautions when hiking and camping near waterways. Increased mid-to-upper level moisture from the Gulf of California will surge northward around the western periphery of the ridge, bringing increased chances for showers and thunderstorms each afternoon and evening Wednesday through Saturday. Long-range ensemble guidance hints at the upper-level ridge axis moving over the northern Rockies early next week, which would cool our region by about 5 degrees Sunday, with highs in the upper-80s to low-90s across the lower elevations and upper-70s to low-80s in Sierra valleys. However, these temperatures will still be roughly 10 degrees above average. Some model guidance shows a shortwave trough pushing across the region early next week, which would keep the potential for afternoon thunderstorms around. However, the depth and placement of this upper-level trough will modulate where convective development occurs. -Johnston && .AVIATION... VFR conditions continue today, with thickening mid-to-high-level clouds overspreading the region. Areas mainly north of US-50 could see lowered CIGs, which may generate mountain obscurations. Brief -SHRA will also be possible between 14-22z. Westerly winds will increase across all regional terminals, with gusts approaching 25-30 kts from 18Z-03z Tuesday. FL100 winds will also increase, with gusts around 50-55 kts. Light to moderate turbulence and low- level wind shear are also expected. A heatwave is expected Wednesday into the weekend, with highs in the mid-to-upper 90s across lower elevations of western Nevada and northeastern California and 80s in the Sierra. These increased highs will bring density altitude concerns for naturally aspirated aircraft. Density altitude at KTRK Wednesday-Friday afternoon could approach 7500-8500 ft MSL (1500-2500 ft above field elevation). We will also see increased chances for showers and thunderstorms each afternoon Wednesday into the weekend. -Johnston && .REV Watches/Warnings/Advisories... NV...Lake Wind Advisory from 9 AM this morning to 5 PM PDT this afternoon NVZ002. Lake Wind Advisory from 11 AM this morning to 8 PM PDT this evening NVZ003. Lake Wind Advisory from 1 PM this afternoon to 8 PM PDT this evening NVZ004. CA...Lake Wind Advisory from 9 AM this morning to 5 PM PDT this afternoon CAZ072. && $$