Outlook from March 9, 2024

A rainy start to Saturday as seen by radar

Rainfall will continue to work through the day today in to the overnight, before colder air works in and we see things begin to flip to some snow activity. 

Before the changeover to snow, rainfall tallies look to range in the .75 to 1.50 range

6z ECMWF below

6z GFS below

The chilly temps of this morning, mainly 30s,40s

Those number will not go far today under the wet conditions. 6z ECMWF temps below

As the colder air works in, so does the opportunity for snow activity.  That snow activity should increase through the day Sunday. We are in March now. The higher sun angle adding surface warmth with the cold unstable air mass pushing in will only add to the instability through the afternoon and in to the early overnight Sunday.

Expect squalls and enlongated squalls Sunday afternoon in to the overnight. With those, some areas do miss out on the snow while others are in the snow. With the higher sun, slightly warmer ground. Some mid range elevations in the upslope zones 2500′-3000′ and below areas may even bare off from the lighter morning snows unless under some more persistent activity. So overall snow totals will vary. Location to location.

1- elevation, 2- persistentcy of snow activity will play a role in accumulation totals.

That said, those warmer roadway temps will rapidly cool under temps in 20s, strong winds and any squalls can rapidly cover roadways creating poor travel.

The modeled snowfall

6z ECMWF

6z GFS

Likely those amounts will be low in places that see persistent squalls. While some of the lighter amounts will even melt off some.

Some of the mesoscale modeling does of better job of hinting at this. Using the Canadian short range here as the U.S mesoscale models look a bit bizarre this morning.

Here you can see the model hinting at streamers and or elongated squalls. Those are the ones where if you are under you are saying wow, this is over performing, if you are not under, oh this is a dud. Impossible to tell where they set up best. A area that frequently seems to get under those is the I68 area.

The NWS is out with advisories. Also the NWS snowfall links are included on the page under “snowfall info” on the drop-down links on mobile or it should be visible on non mobile devices.

The details in the winter weather advisory are as follows

The NWS snowfall map looks like

I’d lean a general 2-4″ totals with higher pops.

This is also accompanied by strong winds. So along with the Winter Weather Advisories are wind advisories

Modeled winds off the 6z ECMWF

Things moderate Monday. The winds stay up, temps back to the 30s, low 40s and then high pressure moves over and those winds die and we have a moderated air mass with more daytime diurnal warmth Tues-Thurs. That’s accompanied by yet low dewpoints and calmer conditions for that duration. Low dewpoints and light winds are the best combo to limit snow melt for the area resorts that will remain open after the weekend. Further out, some rain to snow again as we go through next weekend and models all hint at some bouts of cold and snow from then through Easter. Mild blips will be bound to occur as well.