Rain and Thunderstorms Increase Thursday
Enjoy the mild temperatures while they last because a major change in our weather arrives Thursday.
Big changes in Scott Dorval's video forecast
A storm system moving northeast from California and Nevada will pull moisture into Southwest Idaho overnight. A few isolated showers are possible late tonight, but rain will become much more widespread Thursday.
Boise could still reach the mid 70s Thursday, but showers will increase through the day, with thunderstorms becoming possible during the afternoon.
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Some of the stronger storms Thursday afternoon and evening could produce strong wind gusts, small hail and locally heavy rainfall. The severe-weather threat appears isolated, but it is something to watch closely during the afternoon and evening.
A Soaking Rain for Parts of Idaho
This system has become wetter in the latest forecast, especially across Idaho.
Expected storm-total rainfall through Friday:
- 1.00 to 1.50 inches: Idaho north of the Snake River Plain/Basin
- 0.50 to 1.00 inch: Treasure Valley
- 0.35 to 0.60 inch: Eastern Oregon
Locally heavier rainfall will be possible underneath thunderstorms.
A Flash Flood Watch is in effect for the Wapiti and Crooked burn scars Thursday night into Friday morning, where heavier rainfall could cause rapid runoff.
For Boise, rain becomes widespread Thursday and Thursday night, with rain continuing into at least part of Friday.
Wind Picks Up With the Cold Front
Winds will initially be fairly light, but that changes Thursday afternoon.
Southeast winds strengthen ahead of the storm, with gusts around 35 mph possible between Boise and Twin Falls.
A cold front moves through Thursday night, turning winds west to northwest. Gusty conditions continue Friday, with winds of 15 to 25 mph and gusts around 35 mph possible.
Thunderstorms could produce even stronger localized wind gusts.
Much Colder Friday
Thursday's warmth will disappear quickly behind the cold front.
After temperatures reach around 75° Thursday, Boise is expected to struggle to reach the mid 50s Friday. Rain will gradually decrease Friday, followed by clearing Friday night.
Friday night turns chilly, with Boise dropping into the mid 30s. Mountain valleys will be considerably colder, with lows falling into the teens and 20s in some locations.
Weekend Looks Much Better
The storm pulls away in time for the weekend.
Saturday: Morning fog possible, then sunshine with highs near 59°.
Sunday: Sunny and warmer with highs around 64°.
A temporary ridge of high pressure should keep the weekend dry while temperatures gradually rebound.
Sunday and Monday could eventually run 5 to 10 degrees above normal.
Another Change Next Week
Monday remains mostly sunny and mild with highs near the mid 60s before another Pacific storm system potentially approaches.
There is still uncertainty regarding the track and timing of this next system, but cooler weather could return Tuesday into Wednesday along with precipitation, especially over the higher terrain.
Snow levels could eventually lower to roughly 5,500 to 6,500 feet, bringing the potential for some light mountain snow.
Boise Forecast At A Glance
| Day | Forecast | High |
|---|---|---|
| Thursday | Still mild then afternoon thunderstorms | 75° |
| Friday | Rain ends mid afternoon, windy & much cooler | 55° |
| Saturday | Morning fog, then sunny & breezy | 59° |
| Sunday | Sunny & milder | 64° |
| Monday | Mostly sunny | 64° |
| Tuesday | Mostly sunny, cooler | 59° |
| Wednesday | Mostly sunny | 59° |
Tonight
Isolated showers after 3am. Partly cloudy, with a low around 51. Light and variable wind. Chance of precipitation is 20%.
Thursday
Showers, with thunderstorms also possible after 3pm. High near 75. Calm wind becoming south southeast 5 to 9 mph in the afternoon. Winds could gust as high as 20 mph. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday Night
Showers and possibly a thunderstorm. Patchy fog between 9pm and midnight. Low around 46. East southeast wind 5 to 7 mph becoming calm after midnight. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Friday
Showers, mainly before 2pm. Breezy & much cooler. High near 55. West wind 10-15 mph, with gusts as high as 25 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Friday Night
Mostly clear, with a low around 34. Northwest wind 10 to 15 mph becoming light and variable after midnight.
Saturday
Patchy fog before 10am. Otherwise, sunny & cool, with a high near 59.
Saturday Night
Mostly clear, with a low around 40.
Sunday
Sunny, with a high near 64.
Sunday Night
Partly cloudy, with a low around 42.
Monday
Mostly sunny, with a high near 64.
Monday Night
A 20 percent chance of showers. Partly cloudy, with a low around 38.
Tuesday
Mostly sunny, with a high near 59.
Tuesday Night
Mostly clear, with a low around 37.
Wednesday
Mostly sunny, with a high near 59.
