Freezing Weather and Thundersnow

http://www.almanac.com/blog/weather-blog/freezing-weather-and-thundersnow

On November 17 a massive cold spell brought freezing weather to 49 states. Only Hawaii wasn’t engulfed by the cold and even that sunny state had 31°F weather on the top of Mt. Kea. The massive freeze lingered for days. As noted in my last blog, the abnormally cold polar air mass is suspended just north of us and like the sword of Damocles, it takes very little to encourage it to fall south.
This year, however, the cold is bringing not just cold, misery and snow, but also rare thundersnows—thunderstorms that produce snow instead of rain. High winds, as strong as a tropical storm whip the land. Even worse, this weather event typically brings an additional six inches of snow. Then, when everything melts, a high risk of floods.

December Thaw: Long-Lasting Break From Arctic Chill For Most

http://www.weather.com/forecast/national/news/december-thaw-major-warming-trend

After several rounds of arctic chill this fall, most of the country will enjoy a long spell of warmer-than-average weather over the next week or two -- just as meteorological winter has begun.

 

A jet stream pattern that has encouraged cold air masses from near the Arctic Circle to rush southward into the U.S. will change over the next several days, allowing much milder air from the Pacific Ocean and Gulf of Mexico to become the dominant influences on temperatures nationwide.
Computer forecast models are in strong agreement that this will allow unseasonably warm weather to take over a large part of the Lower 48 later this week and on into next week.

California Rain, Mountain Snow: Drought Relief and Flood Threat

More desperately-needed rainfall is headed toward drought-stricken California this week. As we'll illustrate, there are also side-effects to this welcomed rain and mountain snow.

http://www.weather.com/forecast/news/california-rain-storm


Spotty rain already fell this weekend in parts of California, and it was enough to bring three separate mud/rockslides in the Malibu area Sunday, prompting the closure of a nine-mile stretch of the Pacific Coast Highway in Ventura County.

The southwest winds ahead of this system will allow temperatures to stay on the warm side, keeping snow levels high. However, some high elevation mountain snow is expected, with a couple of feet of snow possible above 6500 feet in the Sierra. Travel may become hazardous over the passes later Tuesday into Wednesday.

Stunning pattern about-face predicted in coming weeks; scope of predicted warming quite dramatic

http://chicagoweathercenter.com/

The global scope of the milder than normal temps is evident from the depiction at the top of this post. The Weather Service’s GFS model, Environment Canada’s GEM ensemble and the European Center’s deterministic and ensemble model are all on board with the onset of a significantly warmer than normal pattern. This doesn’t mean there won’t be some cool days intermingled with the “warmth”. There actually will be. But, these forecasts speak to the overall pattern. Each of these predictions suggest a major pattern about-face heading through mid-December–a radical change from the arctic chill which has dominated the past three months producing the 11th coldest meteorological autumn (i.e. Sept through Nov period) on the books and the 8th coldest November in 143 years of official observations here.

Are prospects for winter cold dead? Don’t count on it. High latitude blocking, a major factor in the cold with which the current season has begun, has been a factor in almost all of our recent winters producing the high amplified (i.e. “buckled” or “”wavy”) jet stream patterns which encourage arctic air to dive into the Lower 48. But, for the foreseeable future, the worst of the chill’s being put on hold. Just where we go from here will be fascinating to observe!

El Niño Temperatures Highest Since 2012, but NOAA Drops El Niño Odds to 58%

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2857

NOAA dropped their odds of an El Niño event forming this winter from 67% in their October outlook to 58% in their November outlook, but a surge of warm water over the equatorial Eastern Pacific over the past week could signal the onset of El Niño. The departure of sea surface temperature (SST) from average in the equatorial Pacific region 120°W - 170°W, 5°S - 5°N (called the Niño 3.4 region) crossed the +0.5°C from average threshold in mid-October, and as of November 10, these temperatures were +0.8°C from average--the greatest weekly anomaly since late August 2012. By definition, an El Niño episode occurs when SSTs are at least +0.5°C from average in this region for five consecutive months, with each month representing a 3-month average. Furthermore, ocean currents along the Equator flowing from east to west have weakened significantly over the past week, as apparent from plots made using NOAA's Ocean Surface Current Analyses - Real time web site. This sort of weakening typically happens at the onset of an El Niño event.

U.S. Lightning Strikes May Increase 50% Due to Global Warming

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2860
A warmer world will have much more dangerous cloud-to-ground lightning capable of igniting more forest fires, according to a study published Thursday in the Journal Science. The research found that for each degree Centigrade (1.8°F) of global warming, lightning in the U.S. is expected to increase by 12%. 
The study makes sense from basic principles, and brings up three major concerns about the impacts of a future world with more lightning:

1) More lightning-caused fires
2) More lightning-caused ozone pollution and thus global warming
3) More lightning direct strike deaths and damages

Over 50 Inches of Snow Blankets Wisconsin Town; Possible State Record

http://www.wunderground.com/news/four-feet-snow-buries-wisconsin-town-20141114

A northern Wisconsin town picked up over 50 inches of snow since Monday, and that may have set a state snowstorm record.

A weather observer in Gile, Wisconsin, technically part of the town of Montreal, measured 50.1 inches of snow from the morning of November 10 through early morning on November 14. 

Yes, you read that right: over four feet of snow in just four days' time in this area about 100 miles east of Superior, Wisconsin, or just southwest of Ironwood, Michigan.

Photos tweeted to meteorologist Jim Cantore by Jason Juno (shown above) showed giant snowpiles, some of which appeared to be over six feet high, in the town Thursday night.

The massive snow accumulation was due to a combination of widespread snowfall from Winter Storm Astro earlier in the week, followed by several days of lake-effect snow as cold air poured over the relatively warm and still unfrozen waters of Lake Superior. 

Significant Lake-Effect Snow Expected This Week

http://www.wunderground.com/news/lake-effect-snow-significant-lake-erie-lake-ontario-20141115

Another arctic front will move across the Great Lakes next week bringing another surge of very cold air. This cold arctic air will pass over the warm waters of the Great Lakes, possibly resulting in significant snowfall over a few days next week.

The large temperature difference between the very cold air and the warm lakes may create enough instability that lightning and thunder may even accompany the snow at times.

Lake Superior and Lake Michigan will first see the lake-effect snow Sunday into Monday. Snow is expected to fall south of Lake Superior and east of Lake Michigan with several inches of snow piling up.

Then more significant snow will develop off of Lake Erie and Lake Ontario Monday night into Wednesday. Another disturbance will move through on Wednesday, with additional lake-effect snow developing behind the system.

Record-Breaking November Arctic Cold: How Long Will It Last?

http://www.wunderground.com/news/arctic-cold-outbreak-november-locked-20141110

A second push of bitterly cold air will blast its way south and east over the next couple of days, bringing an extremely cold start to the workweek for millions of Americans who have already endured nearly a week of January-like chill.

Here are some cold notables so far:

- Burlington, Colorado, on the eastern Plains near the Kansas border, dipped to -10 Thursday, setting a new record low for the month of November.

- Casper, Wyoming, dipped to -27 at 11:59 p.m. Wednesday night, shattering their all-time November record low of -21 on Nov. 23, 1985 (records date to 1939). The temperature stayed at -27 at midnight Thursday, making it the new record low for Nov. 13 as well. Previously, the soonest Casper plunged to -27 was on Dec. 5, 1972. Casper's high of 6 on Nov. 11 was the record earliest single-digit or colder high temperature there. (On Nov. 15, 1955, the high was only -3 degrees). Wednesday, Casper only managed a high of 3 degrees!

 Denver's high of 6 on Nov. 12 was the coldest daily high so early in the season. Only three other November days had daily high temperatures colder in Denver, dating to 1872. Early Thursday morning, Denver chalked up a bone-chilling -14 degrees, easily the coldest temperature so early in the season. (Nov. 17, 1880 was the previous earliest such cold reading in Denver.)

- Livingston, Montana, dipped to minus 21 Wednesday, their coldest so early in the season. That said, they once dipped to minus 31 degrees just one day later in the calendar, on November 13, 1959.

Winter Storm Bozeman Forecast Update: Snow Spreads From Rockies to Midwest, South and Northeast

http://www.wunderground.com/news/winter-storm-bozeman-forecast-oregon-idaho-washington-wyoming-colorado-20141113

Winter Storm Bozeman is moving eastward and will spread snow into the Plains, Midwest, South and Northeast in the days ahead. The storm has already delivered a swath of snow from parts of Oregon and Washington to parts of Idaho, northern Nevada, Utah, Wyoming and Colorado. 

Over a foot of snow has fallen in the mountains of Idaho, western Montana, and Colorado. Some areas also saw ice accumulation from freezing rain, especially in the Pacific Northwest (see below for a recap of the western portion of this winter storm event).

Winter storm warnings and winter weather advisories have been extended into parts of the Plains, the Upper Midwest, and the Ohio Valley.

U.S. Severe Weather Forecast (Convective Outlook)

http://www.wunderground.com/severeconvective.asp

A split-flow upper-air pattern will prevail over the Continental U.S. Through
the day one period. The polar branch of westerlies will remain most
progressive...featuring a short-wave trough translating through the
Great Lakes. Meanwhile...a southern-branch trough from the Central
High plains to northwestern Mexico will become increasingly sheared with a
closed circulation eventually forming along its southern extent.


At the surface...a cold front associated with the polar-branch
trough will advance eastward through the remainder of the Great Lakes
with the southwestern extension of the front moving more southeastward toward the Texas
coast.


..S-central u...


Showers and a few thunderstorms will remain possible today within the
expansive precipitation shield trailing the surface cold front. 12z
observed soundings within the warm sector revealed poor lapse rates
which will limit instability despite the presence of a relatively
moist boundary layer /I.E. Lowest 100-mb mean mixing ratios of
12-13+ g per kg/. As such...no severe weather is expected.

Long Range Outlooks

http://epawaweather.com/long-range-outlooks/


The signs for a warm November were looking promising as we were approaching the final week of October, but a lot of changes have occurred over the past week that has led to many rethinking the November forecast. The computer model and ensemble agreement is strong on a few displacements of very cold air making it down into the United States. Our region will likely not be in the core of this cold but certainly below average for November standards. The main players involved in this rapid change in the forecast are:
1) Super Typhoon Nuri – A Category 5!!!!
2) Rapid build up of snow cover in Siberia
3) El Nino flexing some muscle before winter

Severe Weather Forecast: Thunder Threat, Local Flooding Possible In the Southern Plains

http://www.weather.com/news/tornado-central/severe-weather-tracker-page#rww

Red areas (if any) on the map above indicate areas with the best chance of severe thunderstorms - thunderstorms producing wind gusts of at least 58 mph, hail at least 1 inch in diameter, or a tornado.

Orange areas could see thunderstorms but have a minimal threat of severe weather.
Thunderstorms will flare up along an advancing cold front in parts of the southern Plains through Tuesday, but should primarily remain below severe criteria.

The cold front will temporarily slow down in the Plains and interact with moisture enhanced by . This will lead to a broad swath of two-inch-plus rainfall from central Texas into the Ozarks and Mid-South region through Wednesday morning. Flash flood watches have been issued for parts of southern Texas as isolated flash flooding is possible in areas of more persistent rain and isolated rainfall totals of up to seven inches is possible.

Record Warmth in Western Europe/Record Cold and Snow in Eastern U.S.

http://www.wunderground.com/blog/weatherhistorian/comment.html?entrynum=313#commenttop

The first weekend of November has brought an interesting contrast of weather regimes between the Eastern U.S. and Western Europe. All-time November warmth enveloped portions of Western Europe while the Eastern U.S. endured an early season snowstorm and some daily record low temperatures (in the Southeast).
An anomalously strong upper-level high-pressure dome has brought record warm temperatures to parts of Western Europe the past few days. In the U.K. on October 31st, Gravesend, Kent (just east of London) saw its temperature peak at 23.7°C (74.7°F), the warmest temperature ever observed so late in the year for the nation.

In sharp contrast to Europe, the Eastern U.S. has seen an early-season cold wave and snowfall. In the Southeast 22” of snow accumulated near the summit of Mt. LeConte in Tennessee.
Newfound Gap, in North Carolina also received 22” of snow and amounts over 6” were common above the 2,000-3,000’ level. Snowfall in the Appalachians is not rare for this time of the year but what was unusual were the low-elevation reports of snowfall.

Typhoon Nuri Poised to Become an Alaskan Super Storm; Vance Drenching Mexico

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2851

Typhoon Nuri lost its "Super" designation Monday night, after the top winds fell below 150 mph, but remains poised to transition this weekend to one of the strongest extratropical storms ever to affect Alaska. Nuri intensified from a Category 1 storm with 85 mph winds to a very high-end Category 5 with 180 mph winds on Sunday, tying Super Typhoon Vongfong for strongest tropical cyclone of 2014.

However, once Nuri loses its tropical characteristics and moves into the Bering Sea to the west of Alaska on Friday, a very powerful jet stream will interact with ex-Nuri and cause it to rapidly intensify into one of the strongest low pressure systems ever observed in the Pacific Ocean.

Chicago area on northern edge of projected severe weather risk Monday

The National Storm Prediction Center has outlooked for a slight risk of severe storms (yellow-shaded area on map above) this coming Monday a broad area of the U.S. from the gulf coast states north into a good portion of Illinois and Indiana. As an intensifying low pressure system develops over the Texas Panhandle and moves northeast, strong southerly flow will feed abundant moisture from the Gulf of Mexico into the system.

A strengthening south-north jet stream aloft will provide additional instability and create conditions conducive to strong, possibly severe storms as far north as southern and central Illinois and Indiana. Chicago currently rests on the northern edge of the slight risk outlook area, but this is early in the process and the severe storm area could easily shift farther north or be depressed south, depending upon the actual movement and intensification of the low pressure center.

http://chicagoweathercenter.com/blog/chicago-area-on-northern-edge-of-projected-severe-weather-risk-monday

Flash Flood Threat Targets Plains, Ozarks, Mississippi Valley, Ohio Valley Into Next Week

NO PICTURE AVAILABLE
http://www.wunderground.com/news/flood-threat-plains-mississippi-valley-ohio-valley-ozarks-20141008

Flash flooding has returned to center stage in parts of the nation this week. 

Wednesday, cars were stranded by floodwaters flowing through the Arcadia Wash in Tucson, Arizona. Thursday, Colorado Springs set its record wettest October day, picking up 2.83 inches of rain, almost doubling the previous record (1.63 inches). Almost 6 inches of rain overnight Thursday night into Friday morning triggered street flooding in Chautauqua, Kansas.

First up, a frontal boundary has stalled in east-west fashion from the Ozarks to the Appalachians. Moisture from the Gulf of Mexico flowing into the boundary, along with lift from the jet stream flowing parallel to the quasi-stationary front, will help ignite clusters of thunderstorms with heavy rain near the front through early Sunday.

A deep southward dip in the jet stream, or trough, will dive into the Rockies later Sunday, then swing east though mid-week. 

Tapping deep moisture ahead of its attendant cold front, bands of thunderstorms with locally heavy rainfall will lead the front's advance from the southern Plains, Ozarks and Mississippi Valley late Sunday and Monday to the East Coast by Wednesday.

Cyclone Hudhud Lashes Odisha and Andhra Pradesh, India; Tens of Thousands Evacuated, One Death Reported

NO PICTURE AVAILABLE

http://www.wunderground.com/news/cyclone-hudhud-odisha-andhra-pradesh-india-20141011

A year after Cyclone Phailin made landfall in India’s Odisha state and took 44 lives, millions in the area are bracing for the impact of another massive threat.​ Tropical Cyclone Hudhud picked up strength as the storm churned over the Bay of Bengal on Saturday and could make landfall as the equivalent of a powerful Category 4 hurricane on Sunday local time, according to weather.com meteorologists. 

The storm has already killed at least one person: On Saturday, a nine-year-old girl was killed and an 11-year-old boy was reported missing after a boat evacuating people from a seaside village capsized, the Times of India reports. The boat was carrying 25 people from the Magarakanda village, mostly women and children. 

As Hudhud continues its west-northwest course, the Indian Meteorological Department has issued a cyclone alert for the coastal states of Odisha and Andhra Pradesh, both on the eastern coast of India. The storm was expected to make landfall near Visakhapatnam around noon local time on Sunday. The Indian Meteorological Department has classified the storm as 'very severe,' according to the BBC. The Indian Meteorological Department was predicting a five-to-ten-foot storm surge in low-lying areas in Andhra Pradesh, according to the latest reports. 

Severe Storms to Ignite From Texas to Minnesota Tuesday

http://www.accuweather.com/en/weather-news/severe-storms-to-shift-east-tu-1/34889183

The same system that brought severe weather to the Front Range of the Rocky Mountains on Monday will deliver another round of severe storms to the Plains on Tuesday.

Thunderstorms are set to erupt from eastern South Dakota to the Texas Panhandle on Tuesday afternoon before weakening and tracking eastward during the overnight hours.

Wind gusts exceeding 60 mph and hail as large as golf balls should be expected with thunderstorms that develop across this large swath of the Plains.

A few of the more intense storms in the northern extent of this area may spin up a few tornadoes late in the afternoon with the tornado threat diminishing during the evening.

There is a risk of a thunderstorm reaching Kansas City, Missouri, before the end of Tuesday evening, where the first wild card game of the 2014 MLB post season will take place

Pneumonia front sends temps 21-degrees lower in 2 hours Monday PM; ends warmest spell here in almost 3 weeks.

http://chicagoweathercenter.com/blog/pneumonia-front-sends-temps-21-degrees-lower-in-2-hours-monday-pm-ends-warmest-spell-here-in-almost-3-weeks

Chicagoans head out into a very different air mass Tuesday than the one responsible for Monday’s July-level 83-degree high–a reading 14-degrees above normal and the warmest daytime temperature to occur here in 19 days–nearly 3 weeks!  The passage of Monday’s “pneumonia front” at 5:48 pm set in motion a 21-degree temp plunge in only 2 hours time that followed. The dramatic cool-down which brought 7-consecutive days of above normal temps–including Saturday and Sunday highs of 79 and 78—to an unceremonious end.