Where There is Thunder, There is Lightning

This week is Lightning Safety Awareness week in many parts of the country. If your local National Weather Service office is participating then you may have seen their links to some lightning information on their web page. I'll be sharing some information about this topic in my posts over the next several days.

Lightning is one of the oldest recorded natural phenomena. Despite our long study of lightning (remember Ben Franklin?) it remains on the frontier of atmospheric science.

Lightning occurs throughout the country and in all seasons. The area of highest incidence extends from the central and southern Plains through the Midwest and in the Southeast. Florida is the lightning capital of the U.S. with an average of 27 to more than 33 flashes per square mile per year.

We credit Ben Franklin with discovering that lightning was electrical in nature and was in fact static electricity. Ben was one incredibly lucky man with that experiment.

As Ben discovered, lightning is a sudden electrostatic discharge from a thunderstorm. These giant sparks can extend from the cloud to the ground or objects on the ground, between clouds, within the cloud, or even between the cloud and air.

In many respects lightning is similar to the static electricity spark you may see or feel during the winter when the air is very dry and you touch a metallic object. When you walk across a carpet, for example, electrons move from the atoms in the carpet to you.  You are, in effect, negatively charged. When you touch a metallic object like a door knob, the electrons move from you to the knob. The zap you feel and may hear are the electrons moving from you to the door knob through an electric spark.

Similar processes occur in a thunderstorm. As the thunderstorm develops the updrafts and downdrafts within the storm result in collisions between the precipitation particles within the cloud. Near the top of the storm these are usually small ice crystals. The ice crystals become positively charged and are carried higher into the storm because they are lighter. As a result the top of the storm becomes positively charged, while the middle and lower layers become negatively charged. Small ice crystals and small hail occur in the middle of the storm, while in the lower layer raindrops and melting hail occur. The collisions between these particles cause some to lose electrons and become negatively charged. The negative charge in the middle and lower layers of the thunderstorm cloud induces a positive charge in the ground underneath the storm, and the positively charged anvil induces the ground under the anvil to become negatively charged.

How electrical charges are distributed in a thunderstorm. Credit: NOAA

In the early stages of thunderstorm development the air acts as an insulating layer between the cloud and its surroundings. As the electrical charges build up within the thunderstorm, the difference between, for example, the negatively charged middle portion of the cloud and the ground become large enough to overcome the insulating effects of the air, and a lightning discharge occurs. When this discharge occurs between the middle of the cloud and upper portion of the storm, “in-cloud” lightning occurs.

In-cloud lightning. 
Credit: jpdavey.deviantart.com

When the discharge occurs between the negatively charged region of one storm and the positively charged region of another, it is called cloud-to-cloud lightning.

Cloud-to-cloud lightning over Washington D.C.
Credit: Kevin Ambrose, Capital Weather Gang

 Lightning can also occur between the cloud and the surrounding air.

Cloud-to-air lightning.
Source: YouTube

Cloud-to-ground lightning occurs when the discharge happens between the cloud and the ground.

Cloud-to-ground lightning.
Credit: UK Met Office

Cloud-to-ground lightning strikes account for about 25 percent of the lightning flashes worldwide. They are some of the most spectacular and also the most dangerous because they hit the ground or objects on the ground. The lightning discharge lasts only a few microseconds, but the process of its formation is complex.

Credit: NOAA

A lightning strike begins when an ionized channel of air, called a step leader, develops from the thunderstorm to the ground. As the step leader zigzags toward the ground, the electrical field increases as the quantity of positive charge residing on the Earth's surface becomes even greater. The electric field is strongest on grounded objects whose tops are closest to the base of the storm such as trees and tall buildings (that’s why you stay away from tall objects during a thunderstorm). This charge begins to migrate upward through buildings, trees and people into the air. When this upward rising positive charge – an upward leader or streamer – meets with the leader in the air above the surface, a conductive path is completed. Electrons surge along this path creating the visible lightning bolt. The rapid flow of electrons heats the surrounding air causing it to explosively expand, sending out a shock wave we hear as thunder.

Lightning is the third highest cause of weather-related deaths after flooding and extreme heat, causing an average of 51 fatalities a year with hundreds more injured. The National Lightning Safety Institute estimates that costs and losses due to lightning in the U.S. could be as high as $8 - $10 billion per year.

In my next post we'll look at how people are struck by lightning, the effects of being struck, and some statistics  on lightning fatalities that may surprise you.

Bill Leaving Soggy Footprints

Radar image from Houston, TX at 3:21 p.m. CDT June 16.

Tropical Storm Bill came ashore along the Texas Gulf Coast yesterday and since then has made his way well inland.

Although Bill was downgraded to a tropical depression this morning, there were still tropical storm force winds being recorded in Oklahoma this evening. The big impact from Bill is not the winds but the copious amounts of rain he's laying down along his path.

 

24-hour precipitation ending the morning of June 17, 2015.
Source: NWS Advanced Hydrologic Prediction Service

Rainfall was heaviest yesterday and last night  in Jackson and Wharton Counties between Port O'Connor and Houston, TX.  The CoCoRaHS observer at TX-JK-5 (Ganado 1.5 W) recorded a whopping 11.77 inches of rain for the 24-hour period ending this morning, and a total of 15.06 inches from June 14-17. There were a number of 24-hour amounts in excess of 7.00 inches in this same area. Fortunately there was almost two weeks of dry weather before Bill waded ashore.

24-hour precipitation ending the morning of June 17 in Jackson County, TX

4-day CoCoRaHS precipitation totals for coastal Texas near T.S. Bill landfall as of June 17.

As of noon today T.D. Bill was located north of Dallas and moving NNE. This evening the center of circulation was just south of Ardmore, OK.

Surface map for 7:00 p.m. CDT June 17, 2015

That's another part of the country that really doesn't need any more heavy rain. Expected rainfall in eastern Oklahoma is from 3 to 7 inches, with locally higher amounts. By Thursday and Friday the moisture associated with Bill will be moving into Missouri and the mid-Mississippi Valley, with three to four inches of rain expected there. This will be on top of already soggy ground resulting from the showers and thunderstorms associated with the frontal boundary that has been oscillating north and south this week in a very moist air mass.

There is some good news in all of this. Showers and thunderstorms are likely to drop some healthy amounts of rain from Indiana east through Ohio, Kentucky and through the mid-Atlantic coast. This area has been rather dry the past six weeks, with precipitation from 75 percent to less than 50 percent of normal.

Quantitative Precipitation Forecast (QPF) for the period from 6:00 p.m. CDT June 17 to 6:00 p.m. CDT June 20, 2015

It appears that rain gauges throughout the central and eastern U.S., including the Upper Great Lakes and the Northeast, will be getting a good workout in the next three to seven days.

Quantitative Precipitation Forecast (QPF) for the period from 6:00 p.m. CDT June 17 to 6:00 p.m. CDT June 24, 2015

It's Official - May 2015 was the Wettest Month on Record in the U.S.

The NOAA National Centers for Environmental Information has crunched the numbers, and 4.36 inches of precipitation for the 48 contiguous states during May 2015 made it not only the wettest May on record in 121 years, but the wettest month ever.

The previous wettest May was in 1957 with 4.24 inches of precipitation, and the previous wettest month was October 2009 with 4.29 inches of precipitation.That one number representing the average precipitation across the lower 48 states is calculated using climate division data in each state. An average for each climate division is determined from the precipitation observations mapped to a 5 kilometer grid.

It's interesting to note that the May 1957 precipitation departures were also highest in the southern and central Plains, but also extended west to California. In all three cases the percent of the U.S. that was classified as very wet (in the top ten percent of the historical distribution) was 43 to almost 45 percent.

Percent of mean precipitation for May 1957 which is now the second wettest May on record.

Percent of mean precipitation for October 2009, now the second wettest month on record.

The fact this was a record wet May is not surprising news for those living in the southern and central Plains. It was the heavy precipitation over a rather large area that contributed to the record total. It was the wettest month ever in Texas and Oklahoma, and Colorado recorded its wettest May on record. It was the second wettest May in Arkansas, Kansas, and Utah.

A Weird, Wet May Across Much of the U.S.

The first tropical storm of the season, Ana, developed off of the southeastern U.S. nearly four weeks before the official start of the season. As Ana weakened and moved away, a late spring storm dropped from one to feet of snow on Colorado, Wyoming, and western Nebraska, with lighter but significant amounts in South Dakota and North Dakota.

California continued to suffer through another month of extreme drought, and the eastern U.S. along and east of the Appalachians was dry with less than 50 percent of average precipitation for most of the area. The notable exception was coastal North Carolina which benefited from the rains from the close approach of T.S. Ana. It was very warm across Alaska and many locations experienced a "top five" warmest May. In the eastern Interior and northern Southeast Alaska this was the warmest May of record. A high temperature of 91°F recorded in Eagle, AK on May 23 was the earliest in the season for 90°F or greater to be reached in Alaska.

In much of the U.S. between California and the Appalachians precipitation was much above normal, well more than twice normal from the Gulf Coast northward through the central Rockies.

The heaviest precipitation, however, was concentrated in Texas and Oklahoma, particularly in northeastern Texas through central Oklahoma.

May precipitation was very heavy from the Gulf Coast northward into eastern Kansas with amounts raining from 10 to almost 30 inches.

It was hard not to know what was going on during the three weeks from May 5 to May 26 if you paid any attention to the news. Oklahoma experienced its wettest month ever since 1895 with average statewide precipitation of 14.40 inches, 9.58 inches above normal and almost four inches higher than the previous record of 10.75 inches in October 1941. In addition, many locations in Oklahoma had their wettest month on record. Oklahoma City had 19.48 inches of rain during the month, beating the precious record of 14.66 inches set in  June 1989. Normal may precipitation for Oklahoma City is 4.65 inches.

CoCoRaHS observers were there to document the historic rainfall. Of 204 Oklahoma CoCoRaHS stations reporting in May,  an astounding 59 of them had 20 or more inches of rain during the month. There were 92 stations reporting on at least 28 days (90 percent) during the month, and of these the largest amount was 26.58 inches at OK-PG-7 (Krebs 0.3 WNW), with the lowest 4.48 inches at OK-CM-2 (Keyes 10.5 ESE)

A large portion of Texas experienced heavy rain during May, but the heaviest rain was concentrated in north-central Texas. Of the 1775 CoCoRaHS stations with reports in Texas during May, 672 reported a foot or more of rain during the month. The highest CoCoRaHS amount was 27.32 inches at TX-GA-9, Pottsboro 7.1 WNW in Grayson County along the Oklahoma-Texas border. A U.S. Cooperative observer in Gainesville, TX, (west of Pottsboro in Cooke County) reported a total of 28.90 inches for the month.

The heavy rain brought a dramatic end to the drought that plagued Oklahoma and Texas since 2010. As of the May 26 U.S. Drought Monitor only 5.4 percent of the state of Texas was in Moderate Drought or greater. The last time that number was this low was on May 11, 2010 when it was 3.51 percent. Five years ago this month there was no drought in Oklahoma, but the drought ramped up there in October 2010.  It peaked in the fall of 2011. The drought disappeared briefly except in the Oklahoma Panhandle and the western half of Texas by the spring of 2012, but then reestablished and intensified, persisting at various intensities until this spring.

The drought in Texas in September 2011 (left), when it was at its peak, and on May 26, 2015.

The drought in Oklahoma on September 2011 (left) and on May 26, 2015.

This particular form of drought relief had other consequences as well. Significant flooding continues to occur along many rivers in Texas, particularly the Trinity River and the Red River. A number of locations along these rivers are expected to remain at major flood stage into next week.

Alaska Breakup - the Transition Between Winter and Non-Winter

While attention in the lower 48 states has been on warmer spring weather and severe storms, it's ice breakup season in Alaska.

Heavy rain, snow melt, and sometimes ice jams sometimes result in spring flooding in the lower 48 states. The primary threat for flooding in the spring along Alaskan rivers is ice jams caused by the breakup of ice. Snowpack and precipitation also contribute, but ice breakup on the rivers in Alaska is when residents along the rivers collectively hold their breath.

River-ice break is a major annual event, and the primary ice breakup window is April and May. Thick ice that formed during the long cold winter begins to soften and melt as the weather warms and the sun climbs higher in the sky during the spring.  Breakup tends to occur earlier when temperatures and river flow are above normal.

Ice jams form when ice accumulates at bends in the rivers, causing more ice to pile up at that spot. Water backs up behind these jams, and the river can leave its banks, flooding communities along the river. Flooding might also be caused by the rapid release of water from the breakup of an ice dam, causing more of a flash flooding situation. As you might expect, flooding risks increase when river levels are higher than normal. Even in years where water levels may be low, ice jams can quickly turn a low flood potential into a high flood potential.

Map showing locations of Eagle and Nenana, AK.

Communities along the Upper Yukon River suffered major flooding in 2013 and in 2009. The flood of 2009 marked the highest peak flood stage on the river. During the first week of May an ice jam formed about 10 miles downstream of Eagle, AK, near the Alaska/Yukon border. Homes and other buildings in the Alaskan Native village of Eagle Village were scoured from their foundations by the massive chunks of ice, and the village of Eagle suffered serious flooding. The river rose up to eight feet on buildings, and businesses were damaged by the floating ice. Flooding also occurred on other rivers, but flooding along the Upper Yukon was the worst. The flooding was preceded by a winter with above normal snowfall across most of Alaska. The early arrival of much above normal to record warm temperatures in the spring caused rapid melting of the snow and increased flow into the rivers.

A huge slab of ice sits across a road near Eagle, AK in May 2009.
Credit: www.lightshineministies.org

Ice and damaged homes in Eagle, AK in 2009.
Credit: National Park Service

There are two main processes for ice breakup on the Alaskan rivers, thermal and dynamic. Dynamic breakups tend to produce the worst flooding. These occur when the river levels rise due to runoff from rapid snowmelt or heavy precipitation. The changing water level helps break up the ice, usually into large sheets. These large pieces of ice can easily be jammed up at bends or narrow portions in the river, causing an ice jam. During a thermal breakup the ice melts in place because there is not enough flow to move the ice downstream. It becomes thinner and thinner, and when it does break up it usually is in smaller pieces rather than massive sheets of ice. However, ice jams and flooding are still possible.

After a warm and snow-starved winter, Alaska experienced its 9th warmest and 11th wettest April on record. The heavier April precipitation was offset by the lack of snow and warm weather during the winter and early spring, reducing the flood threat. This year the flood potential is on the low side for most Alaskan rivers as a thermal breakup is likely on most rivers.

It has been much warmer than normal the past 60 days across central and eastern Alaska.

A number of communities have contests to predict when ice breakup will occur. The best know of these is the Nenana Ice Classic. This began in 1917 when railroad engineers bet $800 guessing when ice on the Tanana River would break up,  and it has been conducted each year since. People from all over the world participate. A tripod is set two feet into the river ice 300 feet from shore. It is connected to a clock on shore that stops once the ice breaks up and the tripod tips over. This year the ice breakup occurred on April 24th, and the winner walked away with over $300,000.

The tripod being installed in the river ice for the 2015 Nenana Ice Classic.
Credit: Nenana Ice Classic

The National Weather Service River Forecast center in Alaska and the Alaska Department of Homeland Security and Emergency Management have begun a Riverwatch program to monitor the breakup of river ice and keep communities informed about river conditions and flood potential.

You can read about ice breakup conditions on the NWS Alaska River Forecast Center web site.

Not Where You Would Expect a Tornado

With much cooler air over much of the country this week has been rather quiet with respect to severe weather. Wednesday has been the most active day with a number of severe storms in northeastern Texas, including several weak tornadoes and hail to three inches.

On Tuesday there was a somewhat rare occurrence in the desert of southern California. A landspout tornado developed out of an isolated thunderstorm and caused some damage to a solar panel array near Desert Center, CA, near the California-Arizona border. If you're wondering what a "landspout tornado" is, it's a tornado that is not associated with a mesocyclone or rotating thunderstorm. They are typically weaker and smaller than tornadoes associated with a supercell and tend to have a smooth appearance, similar to a waterspout (hence the name "landspout"). It is a tornado because the rotating column of air is in contact with the ground and with the parent cumulonimbus cloud - the definition of a tornado.

Landspout tornado near Desert Center, Ca on April 21.
Photo via NWS Phoenix Facebook

The tornado was first reported by a pilot flying in the area. The circulation associated with the tornado was not evident on radar since it was at low levels. The nearest radar was in Yuma, AZ, and at the distance the radar beam at the location of the storm is at about 10,000 feet above the ground. A news crew and a number of other people were able to capture photographs of the tornado.

Another photograph of the Desert Center landspout.
Photo by Russell Fischer via Facebook.

This is the radar image of the storm at 4:00 PDT, about 13 minutes after the tornado was first reported by the pilot. This was at the storm's peak strength. Fifteen minutes later the storm had weakened considerably. The tornado icon indicates where the tornado was reported.

Based on early reports of damage, mostly to the solar array, the National Weather Service has preliminarily given this a rating of EF0. A number of panels were bent and twisted and others were damaged by rocks and other debris flung about by the tornado.

Solar panels damaged by the landspout

The NWS will be sending out a team to survey the damage in a few days. A description of this tornado, photos, and maps can be found at the NWS Phoenix web site.

April 9th Tornadoes in Northern Illinois

This year's severe weather season got off to a slow start for much of the country. In fact, the first severe weather watches in March weren't issued until March 24, which was the latest first March watch in 45 years. In the three weeks following another 53 watches have been issued, a rate more typical of this time of year. Last year there were 1045 severe weather reports through April 15, and this year the count was at 923.

2015 severe weather reports (wind (blue), hail (green), and tornadoes (red)) through April 15.

One of the more spectacular, impressive, and certainly damaging events of the year to date occurred on April 9 in the Midwest.

By now you have probably seen some of the photos and video taken of the tornado in northern Illinois. Now that the dust has settled on this event it's a good time to look at some of the summaries and descriptions of the event that are available. It's not too unusual for there to be numerous videos and countless photographs of tornadoes these days, but this event caught my attention because it was, for lack of a better description, so photogenic and several people captured incredible images. Wide open spaces and clear views of storms are usually the calling card of the southern, central, and northern Plains, not northern Illinois.

Last Thursday's severe weather was anticipated and well-forecast by the NWS. The bulls-eye location for this severe weather event extended from eastern Iowa through northern Illinois, an area located southwest of an intensifying surface low. A warm, humid highly unstable air mass was in place over this area, strong winds aloft, converging winds at the surface, and a 30°F temperature difference from north to south of the warm front.

Annotated surface map for 6:00 p.m. April 9.
Source: National Weather Service Chicago

Most of Illinois and eastern Iowa was in an area of Enhanced Risk for severe weather in the 11:30 CDT convective outlook from the Storm Prediction Center.

The convective outlook issued at 11:30 a.m. CDT on April 9 showing and area of Enhanced Risk from Texas to Illinois and Indiana. On the left is a graphic showing the highest tornado probability from eastern Iowa across northern Illinois.

Storms began to develop during the late afternoon in eastern Iowa and northwestern Illinois. By 6:00 p.m. a strong thunderstorm was developing in northern Ogle County. At 6:09 p.m. the National Weather Service issued a tornado warning for this storm.

Radar image at 6:10 p.m.

At 6:29 p.m. a funnel cloud was reported south of the Rockford Airport, and eight minutes later a tornado was on the ground just south of Cherry Valley, IL. This was a short-lived EF0 tornado. The storm that produced the EF4 was was rapidly developing to the southwest of the first storm.


At 6:35 p.m. a tornado warning was issued on the big supercell. A tornado was reported on the ground near Franklin, IL, between Dixon and Rochell just north of Interstate 88.

Radar image at 6:35 p.m.showing warned storm that produced the Fairdale tornado.

The Fairdale tornado just after formation as it intensifies and strikes Crest Foods in Ashton, IL. Debris is clearly seen in the lower half of the funnel.  Photo by Walker Ashley, used with permission.

Over the next 40 minutes this tornado traveled 30 miles, destroying much of the village of Fairdale, IL and producing EF4 damage at several points along its path.this one thunderstorm eventually produced six tornadoes.

When the day was over there were a total of 11 tornadoes confirmed in Illinois, seven of those in northern Illinois, and one in Iowa. There were also three tornadoes reported in eastern Missouri and three in Texas that day.

The path of this tornado was through a lightly populated area of northern Illinois, well west of the Chicago metropolitan area. However, it passed just three miles north of Rochelle, a city of 9,500 people. Had the path of this tornado been located 13 miles to the northwest it would have plowed through the city of Rockford (pop. 150,250). If the track of this tornado were 15 miles to the southeast of the actual path the tornado would have passed through De Kalb (pop. 43,850), the home of Northern Illinois University, and Sycamore (pop. 17,500).

Here is a map of all severe reports received on April 9 superimposed on the outlook issued by the Storm Prediction Center at 11:30 CDT.

There are number of descriptions of the analysis and events of that day that are worth reading. The NWS Chicago office has an updated page, "April 9, 2015 Tornado Event, Including Rochelle/Fairdale EF-4 Tornado". At the bottom of that page are links to event descriptions from NWS Quad Cities, NWS Central Illinois, and NWS Paducah, KY where the other tornadoes occurred. The page has photos, detailed tornado  tracks, radar images, and an analysis of the weather of that day.

Walker Ashley, a professor of meteorology at Northern Illinois University, Certified Consulting Meteorologist,  and well-known storm chaser has written a blog post about his experiences that day chasing the Fairdale tornado, including remarkable photographs and videos he recorded.

The NWS Chicago has a Facebook photo album of storm photos submitted by the public of the storms that day. You do not need a Facebook account to view these.

Dennis Mersereau at The Vane also has a nice blog post with an in-depth look of the tornado.
.

Undertanding Severe Thunderstorm Risk Categories

In October the Storm Prediction Center implemented two additional severe storm risk categories in their outlooks. I blogged about these changes at the time (Changes to Severe Weather Outlooks), but now that we are in the heart of severe storm season I thought it would be a good idea to mention these changes again. You can read a lot more about the specifics in my October blog post. Recently the National Weather Service office in Kansas City (Pleasant Hill) and the Storm Prediction Center in produced a new graphic that should make understanding the differences between these categories easier. The SPC worked with NWS offices and forecasters, communications experts, social scientists, and the public to come up with the descriptions for the severe thunderstorm risk categories.

First, let's take a look at the Day 2 outlook (for Wednesday) issued earlier today, as it shows both the Marginal and Enhanced categories.

This is the SPC outlook for Wednesday, April 8 made on Tuesday, April 7. The Marginal Risk is in dark green, the Slight Risk in yellow, and the Enhanced Risk in Orange.

How should you interpret the risk for severe thunderstorms in each area? Here's the graphic produced by the NWS.
 

You can read more about the science and numbers behind the severe storm categories at the Storm Prediction Center web site.

One important thing to remember is that any thunderstorm, severe or not, is potentially dangerous. Lightning is the second leading cause of weather fatalities in the U.S., second only behind floods. Lightning itself is not a criteria for a severe thunderstorm. Don't be lulled into a false sense of security by a lower risk category.

You can read more about the science and numbers behind the severe storm risk categories at the Storm Prediction Center web site.

Also, on April 14 the SPC will add a new Summary section to Public Watch Notification Messages. Per the SPC, "The new Summary section is a general 1-2 sentence statement of the severe weather expected in and close to the watch area. This new section facilitates consistent, forecaster-driven, concise communication for public consumption. The Summary is intended to be useful for a variety of communication needs including web page headlines, social media and multimedia briefings."

Slow Start to Severe Weather Season

The first Severe Thunderstorm Watch of March 2015

The late but long winter segued into a very slow start to the convective severe weather season in the U.S. Severe weather during the month of March was practically non-existent until the last week of March. The first severe thunderstorm watch of March 2015, and only the fifth of the year was issued for the afternoon and evening of March 24th in eastern Oklahoma, northwest Arkansas, and the southwestern quarter of Missouri. This was the latest first March watch since 1970. Thunderstorms developed as forecast, and when all was said and done there were 70 reports of severe hail (1.00 inch or greater), with three reports of two-inch hail. There were no reports of high winds with these storms.

 

The atmosphere was a little more primed for severe weather on March 25th, and the Storm Prediction Center had a Moderate Risk of severe weather across central and northeastern Oklahoma into extreme southwestern Missouri and northwestern Arkansas.

Storm Prediction Center outlook issued at 11:30 a.m. CDT March 25, 2015

This time the storms were more widespread and spawned a more springlike menu of hail, damaging winds, and tornadoes. There were a number of reports of hail between two and three inches, and one report of 4.5 inch hail in Tulsa.

The bigger news from this event was the tornado that hit Moore, OK. Yes, this is the same Moore, OK that was devastated by a massive EF-5 tornado on May 20, 2013. This time Moore fared a lot better. There was some low-end EF-2 damage, but most was EF-0 to EF-1. A recap of this event, including video, photos, and maps, is available at the Norman, OK National Weather Service office web site.

Those two days were followed by a few days of relatively quiet weather. On March 31st an area of Slight Risk was painted from northern Texas and southern Oklahoma eastward across Arkansas into west central Alabama. There were many reports of hail and high wind but fortunately no tornadoes. Tornado warnings were issued yesterday afternoon for a storm moving through Arkansas but there were no touchdowns, although a funnel cloud was reported by a spotter.

There will continue to be a slight risk of severe thunderstorms through Friday as the cold front now moving into the central U.S. moves to the east coast. Showers and thunderstorms will return to the Midwest and lower Great Lakes next week as a frontal system stalls across the northern U.S.