LWX has a really good discussion this morning about late next week in their morning AFD
Beyond Wednesday, model guidance begins to diverge substantially.
The synoptic scale pattern is a very complex one, as the
aforementioned system from Wednesday will be lifting off toward the
northeast. Meanwhile, a deep trough will reside over the western US,
as a strong ridgebuilding event simultaneously occurs in the eastern
Pacific. Further to our north, an upper low will circulate over
Hudson Bay, with Wednesday`s system passing to its south. The highly
complex interactions between all of these features are leading to a
high amount of uncertainty in the forecast for both Thursday and
Friday.
The main uncertainty on Thursday is how much cold advection ensues
behind the departing system from Wednesday. Forecast high
temperatures in the GEFS and EPS on Thursday range from the 40s to
near 70. There may be some showers around, especially during the
morning hours, but there should be a trend toward drier condtions
during the afternoon as any cold advection starts to occur.
The forecast on Friday is even more uncertain. The strong
ridgebuilding in the eastern Pacific on Wednesday into Thursday
will have a tendency to build overtop the western US trough,
potentially leading to an anticylonic wavebreak and the southern
portion of the western US trough fracturing off into more of a
southern stream closed low. With such a complex interaction
occurring, the guidance is all over the place. Temperatures in both
the EPS and GEFS range from the 30s to the 70s on Friday. Most
guidance does have the southern portion of the western US trough
(whether in the form of a closed low, or a a continual trough)
turning into quite the potent system, and leading to a strong
cyclogenesis event. Most solutions have this strong low tracking
toward the area late Friday into Friday night. Potential solutions
range from this low tracking to our northwest, and having
thunderstorms, to the low tracking well to our south and missing us.
Some solutions also produce a snowstorm. This system could
potentially be a high impact weather event, so we`ll need to keep an
eye on it over the upcoming week. At the moment though, uncertainty
remains high, with many different solutions still on the table.