Given how cold it is this morning across Houston, it’s difficult to imagine warmer temperatures, but the region will indeed warm into the upper 70s by late this week. If you’ve been reading my long-range forecasts for the Houston Marathon, on Jan. 15th, you’ll know that my concern has been that the majority of model guidance has been indicating the heat won’t “break” before race day. However, over the last 24 to 26 hours the forecast models have been shifting their outlook by bringing the next front through sooner. Therefore, although the forecast remains uncertain, there is some cause for optimism. Let’s take a closer look.
GFS model
As has happened a lot this winter, the GFS model has flip-flopped on its forecast in the 7-10 day time frame. During three of the last four model runs the model has brought a cold front through the region on Saturday, Jan. 14th, which would of course be excellent news. If this scenario plays out, we could conceivably see race-time temperatures in the low-40s, with highs in the mid-50s.
This is a nice change from the previous outlooks, but I want to stress that the timing of the cold front remains far from locked in—and a cold frontal passage on Sunday at noon does us runners no good.
The European model
The ECMWF model has also trended colder, but again it boils down to the timing of the next cold front. About half of the ensemble members bring the front in before the beginning of the race, and about half bring it in on Sunday around noon or later. Therefore the European model has a range of low temperatures at race time from 35 to 65 degrees. That’s not very clarifying, is it?
Given the uncertainty, here’s my current thinking is on conditions at the start line:
Temperatures below 50 degrees: 50 percent
Temperatures from 50 to 60 degrees: 25 percent
Temperatures above 60 degrees: 25 percent
Precipitation: Rain chances will be dependent upon the timing of the front. If it comes through on Saturday, Sunday morning should be dry. But if the front pushes through on Sunday, it could make for a messy, wet race day.
Posted by Eric at 9:20am CT on Saturday
Very encouraging change in the forecast! Hope it holds!