WEST MICHIGAN (February 17, 2014) — Ah…the buzz words of the weather world. Polar Vortex, Arctic blast, and several others. Let me throw another one out there…bombogenesis. What is it?
Anytime we talk about the “genesis” of something…it is simply the beginning. How it’s formed…how it’s made. Look at the bible…the first book is Genesis. No different in weather. You may have also heard the term “bomb-out” when meteorologists refer to a developing low pressure system strengthening or deepening over time. In meteorological terms, bombogenesis is simply cyclogenesis on steroids. Confused yet?
Cyclogenesis is the development of a low pressure system. Remember the circulation around a low is cyclonic (anti-cyclonic around a high). That is, air rotates around the low in a counterclockwise direction…hence the term cyclo/cyclone. If a low pressure system is bombing out or undergoing bombogenesis, it simply means the air pressure at the center of circulation is forecast to drop 24 millibars in a 24 hour period. Simply put…it’s deepening/strengthening/growing stronger! These pressure systems are measured with instruments like barometers. Only difference is our home barometers measure the pressure in “inches of mercury” while forecast models and weather observations mainly use millibars…another pressure measurement.
This does not include tropical systems with low pressure at their center…we’re speaking of cold core systems in mid/higher latitudes. You can read more on bombogenesis here. So what’s the point of all of this? Our next low pressure system taking aim on the Great Lakes may actually “bomb-out” as it approaches on Thursday. It’s rare and doesn’t happen often. Forecast models are showing a low at 12Z Thursday morning around 993 millibars. There are two low pressure centers, but the main one is over eastern Kansas. All the purple/blue/green on the map is showing accumulated precipitation. See image below.
24 hours later (below) by 12Z Friday morning the low is at 966 millibars. Note the abundant gray lines around the low that has already progressed quickly in to Canada. Winds will be very strong with this system and it will also bring rain and briefly milder temperatures as well.
Not all forecast models are showing this bombogenesis with this next low, but I thought it was worth mentioning in case it comes to fruition and we are, once again, inundated and plastered with weather terms that seem to come from nowhere. While it sounds like something made up…bombogenesis is real in the meteorological world and may be occurring over the Great Lakes this week. At the very least I would expect the possibility of an icy mix Wednesday night/Thursday morning, then rain (perhaps heavy), windy conditions, temps in the 40s, then snow showers behind this system Thursday night/Friday morning. Stay tuned to later forecasts! You can always get more at www.fox17online.com/weather.