Atmospheric gravity waves, known as undular bores, are waves in Earth’s atmosphere that often show up quite well on satellite and radar imagery. They are notorious for creating wave-like clouds, which clearly propagate as waves when viewed in rapid time-lapse photography. Low-level atmospheric stability is implicated in the formation of undular bores. Large static stability … Read more
On May 25th, 2016, a large and violent, long-track tornado tore through the landscape across north-central Kansas causing extensive damage along Interstate 70 between Abilene and Chapman, Kansas. What was a marginal day for severe weather ended up producing one of the most violent tornadoes of the 2016 season. We visited Chapman on Saturday, July 23rd, … Read more
Definition of Heat Index: The heat index is an estimate of how hot the air “feels” to the human body and provides a relative indication of potential health risks. Among others, the two primary factors in the heat index equations are temperature and water vapor (i.e., moisture/humidity). Humidity affects the efficacy of perspiration to evaporatively … Read more
Interesting rainfall tidbits from the deluge in the Metroplex on Monday 7/4/16 The total rainfall at DFW Airport on the 4th of July 2016 was 3.20″ This shattered the daily record for 7/4 by 141% (previous record: 1.31″ in 2006) Compared with the entire month of July, as well as June + July… It ranked … Read more
Currently at Atlanta’s Hartsfield (ATL) The temperature is: ATL’s heat index is: °F Current Conditions Around Georgia How many days until fall? The summertime heat in the Southeast can be oppressive, despite the fact that actual air temperatures are relatively mild compared to those of the Great Plains and Midwest. For example, the average high … Read more
The summer solstice begins Monday, June 20th at 5:34pm CDT. A full moon, also known as the June Strawberry Moon, will coincide with the summer solstice. A Strawberry Moon is a term given to any full moon in the month of June. The term was used most by Algonquin tribes, who recognized it as an … Read more
Storm chasing is an emotional roller coaster. From operational field missions, to university research, and to the hobbyist and/or nature explorer, storm chasing consists of several thousand miles of driving for sometimes only an hour of action. Each Spring, scientists, meteorologists, hobbyists, and explorers, venture out to the Great Plains to seek some of the atmosphere’s … Read more
Currently at Dallas/Fort Worth (DFW) The temperature is: DFW’s heat index is: °F Current Conditions Around N. TX How many days until fall? It’s pretty much a given that summertime in North Texas will be hot. However, there is a fine line between “hot” and dangerously hot. In other words, “only” a few degrees can … Read more
On Sunday June 5, 2016, Tropical Storm Colin formed in the Gulf of Mexico, making it the earliest “C” tropical storm on record. View iWeatherNet’s tropical cyclone page for more information. See Also: January 2016 Hurricane Alex: Strongest Atlantic Winter Hurricane on Record The Earliest “C” Storms Found in the Historical Record For the Atlantic … Read more
On Tuesday, May 24th, 2016, an outbreak of tornadoes occurred across western Kansas. There were 13 observed total tornadoes a cyclic supercell near Dodge City, Kansas including four sets of twin tornadoes, a set of triplets, and a large multi-vortex tornado and wedge tornado. So far, the National Weather Service in Dodge City, Kansas, surveyed 9 … Read more
Saturday, May 21st, was the start of a week long period of severe weather across the Great Plains. From southern Texas to the High Plains in North Dakota, isolated tornadoes, large hail, and severe winds, were forecasted. Perusing model guidance the night before on Friday, May 20th, we had an idea of our target for Saturday: Western … Read more
From May 21st to May 26th, 2011, destructive tornadoes tore through the Great Plains, impacting thousands of people and leaving billions of dollars in damage in its wake. During this time period, there were 241 total tornadoes, including two EF-5, three EF-4, eight EF-3, thirty-one EF-2, eighty-six EF-1, and one hundred [and] ten EF-0 tornadoes. … Read more
A multi-day dryline setup was in place across the central Plains on Sunday, May 8th; and Monday, May 9th, respectively. Observed conditions from radiosonde, or weather balloon, launches, indicated an environment conducive for widespread severe thunderstorms was starting to filter into the central Kansas and central Oklahoma region. Important to any storm chase is to … Read more
This phenomenon is NOT unusual, but it doesn’t always happen. Today, the dry line and the resulting squall-line were perfectly aligned. The data presented a teaching moment that I couldn’t pass up. At the end of the animation, I zoom in so you can see the wind barbs pointing toward the dry line. The air … Read more
The Result [Tuesday 4/26 8:17 pm] ➡︎ NOTE: Read the original update from Monday 4/25. ***Quasi-Linear Convective System Has Evolved as Expected*** ***Moving toward DFW with winds of 65+ mph*** Winds of 65+ mph detected within the bowing segments… These will arrive in the metroplex over the next two hours… Some wind damage/power outages possible… … Read more
I typically do not share model data because they can be very complex. I do want to show one of the state-of-the-art programs that I use in my operations to analyze model-simulated soundings. The models do not automatically compute these data; the additional software turns the raw output into meaningful information. At least one of … Read more
Global Wind 7-Day Satellite Loop Note: The purpose of this post is to share advanced forecasting techniques, not present formal research at this time. Example Case: Heavy Rain Event in North Texas ◙ I wanted to show some of the 48-hour rainfall amounts as of 7:00 am CDT April 18, 2016 (officially spans a 48-hour … Read more
On the afternoon of March 24, 2016, a stunning mesoscale convective vortex (MCV) formed within a mesoscale convective system as it moved over southern Alabama. I created the animation below using a sequence of radar images provided by the College of DuPage. What is an MCV (Mesoscale Convective Vortex)? An MCV is an area of … Read more
On Sunday, March 13, 2016, DFW Airport (along with many other locations) reached 80 degrees for the first time this year. Prior to 3/13, the last time DFW was at or above 80º was on December 26th. December 26, 2015 was the date of the historic EF-4 tornado that tore a path through the eastern … Read more
On Monday, March 7th, 2016, a spectacular supercell formed in far northwestern Oklahoma and entered southern Kansas. A supercell is a thunderstorm that rotates. Conditions on Monday were favorable for a couple of supercells to initiate off the dryline in far western Oklahoma, and into western Kansas. However, given weak convergence along the dryline and meager … Read more
Our high-resolution maps of accumulated snowfall are updated several times a day for the United States and much of Canada. ● Today’s Snow Cover Stats ● Interactive Map Snow Cover Map (Current – High-Resolution) Note: Refresh the browser if data fail to load Today’s Snow-Cover Percent, Depth, & Liquid Equivalent (SWE) These stats include the … Read more
Every emergency guide out there suggests you get a backup generator to power your home after the electricity goes out, so learning more about home generators work and what they can do is a must if you want to be prepared. Hurricanes, winter storms and even simple outages can happen at any time; no matter … Read more
Friday 2/12… For the sake of conversation, I wanted to share some thoughts about forecast variance (i.e., the tendency for forecasts to vary from one meteorologist to another), forecast advancements, and forecast techniques. It goes without saying that atmospheric prediction is *extremely* difficult and time consuming. During an active pattern, a forecast for a 36-hour … Read more
Final Update [Tuesday, February 9, 2016] Forecast Verification [Previous Forecasts Further Down the Page] Forecast Update #2 for Atlanta – Posted Friday 2/5/16 ***No Forecast Changes*** ***Light snow Monday night/Tuesday*** ***Some light accumulations possible*** ◙ A strong cold front will bring drastic temperature changes to Georgia Monday night… ◙ To get caught up … Read more
Brief Overview of the Storm’s Evolution SST Anomalies Evolution of the Surface Low (Animation) After the surface low emerged over the anomalously warm ocean water on the morning of January 23, it deepened and intensified for another 12 to 15 hours with the central pressure reaching a minimum of 983 mb on the evening of … Read more
Forecast Update [Saturday 1/30 7:45 am] ***80º today ~ 25 deg above normal*** ***Wind gusts to 40 mph late afternoon/tonight*** This is an update to the original forecast from Monday 1/25 — The only change is to raise high temperatures for today as I mentioned would be possible in the Monday forecast update. The springlike … Read more
➡︎ Quick Links: ● Latest update ● Initial forecast (Tues 1/19) ● Snow forecast ● Radar Special Update (Thursday 1/21 3:30 pm) Flood Watch now in effect for tonight through Saturday morn Winter Weather Advisory for accumulating snow effective Fri 3 pm – Sat 7 am. NOTE: I do not expect any snow in the … Read more
January 14, 2016 (1 pm EST) Max-Sustained Wind: 75 kt / 85 mph / 981 mb / Category 1 View the list of active tropical cyclones Interesting Statistics about Hurricane Alex Alex is only the 2nd-known Atlantic hurricane to form during the month of January since records began (partial record as far back as 1842). … Read more
Special (1/14/2016) Alex became a hurricane on Thursday Jan 14, 2016 Update [Wednesday January 13, 2016 at 5 pm AST] Sub-Tropical Storm Alex has formed in the East Atlantic. As discussed below, Alex is only the second-known storm to form during the month of January in the 174-year database (1842-present). ➡︎ See also: Forecast #1 … Read more
December 2015 was unseasonably warm for Atlanta, Georgia. The temperature fell below freezing only one time, on December 19th when the low temperature was 29ºF. The day prior, on December 18th, the low was only 32ºF. In 2015, the average temperature (combined high and low) was 57.5ºF, which breaks the record previously set 126 years … Read more