Area Forecast Discussion
Issued by NWS Las Vegas, NV
Issued by NWS Las Vegas, NV
439 FXUS65 KVEF 150823 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 123 AM PDT Wed May 15 2024 .SYNOPSIS...An upper low morning from southern California into Arizona today will keep limited moisture and instability over our region, leading to isolated light showers or sprinkles along with a few thunderstorms through Wednesday. An eastern Pacific ridge nosing inland will bring even warmer weather by Friday with highs climbing around 10 degrees above normal. A slight cooling trend with increasing southwest winds develops late this weekend into early next week. && .SHORT TERM...through Thursday Night. The area will remain in a sandwich area between the ridge building to the northwest and an area of low pressure sliding through southeast California into Arizona today. This afternoon`s weather set up with be similar to yesterday just everything shifted southeast. Expecting dry conditions through the morning before scattered showers and isolated thunderstorms develop this afternoon in response to decent lift in a convergence zone linking up with low end moisture and instability. Showers and thunderstorms should favor the terrain in areas southeast of the I-15 this afternoon which may or may not blow off into the surrounding valley late in the afternoon or the evening. There is a consistent signal across hi- res short term models for precipitation to congeal into southern Mohave County and eastern San Bernardino after 5PM. Impacts from precipitation will remain low as instability and moisture are low, however the very dry low levels will bring the chance for sudden gusty outflow winds from showers and thunderstorms. DCAPE over 1000J/KG and inverted-v type soundings support this potential, with sudden winds gusting 40 to 50 MPH possible at times. Precipitation will slowly diminish after sunset, with things ending by midnight at the latest.High pressure will build in tonight and Thursday behind the low pressure as it exits to the east. Once precipitation ends tonight, dry conditions are expected for the rest of the week. Temperatures will slowly warm today and Thursday with above normal temperatures expected for most locations. Moderate heat risk is expected by Thursday in many valley locations of southeast California into the lower Colorado River Valley due to persistent warm temperatures including overnight. Anyone with outdoor plans should be prepared for the heat with extra water, especially if you plan on being outdoors with no way to escape the heat for a prolonged time. .LONG TERM...Friday through next Wednesday. A growing ridge over the eastern Pacific will continue to grow over the western United States late-week into the weekend. Temperatures will remain 10 to 12 degrees above seasonal averages, with desert valleys increasing to "Moderate" HeatRisk. Chances of Las Vegas measuring its first 100F of the year continue to waffle on Friday and Saturday, with a current NBM4.1 percentage of 30% on Friday and 10% chance on Saturday. ECMWF ensemble means and GFS ensemble means are in fairly good agreement regarding a pattern shift over the weekend into the start of next week. The ridge over the eastern Pacific will start to deteriorate as a longwave trough over the north-central United States starts to sag. Meanwhile, a weak closed low will meander eastward into the northern Baja Coast this weekend, with both sets of ensemble means indicating that this low will open up and phase with the longwave trough. As such, expect breezy afternoon winds each day through the weekend into the start of next week. Details regarding precipitation and temperature will come more clear as we move through the work week. && .AVIATION...For Harry Reid...Light, generally southwest winds are expected for the remainder of the overnight hours. Winds are expected to shift to a northeast direction after 17z with speeds generally between 6-10 knots with only a 10-15% chance of sustained winds reaching over 10 knots. We are expected to see some isolated convection develop late morning and afternoon with cloud bases AOA 12k feet. There is a slight chance of showers/thunderstorms reaching the valley along with any associated outflow. If any outflow winds do occur, we could see winds between 25-35 knots. Convection will diminish after sunset. For the rest of southern Nevada, northwest Arizona and southeast California...Most areas will see winds less than 10 knots through this afternoon with the exception of KDAG where west winds will be between 10-15 knots. Expect to see isolated showers and thunderstorms over portions San Bernardino, Clark, and Mohave Counties between 19z-01z this afternoon. The main impact from these showers/storms will be gusty outflow winds where wind gusts up to 40 knots will be possible. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Nickerson LONG TERM...Varian AVIATION...Gorelow For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter