Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Boise Idaho
241 PM MDT Thursday may 28 2015
Short term...tonight through Saturday...isolated shower and
thunderstorm activity over the central Idaho mountains this evening will
dissipate by sunset. Dry conditions persist elsewhere across southeast
Oregon and SW Idaho overnight. A flat upper ridge develops over
the Pacific northwest for Fri/Sat. The accompanying west-SW flow will increase
moisture transport off the Pacific. This will keep an afternoon
shower and thunderstorm threat over the east-central Oregon and
west-central Idaho mountains and high terrain along the Idaho/Nevada border
Friday and Saturday. Cloud-cover will also be on the increase...
especially on Saturday...so have cooled forecast temperatures a couple of
degrees. Temperatures both days are around 10 degrees above
Long term...Saturday night through Thursday...the upper level ridge
will be kicked out of the region by Sunday night ahead of an upper
level closed low. Minimal cloud cover and a southerly flow will
allow temperatures to reach 10-15 degrees above normal on Sunday.
Favorable dynamics ahead of the trough will allow for a slight
chance of thunderstorms overnight Sunday into Monday. As the cold
front moves through the region Monday morning...the region will
see chance showers and thunderstorms throughout. The rainy pattern
and possible afternoon/evening thunderstorms will continue until
the end of the period as the trough takes it/S time heading east.
Temperatures will be slightly below normal through the extended.
Aviation...VFR. Few to scattered middle level clouds...becoming few
to clear overnight. Isolated showers and thunderstorms developing
east of a McCall-Idaho City-Jerome line this afternoon and evening.
Surface winds...variable 10 kts or less. Winds aloft at 10k feet
mean sea level...northwest 5-10 kts...becoming light and variable by 29/12z...before
turning SW at 5-15 kts by 30/00z.