Monday Severe Weather Update and Nowcast

10:05 PM:

As you have seen, there has been many tornadoes today in Maryland. An isolated tornado was possible, and I wasn't too surprised when I saw the first warning go up, but there was way more than expected. And it was mainly in the areas where there wasn't even a marginal risk; just a general risk. This event was much worse than expected. And, this event is far from over. The event will last into Tuesday. There still is a threat for isolated tornadoes. You should be prepared to shelter in the night and have ways to get severe/tornado alerts. A weather radio will come in handy. Be prepared. It will hopefully get better. But you never know, since today's tornadoes in the TSTM risk and the sheer amount of them were unexpected.

9:30 PM:

Tornado warning for baltimore county. Seek shelter if you are there.

9:00 PM:

Tornado warning for Westminster and Hampstead, MD. Seek shelter now!

8:55 PM:

SVR TStorm warning for Mount Airy. Wind up to 60 MPH, penny sized hail, and a tornado is possible

8:35 PM:

Tornado warning for Carroll County... seek shelter now.

8:20 PM:

THE TORNADO WARNING HAS BEEN EXTENDED UNTIL 8:45 PM. IT HAS BEEN CONFIRMED. THIS IS A LIFE THREATENING EMERGENCY! TAKE COVER NOW! TREES WILL LIKELY BE DAMAGED, DAMAGE TO ROOFS, SIDING, WINDOWS, ARE POSSIBLE, AND MOBILE HOMES MIGHT BE BADLY DAMAGED OR COMPLETELY DESTROYED. FLYING DEBRIS MAY BE DEADLY TO THOSE IN THE WARNING! PLEASE TAKE THIS SERIOUSLY!

7:45 PM:

There is a rain wrapped tornado for Frederick, Discovery, Libertytown, and Linganore Maryland. GET INSIDE AND SEEK SHELTER NOW!!

7:10 PM:

The SPC has issued a mesoscale discussion for our area, stating the chance for an isolated threat for damaging winds and a brief tornado in the next few hours. A weather watch is unlikely though.

7:00 PM:

There have been multiple tornado warnings and severe t storms throughout the region, I wasn't able to cover them because I was on a walk. I will try to cover them now.

5:40 PM

There is a severe thunderstorm warning for Lake Holiday, VA. A tornado is possible, and wind up to 60 mph and penny sized hail can be expected.

There is a severe weather risk for tomorrow, and not much has really changed. Most of the areas who are in the marginal risk are near or south of I-70. The main threat is damaging winds, heavy downpours, and small hail. Isolated flooding is possible with these thunderstorms due to heavy downpours and rainfall. The timing is mainly from 2 PM - 12 AM Tuesday.

As you can see, most of the region is under a marginal risk. The main threat is damaging winds.

The SPC gives us a 5% chance to see damaging(55+ mph) winds 25 miles away from any given point.

The 16z HRRR run shows around 1000 MLCAPE throughout the region(around 6 PM EDT), with some areas a bit over 1000 MLCAPE (MoCo is in the 700-1000 MLCAPE range). The NWS forecasters discussion for our area states an instability at around 1000 CAPE later today. Some breaks of sun will occur throughout the region today, allowing instability to build.

The 16z HRRR(6 PM EDT) shows around 35-55 KT of shear in the atmosphere for a good chunk of the region, with MoCo in the 40-55 KT shear area. This will be enough to cause some damaging winds. The NWS forecasters discussion for our area states 40-45 KT of vertical shear, which would be enough to cause strong tstorms to become severe locally.

This is the 16z HRRR in MoCo at 6 PM EDT. Although today is mainly a wind threat, some tornadoes are not out of the question at all. This sounding shows a good amount of shear at 500mb, with good LCL placement and a good amount of CAPE(1000). The SigTor parameter is around 1, meaning that this tornado is around an EF0. The storm slinky is a "C" shape, which is decent for tornadoes, and the critical angle is not bad either. In hours(3 PM EDT onwards) before this, they show marginal severe weather, and even after 6 PM EDT, it still shows severe weather for us. As said before, the main threat is damaging winds, so I assume for most of the "marginal severe hazards" on the HRRR soundings will be for strong winds and maybe small hail.

There is another severe threat on Wednesday, and I think that has much more potential than this one. Some models are showing a lot of CAPE in the atmosphere. I will make a post tomorrow about it. I will update this post whenever something new happens(nowcast).