Here's Your Weekend Forecast! You're Best Weather Bet is Sunday!

Good Morning,

The upper-level wind flow, or "jet stream pattern" across the Lower Forty-eight states the next

few days will be featuring some big contrasts... By and large, the average position of a fairly

strong low pressure trough will be located in the eastern third of the nation... Conversely, an

equally strong ridge of high pressure will bring some scorching heat to parts of the West... With

this in mind, we know right off the bat that, even though temperatures this afternoon will soar well

into the 80s to near 90 on several thermometers across the mid-Atlantic states and in the

Northeast, this won't be common over the next 3-5 days... Instead, temperatures over the weekend

and early next week should actually average 2-4 degrees below normal for this time of year... For

many of us, that will mean temperatures between 80 and 84... As they say: "Half the fun is getting

there..." So, we'll dive into what will be bringing about these changes:

Early this morning, a ridge of high pressure located near the mid-Atlantic Coast is poised to drift

offshore... Meanwhile, there is a cool front (a low pressure trough) located in the eastern Great

Lakes as of this writing, and it has had a history of causing showers and thunderstorms in much

of the Ohio and Tennessee valleys since late yesterday... It is worth pointing out that the

thunderstorms across Michigan and in Ohio were not as strong as what was anticipated... Instead,

the strongest thunderstorms late last evening and during the overnight hours have been occurring

much farther to the south, or primarily in Kentucky and across middle Tennessee... The "take away

point" from this is: the most potent upper-level energy available the last 12-18 hours has been in

the southern Tier of states, and not farther north... As the surface cool front moves into the

Appalachians this afternoon, its forward progress will start to slow down just a bit... It will bring a

few showers and thunderstorms along a corridor that extends from southeastern Canada and

northern New England on down to Georgia... By early tonight, most of these showers and

thunderstorms (which should be 'scattered' in nature) will be impacting areas close to I-95... In our

forecasts, we're allowing for a shower and thunderstorm in areas close to the big, coastal cities

later this afternoon (or, between 4 and 8 p.m.) but it does appear that the bulk of the rain most

coastal communities and even the larger cities will be getting should happen tonight into

tomorrow... There are still some differences between the global models regarding tomorrow, and

they can be directly attributed to how they are handling this front once it reaches the East Coast...

The 'faster-looking' American version of the medium-range forecast model is implying that all of

the shower and thunderstorm activity will be gone by mid- or late tomorrow morning, especially in

areas located NORTH AND WEST of Interstate-95... But along the immediate coast and in some of

the big cities, it would be prudent to allow for a shower or thunderstorm tomorrow at virtually any

time...

There are still some differences between the global models regarding tomorrow, and they can be directly

attributed to how they are handling this front once it reaches the East Coast... The 'faster-looking' American

version of the medium-range forecast model is implying that all of the shower and thunderstorm activity will

be gone by mid- or late tomorrow morning, especially in areas located NORTH AND WEST of Interstate

-95... But along the immediate coast and in some of the big cities, it would be prudent to allow for a shower

or thunderstorm tomorrow at virtually any time...

And, we want to make it clear, this does not imply we're expecting tomorrow to be a "wash-out", but the

slower this front moves as it reaches the East Coast, the more likely a couple of showers and a

thunderstorm will tend to linger well into the afternoon and perhaps even the evening hours before drier air

arrives... We mentioned yesterday that the "best-case scenario" would involve the showers and

thunderstorms ending during the morning, and that appears as if it will be the best call to make at this time

for places like northwestern New Jersey, the Hudson Valley, the Catskills and across much of eastern

Pennsylvania... But for New York City, the Jersey Shore, coastal Connecticut and on Long Island: NOT SO

FAST!!

In an attempt to strike a compromise between the quantitative precipitation forecasts of the European and

the G.F.S. -- we'll forecast rainfall amounts of 0.50 to 1.00" for the 18-hour period ending at 4 p.m.

tomorrow (therefore, this period begins at 10 a.m. today)... There may be some totals that will EXCEED AN

INCH along the coast, and other areas farther inland may see less than half an inch...

By Sunday, there will be a ridge of high pressure spreading out across the Ohio Valley and into the

Northeast... And, even though there may be a wave of low pressure which forms along the old front in

Virginia or the Carolinas, leading to more rain for areas south of the Mason-Dixon Line, the prognosis for

areas farther north will be for some dry weather... It may not be "totally sunny" on Sunday because of the

interaction between the strong August sunshine and some colder air aloft, but it should be a rain-free day...

Have a good weekend!!!