November 2025 EZNews
- Dr. Scott Dennstaedt
- 17 hours ago
- 7 min read
Hello and thank you for taking a few minutes to read the 55th edition of EZNews!
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In Flight Weather Essentials recording now available for purchase!
If you were not able to attend the live In Flight Weather Essentials for Pilots class that finished on November 3rd, you now have the option to purchase access to all eight recordings from this live 8-week class. Order today to save $50. The Summary Guide that you will download upon purchase is a PDF file and includes the following -
Table of contents
Hyperlinks to the eight unlisted YouTube video recordings of each class
Hyperlinks to a PDF containing the slides for each class
Hyperlinks to the quizzes and answer key for each class
Access to the content provided is strictly for your personal use. Please do not share this PDF or any of its contents or post it online. We appreciate your cooperation. This offer is available for a limited time and ends on November 30, 2025.
If you want the best savings, purchase all four recorded classes that include the following:
Weather Essentials for Pilots (12 classes)
Advanced Weather Essentials for Pilots (10 classes)
Skew-T Weather Essentials (12 classes)
In Flight Weather Essentials (8 classes)
Get all four for $995. That's a savings of over $500 if purchased separately. Hurry this offer is only available for a limited time.
The value of the 700 mb constant pressure chart
As we move into late fall and winter, the 700 mb constant pressure imagery should be included in your preflight weather guidance. This chart describes what is happening at 700 mb or roughly 10,000 feet MSL. Even if you are planning to fly much higher, the 700 mb chart still provides important guidance for the potential of mountain wave activity as well as areas of strong low-level wind shear.
Let's take a look at an example. At 1250Z, the Aviation Weather Center (AWC) issued the SIGMET shown above for severe turbulence below FL240. Although it is likely the forecasters relied on pilot weather reports (PIREPs) as stated in the SIGMET text (RPTD BY ACFT), this particular event was fairly easy to visualize on the 700 mb constant pressure chart below.
Plotted on this chart are lines of constant height (black contours) and omega. Both of these can help identify potentially dangerous areas of turbulence in the lower part of the atmosphere. First, notice that there is a lee-side trough just downwind of the Rockies as depicted by the U-shaped pattern in the height lines. This feature is very common during significant low-level turbulence and mountain wave events.
The other field shown is called omega sometimes referred to as vertical velocity. It's units are microbars per second (μb/s). In this context, omega measures how quickly the pressure is changing at a specific point in the atmosphere, which corresponds to vertical motion through that particular pressure level...in this case, 700 mb. Positive values show downward velocities (toward the ground shown as shades of blue) and negative values show upward velocities (away from the ground show by shades of red).
Generally speaking, extreme values of omega should get your attention in most instances. This vertical motion often is related to a large scale feature and does not represent significant updrafts/downdrafts like you may experience in convection. Please note that during the warm season it is very common to have high negative values of omega over a good portion of the Intermountain West that simply represent regions of harmless thermal activity.
The 700 mb chart above is valid at 12Z just prior to the issuance of the SIGMET. Notice the highly positive omega (blue) values just along the front range of the Rockies. This is a good sign that significant turbulence due to low-level wind shear or mountain waves may be in the making. If those waves reach the surface this can produce significant wind gusts for airports in the High Plains. For example, on the northern end of the SIGMET Greeley-Weld County Airport (KGXY) was experiencing surface wind gusts over 40 knots throughout the early morning hours during this event as shown below.
The omega field can also show regions of significant vertical development that may be associated with convection or a frontal boundary. This would be represented by negative omega (depicted in red). The 2-hour 700 mb forecast below valid at 12Z clearly depicts a fairly intense line of negative omega just off the east coast of the Mid-Atlantic and ahead of a deep negative-tilted 700 mb trough.
Below is the surface analysis chart also valid at 12Z, shows this surface cold front extending from an occluded area of low pressure in extreme southeast Ontario, Canada that is coincident with the line of negative omega.
Given the negative tilt to the 700 mb trough and sharp line of negative omega, this frontal boundary is likely to produce a line of convective activity that contains dangerous low-level turbulence. In fact, the forecast radar depiction shown below from the High Resolution Rapid Refresh (HRRR) model valid at 17Z depicts an intense line of returns that is associated with convection along and ahead of this intense cold front.
The true value of the 700 mb chart has less to do with what is occurring at the present moment and more about using this chart to determine what is likely to happen over the next day or two when planning a flight. In other words, long before any convective and nonconvective SIGMETs are issued, this chart will be handy to look at the night prior to your flight to give you a way to assess the adverse weather along the your proposed route based on your optimal time of departure.
Now that you can see the value of the 700 mb omega forecasts, where do you find these constant pressure charts? They are available from many websites that provide model-based weather guidance such as pivotal weather. However, look no further, you can also get these charts within the EZWxBrief progressive web app. Simply visit the static imagery view and look for the GFS or HRRR models. Both of these models have an option in the Imagery dropdown menu for the 700 mb constant pressure chart that includes the omega field. Show to the right is the selection for the 700 mb Omega forecast from the HRRR model.
Therefore, add this chart to your routine when planning a cross country flight. It will highlight those problem areas even for flights you may not be taking for a few days.
Where's the front?
When viewing the meteogram in the Airport Wx view, it's often easy to know when the frontal system is expected to move through the terminal area for an airport. Show here is the meteogram clouds (CLDS) depiction forecast for Bismarck Municipal Airport (KBIS) that also includes isotherms or lines of constant temperature.
There are often many clues to know when a frontal passage will occur. This includes a change in pressure, wind direction shift and a change in temperature. It's clearly easy to see that around 09Z on Monday, October 20th, there it is an expected drop in temperature over time by looking at the pattern in the isotherms.
There is warmer air ahead of the front at 05Z depicted by the yellow lines that represent temperatures above 0°C. The red line is the 0°C isotherm, also known as the melting level. Cyan lines depict temperatures below 0°C. This is a very common pattern for a cold or occluded frontal passage.
In fact, there was an occluded front that moved through the Bismarck terminal area just before 09Z as shown below. Although surface temperatures did not drop significantly after the passage of the front, cold air aloft spilled in quite effectively as shown in the meteogram above.
EZWxBrief v2 News
EZWxBrief v2.0.3 is the current version. There have been no new releases at this point in time. However, on the morning of October 16th we upgraded the EZWxBrief servers to a new and improved platform. This has been an effort that has taken nearly six months to complete. The upgrade went extremely well with no appreciable downtime of the app. This new and improved architecture provides higher security to keep intruders from hacking into the system. It also provides a capability to push out new releases in a seamless fashion to minimize downtime of the app.
The NWS has been slowly removing access to some of the model-based datasets over the last few months. These datasets are used by EZWxBrief to build the EZForecast on the Map and on the meteogram and route profile views. This has caused sporadic data outages due to missing weather guidance. In order to provide the best forecast data, we needed to pivot and utilize other weather guidance. Moreover, the NWS has plans to remove static imagery that was imported into the Imagery view. To avoid any disruption in this imagery, we had to build that imagery from the raw gridded-binary data that still remains available. Doing this required additional development and ongoing compute resources. Therefore, as of December 1, 2025, the EZWxBrief app subscription will be increased to $8.99 per month to help offset these costs and to help sustain EZWxBrief for at least one more year.
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