The weather is finally clearing across North Carolina but the problems with flooding will continue much of this weekend and into the weekend. It’s a very bad situation for North Carolina.

Out focus turns to the Northeast and Mid-Atlantic as the remains of hurricane Florence need to move through today into Tuesday. As you can see on the map above, heavy rains will impact areas from the eastern Ohio Valley into New England where 1-6 inches of rain will fall. Some of these areas of already saturated from Gordon and any heavy rains means flooding will occur again.

Severe storms will also occur in the Mid-Atlantic. These will be scattered storms with the potential to produce quick hitting tornadoes and damaging wind gusts. Florence still has a lot of spin left so that is why the tornado threat exists for that area.

The HRRR model below gives you an idea of the rainfall through this evening. Keep in mind, more rain will fall tonight into Tuesday.

Total Rainfall Today

Links:

• Excessive Rainfall Maps
• Hazard Maps
• Severe Weather Maps
• Upper Air Maps
• Current Surface Map
• Regional Radar

We have two days of severe weather as the vortex over the Upper Midwest drops into the Great Lakes and Ohio Valley. As Mentioned before in previous blogs, this is a highly unusual pattern with an upper level low this time of the year. So think of this, you have upper levels of the atmosphere more like a fall pattern while at the lower levels it’s hot and humid. This will lead to big thunderstorms, some with very large hail, high winds and tornadoes.

I still think the tornado day is Friday as the 250 mb jet noses into the southern Ohio Valley. That means intense upward motion and the tendency for thunderstorms to rotate. You can see on the rotation tracks image that areas of the southern Ohio Valley into the Tennessee Valley has many rotation tracks, some even strong. That shows that rotation will exists in the supercell storms that develop. I will not be surprised we are faced with a tornado outbreak Friday.

Below is the HRRR model showing the simulated radar for this afternoon.

Related Link:

SPC Severe Weather Maps

Upper Air Maps

Simulated Radar for this Evening

An upper level low will begin to dive southeast and over the next 4 days, we will severe weather around that upper level low. As mentioned yesterday, this is a little unusual to see such a vortex developing this time of the year. The implications mean severe weather given we are at the heart of summer.

Rotation Tracks

Storms will erupt this afternoon and continue into tonight. The first several hours of the event is when tornadoes may occur.  The rotation tracks based off the HRRR model show that areas of central South Dakota into eastern Nebraska could see tornadoes or very large hail. In addition, winds in the storms can gust well over 60 mph and cause considerable damage.

I do think that a nocturnal thunderstorm complex will develop and head southeast into Kansas and Missouri, perhaps all the way to northern Arkansas by Thursday midday.

Below is the simulated radar for this afternoon. Other blogs will cover the severe weather Thursday and Friday.

Simulated Radar for This Evening

Surface Map for Thursday Evening

I might be going out on a limb here, but the pattern will lead to an unusual vortex developing over the Great Lakes by this weekend. The trough will take on a negative tilt and strong jet streak will come down from the northwest which will add lift for thunderstorm development. The configuration looks more like an Northwesterly Flow Severe Weather Outbreak starting Thursday and last into Friday.

While severe storms will occur across the Plains Wednesday, the nasty storms will come late Thursday into Thursday night in the areas shown on the map above. The storms that develop should move southeast and redevelop across the mid-Mississippi Valley into the Tennessee Valley Friday. It’s not out of the question that a third day of severe weather occurs across eastern Ohio into eastern Kentucky Saturday.

A jet like this diving southeast will create a strong shear profile and the potential not only for damaging winds but also for tornadoes. I could see how this all leads to a tornado outbreak, especially Friday as shown in the purple areas on the map.

Keep in mind, this is my first look at what could be a nasty two-day event, I wanted to get the word out so that people in the Plains into the Ohio and Tennessee Valley understand that this is not your normal summer pattern but one that looks more like spring severe weather.

I think we will see SPC folks showing a risk of severe weather for day 2 and 3.

250 mb Jet Stream. Notice the Jet Streak in the Middle Part of the Country