UPDATE: Wednesday – 6/4/2014, 3:40pm ET
WASHINGTON – The timeline has not changed too drastically from what I was thinking Tuesday. There were a few models overnight and this morning that were suggesting most of the activity would hold off until after 11 Wednesday night.
But my current thinking from yesterday still stands. Rain and storms will move into the region from the west to east after 7 p.m. in the western suburbs and after 8 p.m. in the immediate metro area.
This is a look at the model for 8 p.m. tonight:
The storm system could speed up and it could slow down. But with all the data, after about 8 p.m. seems to be the most consistent start time for rain. That unfortunately means that part of the Nationals game against the Phillies could get rained out. (Keep an eye on our own radar here if you are out and about).
The storms are not expected to be as strong for our area as were in the Midwest during the past 24 hours (due to the mountains to our west and the fact that they are overnight).
However, that doesn’t mean we couldn’t see a few strong thunderstorms and some could approach severe conditions – with damaging winds and hail being the primary threats during the overnight hours. The Storm Prediction Center has given the entire WTOP listening area a 5 percent chance of damaging winds – winds over 58 mph, and hail more than 1 inch in diameter.
The Thursday morning commute could be a little on the messy side as this cluster of rain and thunderstorms exits the region. Leave yourself some extra time in the morning just in case. I expect the precipitation to be out of here by the mid-morning, if not before, giving way to partial clearing in the afternoon as we start to dry out.
Temperatures on Thursday will be much more comfortable than on Wednesday, topping out around 80 degrees with a slight breeze.
EARLIER: Tuesday – 6/3/2014, 3:47pm ET
WASHINGTON – Finally we are getting into the pattern of summer weather: Warm and muggy days followed by dodging and evening thunderstorms.
Showers and storms are expected to move through during the overnight hours Wednesday into Thursday, some of which could be strong.
Those storms are currently in the Midwest and bring a potential for a derecho event Tuesday night – specifically from eastern Nebraska, southern Iowa, to northern portions of Missouri and into western central Illinois.
By the time the storm system reaches our area, it will likely just be a cluster of thunderstorms – or what meteorologists refer to as a Mesoscale Convective System.
(Just a quick weather lesson: A Mesoscale Convective System is an all-encompassing term that can include any of the following storm types: a Mesoscale Convective Complex (MCC), a Mesoscale Convective Vortex (MCV), or a Derecho. All of these types of storms have very distinctive and specific parameters such as wind speed, duration, size, cloud-top temperatures, etc. Therefore, using any of these terms loosely is not scientifically correct because each has particular attributes.)
Ever since June 2, 2012, more and more we hear the term derecho being thrown around. Although derechos are more common in the Midwest, they are still possible in the Mid-Atlantic. But according to the Storm Prediction Center, derechos are typical in the WTOP listening area only about every two to four years.
So enough of the science lesson, but I just felt like I should just do some minor explanations because I have already seen the term “derecho” all over the internet associated with the coming storm system. Although strong storms are headed to the region, they are not expected to generate derecho-like conditions.
So back to our forecast: After a warm and muggy day on Tuesday with a few afternoon downpours, we will clear out nicely for the overnight hours with humidity dropping off a smidge and temperatures falling into the 60s.
However, in the Midwest, storms will get going on Tuesday afternoon and continue into the evening and overnight hours. These are the storms that will eventually be knocking on the D.C. door Wednesday night although they will not be as strong.
The severe threat lies in the upper Midwest Tuesday afternoon.
By Wednesday, sunshine will start our morning with temperatures eventually rising into the mid-80s with a less humidity than on Tuesday. Clouds will begin increasing throughout the region during the afternoon hours.
Most of the day will remain dry and I believe we will be able to, at the very least, get the beginning of the Nationals game off at 7:05 p.m. However, after 8 p.m., we will see some rain and storms move into the west portion of our listening area. This cluster of thunderstorms, or what we will classify as a Mesoscale Convective System, will travel across our region during the overnight hours and through early Thursday morning.
We could see some damaging winds and hail with an isolated chance of tornadoes. There are a few models that suggest this piece of energy floats north of the D.C. area overnight while there is other information to support the energy rolling right through the WTOP listening area during Wednesday overnight and into early Thursday morning.
By the Thursday morning commute, a few showers and storms could still be around as they push to the east. But it looks to clear during the mid-morning hours on Thursday. Expect a breezy but comfortable day on Thursday as the sunshine returns. That sunshine sticks around, as well as the low humidity levels for both Friday and Saturday.
As always, we will have more updates through Wednesday as this system edges closer to our region.