April 30 Wind And Rain Storm Brings Possible Flooding Today

Thursday April 30

Today is our storm day! There are only a few hours left in April, but it seems fitting the month ends with weather that brings strong winds and heavy rain. We’ve had quite a few storms this month that has brought 20 days with some measurable rain across Maryland. Baltimore already has double the normal monthly rainfall at 5.20 inches, and we could add another 2 or more inches today.

Two things I will focus on in this report: Strong Winds and Heavy Rain/Downpours (timeline slider below)

Wind Advisory

The National Weather Service has this advisory for Maryland’s Eastern Shore and Delaware for gusts up to 50 mph. However winds have pushed to 30 mph already this morning in central Maryland and models show and increase peaking mid afternoon.  I would treat this as a wind storm as well in Washington, Annapolis, Baltimore, and York PA. Trash cans and lawn furniture can fly away. Branches and trees could come down, so check on batteries and flash lights in case of a power outage.

 

Wind Forecast

Note that wind speed is a one minute average.  Wind gusts are peak winds that may last a few seconds and can be much faster.

Wind Speed Forecast

Notice the direction from the Southeast. This will pile water up the Bay and on the Atlantic coast. It is also a direction that enhances storm events in Central Maryland.

 

Wind Gust Forecast

All places that can reach 50 mph should be under a wind advisory. This is why I think it may be expanded.

 

Temperatures (result of the wind)

This morning started in the 60s and will remain mild through the event.

 

Rainfall

Flood Watch

 

Morning Radar Loop

4:35 AM to 7:10 PM

This slow moving line has a connection to the Gulf of Mexico. There is a lot of moisture available and will pump in with downpours.

 

 

Rain Timeline

The model I am about to show you is just one solution and is NOT perfect. However, I would use this as a gauge within 1 to 2 hours of when the main storm line should pass through. Please consider these notes before viewing the timeline:

Training: This describes when heavy precipitation cells continue to pass over the same area.

• The movement of the heavy rain will be from south to north. The LINE of rain will slowly move to the east. This will allow for a few hours of very heavy rain.
• 8 AM to 12 PM– Western areas.
• 12PM to 6 PM– Central Maryland and the Big cities
• 5 PM to 10 PM – Delmarva.

Meso-Low: A circulation can develop within a long of heavy precipitation along a front. This is what I annotated on the simulation below.  If this forms:

• Timing will be between 2 PM and 6PM somewhere along the Bay.
• Track will be close to the Chesapeake Bay
• The entire line of rain will slow down its forward movement, and allow any place along the path to increase totals.

Please note that the features may be off by an hour and within roughly 60 mile east or west of what is shown here. So we will have to monitor

Radar Simulation —> slider

Looking Ahead

• Friday: Rain showers redevelop.
• Saturday: Dry and mild. *Pick of the weekend.
• Sunday: Rain will race back in by afternoon