Saturday, April 19, 2014
Late last month I wrote about how the first part of March would end up being chilly and somewhat stormy. Now, five days into the month, this is proving true for much of the country. Thus far, we have not had any major snow here in Maine. Today we are watching an area of low pressure move out of the Ohio Valley and head for the mid-Atlantic coast. As this storm emerges off the coast, it will bring heavy amounts of precipitation in its path. Where temperatures are cold enough, snow will fall. Coastal and southern areas are going to be most susceptible to effects from the storm.
I'll be updating my weather forecasts on Twitter at @growingwisdom please follow me there.
Strong wind and some waves
How far north the storm moves will determine if coastal Maine sees any flooding issues. Flooding is an interesting term that we should look at a bit more closely. When a flood warning is issued, it means that the water is going to exceed a specified height by some amount. The critical question to ask is, by how much will an area flood? This time of year flood warnings can be issued for rivers and streams, even without much precipitation. Ice jams can cause problems in rivers, and are commonplace in early spring. A flood warning means that the water will come up high enough to overflow the banks of a river. Even if the water exceeds the banks by only one inch, the river is said to be "in flood." However, that example would do nothing more than add a bit of water to a few back yards. The same is true for the ocean. Flood warnings are issued when the tides or wave action will exceed a given level. The devil is in the details. You might hear that a flood warning is issued for coastal York and Cumberland Counties, but the reality is that the water rises only several inches higher than the highest tides. What to listen for is whether the flooding will be minor, moderate, major or catastrophic. Note how much higher than normal the tides are forecast. Too often the flood warning ends up as a headline, when in reality it isn't worthy of one.
Our latest storm
There is another storm threatening Maine. There are coastal concerns because of a predicted long duration of onshore winds. However, while there might be pictures of beaches being eroded and even some homes in danger to our south, for the majority of Mainers, this is a non-event. That’s what makes these coastal storms so challenging to convey. This morning I am confident that a major ocean storm will form and that heavy amounts of precipitation will move into parts of southern New England; whether or not the precipitation ever makes to southern Maine is still somewhat in question.
As is usually the case, we have two camps of forecasts for the weekend. Camp one is the American model. In this camp the big ocean storm moves north far enough to bring heavy amounts of precipitation and some warm air off the ocean to Maine. Camp two is the Europeans and that model. This camp shows the big ocean storm moving far enough north to bring us some precipitation, but keeps the warm air just far enough offshore to keep anything that does fall in the form of snow. The two camps can’t figure out if a weather system to our north, acting as a block to the storm, will hold the storm away or not. A difference in 50 miles will make a huge difference to what you wake up to Thursday and Friday morning. Right now a winter storm watch is up for southern New Hampshire and may be extended into Maine tomorrow.
There is a saying in this business when dealing with models and that saying is that “the trend is your friend.” This means that if you look at the trend of the models, ultimately what happens is usually leaning in that direction. The trend of each new set of weather models has been for this storm to have a greater impact on New England, not less. I am thinking that we are impacted with precipitation later Thursday through early Friday. The greatest chance for accumulating snow will come Thursday night when temperatures are coldest. This time of the year, it becomes harder for snow to stick on the roads, unless we have very cold air present, which won’t be the case. Any snow that does fall will be heavy and wet and because there will be wind with this storm, I am already thinking about the potential for power outages where snow does fall.
It’s too early to speculate more about this right now, but I will be evaluating that possibility closer later today and if the heavy snow scenario starts to look more likely, the power issues will be a factor. The greatest snow threat will be south of Portland and especially southern interior York County and into New Hampshire. There will be a very sharp cut-off line to the northern extent of the storm.
The weekend looks quite nice with temperatures in the upper 30s and lower 40s with drier conditions. That is just a break in the pattern, not a change. There is another storm of rain or snow likely for later next week.
Gardening this week
Depending on how aggressive you want to be in the garden, March does begin planting season. Fava beans, peas, lettuce, radish, carrots, and other cold weather crops can be planted by the end of the month. Inside, you can start many of your seedlings this month. I generally start my tomatoes in the first couple of weeks of March, which is about 8 weeks before they will go into the ground. Early this month is also the time to prune your blueberry bushes. In this week’s video I show you how to keep your blueberry bushes healthy and yielding big, juicy berries. I'll be updating my weather forecasts on Twitter at @growingwisdom please follow me there.Tweet
David Epstein has been a meteorologist for more than 25 years. He spent 16 years in Boston and currently freelances at WGME13 in Portland.
In 2006, David founded GrowingWisdom.com, a business producing educational and marketing videos for the green industry. He currently is a professor at Framingham State College, teaches Jan Plan at Colby College and owns Bloomscapes Inc., a landscape design business.
David authored "Gardens Of New England" and his work has been published in Grolier's Science Annual for 10 years. He lives in South Natick, Mass., and has a summer home in Harpswell.