Wednesday, January 16, 2013

Why the Panic about Winter?

I see a lot of people panicking over this winter; many feel this is going to be a repeat of 2011-2012. This is in part due to how forecasters handled the setup leading into last winter..

Because of this, I thought it would be a good time to go back and look at the winter that wasn't. I can't speak for other forecasters winter outlooks last year. But if they did what I did, then they put too much faith in the fact that it was a La Nina year. And as most of us are aware the winter of 2011-2012 didn't behave the way a typical La Nina should. I paid less attention to the NAO,AO and PNA than I should have. Because of that I busted my long range winter outlook .

Last winter had a lot of things going against it.

1. + NAO and + AO

I wrote about the NAO and AO enough, that I think most of us know they have positive and negative phases. When both are negative, The Northeast sees some of our coldest outbreaks of arctic air, So based on this it shouldn't be hard to figure out that last winter; the phases were a lot more positive than negative.  In fact the winter of 2011-2012 saw the largest sustained positive pressure gradient in recorded history.

On the other hand, winter of 2009-2010 saw the exact opposite, the NAO at that time had some of the lowest pressures ever observed. The result was an extremely active winter across the Northeast.

Here’s a link to a article in Scientific American that goes into this a bit more. it can be found here.   

2. The Polar Jet stream.

The polar jet stream divides cold Arctic air to the north from warmer air to the south. The Jet stream stayed north of the boarder for almost the entire winter. Staying that far north allowed warm southern air to move north and into the Northeast; it also prevented cold fronts to move out of Canada. As a result the cold arctic air stay bottled up in Alaska and northern Canada.

The NAO was one of the Primary reasons the polar Jet acted as it did.  2011 was a very extreme year for severe weather, this was also the result of the Jet stream...The Jet stream being stuck north of the border keep the northern half to the U.S. very warm. However, the south saw a colder winter than usual, in fact Texas saw a White Christmas.   

Here’s a video that explains about the Jet stream.




3. A quiet subtropical jet.

The Subtropical jet is normally quite active and with strong winds during the winter and early spring. Last winter this was not the case., During winter, subtropical jets intensify and can be found between 20° and 50° latitude. Their maximum speed approaches 300 knots, although these higher wind speeds are associated with their merger with polar-front jets. During the winter the subtropical jet will drift northward and merge with a polar-front jet. When they phase we can see very powerful winter storms in the Northeast. The subtropical jet last year was very lackluster. So with the polar jet staying in Canada; along with a quiet subtropical jet; our pattern stayed zonal with not much in the way of storms.  

So far this year.

In my outlook this year I said, this winter would be a slow starter, that the first half would be warmer and less stormy than the second part of winter. The arctic outbreaks that are being forecasted bares out the truth of what I was saying. The pattern in the long range is also looking much more active than we've seen.

In fact the southern Mid-Atlantic is going to be hit by its first major snowstorm tomorrow, this winter! A The snow will start in the morning hours in the higher elevations and will work east through the afternoon and evening. Snowfall amounts of 2-4 inches will be common from DC to Richmond with 3-6 inch snowfall amounts in the higher elevations. As for the Northeast many of us have seen more snow this year than we saw during the entire winter of 2011-2012.

The NAO and AO.

nao_sprd2


Looking at the NAO chart you can see that since November 19th the NAO has been mostly negative. . It is likely to remain predominantly negative for the remainder of the month. Looking back at 2010 we see a notable long-lived block that developed in the 11/20-12/10. The winter of 2009-2010 saw many long lasting blocking regimes as did the winter of 2009-10 and 2010-11. This blocking lead to very high snowfall totals across the Northeast.


This year the Jet streams are acting completely different than they did last winter. Here's a diagram of how the Jets should behave this winter. As you can see the Northeast is where the two Jets will be battling it out.....So The northern Mid Atlantic and New England should be more active than not.

   2012-13_jet_amplified


In my outlook I also said, this winter would see swings between warm and cold outbreaks..So far this too has been the case. The long range teleconnections are pointing in the direction of more cold air intrusions and less in the way of warmer air intrusions for the 2nd half of winter.

So don't lose faith I still think this winter will end up slightly below average in the temperature department with at least average snowfall across the region.........    

Rebecca



Tuesday, January 8, 2013

Will the midmonth arctic air outbreak be record breaking?

 
With the high pressure building in and a southwest flow.....we will see fairly warm temps going into the upcoming weekend....Tomorrow we will see a strong low pressure center in Canada....it will cause the wind to be  bit breezy and gusty wind gust could be in the strong breeze slot on the beaufort wind scale 25-31 mph. There could be a little precipitation over the Tug Hill, Adirondacks, and  northern Greens. Some of this could be in the form of snow...but accumulations will be light.  Then Thursday night, we will have another system approach the region. The Euro is running a little slower on timing then the GFS, Canadian, and Nam So any precipitation should be late.  During the overnight, the precipitation could fall as freezing rain and sleet. The precipitation on Friday should be mainly rain. Temperatures on Saturday will be in the 40's and perhaps low 50's.
 
 
OK let's get to the arctic cold outbreak for midmonth.
 
As I’ve been saying there are several signals pointing at a dynamic cold air outbreak.
  

Polar vortex:
 
  
If you look polar vortex (PV) you will see something like this; the large scale cyclonic circulation in the middle and upper troposphere located near the polar regions. in other words it's a strong wind flowing around a low-pressure system normally present over the Arctic in winter. I think that reads a little easier.  The PV is analyzed at 500 millibar level of the atmosphere. It can often be located over Canada or Siberia since the coldest surface air is often found over these regions.
 
 

 
 
Here's a look at the 500 mb chart showing the PV
 
 
500 mb
 

  
How does the polar vortex influence our weather?



Strong Polar Vortex:

Strong is the more common state of the polar vortex. When the polar vortex is strong, this creates strong low pressure in the Arctic region.  Because of the pressure difference between the Arctic and mid-latitudes, air flows into low pressure and this confines the cold air to high latitudes closer to the Arctic. Therefore it is often mild across the Eastern US, Europe and East Asia during winters when the polar vortex is strong.

During strong polar vortex, the air flow is fast and in a direction from west to east.

Low pressure in the Arctic region is referred to as the positive phase of the Arctic Oscillation AO and the North Atlantic Oscillation NAO.


 Weak Polar Vortex:
 
When the polar vortex is weak or “perturbed”, the flow of air is weaker and meanders north and south (rather than west to east). This allows a redistribution of air masses where cold air from the Arctic spills into the mid-latitudes and warm air from the subtropics is carried into the Arctic. This mixing of air masses also favors more storms and snow in the mid-latitudes.
 
During a weak polar vortex, high pressure occurs in the Arctic region and is referred to as the negative phase of the AO and NAO. Air flows away from the high pressure Arctic. The north to south direction of the polar vortex carries cold Arctic air into the mid-latitudes of Eastern US, Europe and East Asia. Therefore it is cold across the Eastern US, Europe and East Asia during winters when the polar vortex is weak.
 
   
Here’s a look at the NAO and AO are forecast to be.
    nao_sprd2 for the cold
  ao_sprd2ao for the cold
    
As you can see they are positive now ...but they will be negative by midmonth
     


Here are the current and the next weeks Euro 30 Hpa geopotential height.


  a30hpaEuro




 
In the image for next week you can see the vortex over Canada and the Northern U.S. If we see a negative NAO and AO this could  mean we will see near record cold around mid month into the end of January.

 

ecmwf100f240touse in blog for nextweek




I saw a blog post today where they were talking about the arctic air outbreak of January 1985. So I wanted to compare and show you how the two might stack up. Here is an image from January 1985.





compday_50_122_174_38_7_16_9_0 1985





If you look at the Euro forecast for next week and compare it to the one from 1985. you will notice that they look very similar. The arctic outbreak in 1985 also was accumulated by a negative NAO and AO. The arctic outbreak 28 years ago was record breaking. This outbreak was the result of a shifting of the polar vortex farther south than is normally seen. Much the same as the potential outbreak beyond midmonth looks to be. Back in 1985 hundreds of cities in the United States saw record low temperature readings. The cold encompassed the entire Eastern Seaboard, Midwest down into Texas and the Gulf Coast. In fact the West Coast was cold too. Here is a temperature map from January 21, 1985. one other interesting fact is it was unusually warm weather in the eastern U.S. in December 1984, suggesting that there was a build-up of cold air that was suddenly released from the Arctic. Sounds a lot like the Summer of 2012. I'm not saying that this January 2013 outbreak. But you had to admits there are a lots of similarities, between this year and January, 1985.
   

Here’s a temperature map from January 21, 1985.
  800px-January_21,_1985_temperature_map
     


 
Sudden stratospheric warming:
 
Something known as a sudden stratospheric warming has occurred in the Northern Hemisphere arctic region over the last few days. This most likely the same thing that happened back in 1985.
what is a sudden stratospheric warming ( SSW)? This is when the winds in the PV slow down or reverse from the normally westerly direction. Frequently when a SSW takes place, it displaces cold air in the mid and upper levels and then build in the lowest layer of the atmosphere; once this happens it will move southward into the continental U.S.


   wk1_wk2_20120107_z500
   wk1_wk2_20120107_z500week2


As you can see from the image above that there was a another burst of cold at 150hpa giving the extra momentum. I see it nearing the end of its rule so will be looking for effect from that warming to reach further down through the stratosphere.
   
 
The outbreak will most likely move into the Northwest U.S and into the northern Plains. From here it will gradually move south and east. We could have storms impacting the East Coast. Because of this, the Cold could take awhile to build into the Northeast and the rest of the East Coast. Right now, most likely reaching the Northeast around the 23 to the 26th. We will see several waves of cold air move out of Canada, each one colder than the last. Once the arctic air reaches the Northeast it could take awhile for it to leave...it could be longer than ten days.  It's too early to know if we will see storms during the outbreak...but we could very well see storms ride along with the cold air.
 
 
 
That’s it for now. I just wanted to give you the latest information.
 
 
 
 

Rebecca.
 



Thursday, January 3, 2013

Top ten weather events in the Northeast during 2012

Here's my picks for the most significant weather events for 2012 in the Northeast. I choose these after careful consideration. There might be an event that you think should be on the list......if so let me know and we can discuss it on my weather page and in the blog.....Before I get started I was asked by someone what states make up the Northeast? The Northeast region borders Canada to the north and the Atlantic Ocean to the east and abuts the Middle West and South East regions. The region's states include Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Delaware and Maryland, as well as the District of Columbia. With that out of the way...let's get started.


Honorable Mention:  

February 29 Thru March 1 Snowstorm:  

A complex multi-part snowstorm that lasted as long as 36 hours struck parts of New York State and New England. The storm blanketed the southern Adirondacks, southern Green Mountains, greater Capital Region, and western New England with 3-15 inches of snow. Snowfall was heavy at times with snowfall rates of 1 to 2 inches an hour during the afternoon into the early evening hours.  

The storm would have dropped even more snow. However, a secondary low began to form in the mid-Atlantic region early Thursday morning. This resulted in a double-barreled low pressure system which moved eastward during the day Thursday. The wintry mix transitioned back to snow which persisted most of the day. However, the snow had trouble accumulating in some locations as temperatures warmed. This limited significant accumulations from occurring across the Capital District and to points to the south and east.  

So even though the winter of 2011-2012 had virtually no snow for most areas....we did have one decent snowstorm, in fact if not for this storm many of us might not have seen any snow.    

10) Snowstorm December 26-27, 2012:  

Now I know this was not a major snowstorm. But due to the fact that this was the largest snowstorm we've seen in almost two years makes it noteworthy. From western NYS and PA into New England saw between 6-18” of snow over a 24 hour period.  which was a welcomed relief from the snow lovers and ski resorts.  

9) September 18th Severe Event:  

We saw a very complex and powerful low pressure system moved across the region on September 18th The storm system brought damaging winds and widespread heavy rainfall. The system approached the region from the southwest during the day. At roughly the same time as a strong cold front approached the region form the Great Lakes. These systems merged and moved across the northeastern United States. Moisture was transported into the region on a very strong low level jet.   With a very strong environmental wind field aloft (60-70 kt at 850mb and 50-60 kt at 925mb) The setup was such that a tornado watch box was issued for the entire Eastern NYS and parts of western New England, except for southern VT. However, with surface based or mixed layer CAPE in the 200 - 250 J/Kg range and poor lapse rates across the area kept instability fairly limited. So, no tornadoes occurred in the Northeast.  

Inspire of a lack of instability, the wind field overhead was so strong that showers and low-topped thunderstorms were able to transport stronger damaging winds to the surface. The heaviest rainfall occurred along a wide stripe from the southwestern Catskills extending northeastward through the eastern Catskills, through Albany County. Rainfall amounts of 4 to 7 inches were common. Despite dry ground conditions, flash flooding occurred first in portions of Greene and Ulster County due to extreme rainfall rates and 5 to 7 inches of rain falling in less than six hours. Flash flooding also occurred into portions of the Capital Region, where 3 to 5 inches of rain fell in a relatively short amount of time. Most of the flash flooding reported was due to road closures in urban areas.    

8) September 8th, 2012 Severe Event:  

An increasing warm and moist southerly flow of air moved into the region in advance of a powerful cold front. The combination of partial sunshine, increasing instability and strong wind dynamics with this system placed our region into a rare Moderate Risk by the Storm Prediction Center. Several supercells developed in advance of the main squall line (QLCS) with the potential for tornadoes. The main hazard with this event was straight line damaging wind gusts that resulted in numerous power outages and trees down.      

7) May 16, 2012 Severe Event:    

The synoptic set up was conducive for severe weather in the Northeast, with a strong negatively tilted mid level trough and cold front moving out of the Great Lake and through the region. A strong mid level wind max, with the core positioned just to the northwest of our area, was associated with this upper level disturbance and was mainly responsible for the large magnitude of deep layer vertical wind shear of 40-50 knots. Storms started to build west of Utica, around 11:00 AM. With mid level lapse rates at 7.1 C/Km and Cape between 1500-2000 J/Kg, at 12:27 AM EDT, the first Mesoscale Discussion (0824) for the Northeast for the severe season was issued by the SPC.  

At the surface, as is typical for this area, there were at least two distinct boundaries present. One was a pre-frontal trough that progressed eastward from central NY during the morning/early afternoon. Dewpoints dropped in the upper 40s to lower 50s to the west of this boundary, while to the east dewpoints were in the upper 50s to lower 60s. Convection was initiated along this boundary, over the western Adirondacks and Mohawk Valley early to mid afternoon and progressed eastward. The second boundary was a cold front over western NY. By 1:30 PM Temps were approaching 80 and winds were increasing, in the Western Mohawk Valley. Around 1:54 PM a line of thunderstorms started to form west of Utica, The areas at most risk were southern Herkimer, Fulton, Montgomery, Hamilton, and Otsego Counties. The thunderstorms were responsible for dozens of hail and wind damage reports. Here is an image of the line in Central NYS, Litchfield and Hartford were already under a Thunderstorm Watch , outlined in Pink.

   

6) The Winter That Wasn’t:  

Sometimes the lack of something can be noteworthy. While no two winters are alike, the winter of 2011-2012 was in a league all its own. winter is one we'll all remember.  The contiguous U.S. saw its 3rd lowest snow cover on record during both winter and spring, and the winter of 2011 – 2012 was the 4th warmest and 24th driest winter in U.S. history, going back to 1895. The primary cause for the warm temps and lack of snow; a large ridge of high pressure parked itself over the Great Lakes region for much of the season. The abnormally warm air allowed for a large tornado outbreak (one of very few in 2012) to impact the Midwest and Ohio Valley on March 2. I did a blog post on this outbreak that can be found here.The jet stream that largely stayed to the north of its usual winter configuration, outside a couple of dips south, it more or less stayed in this configuration for most of the winter.. We also had an extremely positive NAO index (+2.52) in December, which was the largest difference in pressure between Iceland and the Azores ever observed during the month of December. The positive NAO for most of the winter stopped arctic air from plunging into the United States. Because of this most areas saw a near record lack of seasonal snowfall. The lack of snow had more to do with temperatures than precipitation. Several of our winter storms brought rainfall across the region.    

5 ) The Dry/Warm Summer:  

After the virtually snowless winter; we had a abnormally dry and warm spring heading into the Summer. To give you an idea how warm it was even before we got to summer, "799 daytime heat records were broken in the first five days of January in the US," says Jake Crouch, a climate scientist from the NOAA National Climatic Data Center. Breaking the 2012 warm spell down by state, it was the warmest first seven months of the year in the 4 New England states, Delaware, Maryland, New Jersey and New York. Northern NYS saw its 2nd warmest summer on record during 2012. The Northeast Regional Climate Center at Cornell University reported Tuesday that the average temperature in the 12-state region was 49.9 degrees from January through July. That's the warmest seven-month period since 1895, the year systematic record keeping began. The second-warmest comparable period was 1921, when the seven-month average was 49.2 degrees. The Northeast endured a sweltering July with record-breaking temperatures around the region. Syracuse hit 101 on July 17 and Washington's Reagan National Airport recorded 105 degrees on July 7. It also was the warmest 12-month period in the Northeast through July.    

Here is data issued by NWS Albany:  

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE ALBANY NY 959 PM EST TUE JAN 1 2013 ...2012 GOES DOWN AS THE WARMEST ON RECORD FOR ALBANY NY...

THE AVERAGE TEMPERATURE FOR ALBANY NY FOR 2012 WAS 51.6 DEGREES WHICH IS 3.3 DEGREES ABOVE NORMAL. THIS MAKES IT THE WARMEST YEAR ON RECORD SINCE 1820. THE OLD RECORD WAS 51.4 DEGREES SET BACK IN 1828. 2012 HAD 13 DAYS WITH HIGH TEMPERATURES OF 90+ DEGREES. THE TEMPERATURE EXTREMES WERE 98 DEGREES ON JULY 17TH AND ZERO DEGREES ON JANUARY 15TH AND 22ND.
 PRECIPITATION WAS BELOW NORMAL FOR ALBANY IN 2012 WITH 36.99 INCHES WHICH IS 2.36 INCHES BELOW NORMAL. THIS WAS QUITE A CHANGE FROM 2011 WITH 53.68 INCHES. THE LAST TIME ALBANY`S PRECIPITATION WAS BELOW NORMAL WAS IN 2010 BUT IT WAS ONLY BY 0.76 INCHES...UNLIKE IN 2001 IN WHICH ONLY 28.59 INCHES OCCURRED.    

THE AVERAGE TEMPERATURE FOR GLENS FALLS NY FOR 2012 WAS 48.7 DEGREES WHICH IS 3.8 DEGREES ABOVE NORMAL. THIS MAKES IT THE SECOND WARMEST YEAR ON RECORD SINCE 1949. THE WARMEST YEAR OCCURRED IN 1998 WITH AN AVERAGE TEMPERATURE OF 48.8 DEGREES. 2012 HAD 8 DAYS WITH HIGH TEMPERATURES OF 90+ DEGREES. THE TEMPERATURE EXTREMES WERE 96 DEGREES ON JUNE 21ST AND JULY 17TH AND 6 DEGREES BELOW ZERO ON JANUARY 22ND. PRECIPITATION WAS BELOW NORMAL FOR 2012 WITH 34.76 INCHES WHICH IS 4.30 INCHES BELOW NORMAL. 2011 CAME IN WITH 46.90 INCHES.    

THE AVERAGE TEMPERATURE FOR POUGHKEEPSIE NY FOR 2012 WAS 53.4 DEGREES WHICH IS 3.6 DEGREES ABOVE NORMAL. THIS MAKES IT THE WARMEST YEAR ON RECORD SINCE 1949. 2012 HAD 22 DAYS WITH HIGH TEMPERATURES OF 90+ DEGREES. THE TEMPERATURE EXTREMES WERE 96 DEGREES ON JUNE 29TH...JULY 17TH AND JULY 18TH AND 1 DEGREE ABOVE ZERO ON JANUARY 22ND. PRECIPITATION WAS BELOW NORMAL FOR 2012 WITH 36.48 INCHES WHICH IS 10.05 INCHES BELOW NORMAL. 2011 CAME IN WITH 59.19 INCHES.    

THE AVERAGE TEMPERATURE FOR BENNINGTON VT FOR 2012 WAS 49.4 DEGREES WHICH IS 3.4 DEGREES ABOVE NORMAL. 2012 HAD 7 DAYS WITH HIGH TEMPERATURES OF 90+ DEGREES. THE TEMPERATURE EXTREMES WERE 94 DEGREES ON JULY 17TH AND 4 DEGREES BELOW ZERO ON JANUARY 16TH. PRECIPITATION WAS BELOW NORMAL FOR 2012 WITH 32.50 INCHES WHICH IS 8.20 INCHES BELOW NORMAL. 2011 CAME IN WITH 46.91 INCHES.    

THE AVERAGE TEMPERATURE FOR PITTSFIELD MA FOR 2012 WAS 48.8 DEGREES WHICH IS 3.5 DEGREES ABOVE NORMAL. 2012 HAD 3 DAYS WITH HIGH TEMPERATURES OF 90+ DEGREES. THE TEMPERATURE EXTREMES WERE 91 DEGREES ON JUNE 20TH AND JULY 17TH AND 8 DEGREES BELOW ZERO ON JANUARY 16TH. PRECIPITATION WAS BELOW NORMAL FOR 2012 WITH 36.35 INCHES WHICH IS 9.03 INCHES BELOW NORMAL. 2011 CAME IN WITH 59.46 INCHES.    

4) The 29 May, 2012 Severe Outbreak:

On May 29th the first significant severe weather outbreak of the summer season occurred . This event occurred during the climatologically favored time period of late May to early June, when some of the biggest severe weather outbreaks have occurred in the past in the Northeastern United States. We had a warm front move through and stall over Vermont into central Massachusetts and down into Rhode Island. Because of this A warm, humid and unstable air mass was in place across the region. Thunderstorms broke out in the Adirondacks over into Rutland County in Vermont late in the overnight into the morning of the 29th. These storms caused small scale outflow boundaries to form...These boundaries would have a key part into what was to unfold later in the day.  

The daytime temperatures quickly rose, by the afternoon these temps would be in the upper 80s and lower 90s with dewpoints hovering around or slightly higher than 70°. The instability overhead also increased through the morning and the afternoon. With the aid of cap (warm layer aloft). CAPE (convective available potential energy) climbed to between 3000 and 4000 j/kg. CAPE values this high allow for strong updrafts, supportive of severe weather. We had all the ingredients in place now we needed a match. That match came in the form of a cold front and neutrally tiled trough aloft. As the front slowly approached western New York a pre-frontal trough over the west-central part of the state broke the cap and allowed thunderstorms to explode. The conditions were such that SPC issued a tornado watch at 1230 pm.  

The event came in two stages. The first part went from 12:30 pm thru 4 pm and impacted Herkimer, Hamilton, Fulton, Warren, northern Saratoga, Washington and Rutland counties. between 12:30pm and 4pm. Some to the thunderstorms that developed were also discrete supercelluar type thunderstorms (storms with rotating updrafts). These mesocyclones (small scale rotating centers) produced very large hail, torrential rain, and frequent lightning.  

The second stage of the event developed as storms expanded further south through the remainder of the Mohawk valley and Capital Region and developed into Otsego and Delaware counties. These storms were more linear in structure, forming into short multicell lines and clusters developing into bowing segments. The severe mode shifted from giant hail to more of a damaging straight line wind and smaller hail situation, with significant pockets of wind damage in Fulton, Saratoga, and Washington counties reported.  

The line segment that went through Saratoga County late in the afternoon produced almost continuous lightning and torrential rain in addition to damaging wind and hail up to one inch in diameter. Locally severe multicell storms propagated south into the mid Hudson valley and Berkshire and Litchfield counties, pulling out of Berkshire and Litchfield counties between 7:30pm and 8:00pm. From here it moved into other parts of New England. In the storms wake there were over 200 severe reports.  

Most of the damage occurred in New York (114 reports) and Pennsylvania (77 reports). Vermont and Western New England (over 50 reports). This severe weather event included a confirmed EF0 tornado near Glover, Vermont, along with numerous reports of large hail and damaging thunderstorm winds. Hail up to baseball size was reported near Crown Point, New York and trees and power lines were down in Milton, Vermont from the powerful storms. Furthermore, the thunderstorms were accompanied by very heavy rainfall amounts of 2 to 4 inches with localized radar estimates near 6 inches across the southern Champlain Valley, which caused significant flash flooding. Many roads were washed out and numerous rivers and streams had sharp rises, as a result of the heavy rainfall.


   Shelf cloud segment over Mechanicville, May 29, 2012                                     Taken near Machanicville, NY photographer unknown

     

3) The June 1st Maryland And Virginia Tornado Outbreak:  

A few days later on June 1st severe weather stuck again. This time in Maryland and Virginia. New York State and Western New England  dodged a bullet  if the system had been just a little more to the east, we would have seen this too. A large upper-level low pressure system, and its attendant surface storm northwest of Maryland, set the stage for rotating thunderstorms across Maryland and Virginia. A warm front crossing the area during the day helped focus the threat, a a cold front swept through Triggering the tornadoes.  

The NWS  filed 58 wind damage (mostly downed trees) and 28 flash flooding reports from northern Virginia, central Maryland, and the District of Columba. Maryland saw the worst of it. The NWS has confirmed 12 tornadoes  in Maryland. The two most powerful in Maryland were in the Watersville area of Howard and in the Pleasant Hills area of Harford, where two injuries were reported.  Harford County MD  saw the worst of it with over $1,000,000 dollars in damage. A tornado in the Hampton, Va., area was estimated at 98 mph. A second Virginia tornado, near Petersburg, was estimated at 80 to 85 mph. In Montgomery, two tornadoes touched down near Damascus and a third in the Countryside area, the Weather Service said. In Prince George’s, the tornado touched down in the Springdale area, east of Route 50 and the Capital Beltway.  

Fortunately, none of the tornadoes were very strong or long-lived locally. Heavy rain and flash flooding turned out to be the biggest impacts from this tornado outbreak, but there were scattered wind damage reports, numerous funnel cloud sightings.

   from Brambleton, VA from taken by Kalina Malina Zelkata                                         Brambleton, VA picture taken by Kalina Malina Z
    

2) The July 26th NYS Southern Tier And Pennsylvania Tornado Outbreak:

On the afternoon of July 26th, a significant severe weather event impacted portions of the NWS Binghamton forecast area. By the late morning/early afternoon, a warm front had lifted north through the region placing much of the Binghamton forecast area in a moderately unstable airmass. We also had several upper-level shortwave troughs moving out of the Great Lakes during the early afternoon hours; this helped in energizing the thunderstorms that would develop. Another key factor for what was to develop was dry air in the mid levels, which set the stage for strong damaging winds.  

Early in the afternoon, thunderstorms started to develop over southwestern New York and northwestern Pennsylvania. The atmosphere was such that the storms quickly matured into a multicell line. Based on reports out of western NYS, multiple severe weather warnings were issued at 2:25 PM for Steuben County, NY.  

As the storms rushed east at 50 to 60 mph through southern Steuben County, NY, the line developed a well-defined bow echo. As the storm was entering western Chemung County, a well-defined inflow notch (A signature seen on radar that's characterized by an indentation in the reflectivity pattern on the inflow side of the storm, inflow notches are particularly conducive to severe weather if they ingest high momentum and dry air into the storm). There was also
broad rotation noted around the inflow notch. Doppler radar also noticed a low-level rotational couplet (rotation with strong inbound and outbound velocities) heading towards the Elmira, NY.

As this rotational couplet moved towards Elmira, an EF-1 tornado touched down in West Elmira. The tornado then continued east into Elmira where it affected the downtown district where it cause quite a bit of damage. The tornado lifted just east of the city.  

After moving through Elmira, the storm system moved east into the Twin Tiers, where numerous damage reports such as trees and wires down were received. As the system quickly moved into the Binghamton area a tornado warning was issued for eastern Tioga and much of Broome Counties at 4:24 PM. As this storm entered the county, strong mid-level rotation was noted on Doppler radar. A downburst produced straight line wind damage in the Township of Sugarloaf. The storm continued to move east where it produced additional straight line wind damage along East Foothills Drive in the Town of Hazel. As the storm entered western Foster Township, a brief tornado occurred just southwest of Freeland at 5:44 PM

The storm continued to race east causing considerable more damage........The storm produced a total of 7 tornadoes and dozens of wind damage reports due to the eastward moving bow echo.  

Here’s a list of the tornadoes and downburst…..the links will take you to the NWS Binghamton site.  

New York State
 
EF1 Tornado Confirmed Approximately 7 Miles South Southwest of Corning in Steuben County New York

EF1 Tornado Confirmed near South Corning in Steuben County New York

EF1 Tornado Confirmed in Elmira in Chemung County New York

EF1 Tornado Confirmed in the Chemung and Tioga Counties in New York

EF1 Tornado Confirmed in the Town of Kirkwood in Broome County New York

Pennsylvania

EF1 Tornado Confirmed near Bridgewater Township in Susquehanna County Pennsylvania

EF1 Tornado Confirmed in Foster Township in Luzerne County Pennsylvania  

A list of the four microburst associated with this event:

New York  

Microburst/straight Line Wind Damage Confirmed near Barton in Tioga County New York

Macroburst/Straight Line Wind Damage confirmed in a Swath from Southern Steuben to Southern Chemung Counties in New York

Pennsylvania

Microburst/Straight Line Wind Damage/Confirmed near Harford in Susquehanna County Pennsylvania

Microburst/straight line wind damage confirmed near Orwell in Bradford County Pennsylvania    


1) Sandy

For most of us Sandy is a name that will live in our conscious mind for the rest of our lives. Sandy will be remembered along names like Connie, Carol, Hazel, and Diane. To say Sandy caused devastation would be a gross understatement. I won't go into a lot of detail about this monster storm, as most of us know about her all too well.  

Sandy developed from a tropical wave in the western Caribbean Sea on October 22, quickly strengthened, and was upgraded to Tropical Storm Sandy six hours later. Sandy crawled northward toward the Greater Antilles and slowly but surely intensified. On October 24, NHC designated Sandy as a hurricane. Soon after, she made landfall near Kingston, Jamaica, a few hours later, re-emerged into the Caribbean Sea and strengthened into a Category 2 hurricane. Sandy made another landfall on Cuba on October 25 where she weakened to a Category 1 hurricane. in the ensuing days Sandy moved through the Bahamas, the Caribbean, and moved up the East Coast of the US.

Early on October 29 Sandy hit The Greenland block in the Northern Atlantic. Because of this and an incoming storm system over the continental United States, she recurred back toward the US Coast making landfall south of Atlantic City New Jersey. The damage in the US is estimated to be between 60 and 100 billion dollars. Sadly Sandy took at least 253 lives during her lifetime. This tally includes 131 Americans and two Canadian lives. If you want to know more about Sandy, I did several post on her, including a timeline...which can be found here.  
 

Well that’s my list…… I hope you enjoyed reading it….    



Rebecca