November 2013 - Page 4 of 6 - New York Metro Weather

SPC issues rare High Risk over Great Lakes, Ohio Valley

November 17, 2013/0 Comments/by John Homenuk

A major severe weather outbreak is forecast this afternoon across much of the Great Lakes and Ohio and Mississippi Valleys. The Storm Prediction Center has issued a rare “High Risk” for severe weather across much of Illinois and Indiana as well as parts of Southern Michigan and Western Ohio. A highly unstable atmosphere, juxtaposed with an impressive storm system both aloft and at the surface, will act to trigger the development of impressive late-season severe thunderstorms. Impressive low level shear and wind turning will allow for the potential of widespread tornadoes, some of which could be violent. With time, the storms will organize to pose more of a damaging wind threat as they shift eastward towards the Ohio Valley. For more on the developing threat, stay tuned to the Storm Prediction Center page which will display all outlooks, watches and warnings.

In our area, the SPC has extended a “Slight Risk” for severe weather to include all of New Jersey, New York and Connecticut. As the associated cold front sweeps through the Ohio Valley and eventually the Northeast US later today, the potential for isolated strong wind gusts is expected to continue. The threat, and intensity of the storms, is not expected to be nearly as severe as it will be back across the Great Lakes and Ohio Valley.

Storm Prediction Center Day 1 Categorical severe weather outlook from 11/17/13, showing a High Risk over parts of IL, IN and OH as well as a Slight Risk in the NYC Area.

Warm weekend, severe weather to our west

November 16, 2013/1 Comment/by John Homenuk

Warmer weather settled into the area this morning behind a warm front, which moved northward as a result of a strong system over the Central United States. The warm weather comes on the heels of some of the coldest weather so far this season, which swept through the Northeast on Tuesday. The snow and cold seems like an afterthought at this point, with temperatures well into the 60’s and plenty of sun. But a progressive pattern in the mid and upper level of the atmosphere means the changes will continue.

For the remainder of Saturday, the main idea will be pleasant and dry. Temperatures will undoubtedly cool down with sunset (which is starting to come at an even earlier hour as we approach later November). But southwest winds, which will become increasingly apparent ahead of a cold front on Sunday, will keep the air much warmer than it has been over the past several nights. Lows will only fall into the 50’s in urban areas — and we’ll dodge a few scattered showers as well.

NAM model showing a significant mid and upper level disturbance moving through the Central US on Sunday.

Weekend warmup will feature unsettled weather

November 15, 2013/0 Comments/by John Homenuk

Much has been made of the cold and snowy weather this week, and rightfully so. Temperatures fell into the teens and 20’s on Wednesday night after snow on Tuesday, and high temperatures Wednesday afternoon barely scraped into the upper 30’s. Those temperatures are more typical for overnight lows this time of year. But there is another story line in the weather pattern, and it is one that will certainly keep appearing until there is a large scale change: the pattern is progressive. In the mid and upper levels, the pattern shows no signs of slowing down, meaning any airmass that settles into the area (no matter how anomalous) won’t meander around for long.

Not surprisingly, the very cold air which moved through the area early this week is well out of the picture. Temperatures will warm into the upper 50’s on Friday and the warming trend will continue through the weekend. Along with the warmup, unfortunately, will come some unsettled weather. As a mid level ridge builds over the Central and Eastern US, multiple disturbances will ride eastward through the Mid Atlantic states. The result, in terms of sensible weather, will be increased potential for clouds and showers on both Saturday and Sunday — but not a washout.

NAM model showing multiple disturbances moving into the Mid Atlantic states this weekend. Image courtesy weatherbell.

New images of Comet ISON in outburst

November 14, 2013/0 Comments/by John Homenuk

Two weeks from perihelion (its closest approach to the sun), Comet ISON is finally brightening at a rapid pace. Observations taken over the last week had shown the structure of the comet developing. Initially, bifurcation of the comets tail was observed. Shortly thereafter, the tails split into two and three — followed by a disconnection event. All of these were indications of Comet ISON interacting with increased solar winds. Late on Wednesday, amateur astronomers began reporting dramatically increased brightness, and new observations confirm that Comet ISON is likely in “outburst”. Outburst occurs when the comets volatiles (dust, gas, ice on the surface and within the comet) begin to react to the suns heat and solar wind.

It remains to be seen if the outburst will be short lived, or if it will continue until perihelion. The comets fate still is very much up in the air, partly because not much is known about the comets makeup. Originating from the Oort Cloud, Comet ISON is the first of its kind to be observed with modern day instruments. Scientists have been hoping to get a bright, in tact comet to study. But ISON could still break up as it interacts with the suns heat and wind. It could brighten sharply over the next few days and then simply burn out, it could survive until it reaches the sun, or it could survive well past perihelion. The ladder of the three possibilities would offer a terrific show here on earth, as the comet would all but certainly shine extremely bright with a spectacular tail as it moves away from the sun. The next few weeks will certainly be interesting — and we will be watching very carefully! Check out a series of images from the past few days below.

Archive for month: November, 2013