Snow in the East, Another Stormy Period for the West

Surface map for 7:00 a.m. EST November 28.

It has been a cold but dry week across the middle of the U.S., while two storm systems book-ended the lower 48 states. On Tuesday a low pressure system with a trailing cold front brought precipitation to an area from Mississippi up through southern new England. Rainfall amounts were around an inch along the Gulf Coast, but less than half that up through the southeast U.S. The other area of significant precipitation was the mid-Atlantic coast, particularly New Jersey.  Two to four inches of snow covered the ground in the northwestern half of New Jersey and parts of southeastern Pennsylvania this morning.  Lighter snow amounts were reported north through New York and new England.

CoCoRaHS precipitation map for November 28.

Another stormy period is ahead for the Pacific Northeast this rest of this week. CoCoRaHS observers will get another good workout for their rain gauges, with perhaps as much as 6 to 12 inches of rain expected in the next several days, especially in northern California and Oregon. Heavy snow is expected for the next several days in the higher elevations of the Shasta, central and northern Sierra Nevada, and Sawtooth mountain ranges.

Left:  5-day Quantitative Precipitation Forecast.  Right: Probability of >8 inches of snow in 48 hours
Forecasts issued by the NWS Meteorological Prediction Center.

In the meantime, there will be significant warming across the central and eastern U.S. through the weekend. The snow currently on the ground in New Jersey will just be a memory by the weekend.

However, this could be the last period of mild weather for awhile for the eastern two thirds of the U.S. It appears that cold air will likely spread over the U.S. east of the Rockies by the middle of next week, and may be followed by several reinforcing pushes of cold air in the days to follow.

Storms Slam into Pacific Northwest

While most of the country has enjoyed tranquil weather for the last week or so (evidenced by the many gray dots on the CoCoRaHS national map), the Pacific Northwest has been pounded by a series of storms that have brought hurricane-force winds, torrential rain, and heavy snow. Flooding closed roads, winds toppled trees which in turn brought down high voltage power lines, heavy rain caused mudslides, and the avalanche danger was high from the heavy snow.

The first of these storms moved ashore from the Pacific on Saturday, followed by another on Monday.

Surface map for Saturday, November 17 (L) and for Monday, November 19 (R).

 The 7-day precipitation accumulation map shows accumulations ranging from five to more then ten inches all along the Oregon and Washington coasts.  Most of that precipitation came with Monday's storm, which has been the most intense one so far.

7-day precipitation accumulations through 5:00 a.m. PST November 20

CoCoRaHS observers in Oregon reported more than nine inches of rain.

CoCoRaHS map for Curry County in southwestern Oregon for November 20.

A number of observers in Oregon noted that today's rainfall was the highest 24-hour amount they have ever recorded. The general nature of the rain and flooding apparent from this comment from the CoCoRaHS observer at Oakridge 4.6 NE in Lane County who measured 4.03 inches of rain:

Nope that's not a typo, we did get over 4" and almost all of that came after 5 PM. It rained off an on during the day but never heavily, less than a 1/2" before 5, and then it started really raining. We don't get flooding up here to speak of. Compared to other areas what we have right now is minor, but it is significant for us. I marked the flooding as minor because on an absolute scale that's what it is, but it is not typical for us. Last time I saw this sort of general standing water on our property was the heavy rains the winter of 05-06. We have had heavier flooding in the area, but from creeks overflowing, not just general standing water. The creeks are high right now, but not overflowing. 

Washington also received heavy rain, and there were a number of new daily rainfall records, including daily rainfall records at the Seattle-Tacoma International Airport (2.13", old record 1.23" in 1962) and at the National Weather Service Office 2.60". old record 1.16" in 2003).

CoCoRaHS map for King County, WA for November 20.

There were many wind gusts in excess of 70 mph reported yesterday with this storm. Here are a few of those gusts.

114 mph      Naselle Ridge in the mountains of southwest Washington
106 mph      Mt. Hebo nearTillamook, Oregon
101 mph      Astoria bridge, Washington
101 mph      Megler, Washington 
  98 mph      Yaquina Head, Oregon
  92 mph      Astoria, OR
  90 mph      Garibaldi, Oregon
 

It appears the stormy weather will continue through the end of the week. A third storm will hit the Pacific Northwest Wednesday, and yet a fourth storm is forecast to arrive on Friday. Additional rainfall of one to three inches is expected from Washington south through northern California and a foot or more of new snow in the high Cascades and the northern Rockies by Wednesday night.

Forecast surface map for the morning of Wednesday, November 21

November Snow

Winter weather has come early to the lower 48 states this year.  First there was the heavy snow in the Appalachians associated with Sandy, and then heavy snow in New Jersey and southern New England with the nor'easter the following week. While attention has been focused on the east, snow has been falling with some regularity in the western U.S. In fact, snow cover across the northwestern quarter of the lower 48 states is above normal for this time of year.

There are a number of online resources for following snowfall across the U.S., and in fact across the northern hemisphere.  The National Operational Hydrologic Remote Sensing Center website has an entire suite of products dedicated to monitoring snowfall, snow depth, and related measurements across the U.S.  Here is the depiction of snow depth across the U.S. as of this morning. This map is based on modeled snow pack characteristics updated each day using all available ground, airborne and satellite observations.  Note that the model analysis can be off in places. For example, the snow depicted in central and northwestern Illinois is overdone, and may be just a trace in a few spots.

 The NOAA U.S. National Ice Center also monitors ice and snow cover across North America and the Northern Hemisphere. This analysis shows only where snow is on the ground, and does not show snow depth.

For a view of the Northern Hemisphere in somewhat more detail, the Rutgers University Global Snow Lab provides a suite of charts and graphs that monitors snow cover. A nice feature of the Global Snow Lab are the snow climatology maps and the departure maps, which show where snow cover is above or below normal as of a certain date. Note that like the National Ice Center maps, these maps depict the extent of snow cover and do not provide any information on snow depth.

Maps from the Rutgers University Global Snow Lab for November 13, 2012

Of course, last but not least are CoCoRaHS maps. The national map from Tuesday morning clearly shows snow on the ground in the west as well as the upper Midwest and northeast..

 The greatest snow depths on the CoCoRaHS maps were found just east of Salt Lake City, where 7 to 13 inches of snow covered the ground as of Tuesday morning.

Snowfall and snow depth measurements from CoCoRaHS observers are needed and used by variety of people monitoring snow across the country from the National Weather Service to municipalities to snow removal services. Now is the time to review and refresh yourself on snow measurement procedures. The snow measurement training program is available on the CoCoRaHS web site, and the Snow Measurement webinar video is available on YouTube.

"When the gales of November came slashin'... "

Today is the 37th anniversary of the sinking of the Great Lakes freighter the Edmund Fitzgerald. The first time I really became aware of this incident was when I first heard Gordon Lightfoot's haunting ballad "The Wreck of the Edmund Fitzgerald".  The Great Lakes have a long history of intense fall and winter storms and the wrecks of hundreds of ships litter the lake bottoms.  The weather during the fall can quickly go from good to very bad, and such was the case in November of 1975.

Surface map on November 6, 1975

The week of November 3 was unseasonably warm week across the eastern two-thirds of the country. A surface ridge of high pressure stretched from the southern tip of Texas to Quebec, Canada keeping the eastern two-thirds in southerly flow.  In the days leading up to November 10, 1975 temperatures reached the middle 60s as far north as the Minnesota-Canadian border.

In Superior, Wisconsin the Edmund Fitzgerald was loaded with more than 26,000 tons of taconite pellets destined for a steel mill near Detroit. The weather while the Fitzgerald was in Superior was, well, superior. Temperatures early in the week reached 74°F, and when the Fitzgerald left port at 4:30 p.m. on November 9 the temperature was in the 50s°F and skies were cloudy.  She soon joined up with the Arthur M. Anderson, another freighter which left Two Harbors, Minnesota bound for Gary, Indiana.

Surface map for the morning of November 9, 1975

At 7:00 p.m. the National Weather Service issued gale warnings for Lake Superior, forecasting E to NE winds during the night, shifting to NW to N by the afternoon of November 10.  At approximately 10:40 p.m. the NWS revised its forecast for eastern Lake Superior to easterly winds becoming southeasterly the morning of the 10th. At about 2:00 am November 10 the NWS upgraded the gale warning to a storm warning with a prediction of "northeast winds 35 to 50 knots becoming northwesterly 28 to 38 knots on Monday, waves 8 to 15 feet".  The captains of the two freighters decided to take a route closer to the Canadian shore which would protect them from the northeast winds.

The surface weather map for the morning of
November 10, 1975, about 12 hours before
the Edmund Fitzgerald sank.

The center of the storm passed over Lake Superior on the morning of November 10. As the center of the low passed over the ships the Anderson reported winds dropped for a time to 5 mph. As the low moved to the northeast, the winds shifted into the south, then west and northwest and rapidly increased speed. Visibility dropped as snow began falling in the cold air plunging south behind the storm. The observed winds by the Anderson and by the Stannard Rock Weather Station during the afternoon of November 10 were from 40 to 58 knots from the west-northwest, gusting to 65 knots. The Anderson also observed wave heights of 18 to 25 feet during the afternoon of November 10 and later reported wind gusts from 70 to 75 knots.

The northwest winds were the worst possible situation for the Fitzgerald. The winds had a large fetch over open water allowing large waves to build. The Fitzgerald by this time was sailing southeast toward Whitefish Bay and passed over dangerous shallow water near Six Fathom Island.

At 3:30 p.m. on November 10 the captain of the Fitzgerald radioed the Anderson and reported that the ship was taking on water and listing. The Fitzgerald had also lost its radar, and was now relying on the Anderson to be its "eyes" in the storm. The first mate of the Anderson contacted the Fitzgerald at 7:10 p.m. and Caption McSorley of the Fitzgerald, when asked how they were doing, said "We are holding our own."  At 7:15 p.m. the Edmund Fitzgerald disappeared from the radar. 

On November 14 a Navy aircraft detected a large magnetic anomaly about 17 miles from Whitefish Point. A Coast Guard cutter located two large pieces of wreckage three days later using side scan sonar. In May 1976 a Navy controlled underwater recovery vehicle confirmed the wreckage was that of the Edmund Fitzgerald.

There are a number of theories on how the Fitzgerald sank. The initial theory was that the ship took on water through poorly sealed hatches, lost buoyancy, and sank when hit by huge waves. Another theory is that the ship may have been damaged in shallow water when it passed near Six Fathom Shoal. The debate continues to this day.

If you would like to read more about the Edmund Fitzgerald, check the following sources.

The Fateful Journey (The Great Lakes Shipwreck Museum)

NTSB Marine Accident Report: SS EDMUND FITZGERALD Sinking in Lake Superior  

A Winter Question for You

We are a little more than a week into November and there have already been many signs of winter in the U.S.  Although the winter solstice is still six weeks away (December 21st at 5:12 a.m. CST), meteorologists and many of us have our own "definition" of when winter starts. It's something I've personally been interested in for some time, and now I am working on a project that requires us to "define" winter. Your answers might help us shape some of this research

This question is open to all - those in warmer climates where winter is the season that isn't spring and summer, and those colder climates where winters can be brutal at times.

So, what defines the start of winter for you?

Post your responses here (preferred), or you can email me at hberg74@gmail.com.It would be very helpful if you would tell us what state you are from.  After a period of time I will compile the results and present them in a future blog post along with a scientific perspective on the seasons.  I think the results will be very interesting.

I look forward to hearing from you!

The Numbers on Sandy

From a meteorological standpoint Sandy was an impressive and historic storm.  Here are some of the more interesting statistics for this historic storm.

Near-record central pressure of 940 millibars (27.76 inches) when the center of the storm was about 35 miles off the New Jersey coast. This was the lowest pressure of any storm that has made landfall north of Cape Hatteras, NC. Hurricane Gladys in 1977 holds the record the for lowest pressure of 938 millibars (27.73 inches), a category 4 hurricane which never made landfall in the U.S.  At landfall Sandy's central pressure was 946 millibars. A number of locations set reord lower pressure readings. Atlantic City, NJ dropped to 948.3 millibars, breaking the old record of 961 millibars on March 6, 1932.

Winds gusted to in excess of 50 mph from Maine south through Virginia, but the strongest winds occurred from Washington DC north through New York City. Here are some of the locations that recorded hurricane force winds:

96 mph  Eaton’s Park,NY
90 mph  Islip, NY
90 mph  Chesapeake Bay Bridge, MD
89 mph  Surf City, NJ
88 mph  Montclair, NJ
88 mph  Tuckerton, NJ
87 mph  Newport, NJ
86 mph  Westerly, RI
85 mph  Madison, CT
83 mph  Cuttyhunk, MA
81 mph  Allentown, PA
79 mph  JFK International Airport, NY
79 mph  Thomas Point, MD
79 mph  Chester Gap, VA
76 mph  Laytonsville, MD
78 mph  Newark Int’l Airport, NJ
74 mph  LaGuardia Airport, NY

STORM SURGE
The combination of the hurricane-force onshore winds, the timing of high tide near Sandy's landfall, a full moon, and coastal topography resulted in destructive storm surge from Virginia to Rhode Island. The storm surge along the Virginia coast was 4 to 6 feet. Of course, as we know the worst surge was near and just north of Sandy's center in New Jersey and New York.

 Here are the most impressive and significant storm surges, measured as feet above normal average low tide:

• 14.38 ft at Kings Point, NY
• 13.88 ft at The Battery, Lower Manhattan. This broke the old record of 10.02 feet reached during Hurricane Donna in 1960.
• 13.31 ft at Sandy Hook, NJ

RAINFALL from 10/28 to 11/1

There were more than 320  daily precipitation records set October 29-31 as a result of Sandy. You can find record values at the National Climatic Data Center web site U.S. Records page.

New Jersey
An impressive 237 New Jersey CoCoRaHS observers reported rainfall during this five-day period. The highest amount report was 12.71 inches at Stone Harbor 1.6 NNW in Cape May County, with 9.73 inches of that total on October 30. Other CoCoRaHS observers in Cape May County had 11.91 inches (Wildwood Crest 0.6 NNE); 11.70 inches (Wildwood Crest 0.1 WSW); and 11.41 inches (Middle Twp 4.4 SW). Other totals from Cape May County were generally greater than 7 inches.

Virginia
CoCoRaHS observers reported period totals ranging from five to ten inches in eastern Virginia. The highest amount reported was 9.83 inches at Cashville .01 S in Accomack County, VA. This total is likely higher, as there were no reports after the morning of October 30.  The heaviest amounts in Virginia were in a corridor from Newport News and Virginia Beach northward and generally ranged from six to nine inches.

Maryland
Amounts reported by CoCoRaHS observers in Maryland ranged from five to almost 11 inches. Here are the amounts greater than ten inches:

10.85     Easton 2.4 SE     Talbot County
10.70     Greensboro 1.4 ENE   Caroline County
10.68     Ridgely 0.2 ESE    Caroline County
10.29     Queenstown 2.6 S    Queen Anne's County
10.22     Easton 1.2 SSW    Talbot County

District of Columbia
The CoCoRaHS observer at Washington 5.1 NW (DC) reported 6.03 inches of rain.

Delaware
Rainfall in Delaware ranged from five to ten inches. The highest CoCoRaHS amount reported there was 9.88 inches at Dover 6.4 WNW (Kent County). There were a number of stations reporting over seven and eight inches.

Pennsylvania
Eastern Pennsylvania also received heavy rain from this system with amounts ranging from three to eight inches. The observer at French Creek 3.4 SE (Chester County) measured 8.19 inches of rain during the period, and the observer at Schellsburg 2.6 WNW (Bedford County) reported 7.94 inches.
The heaviest precipitation amounts in West Virginia were in the higher elevations that also received snow and ranged from four to more than six inches. The highest precipitation amount for the period was 6.84 inches, along with 9.0 inches of snow at     French Creek 3.4 SE in Upshur County.

New York, Connecticut, and north
One to four inches of rain were reported in New York, two inches in Connecticut, one to three inches in Rhode Island, one half to 4.5 inches in Massachusetts, one half to 2.5 inches in Vermont, generally one to five inches in New Hampshire, but with 8.45 inches at Gorham 3.1 S and 6.23 inches at Randolph 1.4 NE, both in Coos County. One half to 3.5 inches of rain fell across Maine.

Ohio
The rain from Sandy extended as far west as Ohio and Indiana. Four to more than seven inches of rain fell in eastern Ohio, with the heaviest and lake-enhanced amounts in Lake, Cuyahoga, and  Lorain Counties which border the southern shore of Lake Erie. More than six inches of rain were measured in these counties, with 7.68 inches at Painesville 3.8 SSW in Lake County and 7.54 inches by the observer at Mayfield 0.2 NW in Cuyahoga County.

SNOW

72-hour snowfall ending October 31, 2012

Snow fell in southwestern Pennsylvania, much of West Virginia, western Maryland, western and southwest Virginia, southeastern Ohio, western North Caorina, and eastern Tennessee.  The heavy, wet snow brought down trees and power lines. Some of the highest snowfall totals were:

Richwood, WV  36"
Mount LeConte, TN:  34"
Snowshoe, WV  32"
Quinwood, WV 29"
Frostburg, MD 28"

Of course, the book hasn't closed on Sandy. At its peak 8.5 million customers in the eastern U.S. were without power. As of tonight  there are still 1 million without power, and the impending storm tomorrow will likely slow the restoration of power and may cause additional outages.

Sadly, Sandy has been responsible for 170 deaths with 111 of those in the U.S., 2 in Canada, and 57 Carribean.

A Tip of the Hat to the NWS

One aspect of "superstorm" Sandy that is receiving little attention is the role of the National Hurricane Center and the National Weather Services offices throughout the east. The accurate forecast of the storm track and the days of warning about the expected impact of this storm without question saved many lives. In the coverage of the aftermath - the astounding damage, the rescues, and the heroic stories, it's easy to lose sight of the fact that without the skill and dedication of these forecasters, the human toll could have been much, much worse. No one can say "We didn't know this was going to happen."

Improvements in computer models were intrumental in the accurate forecast of Sandy's track and intensity. However, models are far from perfect and it takes the knowledge and skill of a human forecaster to interpret the computer forecasts and make the final forecast and issue the appropriate warnings. Those models also require accurate data to initialize correctly. NWS offices across the U.S. launched two extra upper-air soundings each day for three days prior to Sandy's arrival to provide more up to date and accurate data for the models. Normally there are two soundings per day.

This graphic was prepared by the Huntsville, AL NWS office and shows
the forecast tracks for Sandy three and five days prior to landfall

Forecasters and staff in the individual National Weather Service offices from the Carolinas through Maine worked continuously to update the warnings and advisories that kept emergency officials and the public informed about the storm and its impacts. In the hardest hit areas staff worked while their families were home dealing with the storm. This is the case when severe weather is occurring anywhere, be it a hurricane slamming into New York or massive tornadoes swarming through the southeastern U.S. The NWS facilities aren't immune to the wrath of these storms, either.  At this time a cut fiber optic cable and other communications issues are affecting the web sites in the Eastern Region and they are operating in backup mode. The Eastern Region Headquarters is in Upton, NY.

A press release from the World Meteorological Organization also gave a thumb's up to the National Weather Service.

"WMO’s Director of Weather and Disaster Risk Reduction Services, Geoff Love, said there is virtually no difference between the analysis of likely events and the forecast.  He said the 48-hour forecast was spot-on.

“The environmental conditions were perfect. The forecasts were very, very, very good and, of course, we have seen on the media the U.S. emergency authorities all responded exceedingly well," said Love. "So, from the WMO perspective, it is a disaster. But, boy, all our systems worked really well - the U.S. forecast, the U.S. Emergency Management systems. And, it will be seen as, probably, a text-book case in how well you can do.”

So, a tip of the hat and pat on the back for a job well done to the men and women who monitor and forecast our weather for the purpose of protecting lives and property.

Sandy's Continental Connection

This graphic from the NWS Alaska Region web site shows how cold Arctic air is affecting the development of the massive east coast storm. This cold air is being drawn into the storm circulation's southwestern quadrant, helping to maintain the storm intensity over land now that it is not tropical in nature. One of the mechanisms that drives cyclone development is large temperature differences. That is why we often have strong mid-latitude storms in the spring and fall - the transition periods between summer and winter when temperature contrasts can be large. The cold air drawn in to the west side of the current storm is producing the winter storm conditions over West Virginia, Virginia, and western North Carolina.  CoCoRaHS observers in those areas were already reporting snow starting to fall this morning. Here is a map of the latest watches and warnings from the Charleston, WV National Weather Service office. Two feet of wet snow is expected at the highest ridge tops in the central Appalachians.

As of 7:00 p.m. EDT the eye of now post-tropical storm Sandy was about 20 miles off the southern New Jersey coast. The storm had weakened slightly from earlier today, but still packs a knockout punch.

Radar mosaic for the northeastern U.S. at 6:58 p.m. EDT

The Start of a Long Week in the Eastern U.S.

Even though Sandy still remains almost 300 miles east of Cape Hatteras, NC as of 11:00 p.m. EDT, her effects are being felt up and down the eastern seaboard.

Position of Hurricane Sandy and forecast track as of 11:00 p.m. EDT October 28

The footprint of this storm is huge, and extends from the Outer Banks all the way to Bermuda. The orange area in the map below is the area being affected by tropical storm force winds (>=39 mph).

Rain bands associated with Hurricane Sandy are already soaking the mid-Atlantic coast from New Jersey south to the Outer Banks of North Carolina and east into Virginia.

Radar image from the Dover AFB radar at 11:12 p.m. EDT October 28, 2012

Strong winds are being recorded as far north as Nantucket, MA, where northeast winds are sustained at 20 mph and gusting to 35 mph at 11:00 p.m. EDT. At Norfolk, VA winds are north at 24 mph gusting to 39 mph. The weather will continue to go downhill tonight from Virginia to southern New England.

Warnings, watches, and advisories of just about every variety cover the eastern third of the country because of Sandy and the eventual "morphed" monster it will become in the next 24 hours. High wind watches are in affect for areas as far west as Lake Michigan. Winter storm watches are in effect for the high elevations of southeastern West Virginia, southwestern Virgina, and western North Carolina, where 4 to 8 inches of snow may accumulate. High wind warnings are in effect or will be in effect for coastal areas from Virginia to Maine, with winds expected to gust to 50 to 60 mph over a period of 18 to 36 hours.

The NWS watch/warning map as of 11:39 p.m. EDT October 28.

This storm is going to affect a large number of our CoCoRaHS observers. We of course will appreciate any reports you can provide during the week. However, your safety and the safety of your families comes first, so do not take any unnecessary risks to make an observation. With power likely to be out for a large area of the east for anywhere from a day to perhaps more than a week, many of you will not be able to send in any observations you may be able to make. Your fellow CoCoRaHS observers across the country are hoping that all of you affected by the storm come through this safely and with minimal damage.

East Coast Bracing for a Big Storm

It appears the ingredients for a major East Coast storm will be coming together early next week. Hurricane Sandy has been in the news the past few days, and it is affecting the Bahamas tonight after leaving 11 dead in Cuba. In addition to Sandy, as if that weren't bad enough, forecasters are closely following the development of a strong low pressure trough aloft that could interact with Sandy early next week, and not in a good way. Forecasters saw this possibility as early as Sunday and it's been something forecasters across the county have been watching closely.  This potential storm was the highlight of a forecast discussion from the National Hydrologic Prediction Center earlier today. I'm not sure if this is where the name "Frankenstorm" first appeared, but the name has now taken on a life of it's own in the media.

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
313 PM EDT THU OCT 25 2012
VALID 12Z SUN OCT 28 2012 - 12Z THU NOV 01 2012

...HIGH IMPACT MERGING OF ENERGETIC SYSTEMS ANTICIPATED OFF THE
MID ATLANTIC COAST...

PRELIMINARY UPDATE...

DESPITE A MODEST CLUSTER OF OUTLYING DETERMINISTIC SOLUTIONS AND ENSEMBLE MEMBERS FROM THE VARIOUS MODELING CENTERS, THE LION'S SHARE OF GUIDANCE INDICATES THAT THE CIRCULATION ASSOCIATED WITH HURRICANE SANDY WILL PASS CLOSE ENOUGH TO THE AMPLIFYING POLAR TROUGH OVER THE EASTERN UNITED STATES TO BECOME INCORPORATED INTO A HYBRID VORTEX OVER THE MID ATLANTIC AND NORTHEAST NEXT TUESDAY. THE HIGH DEGREE OF BLOCKING FROM EASTERN NORTH AMERICA ACROSS THE ENTIRE ATLANTIC BASIN IS EXPECTED TO ALLOW THIS UNUSUAL MERGER TO TAKE PLACE, AND ONCE THE COMBINED GYRE MATERIALIZES, IT SHOULD SETTLE BACK TOWARD THE INTERIOR NORTHEAST THROUGH HALLOWEEN, INVITING PERHAPS A GHOULISH NICKNAME FOR THE CYCLONE ALONG THE LINES OF "FRANKENSTORM", AN ALLUSION TO MARY SHELLEY'S GOTHIC CREATURE OF SYNTHESIZED ELEMENTS.

 "Blocking" refers to the effect of high pressure to the north of the two low pressure systems preventing them from moving toward the northeast in this case. Here is what the potential interaction looks like on the upper air forecast charts.

This is the forecast 500 millibar map for 2:00 p.m. EDT Monday, October 29, 2012.

There are several reasons East Coast residents should be taking notice. Hurricane Sandy will be drawing large amounts of moisture from the Atlantic inland, setting the stage for widespread flooding. The polar trough approaching from the west will be accompanied by cold air which help maintain some intensity of Sandy, even after she loses tropical characteristics.  In addition, the storm will be moving very slowly because of the blocking high to the northeast. The large difference in pressure between the blocking high and the cyclone will produce sustained high winds that will damage trees and power lines.That means East Coast residents will be dealing with this for not just hours, but days. As of 11:00 p.m. EDT on October 25th. the expected forecast track of Hurricane Sandy will bring her ashore somewhere in southern New Jersey Tuesday morning. 

For the latest updates on Hurricane Sandy see the National Hurricane Center website.  Be sure to check your local NWS office website for updated forecasts for your specific area.

Big Change Ahead

500 millibar map (about 20,000 ft) for 7:00 p.m. CDT October 18

This weekend will mark the start of a significant change in the weather pattern across the U.S
Right now the eastern half of the country is chilly as a large upper low spins over the area. Out west, it has been very warm recently under an upper level ridge. Temperatures, for example, in northern California have been in the upper 80s and low 90s. Yesterday new high temperature records were set in San Francisco and Oakland.




RECORDS SET...

 LOCATION                NEW RECORD   OLD RECORD AND YEAR
 --------------------------------------------------------
 SAN FRANCISCO AIRPORT     86           85         1988
 OAKLAND DOWNTOWN          87           84         1974
 OAKLAND AIRPORT           87           83         1974
 MOUNTAIN VIEW             89           87         1995

A number of daily temperature records have been set in southern California as well. On Wednesday El Cajon reached 102°F, breaking the old record of 96°F set in 1996.

As this weekend progresses, the pattern will shift as the upper low lifts out of the Midwest, and a strong trough develops off the west coast.

Forecast 500 millibar map for 7:00 a.m. CDT Sunday, October 21.

What's this mean? Well, the central and eastern U.S. will enjoy a period of mild fall weather. October so far has been cooler than normal from the Rockies eastward, and near to above normal west of the Rockies.

The west coast, from Washington south through northern California, will be in for a period of stormy, cool weather.

Do you have a question you would like answered or suggestions on topics you would like to see in future blog posts?  Feel free to email me your questions and suggestions at hberg74@gmail.com

A Stormy Season Down Under

Vehicles stranded on road west of Sydney, Australia

Both Australia and New Zealand are still dealing with winter weather well into their spring. This past weekend a strong spring storm brought heavy snow to parts of Australia and heavy rain and snow to New Zealand's South Island.  The heavy snow near Sydney stranded more than 300 motorists and knocked out power to 2500 homes.

Four inches of snow and almost six inches of rain in 24 hours in South Island stranded travelers and caused flooding.  The storm, which came in from the Tasman Sea, caused high winds and power outages in Auckland and triggered a massive landslide that sent huge boulders crashing down on roads.

Surface weather map for 5:00 p.m. Australian EDT October 12, 2012.

If you are interested in learning more about the weather down under, check out the following web sites:

Australian Meteorological Bureau

Meteorological Service of New Zealand

Fire and Ice

Last week a strong storm system dropped 12 inches of snow in northwestern Montana and 12 to 14 inches of snow in northwestern Minnesota. A number of daily snowfall records were set in both states.

Snow depth on the morning of October 6, 2012.
Map from the National Operational Hydrologic Remote Sensing Center

The snow in northwestern Minnesota was particularly beneficial. It fell on an area of the state where two large wildfires have been burning since early September. The snow helped knock down the fire on the surface, but the fires are now burning layers of peat underground.

While some good rain and snow events have chipped away at drought in the eastern half of the country, the western U.S. is still suffering from long-term dry conditions. Numerous wildfires are still active, especially in Washington, Oregon, Idaho, and Montana. The largest fire is the Mustang Complex in Idaho, consisting of six fires and encompassing more than 340,000 acres.

This shows the location of fires on October 9 using NOAA satellite data that detects fires and smoke.
Map based on data from the NOAA Satellite and Information Service.

This could be a record year for wildfires in the United States. The current record is 9.8 million acres burned in 2006.  As of October 4, the National Interagency Fire Center reports that more than 8.8 million acres have burned from more than 49,000 wildfires. Idaho has been the state hit the hardest in terms of acres burned with 1.73 million acres affected.

The spectacular fires early this season in Colorado made the national headlines largely because they affected heavily populated areas. However, the wildfire season continues.

This afternoon, a new fire ignited in Rocky Mountain National Park west of Estes Park, Colorado. AS of 5:30 p.m. MDT the fire was 300 acres and was rapidly spreading in steep terrain,

Winter Weather Hits Northern Rockies and Plains

Record snowfall occurred in Montana today, and snow will likely fall across the parts of the Dakotas and Minnesota through Thursday.

Snow accumulations in the Rocky Mountain front in northwestern Montana ranged from 11.0 inches in Teton County to 7.0 inches in Glacier County, and from 1.5 to 5.0 inches further south. Billings received 2.3 inches of snow, breaking the old record for October 3 of 1.3 inches in 1991.

Residents of northeastern North Dakota to northwestern Minnesota will wake up to heavy snow and strong winds causing blizzard conditions at times. Six to 12 inches of snow are expected  to accumulate by Thursday night.  Winter storm warnings are in effect, and further to the east Winter Weather Advisories are in effect for most of North Dakota.

This is the watch.warning map for 11:25 p.m. October 3. The pink shading indicates
Winter Storm Warnings, and the purple indicates Winter Weather Advisories.

Sunny and cool weather is expected over the weekend, so any accumulated snow will be melting throughout the week. Despite the inconvenience of the early winter weather, the precipitation is very welcome.  Precipitation has been less than 50 percent of normal in the Northern Plains since July 1.

The storm is a an early reminder to those CoCoRaHS observers in snow country that it's a good time to start reviewing snow measurement procedures in preparation for the coming winter.

A Chilling Mid September

Frost and freezing temperatures have made an early appearance in the central and northeastern U.S. this year.  Last week's strong cold front that swept through the central U.S. brought the first freezing temperatures to the Midwest as far south as southern Wisconsin  Another sprawling cold air mass spilled south across much of the country east of the Rockies this weekend ending the growing season for many locations as far south as northern Missouri Sunday morning. Last night frost warnings were in effect for eastern Wisconsin, all of Illinois, Indiana, and Michigan (except areas close to the Great Lakes), and parts of Ohio, Pennsylvania, New York, Maine, West Virginia, Virginia, and North Carolina.

The areas in blue indicate the frost advisories in effect for Sunday night, September 23rd.

Low temperatures this morning reached the low to mid 30s south to the Ohio River, and frost was noted on the grass and rooftops in many areas.  On nights with strong radiational cooling, the vertical temperature gradient can be rather steep. The temperature at grass level can be degrees lower than the temperature at five feet, the approximate height of temperature sensors. If the temperature at sensor level is 33°F, the temperature right at the ground can be below freezing.  Even on such days, there may not be much damage to plants.  Damage to plants depends not only on whether or not it is below freezing, but how long the temperature is below freezing.

Minimum temperatures for the morning of September 24.

The colored dots on the map indicate locations where 32°F has occurred this fall.

The first occurrence of 32°F is about on schedule for the upper Midwest and Northern Plains, and anywhere from a week to two weeks early in the central U.S.  The temperatures in the low and mid 20s are a few weeks early.  The maps below show the extend of freezing weather so far this fall n the central U.S., and the median dates for the first occurrence of 32°F and 28°F.

This map shows the median date of the first occurrence of 32°F in the central U.S. Within a range, the earlier dates typically occur in the north and the later dates in the south. However, terrain and surrounding land use can have a significant influence on overnight low temperatures.

Same as the map above, except for 28°F.