With a little more than 10 days to go, we’re still in the realm of considerable uncertainty about the forecast for the 2018 Houston Marathon, but the good news is that the forecast remains fairly consistent from model run to model run. This can give us some small confidence that weather for the marathon will be a bit cooler than normal.
On Tuesday I discussed the use of ensembles, and for the sake of comparison I’ve looked at each individual member of the European ensemble (12z) run from today to determine what kind of temperature anomaly is forecast for the morning of Sunday, January 14th. Broken down by percentages, here’s what we have today:
Warm: 26 percent
Normal: 8 percent
Cold: 64 percent
Very cold: 4 percent
Another way of looking at this is through a meteogram. In this case, I’ve shown the GFS ensemble forecast for Bush Intercontinental Airport for the next 16 days, and highlighted (in red) the forecast for Sunday morning, around the time the run starts.
You can click on the image to make it bigger, but basically what it’s saying is that for all 50 of the GFS ensemble members, the forecast range for temperatures on the morning of the marathon ranges from 31 degrees to 65 degrees, with the higher confidence range from 35 to 60 degrees (this tells you about the kind of uncertainty inherent in medium-range forecasting). The morning low is generally forecast to be normal, but the high temperature isn’t forecast to rise much during the daytime, indicating the probability of cloud cover.
Anyway, the big picture remains the same. A weak cold front will probably move through next Monday, with a general warming trend during the middle of next week. The big question is the timing of a cold front after that, and most of the model solutions seem to think it will probably come through on Friday or Saturday-ish—a day or two before the marathon. But if that front doesn’t make it, we could easily be warm, or if the front is wet, we could easily be wet. I remain cautiously optimistic about this year’s marathon weather, but far from confident.
Fingers crossed on the cooler/normal range (and dry). Last year’s was brutal, so want to avoid that!
Last year was terrible. I think we deserve a cool year this time around! Fingers crossed! Thanks for keeping us updated.