Tuesday 9:45 a.m.
Speculation swirls concerning how Sandy from the tropics, chilly air from central Canada and a blocking high pressure area developing in the North Atlantic will interact. So far the ECMWF model has been most threatening, although its track shifted by more than 200 miles yesterday. This video has more.
In the meantime...
Today is national mole day from 6:02 a.m. until 6:02 p.m. Why is it on this date and only at those strange times? And what's a mole anyway? Every substance has 6.02 X 10 to the 23rd power molecules in a mole of that substance. The number 6.02 times 10 to the 23rd is called Avogadro's number, named for Amadeus Avogadro, who must have had his name changed to cause trouble for all chemistry students who followed. This fact has allowed chemists to measure substances exactly in the laboratory. Since 6.02 is part of the number, it explains why the celebration of mole day runs from 6:02 a.m. until 6:02 p.m. And, since multiplier is 10 to the 23rd, Oct. 23, or 10/23 is the appropriate date.
The only other question is what any of this has to do with the weather, and quite simply, I cannot answer that. However, the chemistry of weather systems across the country during the next week or so will become quite volatile, partly because of thermodynamics. That volatility could mean thunderstorms where chilly air in the north mixes it up with warm, humid air in the south.
Today, we see that interaction between warm and chilly air masses along a boundary stretching from Illinois to New Jersey. In the I95 corridor, the day started with a mixture of clouds and sun, but elements of rain showers could compound your problems in planning your afternoon. Let me remind you that if a thunderstorm charges into your neighborhood, get the lead out and seek shelter. You may need to buffer yourself with a raincoat.
For a while, thick clouds will make it bleaker than a dirty beaker, and anybody who wants light to come into their houses should leave the curtains and valences open.
In areas outside the showery areas, it'll be fine for viewing the autumn scenery.
And, much of tomorrow and Thursday should be fine for being oxide with temperatures in the 60s in the north and 70s in the south.
Toward the end of the week, a southerly flow of warmer should affect the Ohio Valley then the Northeast. At the same time, colder flow coming into the western Great Lakes will make it go lower on the temperature scale. The northwest wind will be the main reducing agent.
Of course, cold weather isn't so radical. It does mean we will be getting out the windchill chart, one of those periodic tables we use during the cold season.
For now, that's our solution for the short term. Keep accuweather.com in mind whatever your plans. Maybe you're doing some bonding. It's whatever gives you a positive charge. For dinner, whether we go out or eat in, some of us will experiment. For that, of course, sliced ingredients and mixtures including lettuce, tomatoes, cucumbers, radishes, onions olives and avogadros number in the millions.
As we go toward the weekend, we'll be trying to iron out the details about the storm threat next week. It is more complicated than a simple either ore situation. It is potentially explosive, but we will work to explain everything until elements of uncertainty argon.
Avogadro go now!
Extensive precipitation straddles both sides of the cold front that was moving through central New York and central Pennsylvania as of mid morning. This radar shows the distribution of rain and snow; some temperatures are added.
The cold front approaching the East shows up quite well in this pressure analysis. Several temperatures are plotted to give you a sense for how much the temperature changes behind the cold front. At Chicago, it went from 60 at 4 a.m. to 39 at 5:19, a 21-degree drop in little more than an hour.
Temperatures on Sunday and Monday will range from the 60s in parts of New England to near 80 in Maryland and Virginia. However, a strong cold front will then trigger and perhaps a few thunderstorms as it ushers in air that will be 30-40 degrees colder than it will be ahead of the cold front.
During the early morning hours of April 15, there will be a total lunar eclipse visible across North America. This eclipse is the start of a <em>tetrad</em>, a series of four total lunar eclipses over a two-year period. The totality begins at 3:07 a.m. ET, 2:07 a.m. CT, etc.
Severe Weather Awareness Week activities are conducted by National Weather Service offices nationwide at various times during the spring. There is a lot of information for everyone (from children to seniors) available online. You can start <a href="http://www.ready.gov/kids/know-the-facts">here</a>:
However, after the warmup, another cold front will move through the Great Lakes and Northeast with at least some rain. This map contains the forecast for Sunday evening.