Weekend Northern Ohio Radar Loops - Temperatures

CHECK OUT THE CURRENT RADAR LOOPS AND CURRENT OHIO TEMPERATURES




Current OHIO temperatures


Current Ohio Valley radar loop


.

Radar Loops, Heavy Rainfall Forecast

More steady rainfall today. CHECK OUT THE CURRENT RADAR LOOPS AND CURRENT OHIO TEMPERATURES...RAINFALL FORECAST AT THE BOTTOM




Current OHIO temperatures


Current Ohio Valley radar loop



Projected rainfall amounts are significant. Flash Flood Watch will need to be issued later today by the NWS.

Severe Weather, Heavy Rain Outlook

The same system that produced the severe weather Monday has stalled across Ohio focusing more rain and storms over the next 36 hours. Notice the amount of moisture and its Gulf of Mexico origin.

Precipitable Water: WARMER colors mean more available moisture

Projected rainfall amounts are significant. Flash Flood Watch will need to be issued later today by the NWS.

Northern Ohio radar loop


Current OHIO temperatures


Current Ohio Valley radar loop

Northern Ohio Severe Weather Recap. ONE TORNADO CONFIRMED

A pretty big weather day yesterday across northern Ohio. Many severe storms with heavy rainfall (2-5"), 1" hail reported & tornado warnings. 

Many people have complained about our "wall-to-wall" coverage saying that nothing was happening and it wasn't worth it. "No tornadoes on the ground so what is the point of coverage like this?" a few said via Facebook and Twitter.  While its easy to lump this event in with all of the others, this round of severe storm was very different than other severe weather events we've had in the recent past in northern Ohio. Why? First, many of the severe cells had the classic hook echo characteristic indicating strong counter clockwise winds which often indicate a tornado. Thankfully, only ONE TORNADO was confirmed in Lorain County. I thought we'd end up with 4 or 5 easily.

Secondly, many cells also had strong changes in wind direction embedded within them. By using the "Velocity Scan", we can determine which cells have rotational signatures by recognizing those small scale wind direction changes. Green colors mean wind moving toward the radar. Red colors mean wind is moving away. Notice the abrupt change and the implied rotation.

For these reasons, the National Weather Service issued tornado warnings. As a public service, it is mandatory to inform the public of the tornado warnings. Given the numerous storms, we needed to break into programming to cover this event BIG TIME! 

For those of you who claim that more tornado warnings are being issued for northern Ohio, that's not the case. After doing some exhausting research compiling tornado warning history, I found that the issuance of tornado warnings at the National Weather Service office in Cleveland, Ohio (our home office) is trending lower since the early 1990s. Also, the percentage of tornado warnings that result in actual tornadoes here in northern Ohio during the same period is comparable to the national average.

=======================================================================

As we recap yesterday's severe weather, its a good idea to review what constitutes a severe thunderstorm as defined by the National Weather Service.

Most storms NEVER reach severe limits. A very small number of severe storms actually produce a tornado. That's comforting news for all of us. That said, the mere mention of the word "severe" has extreme connotations. Many people believe that the word "severe" means "tornado". Nothing could be further from the truth. Here are the tornado facts and figures that I hope set the record straight.

* 5% of storms are severe. Only 1% of storms produce tornadoes

* Tornado warnings are issued for about 75% of all tornadoes

* In 2007, the National Weather Service started to issue warnings on a more local level versus on a county basis. These "polygons" localize the threat inside a specific part of a county.

* Tornadoes occur over a wide spectrum of strengths, sizes, and lifetimes.  Of the 800–1400 tornadoes reported in the United States each year, about 86% can be characterized as weak, 13% as strong, and 1% as violent.  

* In general, weak tornadoes (86%) have lifetimes less than 10 min, widths around 100 m (yards) and paths less than 1.6 km (1 mile) in length.  National Weather Service radars can complete ONE SCAN every 4 to 6 minutes! 

* Typical tornadic wind speeds are on the order 110 mph.   

* The average “lead time” for tornado warnings was less than 5 min in the late 1980s. By the late 1990s, lead time was up to 10 minutes; 13 minutes today (2014)

* National Weather Service forecasters provided a 24-minute lead time for tornado warnings in Joplin, Missouri back in 2011, almost TWICE the national average. 

* According to one study in 1978, there was a 22% probability of tornado detection with a 3 minute warning lead time. By 1998, the probability had jumped to 65%! 

How far Behind Is The Growing Season?

The growing season is starting off slower than last year. The soil temperatures have been slow to recover after the very cold winter and early spring.

Agriculture experts use GROWING DEGREE DAYS as a measure of GROWTH RATE in plants and insects. By tracking the average temperature and plugging it into a simple equation HERE, a measure of whether or not the growing season is ahead/behind can be found. Notice that this year's growing season (through May 7th) is very similar to 2011 but way behind last year. Incidentally, the start of the 2010 and 2012 growing season was the earliest in 140+ years of northern Ohio record keeping using the GDD measure. To put this another way, last year's (2013) growing season was at this year's level (151) more than a week ahead of this year.  In the record setting warm spring of 2012, the growing season was at this year's level on MARCH 21st!

Each plant, tree and insect has its own thresh hold depending on the specific location. Just plug in your ZIP CODE. By checking a plant or insect's GROWING DEGREE DAY, you can determine when it will first bloom or hatch.  Here is brief summary of the list for Medina, Ohio. You can see what has bloomed and what will bloom in the near future.

Current OHIO temperatures, Radar Loop Over Ohio Valley & Northern Ohio

Current Ohio Valley radar loop


Current OHIO temperatures


Northern Ohio radar loop

Detailed Summer Outlook: How Many 90 Degree Days/70 Degree Days?

Last week, I wrote about how we derive our summer outlooks by analyzing ocean sea surface temperature patterns (El Nino, etc), pressure patterns over the Arctic and North Atlantic among some others. The elements just mentioned are matched up with other years of occurrence. A best possible fit is created. Remember that specific day-to-day weather is never the objective.  Its impossible to determine the weather for specific days months out contrary to what the Farmers' Almanac says.

So what were CLEVELAND summers like in years that match up similar to 2014?  90 degree days, overall rainfall, days with below normal temperatures? Here is a quick graphic...

Severe Weather Update; Frequent Rains for Ohio Valley

CURRENT RADAR IMAGE FOR NORTHERN OHIO. LOOP HERE

James Bryant, Associated Press

The fatality free start to the tornado season ended yesterday (Sunday, April 27th) when an 11 month old baby was killed following a roof collapse. This was the longest stretch without a tornado fatality since 1915!  We can thank a colder than normal winter with a jet stream that kept unstable air away from the US. Add to that the high resolution radar grid across the country which gives us much better lead time when tornadic weather strikes.

Here in northern Ohio, severe weather threat will be small but the rainfall totals will be significant through late Wednesday.

Severe weather will develop today across northern Mississippi, Alabama and central Tennessee. Moderate risk across the deep south.

Current radar images for Central Tennessee and northern Mississippi and Alabama.

Summer Outlooks Are Different Than Day-to-Day Forecasts

Our WJW FOX8 Summer Outlook first aired on Thursday, April 24th. Not long after, comments and criticism started pouring in stating in part that we should concentrate on getting the daily forecast right rather than trying to forecast the weather months out. This isn't new. It happens after each seasonal outlook.

Actual day to day weather forecasts are developed with analyzing current conditions, radar, satellite and other parameters to make a forecast for a short period of time in the future. 12 Hours, 24 hours, 36 hours, 48 hours. We utilize computer model projections as guidance. Yes, these projections are getting better as more data is utilized and plugged into faster and faster computers with more sophisticated equations.

Seasonal long range outlooks (winter weather forecast, etc) are created by looking at the ocean sea surface temperature patterns (El Nino, etc), pressure patterns over the Arctic and North Atlantic among some other long term atmospheric trends. Some scientists use solar output and other variables. The elements just mentioned are matched up with other years of occurrence.  A best possible fit is created. Sometimes this works out well.  Sometimes it doesn’t.  Again, this is a trend outlook not a specific forecast for a specific day. Individual storms cannot be seen this far out. Forecasts for specific days? Forget it. Too much randomness in the atmosphere that is way beyond our abilities. But by looking at parameters that existed in the past during other storm events, we can say that the chance of say a hurricane making landfall is greater this year than in years past. 

For most, all of these forecasts and trend outlooks are lumped into one group even though each are derived using entirely different information. I get it. Its human nature to generalize and simplify complicated subjects like the science of weather prediction. So as a result, we formulate a concrete, black and white, overly scaled down version of the weather.  Whether its a long range winter outlook, a climate average for a wedding day, the thunderstorm chances for later this afternoon, lake effect snowfall amounts or a hurricane forecast track. Its all the same animal to most. We subconsciously eliminate the nebulous science, weird looking equations and fancy internet computer animations in favor of a narrative that tells a better story.  In short, The Old Farmers’ Almanac fits with how our brains are wired.  Its simple. Its folksy with just enough science to make it credible.  Why do we continue believing the Old Farmers’ Almanac?  The simple answer is it makes us feel good!  While I love the Old Farmers Almanac for its articles, I'd trust an actual Meteorologist's forecast first.  I wouldn't preemptively dismiss the scientific explanation, ignore the random changes and replace them with the Old Farmers Almanac figuring that its more accurate.  Just saying...

So remember that Seasonal Outlooks are by their very nature formulated differently than day-to-day forecasts.  Let's sit back and see if this summer will behave like we think it will.

Is Spring Disappearing?

"It seems like we go straight from winter into summer nowadays."

Its by far one of the most frequent comments I get this time of year. But is it true? Are those traditional spring days from yesteryear being replaced by quicker transitions from winter to warmer days?

A tall order for sure. So rather than relying on our perceptions (I've written extensively how our senses and selective memory fools us by placing more weight on more recent events that match up with our inherent biases) in determining whether or not this "winter-to-summer" trend actually exists, I looked up the average temperatures each day during the meteorological spring months (March through May) over the last 50 years. I plotted the average daily temperature and ran a linear regression of all 92 days (March through May) for each year since 1964 (last 50 years) to determine the rate of warming for each spring.

For example, 2013 looks something like this: 

The "slope" if you remember from grade school math represents the trend. So in last year's case, the slope or trend was a 0.46 degree INCREASE per day from March 1st through May 31st.

That's great but that's only one year. How about the other 49 years?  I won't bore you with each temperature scatterplot but some interesting years stand out. The largest increase per day occurred in 1975. The smallest increase per day occurred in 1973.

Here are the TOP 10 and BOTTOM 10 with the year of occurrence:  Only 2 of the TOP TEN occurred in the last 20 years.
 

Back to the original question? ARE SPRING TEMPERATURES DISAPPEARING IN FAVOR OF A FASTER TRANSITION FROM WINTER TO SUMMER?  MORE IMPORTANTLY, IS THERE A LONGER TERM TREND IN THESE YEARLY SPRING TEMPERATURE TRENDS?
 
I plotted each year's trend with the trend line. The long term trend over the last 50 years is negligible.

However, the same temperature trend data in bar graph form shows HIGHER INCREASES in consecutive years since 2000 (except was 2012).  The increase over the last 15 years is steady around 0.35 degrees per day in spring. We also saw some long stretches in the 1980s equal to recent years.

The 1970s though saw WIDER VARIATION YEAR-TO-YEAR with SMALLER INCREASES compared to recent years of about a tenth a degree lower than the last 15 years. 
 

So when someone says "Its seems as if spring is shorter" or "We're jumping from winter into summer faster now than in past years", it seems they would be right...but for a different reason.  These changes of a few tenths of a degree over many years are imperceptible to us. My guess is that we take the short term weather changes (a sudden drop from 75 to 35 for example) and believe these changes reflect bigger changes over longer periods. Its a classic example of the RECENCY EFFECT.