BOSTON (CBS) — Getting perfect weather in April for the Boston Marathon is not easy. Perfect weather is defined differently among the racers and the spectators but I think everyone will agree that last year’s Boston Marathon weather was terrible. Despite last year’s steady and penetrating cold rain, statistically, the chance of rain falling during a Boston Marathon is only about 10 percent!
So it would be rather unusual to get two consecutive Boston Marathons featuring drenching rain. While the risk of early morning downpours and the threat of lightning is possible, the good news is there looks to be a period of drier weather with warm and humid conditions for the runners and spectators before another risk of an isolated shower later this afternoon.
Temperatures will be MUCH higher than last year by 20 degrees or more during the day! The higher humidity will definitely be noticeable as well in the morning.
The wind will not be a real big factor until late in the afternoon when westerly winds will ramp up to 15-30 mph with some gusts to 40-50 mph possible by late afternoon into the evening. Presently, the setup is favoring a cross wind mainly blowing from right to left but speeds should be mainly in the 10-25 mph range through the morning into the afternoon before a cold front arrives and changes the wind direction to a strengthening tail wind near or after 4 p.m.
If the current trend continues, much of the rain SHOULD exit Hopkinton by 8-9 a.m. and eastward along the entire race course to be out of Boston near or just after 9-10 a.m.
After that, the overcast could thin and break to allow some splashes of sunshine between passing clouds. As a cold frontal boundary approaches from the west during the afternoon, a few scattered showers and possibly a relatively narrow string of them will transit across the state between 2-5 p.m. The rain could briefly be heavy with spotty lightning possible and the rain would last no more than 20-30 minutes in any one location.
The wind will increase and become gusty later this afternoon. Damaging gusts 40 to 50 mph are possible. A Wind Advisory will go into effect at 2 p.m in central Mass. and 4 p.m. for the Boston metro area and continue through 8 a.m. Tuesday.
9 a.m.: Wheelchair Start & 9:30 a.m. Elite Women Start
Conditions: Generally cloudy with a decreasing risk of any remaining rain.
Temperature: 60-62 degrees and quite humid in Hopkinton.
Wind: South-southwesterly at 10-15 mph. mostly a cross wind from right to left.
10 a.m. Elite Men & Wave One Start
Conditions: Generally cloudy with some brightening and peeks of sunshine possible.
Temperature: 62-64 degrees and gradually turning less humid in Hopkinton.
Wind: Southwesterly at 10-15 mph more of a tail wind component developing.
10:25 a.m. Wave Two, 10:50 Wave Three & Wave Four Right After Wave 3 Runners Are Past The Start Line
Conditions: A mix of clouds yielding breaks of sunshine
Temperature: 63-65 along the race route with decreasing humidity.
Wind: Southwesterly at 10-15 more of a tail wind component much of the time.
Noon To 2 p.m. Elites Finish
Conditions: Intervals of sunshine between passing clouds with a slight risk of a quick passing shower.
Temperature: Climbing to the middle to upper 60s along the race course but the air will be much drier.
Wind: Southwesterly at 12-25 mph… tail wind component much of the time.
2 To 4 p.m. Most Of Rest Of Field Finishes
Conditions: Possible intervals of sunshine yielding to building clouds followed by a higher risk of a moderate to heavy shower perhaps with some lightning in a few locations somewhere in the time frame of 3-4:30 p.m.
Temperature: Upper 60s to lower 70s probable with low humidity.
Wind: Southwest to west wind at 12-28 mph… mostly more of a tail wind. Beware that the wind will increase to 20-35 mph with some gusts to 40-50 mph by 5 p.m. and beyond into the evening from the west.
Marathon officials will be working in conjunction with the National Weather Service, WBZ-TV, and MEMA to ensure the safety of everyone along the race route.
WBZ-TV is the exclusive local broadcaster of the Boston Marathon. Pre-race coverage begins at 7 a.m. followed by race coverage at 9 a.m. WBZ-TV’s coverage will be streaming here on CBSBoston.com beginning at 9 a.m. The stream is limited to New England.