Happy Independence Day,
A huge upper high is expanding out over the United States on this July 4th. And it will be centered over Kansas and Missouri the next three days. Temperatures will inch up a couple of degrees today and we are forecasting 105° again later in the week:
The map above shows the flow aloft at around 18,000 feet up. We call this a high “height” area and not high pressure aloft. This is the 500 mb level, and the pressure is the same at each point, but the high is located where this 500 mb level is at it’s highest position. The center of the high is around 595 dm, or 5,950 meters above sea level. The air underneath these highs sinks and warms. The subsidence, or sinking air, warms on it’s way to the ground and this is why I call these anticyclones “heat wave” creating machines. This year’s versions are certainly being rather effective at creating heat waves.
A very weak cold front will arrive this weekend with some cooling, but right now only a slight chance of thunderstorms. Ahead of this front we should have our hottest two days of the heat wave so far on Friday into Saturday.
Snow cover has been decreasing significantly across the Northern Hemisphere summer. This map on the left shows the snow cover anomalies across the Northern Hemisphere during the month of June and as you can see, during the past decade there has been a steady drop in overall snow cover as compared to normal and this year is by far the lowest anomaly in the 45 years of this chart.
Have a great 4th of July! I will be working tonight with Stormy the Weather Dog. If you have a dog keep in mind how hard of a day this is for them with all of the booms from the fireworks and firecrackers. I suggest turning on music inside to drown out the noise and certainly don’t leave your dogs outside.
Thank you for spending a few minutes of your day reading the 41 Action Weather Blog. Let us know if you have any questions or comments.