Lucky Friday the 13th….  Mammoth Mt opens for the season….   See:

I Just finished looking at this mornings guidence and the many weather sites around.  Lots of discuessions!   Lots of pretty maps!   What do thay all mean?  Then I remembered what an old friend of mine that used to work for the National Weather Service in Reno once said decades ago, when I enthusiastically called him on a midnight shift at 1:00AM in the morning.  It still rings home to me. Doug said,  Howard….   “Guidence is not a Forecast!” I never forgot those words!

DId have a peak at the new 12Z Euro Ensemble.  5 and 7 day means….No surprises. Mammoth flurts with 573 to 570 mean heights at 500MB.  That’s fairly high snowlevels and well south of the polar jet. So…mainly light amounts of precip here,  more orographic in nature than forced.  Tahoe will fair better to our north, but it will be pretty wet snow at 7K.   As in my discuessions below, the dynamic models are showing quite the blow up in the Convection with MJO over the Indian Ocean. The Hovemuller time series for the MJO, shows, the outgoing long wave radiation from convection forecasted to be very strong, as projected by the Climate Forecast System. The Dweebs are very encourged with this development. Timing after the 20th…..In the meantime, I am not expecting much.


Dr Howard and the Dweebs………………………..:-)



It was an amazing change we had in the weather last week.   We went from a Fall Scape to one of winter in a few days. The best part of the change was to put the kabash on the Creek fire so we could all breath a lot easier.

Snowfall:  The Dweebs Forecast of 10 to 15 inches worked out to the tee as Mammoth Mt reported 11 to 14 inches storm total. Its a good start, but of course we need a lot more snow!

To understand our Weather on a climate scale this year, we have to consider the base state of the Strong La Nina, now in process in tropics. The Latest CPC information put current sea surface anomalies over the NINO 3.4 region at -1.5C. This is regarded as a strong La Nina.  The ONI which is a lagging indicator was at -.9 for AUG, SEPT and OCT.   Projections show this La Nina possibly colder than -2C by Late Dec.   With a signal this strong, the stats favor a drier than normal winter for Central and Southern CA, vs the weak la Nina which can be wetter in many cases.   Nevertheless, we will have more storms this winter and the Dweebs will be reporting on their prospects, even on an interseasonal scale time frame

Getting back to the current La Nina Base state; it suggests that tropical convection will most likely remain far west of where it would normally be during a winter.  The colder waters just west of the date line eastward to the Central American coast will constructively interfere with the MJO this Winter, until it gets over the Indian Ocean!  Thus, it is very unlikely that Central or Southern CA will experience any MJO induced Pineapple Connections.

The Western pacific westward to the Maritime continent will have the most thunderstorms. Why is this important?  Because with persistent forcing in that region, that teleconnects to the positive phase of the Pacific North American circulation pattern, (-PNA; trof in the west) or (+PNA, Ridge in the west dictates either wetter or drier conditions out west. The -PNA teleconnection pattern is the one we want. And…. although it does not “Always” mean snow for Mammoth, more often than not it does in the winter.  Persistent tropical forcing in the Western Pacific and Maritime Continent usually is associated with the +PNA teleconnection. The PNA teleconnection is pretty neutral for now.

Current Forecasts:   The Short, (1 to 2 days; Medium 3 to 5 day and Long Range 6 to 10 day forecasts are not wet for Mammoth. There is some possibilities for light precipitation this Saturday with the chance of some 1 to 3 inches of snow over the crest.  Maybe just a skiff in town. This is a warm advection pattern whereby moist air is moving over the colder air currently in place, left over from last weekends storm. However of note, there is a strong NW jet punching into Northern CA tomorrow Friday. That is usually a windy pattern but a dry one at that.  The Medium Range guidance does show a rise in the freezing level this weekend so it will be warmer Sunday and Monday and with Ridging building in early next week, it will get warmer yet. Even through there are storms hitting the pacific northwest south to Northern California, they will not do much for the Mammoth area next week.  We need a change in pattern and change in the PNA teleconnection pattern that is negative in the PNA!! (PNA acronym for Pacific North American Circulation Pattern which is the most common teleconnection for the West.


Interseason Forecast:

Those that have been following the Dr Howard and the Dweebs page for years know that the Dweebs have stuck their necks out a long ways at times to forecast changes in patterns that can affect Mammoth Weather. There are times when the dynamic models show a signal that affects other signals that make it possible to perform outlooks some 3 to 4 weeks out in the future. This is one of those times when the Dweebs will do just that. However, it is just an outlook, and not a forecast yet and there is a difference.

MJO:   The Madden Julian Oscillation was pretty much wiped out as La Nina destructively interfered with it. Its convective envelope is still creating a favorable environment for tropical storms over the West Atlantic. The Prind point here is that the Dynamical model MJO index forecasts favors continued eastward propagation, with a potential of a “New Indian Ocean MJO event” materializing during Week-2. Should this occur, conditions would become increasingly favorable for Indian Ocean tropical cyclogenesis during the outlook period, and may promote renewed West Pacific activity beyond the two-week outlook period.  Indian Ocean MJO events also teleconnect well with a two-week lagged midlatitude pattern featuring troughing over Western North America and ridging over Eastern North America, which is consistent with model guidance for the Week 3-4 period with the Climate Forecast System. A flip in the PNA to negative is possible during the latter part of Week 2. This means that it is possible that a stormy pattern with enhanced snowfall potential will develop during the last 10 days of November into the first week of December…..


Stay Tuned to the Dweebs…..They will update on this next Wednesday!


Dr Howard and the Dweebs………………………:-)