2008 Boston Marathon Weather
The 112th Boston Marathon is scheduled for Monday, April 21, 2008, and one month out now, it still looks like we will have good weather. You may remember that after receiving pre-race emails from the BAA warning about extreme conditions, last year's runners saw race day conditions improve at the last minute, warming from near freezing temps and a very strong headwind, although the rain and some headwind persisted.
According to the CPC, the current ENSO outlook is for the current LaNina conditions to continue through race day. For the Boston Area, this usually means about average temperatures and chance of precipitation. . Last year's race came after a waning ElNino and under the ENSO neutral pattern. Of course, much more than the the ENSO signal will determine the race day weather. NWS 30 day outlook discussion.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
According to WU almanac/archives, the averages for 4/21 are:
The Average High Temperature is 62 F with a historical range of 48 F to 87 F
The Average Low Temperature is 44 F with a historical range of 36 F to 55 F
There is a 57% chance of a Warm Day (temperature over 60°F / 16°C).
(16 days out of 28 in historical record)
The Average Daily Precipitation is 0.11 with a historical range of 0.00 to 0.67
There is a 36% chance of a Precipitation Day.
Average Cloud Cover is partly cloudy
There is a 18% chance of a Cloudy Day.
The Average Wind is 10 mph with a historical range of 5 mph to 17 mph
There is a 43% chance of a Windy Day (average wind over 10 mph / 15km/h).
The Average High Dew Point is 45 F with a historical range of 23 F to 59 F
The Average Low Dew Point is 30 F with a historical range of 10 F to 49 F
There is a 0% chance of a Humid Day (dew point over 65°F / 18°C).
The 26.2 mile race starts further inland in Hopkinton, MA, and they average 2F colder than Boston. Graphical Averages
Historically, race day conditions are either cooler than normal, with a headwind, or warmer than normal, with a tailwind. As the Boston Marathon is a straight point-to-point run, the wind shouldn't change much during the race, but a wide swing in conditions during the race is a possibility (especially for those who, like me, are going to take several hours to complete the run). A survey of race day weather from past Strong LaNina years indicates that slightly warmer than normal temperatures and a tailwind are favored. Since I live and train in Florida, I will be just as happy if we see a record high temp.
While I will be prepared for most any weather, I will be looking for a temp at start time of 55F with a high for the day of 70F, few clouds, and no rain. The forecast for this race is notoriously labile, and with the pattern now just settling into a zonal flow, by race day in four weeks we could see a change to a stormier pattern. I will update this as we get closer to race day, and I will try to post "eyewitness" reports from Hopkinton (starting line) beginning two days before the event, with an update race morning.
Massachusetts locals and others with insight into this forecast are especially welcome to add comments. Runners?
Three weeks out now & the Jet Stream , while showing signs of a more amplified pattern (stronger storms, maybe colder/windier), either way is bringing a series of storms (as eyewitnessed by NEwxguy) through the area. How far north it will retreat between now & April 21 is anyone's guess, but the averages for this date (3/31) for the Boston area are wetter than for 4/21. This weeks weather(3-31-08) looks only good for running two days as progged by WU.
Wind chill outlook
"Strong positive phases of the NAO tend to be associated with above-averagel temperatures in the eastern United States...Opposite patterns of temperature and precipitation anomalies are typically observed during strong negative phases of the NAO."
Looking over the pages at the link above appears to show that there is greater correlation of the NAO phase to temperature than to precipitation for the NE US, and that near term Progs lean toward (-) NAO & possible cooler temperatures for Boston for the next two-three weeks.
This graphic will update so the forecast may have changed since posted.
3:20 PM EDT on April 02, 2008
As of this post date, the 384 Hour GFS Model loop doesn't yet go out to race day, but it appears to show a storm moving through about every three days. It that were to bear out, low pressure would return to the area on the 19th & 22nd, good for a race on the 21st. But that is supposition based on a long shot. Wishcasting? Maybe. With some help from more experienced WU bloggers, I will try to get this dialed in for you runners & spectators.
Just out today
One more long run (with multiple bridges) to go & race day is within the scope of the GFS model. I interpret it to show about 42F at race start with S to SW winds 10 increasing throughout the day as does the chance of rain.
GFS 4-panel chart 12:00 04/21/08 (312 hour)
Local and/or experts feel free to comment here!
Beginning the 15th, the WU Boston page will have a forecast.
Longest training run out of the way. A little sore - hope it goes away before the marathon & my late taper doesn't backfire. For about 22,000 friends, the hard part is over, list items are collected & ready to pack.
The 18Z run 4/10/08 of the GFS model, on the 252 hour panel for race start time has us back near where I started this blog, with Boston on the back side of high pressure planted off the Eastern seaboard providing a warm 50F, high of 70F, light S-SE crosswind & little or no precipitation on race day. Great for a runner from Florida who was less than thrilled about leaving the 86F that I trained in yesterday to run in anything near freezing. But we'll see, 1t's still pretty far out. The forecast changes daily, but is beginning to firm up.
The ECMWF model seems to be in agreement.
8 days, good recovery, soreness gone, Taking it easy this week. Weather still looks good.
GFS forecast appears to show temps trending a little cooler, with wind E around 10mph thanks to 1029mb high not as far offshore, instead just to the N, SSTs in the 40 reflected in temps in the low 40sF at start & high 50s for a high (but cooler as we get closer to the aforementioned sea surface), still with no rain. Partly Cloudy & warmer Monday evening for those returning.
Late - WU posts the NWS forecast for Monday, April 21.
The 30% chance of rain now is due to the onshore flow..
Easy 12 miler yesterday - no problems. Thought about moving a treadmill into the walk-in freezer to acclimate, but now it's in the low 40s here in Central Florida.
The forecast for Eastern Mass on race day continues to change (we knew it would) & the cross wind previously forecast looks like more of a headwind now up to 13mph (this will help on the downhills:) & some predict higher with gusts to 30, some forecasters are calling for from 30% to 60% chance of light rain, high of 52-58, while the NWS now forecasts:
Monday: Partly sunny, with a high near 62.
Monday Night: Partly cloudy, with a low around 44.
The last 3 marathons I ran were in light rain & windy 40s, so I should be used to it (but I would prefer 70s).
NWS point forecast
I'm out here in Hopkinton, one day of rest before we run. Best of luck to all runners & spectators. Se you out there. The spectators truly have the hardest job!
Nothing to add to the forecast except to tweak the temps back up a little, & the headwind down a little.
From blogger StormW -thanks:
Min. Temp: 44F
Max Temp: 57-58F
Rain Chance: 30-40%
Wind: ENE to E @ 10-12 KTS.
The "eyewitness" weather onscene here verifies the foregoing - the weather probably couldn't be better.
Looking East from the start:
The weather was perfect. It was a great run & a good time was had by all. The volunteers put on a perfect race, got us there on time & took us back. Thanks so much. Oh, and hills. What hills? I didn't notice much wind out on the course either, maybe briefly in Newton.
The Next Day
Ok, maybe there were hills (quads feeling it now).
Check back beginning next March for an early (unofficial) forecast for the 2009 (113th) Boston marathon.
BTW - I got a set of the town signs (see above) refrigerator magnets, and (IMO) the coolest race "T" shirts from the Hopkinton Athletic Assn website. We come & trash their town, show some love!