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!
This map shows a projection from last night's European model. It shows an huge temperature difference in a short distance across northern and central New England.
A number of you have submitted weather photos and graphics that we really enjoy. One person with a keen eye for how to visualize weather and climate events is Ralph Fato of Connecticut, who graciously allowed me to use this graphic about snowfall.
Snowfall amounts yesterday were low from Philadelphia to New York City. Accumulations increased toward the north and northeast.
This map shows the NAM's projection for this Friday night. The isobaric pattern suggests there is a southwesterly flow of mild air from the Gulf states to the Middle Atlantic region. Farther north, we see evidence of the frontal boundary that separates the mild air from chillier air.
A new area of snow now over southern Minnesota should expand southeastward to reach Chicago this afternoon, streak to Pittsburgh this evening, then reach the Philadelphia/New York City area late tonight or early tomorrow morning. This map shows a low pressure area over Missouri.
This map shows expected accumulations.