Doppler Radar Out Of Service: Tracking Rain In Maryland A Challenge

September 25 2020

So, is it going to rain on Friday? That is a question I got form quite a few people getting married locally this weekend. There has been a large number of messages about it. Well, the clouds that have returned to the Mid Atlantic are from former Tropical Storm Beta.  But with High Pressure in control, the rain trying to arrive will be tough to track in Maryland.

The forecast models have been split as to the amount of moisture that can reach us, but we also have primary equipment failure: Our local Doppler Radar is broken!

Under normal conditions I try to quell the concerns. But in this case I think it’s best to at least ‘plan for some showers’, not a washout. Just know, we may not be able to track them very well.

Below is a look at the Doppler Radar Out Of Service, and our forecast maps.

Surface Weather At Noon

Visible Satellite Loop Through Noon

Check out the circulation with Beta in Mississippi, at the bottom of this high resolution view.

Regional Composite Radar

Here it appears some of the light rain has reached southern Maryland.

Doppler Radar View

This view is the single site image from Wakefield, VA. The outer edge shows the light rain in southern Maryland.

Doppler Radar Locations

What is displayed in Delaware are likely false returns since it is so far from the radar site.  The DOX site over Dover was actually clear for the state.

We can use Dover, but there will be gaps of data west of Baltimore, Washington, and in the mountains.

LWX is our primary local Doppler Radar Site in Serling, VA. The National Weather Service noted a failed in data acquisition on September 20. That was when it was dry and not needed.

Technicians will not arrive until Saturday.  According to NWS:

THEY WILL DETERMINE THE FULL SCOPE OF THE FAILURE, AND WORK WITH WFO STERLING ELECTRONICS
PROGRAM STAFF IN TAKING SUBSEQUENT MAINTENANCE ACTIONS. ACTION AND
DIAGNOSIS INCLUDES REPAIRING THE GEAR BOX AND ASSESSING THE HEALTH
OF THE BULL-GEAR.

Forecast: Will it Rain?

This will depend on the strength of High Pressure.

According to the NAM 3 Km: We will have showers Friday afternoon and Saturday. But the GFS looks more sparse.

NAM 3 Km Forecast Maps

GFS Model –> slider

This model shows a smaller chance for rain. However, the initialization was missing the rain in southern Maryland and Virginia in place now. So it’s hard to trust what it shows tomorrow.