Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
159 AM EST Sat Dec 14 2019
Valid 12Z Tue Dec 17 2019 - 12Z Sat Dec 21 2019
Overview and Guidance/Predictability Assessment:
Amplified but progressive pattern will maintain a rather stormy
period for the West Coast. In the east, a lead system will bring
some snow to the Northeast followed by a quieter period until
perhaps next weekend. The models/ensembles diverge in timing/track
right from Tue/D3 in the east and on Wed/D4 in the west, which
carry through the period. For the lead system, the 12Z ECMWF
(though slower) and UKMET/Canadian formed a more consistent
cluster than the quicker 12Z/18Z GFS (though the 00Z GFS was
closer to the ECMWF/UKMET-led consensus). Off the West Coast, most
12Z models/ensembles trended much quicker to bring in a weak
closed low to California which left the once seemingly too quick
older GFS runs even slower than the current models. 18Z GFS/GEFS
could be considered too slow vs the 12Z ECMWF/UKMET/Canadian but
have been pretty consistent. Nevertheless, with decreased ensemble
spread vs previous runs, trended quicker with that system Wed.
Thereafter, the 12Z ECMWF became much quicker with a northern
track into the Great Lakes while the GFS/Canadian were farther
south. Ensembles were split as well with no clear consensus. 12Z
Canadian formed a middle ground solution but confidence was low in
whether it may manifest itself more robustly in the northern or
southern stream. Ensembles do suggest low pressure trying to
organize off the Southeast coast late next Sat. Back to the west,
yet another trough will slowly lurch toward the coast.
Lead system on Tuesday will bring a swath of snow to the Northeast
and parts of the Mid-Atlantic as low pressure exits off the coast.
Colder air (highs 5-10 deg below average) will filter into the
area midweek before a moderation next Fri/Sat. In the West,
precipitation will favor far northern California northward for
most of the period, but with some light rain/snow into coastal
NorCal and the Sierra as the upper trough moves through. By next
Fri/Sat, southwesterly upper flow will provide an atmospheric
river connection back to the subtropics near Hawai'i for far
northern CA into southwestern OR. Several inches of rain are
possible per the latest model guidance.
WPC Excessive Rain Discussion
WPC Short Range Discussion
WPC Extended Range Discussion
WPC Model Diagnostic Discussion
WPC 500 MB Preferred Heights
WPC 500 MB Height Trends
WPC 7 Day Max Temp - Anomaly
WPC 7 Day Min Temp - Anomaly
WPC Significant Lows with Tracks
WPC SLP Trends
Good Saturday morning and welcome to the weekend!
Not a bad weekend in store now that the rain has pushed out. Did you get much in your backyard? Many areas had anywhere from 1-4" with the heavier amounts a little further south. Here's the radar estimated rainfall totals.
While the rain may be over for now, there is more on the way.
Here's a look at the severe outlook.
And here's a look at the additional rainfall we'll have through 7 pm Tuesday.
I wanted to show you this. We are now in one of the quietest solar years in a century.
Low solar winters are cold and stormy. Think 2009-2010. Speaking of that period... on this date in 2010 I set two records here at the house. I set a record low high temperature of 32.0º F and a record low low temperature of 13.1º F, and both of those records still stand.
Again, not a bad weekend with relatively tranquil weather. Time to get out and get that Christmas shopping done! We're in the "12 Days of Christmas" countdown! 🙂
Have a great Saturday!