July 20 2020

This is the second day in a row with temperatures reaching 100ºF. Many would welcome a thunderstorm to relieve the heat and humidity, but only a lucky few will get it. Despite the extreme conditions, the atmosphere is mostly stable.

Check out the temperatures this afternoon. You can see some 80s where storms have cooled things down, but those spots are few and far between.


At 5 PM BWI reported 100ºF with a dew point of 70ºF. The Heat Index was 108ºF
July 20 weather heat temperatures


There is one weakness in the atmosphere that has flared up this afternoon. But only long this line is the best chance to get some action, and the time window is pretty small.

Storm Development:

Satellite Loop

Here is a look at the satellite loop showing the limits cloud development today.  This is about 3 hours through 4:36 PM



Doppler Radar:

Here is the same time frame showing the storm development on radar. There is a disturbance in the mountains, but the west winds rips it apart downscoping to the east. But one other lucky cluster on the west side of Washington DC.



Doppler Radar Snapshot at 5 PM

This is the best nowcast indicator. The storms are a little north of the model plots below. Montgomery County and across western and northern Washington DC are in the path.

July 20 maryland weather thunderstorm radar Monday 5PM



Note: This may be locally strong, but only provide quick relief.

The best chance for storms will be in metro Washington DC through 7 PM.

This may clip Columbia and Laurel on the north end, then Glen Burnie and Pasadena in AACo still on the edge of a hit or miss.

The main line should travel through PG County and Rt 50 to the east. It’s likely to fade a little near I-97, Annapolis, and the Bay. But some clouds and cooler will help through 8 PM.


Radar Simulations

These two models do agree on plotting the cluster near Washington, DC but fading as it reaches Anne Arundel County. So Annapolis will be about 50% to get something. Less likely crossing the Bay. Little to no chance this time farther north near Baltimore and southern PA.


NAM 3 Km Model —> slider

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HRRR Model –> slider
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Heat Advisory and Excessive Heat Warning

July 20 weather heat advisory


That will be tough to challenge with some of the hottest already set on those days

July 20    102ºF in 1930    
July 21    104ºF in 1930   
July 22    106ºF in 2011   
July 23    102ºF in 2011+

Climate Report Today

Record Rainfall set in Baltimore at BWI

See the Weather Observations and Climate Report from this morning for more info about:

July 20 moon phase

📋Observations yesterday

🌡 Climate data today

🗺 Weather Map

☀️ Sunrise and sunset times

🌙 Moon phase



Email Updates

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Also See:

Comet NEOWISE Viewing All July (photos/video)

Comet NEOWISE Bob Gelety

Maryland Strong Love ❤️ 

My ‘bonus’ daughter made this map of Maryland a few years ago. We brought it back for needed positivity. Now on her pick of tanks, and this cool Maryland T for men or women.

Click here or on the image to see more

This is all LOCAL: Made by Maryland Print House; Proceeds support my Maryland Trek 7 this August for Just In Power Kids.




Please share your thoughts, best weather pics/video, or just keep in touch via social media


Maryland Trek 7 

This will go on this August! Let’s hope social distancing will be a memory then. One way to celebrate would be to become part of my team:

  • Consider joining our team for the week, a single day, or even as a sponsor.

Maryland Trek 7



Water Spout OR Scud Cloud on videos and photos near Middle River Maryland


Other  Links:

Was Your County Not Included?

Click this map for more on the regional forecast zones


Baltimore Weather At BWI May Not Be As Hot As Reported

Construction at the airport close to the weather station may be added artificial heat. Click here or the image for the details.




Maryland Trek Cycle Jerseys From Hill Killer

All proceeds will go to the Maryland Trek 6 total and Just In Power Kids programs

Thank you to our Title Sponsor for Maryland Trek 6

Shining on with Smyth and their contribution, our team has raised over $100,000 for Just In Power Kids to provide free programs for kids in and post cancer treatment.

Just In Power Kids:

Proceeds go to our programs Providing FREE holistic care for kids in cancer treatment and up to 5 years post treatment and caregivers.


Shine On

Proceeds from all sales go to Just In Power Kids. Click the image to shop and show your support.