Meltdown for Awhile; Wintrier by Next Weekend?

Temperatures will continue to moderate over the weekend, reaching the mid 40s Sunday, the low 50s (even with clouds & a few shwrs) on Monday, and the upper 50s on a strong southerly/downslope wind on Tuesday. Late Tuesday, strong winds aloft and a cold front will usher in some showers & possible tstorms, turning to a little snow by Wednesday morning. The airmass behind this front will not be terribly cold, and will still actually run somewhat above normal, with low to mid 40s possible again on Thursday and Friday. Most global models have been erratic further out in time, but there is a general trend toward somewhat more wintry temperatures developing during next weekend, with at least some limited snowfall possible. With erratic models will likely come an erratic extended outlook for the next couple of days, so that explains the "?" in the title for this thread.

Cloud Streets

This highly detailed photo was taken by a special instrument on board NASA’s Aqua Satellite on January 3d. What you see here are “cloud streets,” produced by the same process that produces lake effect clouds in the cold weather season. As arctic air moves over the relatively warmer waters of the Atlantic, moisture rises into the cold air and condenses. On some occasions, when these clouds develop sufficiently, a northerly or northeasterly wind can produce “Ocean Effect Snow, “ most commonly across Cape Cod.

Pattern Change Will Mean Business

After a still quite cold Thursday, Pacific air will come rushing in to replace the Arctic Air which arrived late New Year's Day. Friday's moderating temperatures will be accompanied by a Gusty SW wind of 20-30+ mph, so there will still be a significant wind chill. On Saturday, a SSW breeze will boost temps into at least the upper 30's and a weak disturbance may bring a few light rain showers in the afternoon and/or evening. The warmup will strengthen on Sunday, and even moreso on Mon-Wed, with near record warmth possible. Not that much sunshine is likely with this warming, which will be driven mainly by a downslope/southerly flow. Rain will move in around Wednesday night, and may turn to a little snow on Thursday as a chillier (but not terribly cold regime) returns for a few days.

There are signs that around the 15th, we may undergo another pattern change to colder weather with a possible longwave trough of low pressure extending from Hudson Bay down into the central and ern U.S. There are signs that the NAO may be heading toward a Negative/Cold Phase, and the PNA/Pacific Ridge may become positive over wrn North America at around that time. As of today (Wednesday), they are ONLY signs of this shift, and nothing is carved in stone as a few bloggers have claimed on the previous thread. We'll want to see several more model runs confirm this trend before we begin to jump on it.

A few of you just don't want to get it about UNCERTAINTY (my uncertainty thread is still up and available for reading), but that's allowed on a blog. For those of you still in high school considering a science major when you get to college, I strongly urge you to begin thinking in those terms, or you're going to run into lots of trouble with your future professors.

More Wintry Weather on the way...

A Winter Storm WARNING is in effect for Niagara, Orleans and Genesee counties from 4pm Tue - 7pm Wed.
A Winter Storm WATCH is in effect for Chautauqua, Cattaraugus and McKean counties from Tues AM - Wed Evening.

A potent arctic cold front will bring widespread snowfall and the coldest airmass of the winter season so far to WNY. Snow will begin some time after 3 AM tonight. We can expect about an inch of accumulation overnight. Snow will become more widespread Tuesday AM. Most of the precip will fall as snow, but if there is any mixed precip it will be south of the metro and VERY brief. A lull in the precip will arive during the late morning/early afternoon (in time for the Ice Bowl) but don't let that fool you because much more is on the way for later. Snow will resume later Tues. afternoon with daytime accumulations around 3-5inches. The heaviest snow in terms of intensity will arrive Tuesday night with additional accumulations. Winds will also pick up so blowing & drifting snow will also occur. The Lake Effect Machine will turn on Tues night and Wed. on a NW flow. Chaut, Catt and Orleans counties may see up to a foot of total accumulation by Wed evening (total 2 day accumulation.) Wed & Thurs will be the coldest days of our young winter season so far with daytime highs around 20F.