Tuesday, May 27, 2014

The Northeast severe weather outbreak of May 22, 2014.

May 22nd, 2014 was a day severe weather was expected.  I had been posting about it for a few days, so everyone should've had adequate awareness . But the severity of the weather, exceeded the wildest dreams of the NWS, Myself, or any of the weather outlets that I know of. 

By the end of the afternoon heavy rain, damaging straight line winds, flash floods, large hail (large even by Midwest standards), and at least two tornadoes,  struck New York State, Pennsylvania, Maryland, Delaware, and southern New Jersey.

The severe storms caused millions of dollars in damage.

I did a blog post about severe weather outbreaks in the Northeast around Memorial Day.

What is it with Memorial Day and severe weather 

This post will go a little into the atmospheric setup for the 22nd outbreak. It will also touch on some to the hail storms and briefly on the two tornadoes.  It will also discuss the communication issues the National Weather Service (NWS) faced that day.

The setup leading to the severe weather. 

The Storm Prediction Center (SPC) had Southeast New York State, Eastern Pennsylvania , Maryland, Delaware and parts of New Jersey under a slight risk for severe...the main risk was for damaging winds and small hail.  Some of you have messaged me, saying it was a classic textbook setup for what transpired.  But I can assure you, this wasn't the case. We had a setup that was going to allow for scattered severe weather, with isolated damage expected.  The atmospheric setup was marginal  ( moderate at best).  

On Thursday we had an upper level low moving through Ontario, CA, with a trailing cold front stretching back into the Ohio Valley.  Embedded in this upper level feature was a shortwave trough.  Out ahead of the advancing cold front was a stationary front, That would soon start moving eastward.

Thunderstorms had moved through during the overnight and morning.  leaving debris clouds in their wake. But by late morning clearing had developed ahead of the advancing frontal boundary.



By mid day we had the  warm front advancing through Central NYS and moving into Eastern PA.  Out ahead of the warm front a south to southwest flow was allowing  warm and muggy air to move into the Northeast.

As we moved into the afternoon a relatively narrow warm sector was setting up across Eastern NYS, Eastern PA, and down into the Mid Atlantic.  The outbreak of sun, allowed very warm surface temperatures to develop heading into the afternoon, Temperatures were in the upper 70's and well into the 80's for New York State down into Virginia, dew  points in the 60's. At the same time, the 700mb temperatures were much colder. The instability due to the heated surface and rising dewpoints,  started to reverse the cap that was causing convective inhibition, as the cap started to breakdown cells started to develop and build.   At around the same time, mid level  flow was increasing But the low level shear was lack luster.  It was becoming evident that, the boundary between the warm air moving in and the cool air over New England was going to be the focus for some hefty cells.  Due to the lack of low level shear, the threat for tornadoes was thought to be very slight.  

 As we approached 2:00 PM the air became increasingly unstable. CAPE values of between  1500-2200 J/kg overlapped with relatively high surface-500hPa bulk shear values up to 45 to 50 knots. Ahead of the warm front, lifting was enhanced due to the fact that the region was under the left exit region of a jet streak. The setup as sufficient for the production of supercells.  

Mid-Level Lapse rates were in the range of... 6.5 C/KM to 7 C/KM... Also remember we had all that cold air aloft. So the possibility of hail was a no brainer. But the size of some of the hail would go well beyond what anyone had imagined earlier in the day.    

Once the warm surface temperatures and high dewpoints ran into the unstable air. The storms exploded.  The instability extended well over 60,000 feet up. The cells over parts of Eastern NYS, Eastern Pennsylvania, and down into Maryland, Delaware  developed into supercells,  capable of producing hail and strong wind gusts. Several of the cells grew to over 50,000 feet.  The violent updrafts  carried the rain and particulates aloft well above the freezing level, where they formed into hail. The updrafts and downdrafts kept the hailstones aloft, allowing them to grow increasingly larger. But they became too heavy for the updrafts to support. As gravity took over, the hailstones became destructive missiles as they crashed into objects on the surface.  

Hail in some locations in New York and Pennsylvania got so deep that snowplows had to be used.... one of these places was the southern Tug Hill in places like Constableville, NY and Turin, NY, where the hail got several inches deep.   Places around Allentown, PA saw the same thing.  Berks County, PA was hit hard by the hail. The town of Wyomissing saw the worst of the hail damage. where the Berkshire Mall saw extreme damage to buildings and parked cars. There wasn't one car in the Berkshire Mall parking lot, that wasn't damaged...many of these cars were totaled.   Reading, PA also saw a lot of hail.  But gulf ball size hail fell across many places in NYS, PA, and DE. The largest hailstones of the day fell over Amsterdam, NY, where it was measured at baseball and softball size.

A US Air Jetliner also experienced issues with the hail. The plane was landing at Philadelphia International when it ran into the hail.... The hail cracked the windscreen.  

Northern NYS didn't only have hail to contend with. It also saw extremely heavy rainfall, as much as six inches fell in some spots. Between the hail and the heavy rains, flash flooding became an issue. In Port Leyden, NY a road collapsed due to flash flooding.

The supercell that dropped all the hail in Pennsylvania produced a tornado warning once it had moved into Delaware.   

The National Weather Service issued a tornado warning for northwestern Kent County at around 4:30 p.m. to  5 p.m., The NWS issued a second tornado warning for central Kent until 5:15 pm, when a funnel cloud was observed to touch down near Marydel, DE.  

The tornado caused a lot of damage. Two people who lived in a mobile home in western Kent County were injured, when the tornado demolished the trailer. The man was found under a pile of debris in the bedroom, he received numerous  cuts and abrasions, His wife was also injured while in a utility shed behind the mobile home.  The storm also trapped two motorist when high winds toppled utility poles and electric wires. They had the presence of mind to stay in the vehicle, until power was cut by emergency responders.  

The NWS Mount Holly confirmed the tornado was a high end EF1 with maximum winds  rated at 105 mph.

About an hour before the tornado in Delaware. The most impressive supercell of the day was moving southeast through Schenectady County about ten miles from Amsterdam, NY.  As already noted, the cell was dropping very large hail, and it was also producing damaging wind gust, Damage was reported around Gloversville and Johnstown.  The terrain in eastern New York State helped enhance shear at the surface.  At 3:37 pm the NWS issued a tornado warning for  several places including  Duanesburg, NY, Just to the west of  Schenectady.  The tornado was moving southeast at about 20 mph. The storm had  a very impressive inflow notch (hook echo)  on its southwest side.

As the supercell move slowly to the southeast, there was a very tight velocity couplet. Here is a scan of the cell as it was approaching Duanesburg. The image shows gate to gate shear at around 120 knots. 

There isn't much doubt that a tornado was on the ground. Here is another image showing a debris ball as the cell moved over Duanesburg, this confirms that there was indeed a damaging tornado on the ground. 

The tornado caused severe damage to several homes and buildings, including  The town of Duanesburg Volunteer Ambulance Corps building where it ripped a wall down.  On Route 7 the storm hit and damaged a family restaurant.

 Ambulance Corps building.

A house owned by Margaret Krylowicz on Route 20 was completely destroyed by the tornado. 

 As the tornado moved over Interstate 88 it overturned two tractor-trailer trucks.  

The tornado kept moving southeast into Albany County crossing  numerous roads, causing lots of tree damage. The tornado missed Rick Smith's (a Facebook friend and a fellow weather enthusiast) house by a mere half mile........The cities of Albany and  Schenectady dodged a bullet with this storm.

NWS Albany confirmed the tornado was a EF3 with maximum winds rated at 140 mph, with a damage path one quarter of a mile wide, and a damage path length of seven miles.

The National weather service's communication issue.

Right in the middle of the severe weather outbreak hitting the Northeast and Mid Atlantic. The NWS warning dissemination system failed. This system is critical to the NWS's mission to protect life and property. The NWS said in NWS Chat and a email, "It appears that all NWS warnings did not properly disseminate during the outage, and significant severe weather was occurring during the outage," Basically this means very few people were getting timely weather warnings and alerts. Most media outlets such as TV and radio  get their warning information from the NWS, with the system down for half an hour( around 4:00 pm - 4:37 pm)   they weren't getting the Vital data.  

Online radar data was also effected. 

The system went down as dangerous severe thunderstorms were impacting the Northeast. Such as  a damaging tornado heading for Albany, NY...and possible tornadic supercells heading for Washington DC.

There can be little doubt, that some people were caught unaware as dangerous weather was heading their way....people caught in situations like supercells dropping large damaging hail.

 The really scary question is, why doesn't the NWS have the equipment and resources it needs to carry out its mission? Will something like this happen again? Will people die who rely on the NWS alert messages?

The NWS is staffed by great meteorologists, who are dedicated to their job. I'm sure they're as frustrated with this issue as I am.

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