The cold front is on our doorstep and may do a little sidestep. There is an indication that the pool of cool air responsible for ending our heat and humidity will be slowing down. That means the front itself could slow down or stall. The downside is that it will keep the threat of rain into the morning for many of us, and linger showers into Saturday afternoon from near the Bay Bridge through Ocean City. That may not be the new you want if you are going to Silopanna Music Festival or any of the other outdoor events, but it is great news for drought stricken farmers on the Eastern Shore.
Before we can be concerned about the weekend plans, how about the line of potential severe storms? After heavy rain this morning, the sun has broken out and helped to destabilize the air once again. That is only more fuel for an already strong cold front. There are showers already firing up, but the main event is slated for Friday night. If you have plans outside this evening, they may not be a rain out, but could be a chase out depending on the timing.
How about the timing of our worst weather lately. Friday seems to be our day:
- June 1st: Record 10 tornadoes in Maryland
- June 29th: The Derecho
Related stories and good reading material on a day like this:
- Lighting Safety tips, pics, and video
- Lightning seen from space: Red sprites and blue jets
- Hail protection (video)_in your car that might surprise you
- Tornado Safety: What NOT to do when driving
The other factor is the wind direction. Our part of the world can influence the storms that arrive from the west. If the winds are from the west, they flow down the mountains and dry out. This often tears storms apart and leaves the I-95 region with much less than radars and computer models indicate. But a wind from the east comes off of the Chesapeake and rides up the hills, feeding approaching storms. That can enhance them as they arrive. This afternoon’s winds are primarily from the south. That doesn’t necessarily help the storms, but it doesn’t break them up either. So as we are glued to the radar screen, what we see out west could very well be what we get.
Speaking of winds, they are cranking up in the tropics. A storm is about to be named Gordon and it follow in Ernesto’s footsteps
Severe Storm Risk:
The Storm Prediction Center has much of the east in a 15% chance for any storm that forms to turn severe. The main elements are high wind over 58 mph and large hail over 1 inch in diameter. The tornado threat is closer to the storm track from northern Ohio into New York State closer to Lake Ontario.
The circulation looks impressive and almost like a fall pattern. See the water vapor satellite loop video on the left for more: Also notice the tropical feed of moisture reaching southern Florida…and the upper level flow bringing warm winds up the coast.
Short term hi-resolution computer models have become a forecasters favorite tool, but it can be limiting. These are only a gauge, so consider that the timing may have an error of +/- 1-2 hours. Generally we can expect the mountains to our west to get hit between 5-9 pm, which the I-95 region can look for 8pm –midnight. The Eastern Shore will be tricky since the front could stall right over I-95 and delay the arrival farther east.
The two models I have shared in the slide show give a different perspective on the storm. The general time frame for central Maryland. You will also see that the HRRR model is much more intense with the line of rain than the NAM model. However I should point out the NAM was developed this morning. The HRRR is a rapid update and this has had a chance to identify our afternoon sun and how it might feed into the cold front.