اخبار هواشناسی آمریکای شمالی

[ali_kermanshah]

زمان خبر : 27 ژانویه

Kocet's Corner: Winter Hasn't Taken Hold...Yet

What's wrong with this winter you ask?

There is nothing terribly unusual about it. The atmosphere always goes through these cycles. Sometimes the weather is really bad; at other times it's not.

Quite frankly though, there was more winter at the end of October when that big snowstorm hit the Northeast than there has been for the past two months. Look at those snowfall amounts! Just pitiful!

Last year by this time, there had already been record snowfall from New Jersey across New England. Hartford, Conn., had nearly 90 inches of snow for the entire 2010-11 winter season, and in the Berkshires, winter totals were over 100 inches.

And what about February 2010 when the mid-Atlantic region was hit by a one-two punch that rivaled the biggest snowfalls of all time? During that month alone, Baltimore had 50 inches of snow and southern New Jersey had more than 3 feet.

Why Isn't Winter Getting into Gear?

Naturally, to answer these questions we have to look at the jet stream.

The jet stream has been farther north than it should be which has stopped frigid air masses from migrating south. Furthermore, any cold air that has come down has made a quick retreat before any storm could tap it. Thus the general lack of snow from the Great Plains to the Eastern Seaboard has continued.

So could this pattern persist all winter? Sure, it could. However, something will happen later next week that could be a sign that February will turn out much different than December and January. Look for a major storm coming out of the South later next week followed by an immediate shift to much colder conditions.

Will that last? I can't say, but I have a hunch that there will be a lot more fun and games in February than there has been over the past eight or nine weeks.

 

[ali_kermanshah]

زمان خبر : 28 ژانویه

A weak clipper system will track north of the Great Lakes today, bringing a little snow to portions of the Ohio Valley and Northeast.

Snow will move from west to east and reach the interior sections of the Northeast this afternoon.

Overall, accumulations will be on the light side with generally a coating to an inch expected.

However, some locations downwind of Lake Erie and Lake Ontario will have up to 3 inches of fresh snow as precipitation becomes enhanced from cold winds blowing over lake waters.

While accumulations will generally be light, roadways still could become slick in spots. Use extra caution while driving and be prepared for slower travel.

Farther east, the big cities of the I-95 corridor will stay dry. From Washington D.C., to Boston, a beautiful day is on tap with bright sunshine and pleasantly mild temperatures.

Big changes are on the way however, with much colder air set to plunge into the region on Saturday night into Sunday. A cold front will push through the region, bringing an end to the unusually mild temperatures.

Even though you may be tempted, don't put away those winter jackets just yet.

Even though the air won't be that cold compared to late January averages, it will still feel a lot colder after seeing temperatures 10 to 15 degrees above normal over the last few days.

As has been the case so far this winter, the cold air will not lock into place. After a couple of days of seasonably chilly air, springlike warmth will surge into the East by the middle of next week.

 

[ali_kermanshah]

Another Mild Surge to Impact the East by Midweek

زمان خبر : 28 ژانویه

A brief shot of seasonably cool air will enter the mid-Atlantic and Northeast Sunday and Monday behind two weak clipper systems." However, the cool air won't last long as another surge of mild air takes hold by Tuesday.

Residents of the East which have been basking in the mild weather this month will be happy to hear that another shot of mild air is on the way.

Temperatures once again Tuesday and Wednesday could rise into the 60s from Richmond, Va. to Washington D.C. and Philadelphia.

A series of weak fronts associated with clipper systems will track through the Great Lakes and Northeast this afternoon and again Sunday into Sunday night.

While a little light snow is expected across the Great Lakes and interior New England with these fronts, accumulations will be minimal with a lack of deep moisture.

The real story will be a return to seasonably cool temperatures for Sunday and Monday across much of the east as a shot of cooler air moves in behind these systems.

Temperatures by Monday will fall back to the upper 30s in New York City and near 40 in Philadelphia, both of which are near seasonal average for this time of year.

Still for January, it won't feel all that bad with a good deal of sunshine expected on Monday.

A Return to Mild Weather

High pressure will anchor itself off the East Coast early next week and this will send a southwesterly flow of air into the Great Lakes, mid-Atlantic, and Northeast by Tuesday.

This flow of air coming straight up from the Gulf will send temperatures soaring above normal from Chicago through Detroit and New York City.

Below is the list of forecasted high temperatures for selected cities Tuesday and Wednesday.

The mercury could even approach the 70 degree mark in cities such as Richmond and Norfolk, Va.

The mild weather will be accompanied by a few showers come Wednesday, but with a lack of deep moisture, rainfall will be rather sparse.

The mild weather will persist into the end of the week across the East...however, the potential then exists for a late week storm.

This storm would develop in the form of a wave along the tail end of a frontal boundary over the Gulf Coast. Moisture and rainfall will return to Texas, Oklahoma and the lower Mississippi Valley by Thursday and that feature could lift northward by the end of the week.

Meteorologist Alex Sosnowski explains that "The details of the nature of the storm, and most importantly its critical track, will unfold early next week."

 

[ali_kermanshah]

90-Year Anniversary of Deadly Knickerbocker Blizzard


زمان خبر : 28 ژانویه

oday marks the 90th anniversary of the deadly roof collapse of the Knickerbocker Theater in Washington, D.C., resulting from a massive blizzard that struck portions of the South and the mid-Atlantic.

The weight of heavy snow proved too much for the flat roof of the Knickerbocker Theater, which was built in 1917. Drifting of snow likely led to an uneven distribution of weight that added to the devastating roof collapse that killed 98 people and injured 133 others late on Jan. 28, 1922.

Photo of the Knickerbocker Theater following the collapse of the roof from NOAA's Historical Photo Collection. Click here to see more incredible photos of Washington, D.C., covered in snow from the Knickerbocker Blizzard.

Washington, D.C., was buried by 28.0 inches of snow from the blizzard, setting a record for the heaviest snow in 24 hours. This record still stands today.

Other snow amounts include 19.0 inches in Richmond, Va., and 33.0 inches in Rock Creek Park, which sits along the Washington, D.C.-Maryland border. Railroads between Philadelphia, Pa., and Washington, D.C., were buried beneath as much as 36.0 inches of snow.

Up to 16-foot-high snow drifts occurred with the ferocious winds accompanying the storm between Philadelphia and Washington, D.C

The storm shut down all forms of travel in the nation's capitol, forcing people to travel to work on foot in treacherous conditions. A 24-hour record snowfall in Baltimore, Md., brought
travel to a halt as well.

 

[ali_kermanshah]

No Dice, Phil: More Winter for U.S., But Not Six Weeks

زمان خبر : 5 فوریه

The AccuWeather Long Range Forecasting Team thinks the longest stretch of cold is yet to come for the Great Lakes and Northeast, but spring will arrive early for many.

Phil saw his shadow for Groundhog Day 2012 in Punxsutawney, Pa., forecasting another six weeks of winter for the U.S.

"There is some winter left on the table, but not a full six weeks for most of the U.S.," responds Paul Pastelok, expert long-range meteorologist and leader of the AccuWeather.com Long-Range Forecasting Team, after Phil's prognostication.

Longest Stretch of Cold on the Way for Great Lakes, Northeast

The longest period of chilly weather so far this winter is still in store for the Great Lakes and Northeast. The cold snap is expected to grip these regions during week two into week three of February.

"Each day will be like deja vu, similar to the Groundhog Day movie... every day will be the same.... chilly," said Elliot Abrams, AccuWeather.com chief forecaster.

Temperatures will drop to 3-6 degrees below normal at the height of the cold stretch. It will be even colder compared to normal across northern New England, where the harshest cold will grip.

Along with the cold comes the potential for snow. Pastelok feels that there will be the potential for one or two big storms in the East during February. The best potential for significant snow will be across the Great Lakes and the interior Northeast and northern New England, while mostly rain is expected in the big East Coast cities.

The cold will ease with temperatures returning back to normal late in February across the Great Lakes and Northeast. Jack Boston, an AccuWeather.com Long Range Forecaster, added that it will feel more mild from the last week of February through much of March, with more frequent warm days in the East.

Wet at Times for Tennessee Valley into the Appalachians

On the southern edge of storms heading into the East, mostly rain will fall through February and through the middle of March.

More than one round of rain during February could lead to potential flooding across portions of the Tennessee Valley into the Appalachians.

Another Bad Severe Weather Season

With abnormally warm air across the Gulf of Mexico, February and March are expected to be active with severe weather.

"Deep cold air has not reached the Deep South yet, so the severe weather season is early," said Expert Senior Meteorologist Dan Kottlowski. Gulf water temperatures are warm as a result.

Any time the wind turns out of the south, warm, humid air is easily drawn across the Deep South. High humidity sets the stage for thunderstorms violent enough to produce tornadoes.

An above-normal number of tornadoes are anticipated with areas from Louisiana to western Georgia and Tennessee expected to be in the line of fire.

Snow Drought Continues for the Northern Plains

Snow will continue to be scarce across the north-central Plains through the middle of March. The lack of snowcover in the northern Plains has implications on river flooding during the spring.

"There will be lower chances of flooding along the Mississippi and Missouri Rivers," added Pastelok. This is good news following major flooding during spring 2011.

Farther south, spring will arrive even sooner for the western and central Plains with above-normal temperatures and mainly dry weather by the middle of February.

Flip-Flopping in the West

In the Northwest, the next couple of weeks will remain drier-than-normal in the Northwest. It will turn wetter with more mountain snow by late in February and March.

During the first part of February, it will stay dry in Southern California with some warm-ups. There may be a few storms that bring rain all the way to Southern California during the second half of February, but precipitation should still fall below normal for the month.

March will be dry across the Southland

 

[ali_kermanshah]

Late-Week Cold Press

زمان خبر : 6 فوریه

A press of cold air will drive southward late this week from the Upper Midwest to the interior mid-Atlantic and New England this weekend.

While the cold push will not last long, it will feel like winter for a couple of days.

Temperatures may range from 5 to 10 degrees below normal for a two-day stretch from Minnesota, Iowa and Illinois, eastward to Maine, New York and Virginia.

The cold flow over the warm waters of the Great Lakes will set off lake-effect snow, but probably not in traditional areas.

Surface winds will be from the north and northeast and could create some interesting bands of snow on the west side of lakes Michigan and Huron, over north-central Ohio from Lake Erie and between Buffalo and Rochester in New York off Lake Ontario.

The northerly flow of air over the open waters of the Great Lakes will negate the magnitude of the cold over the Ohio Valley states. However, in portions of northern upstate New York and northern New England, it can get mighty cold for a couple of days, since the air will not take a route over the Great Lakes first.

Farther south along the I-95 corridor, the cold press will be less pronounced, delivering near-normal temperatures (highs in the 30s) for a couple of days, rather than the 40- and 50-degree stuff.

A swath of light and generally insignificant snow will run eastward during the middle of the week, well ahead of the main cold push coming late in the week.

Weekend Coastal Storm?

There is a slight chance of a storm spinning up along the mid-Atlantic coast late this weekend.

Part of the energy from the feature will be bringing drenching rain and mountain snow to Mexico of all places late this week into the first part of the weekend.

There seems to be two options.

The more likely is that dry, cold air wins out and the storm passes by well out to sea.

The other, less likely scenario is the storm strengthens upon moving up, tracks close to the coast and unloads a period of snow on part of the I-95 mid-Atlantic and southern New England during Sunday

 

[ali_kermanshah]

Much Colder Air Heads East This Weekend

زمان خبر : 10 فوریه

One of the coldest air masses so far this winter will descend upon the eastern part of the nation this weekend, but for many it will be gone as quickly as it came.

The brief but fierce blast of cold air will be accompanied by snow showers and squalls, first across the Midwest, including Chicagoland today, then this weekend in the Northeast. This will be due, in part, to a storm forming offshore.

As if cold and snow weren't bad enough for warm-weather fans, gusty winds will drive AccuWeather.com RealFeel® temperatures well below the actual thermometer reading, and in many areas well below zero for a time.

Today, the northern Plains and Upper Midwest will bear the brunt of the arctic blast, with temperatures hovering a few degrees on either side of zero for much of the day across a good portion of the Dakotas and Minnesota

The brutally cold temperatures will be a stark contrast to the relatively mild temperatures experienced for much of the winter.

As a cold front representing the leading edge of the colder air heads south and east, the mercury will be on the decline throughout the day following higher temperatures in the morning from Kansas City to Chicago to Milwaukee.

The same will be true from the Ohio Valley through the eastern Great Lakes late Friday night into Saturday as the proverbial lake-effect snow machine becomes active once again.

Truly chilly air will hold off along the I-95 corridor until Sunday, where temperatures will stay in the 20s for most of the day. Northern New England will fare much worse, with temperatures only reaching the single digits and teens for highs in some areas.

Residents of the South won't be immune to this cold blast either. After basking in upper 50s, 60s and, in some places, 70s today, temperatures will be cut by as much as 20 degrees Saturday and Sunday from Atlanta to Jacksonville to Raleigh.

Early blooming flowers and other plants will face a hard freeze Saturday night, with subfreezing temperatures expected all the way to the Gulf Coast and central Florida.

Unlike in Europe, the cold air will not be able to "lock in," as relatively mild air for mid-February will push back in across the East for the new workweek.