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Delaware: The State of Severe Weather

Delaware weather is a paradox. Literally, in three parts of the state, we can have three different types of weather in a single day.  Yet, living in Delaware is becoming increasingly clearer as we approach the Spring and Summer months.  Delaware is a state with very severe weather risk.

 

Unlike say Tornado Alley between the MId-West and the plains like Texas, Oklahoma, Kansas, etc.. Delaware is starting to see more and more of its a fair share of severe weather. In the last two years, we have had at least three recorded tornadoes. One an EF-2 last May on Memorial Day weekend down near Laurel. And it happened at night which is more terrifying and rare. The most common severe weather that Delaware’s faces are thunderstorms, straight-line storms, and Derechos.  I want to discuss Derechos.

 

DERECHOS

In late June of 2012 Delaware and much of the lower half of the Mason-Dixon states experienced what is called a Derecho severe weather event. It started early in the morning out of thunderstorms in eastern Iowa. Derechos form because of elevated thunderstorms. They are, in a sense, strong thunderstorms that last hours and are damaging by the intensity of the size of the storm.  They also spread over hundreds of miles.

The picture below shows how air billows upon a high-pressure system over the East Coast. This building of airflow above the front can lead to the formation of abnormally higher than the normal mixed layer that leads to intense Derechos.

Add in unbreathable heat and humidity and there is always the possibility of a Derecho of any kind in the Spring and Summer months.

The radar echo shows a progressive derecho forming as a bow that drops from NW to SE. Straight lines just move in one “straight” direction via the winds and upper-level jet.

 

The Derecho event in June of 2012 moved over 700 miles in 10 hours and killed 22 people and left hundreds of thousands without power.

 

We are sure to see something like this as storms are growing more powerful overheated Gulf moisture and heated ocean waters.

OFFICIAL: Winter 2019-20 Dead

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The Madden-Julian Oscillation which determines the eastward propagation of storms from Asia to the Pacific will be entering into the “Circle of Death” after spending some time in Phase 7 which is a neutral zone indicating probable transition into either a colder phase like 8-9-1-2. Yet, all ensembles are pointing inward towards the circle which means it has NO influence on weather patterns.

 

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Likewise, our teleconnections which have been horrible ALL winter are indicating that winter is just simply dead in the Eastern 2/3 of the country. There is no ridging (-PNA), there is no high block in Greenland  (+NAO) and no cold air (+EPO).  And this goes through the 5th of March. And if you add in all of the other factors not favoring anything significant in the East like a coastal storm as we are going into March, then it’s all over folks.

Winter 2019-20 is dead. Adios!

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Featured

The Fall Line: The Difference Between All rain and mostly snow for the I-95 Big Cities

Above is a picture of the major cities of the East Coast. The very fine white area is called the “Fall Line”.   Can weather really straddle a line? Does one or two degrees west or east of the line make a difference? The two answers is Yes, and Yes. If you look to the west of the “Fall Line”,  you will see that the land rises-elevation. Temperatures are impacted by that small difference. In Philadelphia, it could be 34 degrees as a storm approaches. Fifteen miles west of Philadelphia in Montgomery County it could be 32 degrees and falling as a storm approaches.  You could have snow in Lower Merion, and rain in Center City-cold rain at that. In that case, if it’s 34 degrees in Philadelphia you can rest assured it’s 35 in Wilmington, DE almost a certain rain event as you can see Wilmington, DE almost is sinking in the sediment of the Delaware River.  Yet, at the same time, it could be 35 in Wilmington, DE and further north and west of Wilmington, DE in Chadds Ford just a mere 6-8 miles from Wilmington to its south could be startling the freezing line and could either bet wet snow or even just snow.

So, the weather follows I-95 because of I-95 changes in elevation. It’s the strangest, but the most fascinating piece of geography that no other part of the country has.

 

Snowstorm along the I-95. Arctic cold air is the solution if you want big snows in the megalopolis cities of Washington, D.C. to New York City.

 

 

The Lack Of Winter: Warming or Just Normal?

Winter 2019-2020 in the Mid-Atlantic from Washington D.C. to Boston, Mass has been, simply, strange or has it?

According to early winter predictions the NOAA stated in October 2019 very clearly:

“neutral conditions are in place this year and expected to persist into the spring. In the absence of El Nino or La Nina, long-term trends become a key predictor for the outlook, while other climate patterns, such as the Madden-Julian Oscillation and Arctic Oscillation (AO), will likely play a larger role in determining winter weather”

In other words, instead of La Nina or El Nino we’ve had “La Nada”. Nothing. The Pacific waters have had no impact on our winter. The jet streams have been let loose and are so divergent north and south they can’t see each other. Judah Cohen from the Atmospheric Environmental Research is an expert in the area of the AO index. He stated in his most recent blog:

“I know I sound like a broken record when I start every blog by how surprised I am by the stratospheric PV remains on the strong side of normal and even at times near or at record strong for the date. Today there has been some chatter/news about a record daily high for the AO today. But the incessant stretch of positive to strongly positive AO since late December, based on the polar cap geopotential height anomalies (PCHs) plot originated in the polar stratosphere with cold/negative PCHs/strong PV back in mid-December that propagated to the surface over a course of two weeks.”

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The graphic above shows the GEFS ensemble for temperature variation over the globe. (Courtesy of https://www.aer.com/science-research/climate-weather/arctic-oscillation/)

In other words, there has been a pool of cold air sitting on top of the North Pole just swirling around the Arctic Ocean and there has been nothing to push it south enough to allow any major, long sustaining cold weather to give the East wintry precipitation. The extent of the cold has been kept out West and it just seems to be that way this winter 2019-2020.

There have been at least eleven winters in the Philadelphia/Wilmington, DE area of fewer than four inches of snow with 1997-98 being at the top with only 0.8 inches that year. It looks like we could beat that this winter.

Thus, the predominant notion that global warming has caused this snowless winter in the NE corridor from Washington, D.C. to Boston which has had snow but not their gigantic February numbers of recent years, is by far not the culprit.

It’s just this winter.

THE DEFEAT OF THE SPANISH ARMADA BY A HURRICANE 1588

Fifth in a series on how weather impacted and changed world history.

Queen Elizabeth was a wonderful leader and tremendously strong Queen of England. She had astounded others with her vision for England both domestically and in the world. However, she was going to be tested for the dominance of Europe by the Spanish in 1588.

The Spanish were bent on defeating the young Queen and invade England to create a Catholic Europe. And they had the strength of manpower and ships.  Phillip II was awkwardly related to Elizabeth in that he wasn’t Elizabeth’s real father.  Phillip was Catholic and Elizabeth was Protestant. Phillip was King of Spain. He wanted to test his step-daughter.

In early July the Spanish fleet set sail. The English fleet lay in wake of seeing the Spanish. By mid-July, the first ships had been seen.  Initially, the campaigns were back and forth. Yet, the Spanish made a long trip even further by sailing up and around Scotland. It prolonged their return to Spain. As they made this turn around Spain they made a navigational area that sailed their ships directly into westerly winds and to compound that they were the equivalent to a hurricane.

Ships were destroyed. Men were killed in the thousands. And the English took thousands of Spanish prisoners. The end was near for the Spanish.

And England remained Protestant. Elizabeth was now a touted world leader and someone to be feared.

CHALLENGER: IT WAS COLD IN FLORIDA

Fourth in a ten-part series on how weather events impacted U.S. History 

 

ChallengerMission Control: “Challenger, go to throttle up.”  

Challenger: “Roger” “Go to throttle up.” 

Then a massive cracking of the cold Florida air that morning of January 28, 1986. The Space Shuttle Challenger was on its 25th flight with seven astronauts including a civilian turned astronaut Sharon Crista McAuliffe. She was a teacher in a school in New Hampshire who had been chosen to be the first civilian space astronaut in the NASA program.

The launches at the Cape had become almost routine in those days, but this was to be a special morning for all of us. Now, in Florida in the winter it does get cold.

However, this January morning as unusually cold with temperatures in the mid 20’s near takeoff.  NASA cancels flights for all kinds of reasons. A clear, beautiful cold day wasn’t going to stop the mounting pressure to get Sharon Crista MaCullife into space that morning.

NASA knew that specific parts of the ship, as well as the boosters, could be impacted by the cold weather. Ice had built up on the shuttle the previous night with temperatures down near 20. Normally, all of these conditions would have been enough for NASA to cancel the flight and wait for warmer temperatures. Not this morning.

As the shuttle lifted off the space pad it zoomed into the atmosphere with breathtaking speed and a glow of the burning boosters powering away into the cold, brisk morning. Thousands watched on the ground and millions on live TV around the world and country cheered the nervous excitement of takeoff.  As the plane reached 4 nautical miles into the heavenly skies the last words came from the flight deck:

Mission Control: “Challenger, go to throttle up,” 

Challenger: ” Roger” “Go to throttle up.”  and unheard as they muttered these last words according to the flight recorder  and transcript, “Uh-Oh!” 

Challenger was gone. A burst of combustion and a massive, rocking explosion disintegrated the entire ship. The solid rocket boosters shot off into the ocean. Pieces of debris fell all over the Atlantic near Cape Canaveral. Seven beautiful lives were lost. A nation watching as a school teacher who was experiencing the time of her life evaporated in front of her students watching in New Hampshire. It was over in 73 seconds.

Later it was found that due to the cold temperatures the O-ring expanded on the solid booster had started to leak gases which ignited the external tank attached to the shuttle. The ship actually disintegrated not exploded, but the outcome of the crew was never in doubt. They were literally evaporated into thin air. They never felt a thing.

The investigation led to the faulty O-ring but there was a memo circulated around NASA recommending the flight not take place in temperatures below 53 degrees for fear of the O-ring issue. The decision makers never saw that memo.   It was 26 degrees in Cape Canaveral that morning.  It should of never happened. 

 

 

September 11th, 2001: Hurricane Erin missed the East Coast

First in a series of posts about how weather impacted events in our history.

September 11th, 2001 was a day we would like to forget. Yet, just like a lot of historical events in history, weather played a critical role.

The surface map shows the weather map at 7am on September 11th, 2001.  In the blue, we can see a massive round high-pressure system in the Mid-West this gave us and most of the country a beautiful, clear blue sky day. In red is a cold front that had moved through the night before which actually gave NYC rain that night. Also, just to the east in the Atlantic was Hurricane Erin. Erin was threatening the East Coast until that cold front swept it way out to sea.  It’s very possible that IF that cold front had not pushed through Erin would have threatened the East Coast with at least high, thick clouds all down the Eastern seaboard. This could have either thrown off the attackers and given authorities more time to uncover the attack. It was close to being a ring for the FBI and CIA.  They were about to grab some of the attackers.

Yet, it was a beautiful sunny day.  Hurricane Erin missed the East Coast.

Until 8:46am.  Born on that day were 2,996 angels.

 

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Surface Map for September 11th 2001