Within the past week, a college friend and a colleague at the University of Georgia asked me about the weather forecast for the Boston Marathon. The race is scheduled for Monday April 15th. Unfortunately, there looks to be some pretty wet and windy conditions. Meanwhile, the Masters golf tournament is in full swing in Augusta, Georgia. Many of the top names in golf are near the top of the leader board including Tiger Woods. While interest is certainly high in this signature golf tournament, the chance for rain and even thunderstorms this weekend is also. Here are the latests updates on the weather for both of these iconic sporting events.
The Masters is happening as I write this so perhaps that is a good place to start. Round 3 on Saturday is likely to start without major weather problems, but the afternoon could prevent a few challenges. There is a 50% chance of rain showers and thunderstorms after 11 am. This is a good chance to remind you that 50% is not some coin flip estimation. According to the National Weather Service (NWS) Peachtree City website:
The "Probability of Precipitation" (PoP) describes the chance of precipitation occurring at any point you select in the area. PoP = C x A where "C" = the confidence that precipitation will occur somewhere in the forecast area, and where "A" = the percent of the area that will receive measureable precipitation, if it occurs at all.
The 50% value could be arrived at in multiple ways. The forecaster could be 100% confident that 50% of the forecast area around Augusta, Georgia will see rain. However, the forecaster could be 50% confident that 100% of the area is going to see rain. That is still a 50% chance of rain. "Percent Chance of Rain" is one of the most misunderstood elements of a weather messaging and why many in the public misunderstand forecast accuracy.
The culprit for the rain chances Saturday is related to a moist, unstable air mass, a weak boundary, and air temperatures reaching the middle 80 degree range. However, as a meteorologist, I am particularly concerned about Sunday. Sunday is typically the final round and brings high drama at the Masters. The official NWS forecast for Sunday calls for an 80% chance of precipitation (showers and thunderstorms) mainly after 3 pm. Some of these storms could be severe: The NWS forecast discussion warns:
This will bring a line of showers and thunderstorms through the area before noon. These storms should
not be severe, but cannot rule out some stronger storms with gusty winds. A line of convection ahead of the approaching cold front will move in during the late afternoon, and cross the region during the evening.
NOAA's Storm Prediction Center has an Enhanced/Slight risk (see graphic above) for this period, and damaging winds, hail, and a few isolated tornadoes are possible. Later in the evening, another line of storms associated with the actual frontal passage is possible. Unlike the afternoon storms, the instability will be limited because of lack of daytime heating. Officials at the Masters will certainly have to be diligent (and perhaps proactive) about the potential storms in the afternoon on Sunday.
Up in Boston, officials are already being proactive because of the expected weather. According to a report on the WCVB5 ABC website,
Because of that forecast, runners assigned to the fourth wave will start their race immediately after those in the third wave. Originally, a 25 minute gap was scheduled between those two waves.Under the new plan, Wave 3 will start at 10:50 a.m. and Wave 4 will follow immediately afterward.
Organizers are trying to reduce the waiting time for runners as rainfall and windy conditions are expected. There will also be additional medical capacity and resources on hand. The National Weather Service in Boston is calling for a 90% chance of rain on Monday and some of it could be very heavy. In the morning, there may even be patchy fog. The rain is going to be a problem for runners, but there will also be winds blowing at 11 to 14 mph and with gusts to 28 mph. Forecasters are not ruling out the chance for a thunderstorm also. The culprit for this weather is a potent low pressure system (below) that is currently making its way out of the Plains and into the Northeast by Monday. Parts of the southern United States will need to be on high alert for tornadic storms on Saturday because of this same storm system. This is also the same system that could affect the Masters.
