Probability of damaging thunderstorm winds or wind gusts of 50 knots (58 mph) or higher within 25 miles of a point. Source: SPC “Day 1 Convective Outlook,” 12:28 p.m. EDT July 26.
An updated “Day 1 Convective Outlook” from the National Weather Service Storm Prediction Center indicates no remarkable changes in the severe weather outlook for this afternoon and tonight in Indiana.
The entire state of Indiana and all if IMO SKYWARN quadrant two continues to have at least a slight risk of severe weather between 12:30 p.m. EDT this afternoon and 8 a.m. EDT tomorrow. Much of central and southern Indiana continues to have a moderate risk.
No part of Indiana, however, now has any more than a 2 percent probability of a tornado within 25 miles of a point. With the previous outlook, part of southern Indiana had a 5 percent tornado probability.
The next update to the outlook for today is due by 4 p.m. EDT.
Probabilities of damaging straight-line thunderstorm winds of 58 mph or greater within 25 miles of a point between 9 a.m. EDT July 26 and 8 a.m. EDT July 27.Probabilities of hail of one inch diameter or larger within 25 miles of a point between 9 a.m. EDT July 26 and 8 a.m. EDT July 27. Dark red area also has a 10 percent or greater probability of significant hail (two inches or larger).Probabilities of a tornado within 25 miles of a point between 9 a.m. EDT July 26 and 8 a.m. EDT July 27.Probabilities of severe weather between 8 a.m. EDT Sun. July 27 and 8 a.m. EDT Mon. Brown area: 5 percent (below “slight risk” criteria). Yellow: 15 percent (low end of “slight risk”). Red: 30 percent (high end of “slight risk”). Purple: 45 percent (moderate risk). Darkened area outlined in black: 10 percent or greater probability of significant severe weather (see explanation in text).
Most of Indiana and Ohio continue to have a slight risk of severe weather and most of southern Indiana has a moderate risk between 9 a.m. EDT today (July 26) and 8 a.m. EDT tomorrow, according to the “Day 1 Convective Outlook” that the National Weather Service (NWS) Storm Prediction Center (SPC) issued at 8:48 a.m. EDT.
The greatest risks today are damaging straight-line thunderstorm winds of 58 mph or greater and hail of one inch or more in diameter, but a tornado or two is also possible. Remember, however, that a very severe thunderstorm can be more dangerous than a weak tornado.
For today, severe storms are most likely during the evening and overnight hours, according to a “Hazardous Weather Outlook” that the northern Indiana NWS office issued at 6:12 a.m. SKYWARN storm spotter activation might be needed tonight, according to that outlook.
Today and tonight, readers in the Fort Wayne area have a 15 percent probability of damaging straight-line thunderstorm winds of 58 mph or stronger, a 15 percent probability of hail of one inch diameter or larger and a 2 percent probability of a tornado. All of these probabilities fit in “slight risk” category but they’re also all markedly higher than the probabilities for a normal day this time of year. Read more about how to interpret outlook probabilities.
In most of the southern half of Indiana (the purple area on the top map), including Indianapolis, Bloomington and Terre Haute, the damaging straight-line wind probability today and tonight is 45 percent, which falls into the “moderate risk” category.
On Sunday, most of the severe weather risk is farther east, but the Fort Wayne area and all of IMO SKYWARN quadrant two have a slight risk of some form of severe weather between 8 a.m. EDT Sunday and 8 a.m. EDT Monday, according to the “Day 2 Convective Outlook” that the SPC issued at 2:06 a.m.
In addition, part of the quadrant (All or parts of the Indiana counties of Adams, Wells, Blackford and Jay and the Ohio counties of Paulding, Van Wert, Putnam and Allen) have a 10 percent or greater risk of significant severe weather during that period. The SPC defines “significant severe weather” as any one of the following: tornadoes capable of producing EF2 or greater damage, damaging straight-line winds with speeds greater than 65 knots (75 mph), or two-inch-diameter or larger hail.
Day two outlooks do not provide probabilities for each type of severe weather. The text of the outlook, however, indicates threats of large hail, damaging straight-line winds and tornadoes, especially in the 30 percent (red) and 45 percent (purple) areas. Although Fort Wayne and the rest of quadrant two are in a 15 percent probability area Sunday, none of the three types of severe weather can at this time be ruled out.
Any such storms on Sunday are most likely in the afternoon, when SKYWARN storm spotter activation might again be necessary.
It would be wise for anyone who lives in Indiana or Ohio to make sure they have a way of finding out about any watches or warnings the NWS might issue today or tomorrow, whether they are outdoors at fairs, ball games, etc. or indoors sleeping late at night.
The SPC will update its outlook for today by 12:30 p.m. EDT and its outlook for tomorrow by 1:30 p.m. EDT.
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Probabilities of severe weather within 25 miles of a point between 8 a.m. EDT Sat. and 8 a.m. EDT Sun. Brown area: 5 percent (below “slight risk” criteria). Yellow: 15 percent (low end of “slight risk”). Red: 30 percent (high end of “slight risk”). Darkened area outlined in black: 10 percent or greater probability of significant severe weather (see explanation in text). Highlighted counties: County warning area of the northern Indiana NWS office. Source: SPC “Day 2 Convective Outlook,” 1:22 p.m.
Central Indiana now has a 10 percent or greater probability of significant severe weather between 8 a.m. tomorrow (Sat., July 26) and 8 a.m. Sunday, according to an updated “Day 2 Convective Outlook” that the National Weather Service Storm Prediction Center (SPC) issued at 1:22 p.m. The SPC defines “significant severe weather” as any one of the following: tornadoes capable of producing EF2 or greater damage, damaging straight-line winds with speeds greater than 65 knots (75 mph), or two-inch-diameter or larger hail. The significant severe weather area includes most of Blackford County, Indiana and the southwestern corner of Jay County, both of which are part of IMO SKYWARN quadrant two.
In addition to the addition of a significant severe weather risk, the size of the 30 percent severe weather probability area (high end of “slight risk”) has grown since this morning’s version of the day two outlook. It now includes most of Allen County and Whitley Counties of Indiana, most of Paulding County, Ohio and about half of Putnam County, Ohio.
The outlook described above is subject to change (it could get more or less serious tomorrow nears). Our next look at the outlook for tomorrow (Sat.) comes when the SPC issues its “Day 1 Convective Outlook” due out by 2 a.m. EDT tomorrow.
Probabilities of severe weather within 25 miles of a point between 8 a.m. EDT Sat. and 8 a.m. EDT Sun. Brown area: 5 percent (below “slight risk” criteria). Yellow: 15 percent (low end of “slight risk”). Red: 30 percent (high end of “slight risk”). Read more about probabilities. Highlighted counties: County warning area of the northern Indiana NWS office. Source: SPC “Day 2 Convective Outlook,” 2:05 a.m. July 25.
Much of Indiana and Ohio have increased probabilities of severe weather between 8 a.m. EDT tomorrow (Sat., July 26) and 8 a.m. EDT Sunday, according to the “Day 2 Convective Outlook” that the National Weather Service Storm Prediction Center issued at 2:05 a.m. EDT. Some areas have twice as much probability of severe weather, as compared to the “Day 3 Convective Outlook” the SPC issued yesterday.
All of Indiana and Ohio have a slight risk (a probability of at least 15 percent) of some form of severe weather within 25 miles of a point on Saturday, but a large part of Indiana and Ohio — including most of IMO SKYWARN quadrant two — now have a 30 percent probability, which is on the high end of “slight risk” criteria. When you consider that normal severe weather probabilities in these areas are probably 1 percent or less, a 30 percent probability essentially means that severe weather is approximately 30 times more likely than normal. Read more about how to interpret outlook probabilities.
For readers who might have trouble seeing the map above, within quadrant two, the 30% probability area includes southern Whitley County, extreme southern Allen County (Ind.), extreme southwestern Putnam County and all of the Indiana counties of Huntington, Wells, Adams, Blackford and Jay and the Ohio counties of Van Wert and Allen.
Day two outlooks do not provide probabilities of specific types of severe weather, so the probabilities above refer to one or more of the following: tornadoes, damaging straight-line thunderstorm winds or gusts of 58 mph or higher or hail of one inch or more in diameter.
Saturday meteorology
Here’s what meteorologists expect to happen Saturday: A cold front will travel quickly eastward across Wisconsin and Upper Michigan and then become stalled southwestward across northern Illinois, Iowa and northern Missouri and Kansas through evening. A broad belt of southwesterly winds in the low levels will develop and bring substantial moisture northeastward ahead of the front with dew points in the 70s into Illinois and Indiana by late afternoon. The greatest severe wind potential appears to be during the evening and overnight, from central Illinois eastward across Indiana, northern Kentucky and Western Ohio. Computer models are in good agreement, showing a corridor of strong storms.
A large complex of severe thunderstorms, which could persist for several hours, is possible (a severe mesoscale convective system, for readers who are weather geeks). Changes of wind direction and speed with altitude, which are required to sustain a severe thunderstorm (wind shear) will also increase overnight. Significant wind gusts will be possible. In addition, large, discrete rotating thunderstorms (supercells) are possible if the storms that form do not meld together as quickly as expected. If that happens, a couple tornadoes could occur.
Sunday
Probabilities of severe weather within 25 miles of a point between 8 a.m. EDT Sun. July 27 and 8 a.m. EDT Mon. Brown area: 5 percent (below “slight risk” criteria). Yellow: 15 percent. Red: 30 percent. Darkened area outlined in black: 10 percent or greater probability of significant severe weather (see explanation in text). Highlighted counties: County warning area of the northern Indiana NWS office. Source: SPC “Day 3 Convective Outlook,” 3:30 a.m.
Slightly more than half of Indiana and all of Ohio have a slight risk of severe weather between 8 a.m. EDT Sunday, July 27 and 8 a.m. EDT Monday, according to the “Day 3 Convective Outlook” that the SPC issued at 3:30 a.m.
All of IMO SKYWARN quadrant two — including all of Allen County, Indiana — have a 15 percent probability of severe weather within 25 miles of a point. More importantly, the entire quadrant has a 10 percent or greater risk of significant severe weather, which the NWS defines as one or more of the following: tornadoes capable of producing EF2 or greater damage, damaging straight-line winds with speeds greater than 65 knots (75 mph), or two-inch-diameter or larger hail. Obviously, significant severe weather is even more rare, so 10 percent represents well more than 10 times the normal probability.
As with Saturday, Sunday’s severe weather will most likely happen late in the day. Meteorologists expect that by late afternoon Sunday, low pressure will settle over Lower Michigan, while a cold front extends southwestward from Indiana into southern Missouri. Ahead of the front, a very moist and unstable air mass will exist within an environment that has enough wind shear (see above) to support severe storms. Afternoon storm development will most likely happen first along the cold front, from northern Indiana into northern Ohio and extending northeastward across western New York. Supercells (see above) will be the dominant storm mode with very large hail and a tornado or two possible.
It would be a good idea to check today to make sure you have a reliable way to receive weather warnings and watches, especially in the middle of the night Saturday, while you’re sleeping. As always, I recommend a weather alert radio, which you can buy today for around $30 at many local retailers, including Walgreens and Kroger. If you have planned any outdoor activities Saturday afternoon or evening or Sunday afternoon or evening, determine now how you’ll know if a warning is issued while you’re out and where you will take shelter. If you are a SKYWARN storm spotter, be prepared for activation Saturday and Sunday.
The outlooks described above are subject to change (they could get more or less serious as the days they describe approach). Our next look at the outlook for Saturday comes when the SPC updates its “Day 2 Convective Outlook” by 1:30 p.m. EDT. After that, the next look at Saturday comes in a “Day 1 Convective Outlook” due out by 2 a.m. EDT tomorrow. Out next look at the outlook for Sunday comes in Saturday’s “Day 2 Convective Outlook” also due by 2 a.m. EDT tomorrow.
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Yellow area: Slight risk of severe weather between 8 a.m. EDT Sat. and 8 a.m. EDT Sun.
All of Indiana and Ohio have a slight risk of severe weather between 8 a.m. EDT Saturday, July 26 and 8 a.m. EDT Sunday, according to the “Day 3 Convective Outlook” that the National Weather Service (NWS) Storm Prediction Center (SPC) issued at 3:29 a.m. EDT today. The slight risk area also includes part of southern Lower Michigan, which means all 37 counties covered by the northern Indiana NWS office are included.
The entire slight risk area has a 15 percent probability of severe weather within 25 miles of a point. Severe weather is defined as one or more of the following: tornado, damaging straight-line thunderstorm winds of 58 mph or more, or hail of inch in diameter or larger.
Forecasters expect scattered clusters of storms to form by Saturday evening along a front that should be draped from the lower Great Lakes region across parts of the central plains. They expect large hail to be the greatest threat during the late afternoon and evening Saturday. There will also be a potential for one or more swaths of damaging straight-line winds into Saturday night. Forecasters warn that as Saturday approaches, future outlooks might include higher probabilities of severe weather.
Anyone in the slight risk area who plans outdoor activities Saturday afternoon and/or evening should also plan to have a way to be notified of any weather watches or warnings that might be issued. SKYWARN storm spotters should prepare their vehicles and equipment for possible activation Saturday.
The SPC will issue its next outlook for Saturday with its first “Day 2 Convective Outlook” tomorrow. It’s due out by 2 a.m.
Probability of damaging straight-line thunderstorm winds or wind gusts of 50 knots (58 mph) or higher within 25 miles of a point. Yellow area: 15 percent. Brown: 5 percent (below slight risk criteria). No color overlay: Less than 5 percent. Highlighted counties: County warning area of NWS northern Indiana office. Source: SPC “Day 1 Convective Outlook,” 8:58 a.m. EDT.
Northwestern and part of west-central Indiana has a slight risk of severe weather between 9 a.m. EDT today and 8 a.m. EDT tomorrow, according to an updated “Day 1 Convective Outlook” that the National Weather Service (NWS) Storm Prediction Center (SPC) issued at 8:58 a.m. EDT. The slight risk includes part of southwestern Lower Michigan and most of IMO SKYWARN quadrants three and four but none of quadrants one or two.
As you can see on the map at right, however, northeastern Indiana, including Indiana counties of IMO SKYWARN quadrant two, have a 5 percent probability of damaging straight-line thunderstorm winds or wind gusts of 50 knots (58 mph) or higher within 25 miles of a point. That’s below “slight risk” criteria but makes it worthwhile to keep an eye on updated convective outlooks.
SPC plans to issue its next, updated “Day 1 Convective Outlook” by 12:30 p.m. EDT.
I’ve wondered for a while whether tornado sirens (or, as emergency managers often call them, “outdoor warning sirens”) have become so ingrained in our culture over the past several decades that people instinctively treat them as our most important (if not our only) method to receive warning of impending weather danger.
Tornado damage in Smithfield, NY (NWS photo)
Lately, I’ve seen evidence that this is unfortunately the case. It would be unfortunate, because such sirens were never intended to provide warning to people who are indoors and because many, many communities (including the Indiana community in which I live) don’t have enough warning sirens to assure that every person in the community can hear them, even when outdoors.
Why do I think our culture nonetheless puts too much stock in tornado sirens? Here’s one case in point: CBS Evening News reporter Vinita Nair did a report July 9 about a rare New York State tornado that killed four people in the town of Smithfield. In part of her report, Nair said, “Smithfield doesn’t even have tornado sirens.” What prompted that line in her report? I submit that its inclusion indicates how widely-held is the belief that tornado sirens are a primary way to receiving warning of impending danger.
Here’s more evidence to consider. At the 11th International Information Systems for Crisis Response and Management (ISCRAM) Conference in University Park, Pennsylvania, last May, seven authors presented “Tweeting and Tornadoes,” an academic paper that examines the content of geo-located Twitter messages (tweets) sent on the microblog social network during the Moore, Oklahoma tornado of May 20, 2013. Among other findings, the authors noted that the volume of tweets spiked significantly when tornado sirens became audible to Twitter users (see the graph below).
Figure from Blanford, et. al., “Tweeting and Tornadoes”: Temporal distribution of tweets with at least one keyword (gray bars) (e.g., ‘storm’, ‘weather’, ‘take/ing cover’, ‘shelter’, ‘pray’, ‘emergency’, ‘red cross’, ‘help’ and ‘devast’, ‘destruct’, and ‘donat’ in relation to tweets containing the keyword ‘tornado’ (blue area) or ‘siren’ (black line) and how these related to the tornado event (red bar). Tweets were summarized for each hour.
The authors write, “Sirens in Moore were sounded six times with the initial siren occurring shortly after the first NWS tornado warning was sent (14:41hr) with the final warning at 15:20hr (Kuligowski et al., 2013). The first mention of sirens also begins at 14:41hr (N=22 tweets in 4 minutes) with tweets such as ‘Sirens going off now!! Take cover…be safe!’, ‘Sirens sirens sirens. Becoming so real’, and ‘If u hear a tornado siren, uve got 6-8 minutes…’”
The tweet that included the words “becoming so real” particularly got my attention. It almost seems as if the writer of that tweet did not begin to appreciate the seriousness of the situation, until she heard sirens. And it came from a person who was obviously connected to the Internet (either via computer or smartphone) and therefore had at her disposal official tweets from NWS and other information sources to enhance situational awareness before sirens sounded.
If, in fact, sirens have become so ingrained in our culture that we need them for motivation when severe weather threatens, I consider that a dangerous trait. Too many of us will never hear a siren, even if a tornado is about to destroy the home we’re in. Even a person who lives close to a siren will likely never hear it just before a non-tornadic severe thunderstorm drops a tree on his house and kills him (because many, if not most, communities don’t sound tornado sirens for severe thunderstorms without imminent tornado threats).
How do we remove tornado sirens from their strongly held homes deep in our collective psyche? Perhaps we can’t. But it sure wouldn’t hurt if trusted news sources and public officials continue to share information with their audiences and constituents about the shortcomings of tornado warning sirens, the necessity of having alternative means of receiving warnings and the importance of reacting immediately and appropriately to those warnings, regardless of whether a tornado siren is audible. Likewise, if you’re reading this blog, chances are good that you’re the severe weather expert in your family, circle of friends, church, etc. You can help to, by spreading the word in your community.
The sound of a tornado siren is so motivating and our response to the sound is so emotional, that the Indianapolis Colts NFL football team uses that sound to rile up the fans during home games at Lucas Oil Stadium. We might never change the emotion associated with that sound. But perhaps we can help protect our communities by doing what we can to build up the importance of other warning methods.
If we’re successful, perhaps someday, the sound of a weather alert radio’s alarm will prompt a tweet like, “Weather radio sounding off. This is becoming so real.”
What do you think? Add your comments to this post (there’s a link right under the title).
Yep, its certainly unseasonably cool today. And you’ll probably here some folks attribute the cool weather to the Polar Vortex. As WANE TV’s Greg Shoup explains in his blog, we should take any such comments, even from “meteorologists,” with a grain of salt:
This typical July-like pattern will over the course of a few days be replaced by a ‘lobe’ from that ‘vortex’ or circulation that is referred to as the Polar Vortex. This concept is often misunderstood, especially in the national media as it is referred to simply as The Polar Vortex. This is scientifically inaccurate as the vortex or circulation itself moves very little. It has a semi permanent position near the Arctic Circle. That location does not vary and the vortex is never moving into a different location. However, sometimes we see a piece, chunk or scientifically called a ‘lobe’ break off this vortex and make its way to our region. This is not a common feature during the summer months so it is certainly very unusual.
