Indian Summer coming…

Monday, September 29, 2014 at 9:35 am

Summary:

A few weak waves of energy will keep the threat of showers around thru Wednesday (10/1).  Beyond that, we ridge up and dry out with warmer than normal temps expected for the foreseeable future. 

Details:

It’s that time of year again when winter storms quickly become the norm.  Our last system this weekend was more of a hybrid between a winter Pacific trough and a summer monsoonal moisture surge.  The combination of the two led to some impressive rainfall amounts between 1 and 3 inches of liquid.  It also meant that snow levels for most of the event were at, or above, 11k feet.  Only dropping down to about 8k feet after most precipitation had ended.  The mountain peaks received a few slushy inches that should melt completely by the end of the week, so no need to worry about weak base facets in the backcountry just yet.

A broad trough overhead currently means that there are two weak impulses that will move into the region over the next 48 hours.  The first will move through late today (Monday) and bring the threat of showers and thunderstorms (and high elevation snow) this afternoon and tonight.  The second impulse comes in late on Tuesday into early Wednesday and will reignite showers and storms.  Neither impulse is overly moist or dynamic, so don’t expect anything other than widely scattered showers/storms. 

By Thursday, high pressure starts to build just to our west and will strengthen through the weekend.  Temps will warm and we will remain totally dry for at least a week.  Highs in SLC should climb at least back into the low 80s.  Maybe not what most people want, but it should make for some great Autumn recreation weather — good time to get in some last high elevation camping/biking/etc. 

Long range:

At this point, you have to get real speculative to see anything in the way of winter storms in our future.  GEFS ensembles generally keep some sort of ridge overhead through the middle of October.  ECMWF (Euro) ensembles have a bit more hope, with many depicting a trough to develop over the Rocky Mountain region during the second week of the month.  The good news, if you’re hoping for storms, is that Autumn is a transition season and the models are notoriously poor at picking up on pattern changes in the long range.  Wouldn’t be surprised at all if something unexpected popped up in the next few days. 

WSF