ASK TOM WHY: East Coast's June 1972 Hurricane Agnes

Dear Tom,
Irene hitting the East reminded me of a June 1972 hurricane in Washington, D.C., when it rained for three days. What storm was that?

Doug Walega, Berwyn

Dear Doug,
The June 1972 storm was Hurricane Agnes that caused nearly $2 billion dollars of damage along the Eastern Seaboard, making it one of the costliest U.S. disasters at that time. The storm was a minimal hurricane when it made a Florida Panhandle landfall on June 19. Agnes weakened to a tropical depression as it moved through the southeast before strengthening to a tropical storm as it skirted coastal areas from North Carolina to New York. Agnes was a prolific precipitation producer, with Washington Dulles Airport receiving 13.65 inches of rain while Baltimore measured 6.41 inches. The storm produced record flooding and was responsible for 117 fatalities.

Tim's Weather World: Incredible Irene pictures and video

IreneOuterbanks.jpgThe damage toll from Hurricane Irene continues to rise.   Most of the latest estimates are somewhere between $7 and $10 billion.  At least one estimate from the U.S. International Trade Commission has the damage toll up to $20 billion.   It is very likely the storm will rank among the top ten costliest weather disasters in U.S. history.  It is the tenth billion dollar disaster to strike our nation this year.  That breaks the annual record going back to 1980.

It appears now there probably will never be another Hurricane Irene.   Notorious storms that cause numerous deaths and/or significant damage are removed from the list of possible hurricane names.  As pointed out on Today.com, not only are notorious hurricane names retired from the list, they sometimes are retired from use in everyday life.  

And while past hurricanes had actually inspired more parents to name their children after them, the immense devastation of Hurricane Katrina in New Orleans in 2005 may be reversing that trend. “Katrina” plummeted from the 281st most popular baby name in the United States in 2004 to the 815th most popular name in 2009, according to the Social Security Administration.”

Buzzfeed has assembled 25 of the most amazing pictures depicting the destruction from Irene. Those pictures include the photo above of a woman walking along what is left of Highway 12 on the Outer Banks of North Carolina.

NOAA has a time-lapse of the life of Irene superimposed over the National Hurricane Center’s projected path.   It shows just how accurate the track forecast was for this storm.

IreneNoaa.JPG 

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First September to open with back to back 90-degree highs here in 3 years

By Meteorologist Tom Skilling

Late season heat is Chicago-bound.  The first set of back to back 90-degree days since early August and the first such set to occur in the opening 2 days of September in 3 years arrives Thursday and Friday.  The hot air is to hit amid surging humidities which are to propel heat indices well into the 90s to the low triple digits.

The warming begins Wednesday with temperatures rebounding from Tuesday’s cloud-restrained 76-degree high to the low and mid 80s. The expanding dome of hot air, responsible for record-breaking temperatures across sections of four states from Arizona to Louisiana and Texas Tuesday, sends Chicago highs to 90-degrees Thursday and into the mid 90s Friday.

While a weak southerly large scale wind regime allows localized southeasterly lake breezes to modestly temper the heat at area beaches Thursday, powerful southwest winds overcome lake cooling Friday and push hot, humid air across area beaches and out over Lake Michigan.

Hot spell to send Midway’s 90-degree tally to 26; O’Hare’s to 22
 
There has been no shortage of 90s this summer. The area has already logged more 90s than the long-term annual average in the city. And the arrival of more 90s Thursday and Friday is likely to push the 2011 tally to twenty-two 90-degree and higher temperatures at O’Hare and 26 at Midway.  These totals exceed the yearly average of 17 and 23 at each site respectively.
 
 
Warmth, humidity threaten isolated afternoon thunderstorms; more formidable storms could grow severe Friday night
 
A rain-thwarting cap within the incoming hot air mass may subdue a good deal of thunderstorm development until a vigorous cold front arrives Friday night. But, the vertical decline in temperatures through the atmosphere Wednesday and Thursday afternoons is to be steeper than usual, encouraging warm air near the surface to become buoyant and rise. The ascending warm, humid air will cool and there are indications the cap, especially Wednesday afternoon, may break in spots allowing isolated thunderstorms to develop.

Better organized, more powerful thunderstorms threaten Friday night.  The presence of powerful jet stream winds aloft and atmospheric moisture levels approaching 2 inches is to allow the eruption of strong, possibly severe thunderstorms at that time.

The passing cold front stalls just south of Chicago Saturday and additional clusters of thunderstorms may ride along the front in air which is to remain humid but not as hot as on Friday.

Books to close on a wet, modestly warmer than normal August

August comes to an end at midnight Wednesday night having produced man average monthly temperature nearly a degree above normal and a monthly rain tally of 4.50 inches, an amount 2.70 inches wetter than August a year ago but shy of the normal of 4.90 inches.
 
Heat blazes across the southern Plains and Southwest; Phoenix has recorded 100+ temps 82 of the past 83 days
 
Intense heat broke records again over the southern Plains and Southwestern U.S. Tuesday. In Phoenix, where temperatures 82 of the past 83 days have peaked at or above 100-degrees, a record-breaking 113-degree high was observed. That city is on the verge of establishing a record warm August temperature—the warmest since records began there in 1895.

Other records Tuesday included 107-degrees at Tucson, 97 Albuquerque, 103 Roswell, New Mexico and El Paso, Texas; 109 Wichita Falls, 103 Amarillo and at 111 Childress—all in Texas. Midland, Texas’ high of 106 and San Angelo’s 106 peak reading broke records as well.
 

Tropics remain active; Katia on the way to major hurricane status by the weekend
 
Westward-moving Tropical Storm Katia, 885 miles west of the Cape Verde Islands far out in the Atlantic late Tuesday and moving west, was producing 60 mph sustained winds. The storm is headed over warm water and into a low vertical wind shear environment, perfect conditions for intensification. With conditions favorable for further development, Katia is predicted to evolve into a major Category 3 hurricane with 120 mile per hour sustained winds by Sunday.

Current computer track projections turn the storm north before reaching the U.S. coast.  But much can happen in coming days and that’s a prediction not yet carved in stone.
 
Gulf Coast residents eye developing tropical system; precise course unclear but it threatens to be slow mover capable of huge coastal rains
 
Of potentially greater risk to U.S. coastal residents on the Gulf of Mexico is a northwestward-moving tropical wave in the western Caribbean. The system is predicted to enter the Gulf and strengthen in coming days.

While uncertainties abound because of the early stage of this disturbance’s development, forecasters on the Gulf Coast are concerned the system could be a slow-mover capable of the production of torrential coastal downpours somewhere on the Gulf Coast. Tropical storm Frances is being cited as an example of such a storm.  It hit Houston, Texas with more than 20 inches of rain in 1998.

ASK TOM WHY: What becomes of Hurricane Irene after it passes into the North Atlantic?

Dear Tom,
What becomes of Irene after it passes into the North Atlantic? Does it become just a low pressure system and possibly affect Greenland or Europe?

–Frank Suzda, Wilmette

Dear Frank,
Though Irene has lost its tropical characteristics, it remained a potent low pressure area northeast of Labrador late Tuesday and headed for an encounter with Iceland and the northern portion of the British Isles before tracking east into Scandinavia. Dr. Kieran Hickey of the National University of Ireland has done a study on the impact of hurricanes in western Europe, including Hurricane Bill in 2009 and Hurricane Helene in 2006. In 1961, Hurricane Debbie produced wind gusts to 114 mph at Malin Head in northwest Ireland, and in 2006 Hurricane Gordon brought gusts to 81 mph to Cornwall, England.

Showers on the way as warmer and more humid air prepares to move into the city


The last few days in the Chicago area have been on the cool side with high temperatures holding in the 70s along with comfortable humidity levels. That is about to change as a late-season hot spell is about to descend upon the city.
Showers and a few thunderstorms have been working east across Iowa and northwest Illinois this afternoon and evening and will be gradually working their way into the Chicago area overnight.

The showers will be moving out early Wednesday setting the stage for a warm and more humid day with highs reaching the middle 80s.
Heat and humidity will return in full force Thursday and Friday with highs expected to reach the lower and even middle 90s .

August enters final two days warmer and a good deal wetter than a year ago

By Meteorologist Tom Skilling

August 2011, which ends midnight Wednesday night, is all but certain to post a modest temperature surplus and a big increase in rainfall over the same period a year ago.  To date, only ten of its 29 days have posted temperature deficits. Monday, with extremes of 79 and 59-degrees was one of them, finishing two degrees below normal and a lot cooler than a year ago when the high and low were 94 and 71 degrees.  The month is running 2.8-degrees behind a year ago. It’s a difference in temperature which has likely reduced air conditioning usage roughly 21 percent compared to the same period last August.

It’s in the rain department that this August has been much different than its predecessor a year ago. The official measurement to-date has been 4.51 inches, nearly two and three-quarters inches (2.71 inches) more than August 2010.
 
Eastbound disturbance to bring several showers Tuesday night

Scattered showers and perhaps an isolated thunderstorm reach portions of the Chicago area Tuesday night after a day of increasing clouds, expected to filter the area’s sunshine as the day proceeds. The overnight showers are likely to be of limited coverage, affecting perhaps 30 to 40 percent of the metro area and producing anywhere from a few hundredths to as much four tenths of an inch of rainfall.

A shower could linger into the Wednesday morning, then daytime heating and a more unstable atmosphere (temps are to be increasing faster with height than normal) Wednesday afternoon and evening could lead to an isolated thunderstorm or two later in the day.  Coverage on these rains also appears limited.
 
September kicks-off with 90s later this week; first to do that in three years
 
Some big weather changes lie ahead later this week and over the Labor Day holiday weekend. Strong late-week warming is to push temperatures to 90 or even higher Thursday and Friday, the opening two days of September. It’s a month which hasn’t opened with 90-degree temperatures in three years.
While a few isolated thunderstorms may develop as temperatures take off and humidities surge Thursday, it’s Friday afternoon and night which look a bit ominous. Atmospheric moisture levels are to reach or exceed 2 inches later Friday.  That level of moisture in the presence of powerful jet stream winds raises the possibility of strong or even severe thunderstorms. It’s a development we’ll be monitoring and updating as the week proceeds.
 
Heat won’t last; strong cooling by Monday could produce the coolest Labor Day here in 5 to 8 years
 
Thursday and Friday’s spike into the 90s will be short-lived. Temperatures roll back to the 80s Saturday but more sharply to the 70s Sunday.  It’s Monday (Labor Day) which looks especially cool. Some areas may be hard-pressed to reach 70-degrees. And chilly air aloft Monday threatens to destabilize the atmosphere to the extent that daytime heating could quickly produce cloud cover and scatter instability showers by afternoon. It’s possible Monday’s high won’t reach 71-degrees, as was the case on Labor Day 5 years ago. An even cooler high of 68-degrees, which is our current forecast for Monday, would make Labor Day 2011 the coolest in 8 years here!
 
Labor Day cooling across nation’s mid-section could break record north Texas heat wave which has continued unabated since May 22
 
What’s also significant about the cooling predicted by Labor Day is the fact it may reach far enough south that the punishing heat wave which has gripped the southern Plains since May could finally break. In the Dallas/Fort Worth area, where temperatures have surged to 90 or higher on all but three days since May 22 (highs have hit 100-degree or more on 63 days there), a break in the blistering temperatures would be welcomed by the heat-weary population.
 
Models hint tropical system could spin up in the western Gulf this weekend
 
Of interest is the suggestion by computer models that a weather system could spin up over the western Gulf in response to the temperature downturn farther north. The National Weather Service’s GFS model and the European Center’s ECMWF model generate four to eight inches of rain—and even more in spots—along sections of the Gulf Coast. Any migration of these rains into drought-stricken Texas could bring some relief in a prolonged dry spell which is the worst on record there.
 
Final Irene rain tallies hit 20 inches in spots on the Eastern Seaboard; much of it fell in 24 hours!

The final rain tallies are in on Hurricane and Tropical Storm Irene, which pounded the Eastern Seaboard with winds clocked as high as 115 mph in gusts and rains in excess of 20 inches in a few harder hit locations over the weekend. Among the heavier tallies were 20.40 inches near Virginia Beach, Virginia;  20 inches at Jacksonville, North Carolina, 13.30 inches East Durham, New York; 12.96 inches Plum Point, Maryland; 12.09 inches Ocean City, Maryland; 11.27 inches near Freehold Township, New Jersey; 11.23 inches Mendon, Vermont; 9.10 inches Savoy, Massachusetts; and 8.82 and 8.53 inches at Lafayette and Forks Township, Pennsylvania.  Pinkham Notch, New Hampshire was hit with 7.33 inches of rain.

Cape Verde disturbance could be headed for major hurricane status in the Atlantic  by this weekend
 
The Atlantic Basin hurricane season moves into primetime in coming weeks and forecasters are already monitoring another wave in the far eastern Atlantic—a disturbance which may become a major Category 3 hurricane with 120 mph sustained winds by this weekend. The system has moved off Africa in recent days and is expected to spin up into a significant storm, given its predicted movement into a region of warm Atlantic water and limited vertical wind shear. An environment like that favors intensification.

ASK TOM WHY: "Hurricane forecast cones" narrower this year?

Dear Tom,
The “hurricane cones” this year seem to be narrow compared to the cones in recent years. In particular, the cone for Hurricane Irene was very narrow. What is the explanation?

–Tic Michaels

Dear Tic,
Indeed, “track forecast cones” issued in 2011 by the National Weather Service’s National Hurricane Center are noticeably narrower than in previous years. This is a testament to the increasing ability of the center to forecast the future movement of tropical cyclones. The cone represents the expected track of the center of the storm; the width of the cone is set so that two-thirds of the forecast errors over the past five years fall within the cone. The center of a tropical cyclone can be expected to remain within the cone 60-70 percent of the time. Note that this refers to storm position, not to intensity.