This is probably TL, DR for
This is probably TL, DR for most so just jump to the bottom!
Now, let us talk about the weather. You may ask yourself, "How can we talk about the weather on Feb. 4th when we can't even have an educated conversation about the weather next weekend!?!"
Well, the fact is, we can't, but we can guess and speculate and have some general thoughts on what might happen. The 1st thing to consider is climatology and what one might expect a "normal" Feb 4th day to look like:
Avg High - 59 Record High - 78
Avg Low - 40 Record Low - 19 (set last year!)
Now we can look at large scale forcing from La Nina (Spanish for "The Nina") and we see that typically in a La Nina you would expect warmer and drier conditions across that part of Texas. But wait a second?! Wasn't last winter a La Nina as well? Yes, Hmmmmm (see above - Record Low of 19). This hasn't really been a typical La Nina run for Texas last winter or this winter. But I digress, so an avg. day of 59/40 plus toss in some warmth from La Nina and you might expect a high b/w the avg and record... so 65? Sounds like a nice day of running.
But what about the MJO? Another weather phenomenon that can influence the weather down this way. Predicting the MJO out that far is tricky but we have a number of models that we can look at. The MJO for the most part has had a pretty weak signal this winter and that looks to continue. If it does gain some amplitude, then it looks to be in Phase 5 and/or 6 and that is another warm signal.
So, Climo + La Nina + MJO are all combining to hint at a warm day. Wow, that looks like a slam dunk. No so fast my friend! There are a lot of other things to consider and any number of them can out muscle these other factors, esp. in the right combo. I won't discuss the AO, NAO, PNA, EPO, PDO, GW, est. but they all can play a roll.
There are some signs that we may see building cold anomalies in Alaska and W. Canada in the next 7 - 10 days and that we may see that propagate southward in the long range. Will that cold actually materialize? If it does, does it propagate south in a west based fashion or more of an east based fashion just giving us a glancing blow of cold and not really locking it in?
As of today, if I had to bet, I would actually bet colder than avg. for Feb 4 based on some of the other factors that I didn't discuss. Luckily, we should have a much better clue next week around this time.
Now on to something I am much more confident about, will it rain? Well, I don't know about Feb 4 but I do feel very confident that we will see at least 2 or maybe even 3 significant rain events out at the park between now and race day. The trails around here typically need 4 - 6 days to dry out from a good rain. The worst days to run are days 3/4 post rain b/c the mud has kind of "gunked" up and sticks to your shoes like something horrible and you end up running in 5 lb mud boots.
La Nina typically means dry weather for Texas but MJO in phase 5/6 is a wet signal. The pattern so far this winter has been wetter than expected and that looks to continue.
So long story short... the trail will probably be damp to wet and the temp will most likely be warmer than avg. but I think there is an outside shot of cold (maybe 60/40 warm cold split at this point).
