Thursday 9 a.m.
Today's video shows why we are optimistic about weekend sunshine but concerned about locally flooding thunderstorms before that.
When you see our forecasts on AccuWeather.com or listen to the radio or view a newspaper that carries the AccuWeather forecast, it may be difficult for you to decide how rainy or dry any given day is going to be. That's actually one of the best reasons for having our mobile app on your smart phone or tablet, so you can always check the radar for what's happening right now.
Let's face it, in a newspaper that has the whole day's forecast condensed into one icon, or when you listen to a 20-second AccuWeather forecast on the radio, you will not get all the details if it is one of those days when the weather changes frequently. Today, for example, in much of the Northeast we have a forecast that calls for warm, humid weather and a thunderstorm from time to time. While that forecast has a good chance of working out, it doesn't have the level of detail to help you decide whether or not it will rain during a baseball game this evening.
That's where you come in. Since the forecast alerts you about thunderstorms, you will know much more if you check the radar on AccuWeather.com before you leave for the ballpark. It is not a perfect solution, because areas of showers and thunderstorms can change shape and the intensity of the storms can change a lot in a short time. But if the question is simply do I take a poncho to the game or leave it home, you will often make the right choice using the method I outlined.
This map shows where showers and thunderstorms were at 9 a.m. EDT:
map shows predicted rainfall between now and next Wednesday. This will need to be watched in order to assess the risk of flooding.
Looking farther ahead, it appears a summer version of THE POLAR VORTEX will send much cooler air into the Great Lakes and then the Northeast. The first map shows the flow aloft next Tuesday night. The second map shows what could be a heat wave a week and a half later!
There were numerous thunderstorms yesterday. This is the lightning stroke map covering the period from 8 ET yesterday morning to 7:30 ET this morning. Thunderstorms will be less numerous today, but any that do form can cause briefly strong and gusty winds.
One area of concern is Lake Erie, where unprepared boaters could suddenly be blasted by 60-mph winds. The National Weather Service Storm Prediction Center has outlined a large area where the threat of strong wind exists. The map is below today's forecast video.
Tomorrow, a cold front will cross the Great Lakes, then reach the Northeast by the end of Wednesday. Today, a southwesterly current of very warm air is evident on the surface pressure map.
The center of Arthur (shown here at noon ET) should pass less than 50 miles southeast of Nantucket this evening, causing heavy rain and gusty winds across much of eastern New England. Meanwhile, the Great Lakes and much of the Appalachian region have a lovely Fourth (but take a jacket or sweater as you head out to the fireworks).