Saturday evening, December 14, 2024

The strong high pressure that gave us clearing and a cold start to the weekend will play another role as the next storm approaches: cold air build-up. A layer of cold, dense air collects in the valleys between the mountains and coastal areas of the Mid-Atlantic, while a storm brings warmer air and moisture aloft. The net result can occur over a longer period of time winter weather, usually in the form of ice.

This is expected between the high mountains along the Appalachian Mountains and near I-81 across Virginia, Maryland and central Pennsylvania.

Inland suburbs west of Baltimore and Washington to Frederick, Westminster and York PA: There may be some severe weather or light sleet, but this looks like a cold rain event developing in the early to mid afternoon and becoming more steady toward the evening.

Winter weather warnings

Winter storm warning in the higher mountains. I see more of an ice storm, but the National Weather Service has identified the possibility of a flurry and a few inches of snow.

Winter weather information: The models have a longer burst of snow than sleet and freezing rain. I would lean more on the icy voyage since I just gave a model boat. Along and west of I-81 Virginia and Maryland, then north of Harrisburg in Pennsylvania. If you drive this road toward the Poconos, the afternoon will be very slow.

Before we look at the projected schedule…

Preliminary storm expectations

This from the NAM 3Km, which tends to be a bit more aggressive, still has little snow and focuses more on the freezing rain.

Snow potential

This is NOT the main concern.

Potential for freezing rain

That is the main concern.

Saturday setup

The high pressure area was located near Montreal in Quebec, Canada. The pressure of 30.95 in Hg is very high, which helps the code air last longer.

The low pressure/storm center was near Kansas City and already had a band of ice and snow on its northern end. This storm is moving east-northeast and will reach our region by midday Sunday.

No: There will be a number of further storms with warmer temperatures and rain through midweek.

Model forecast maps

There is a bias or error that often causes winter weather events to occur slightly faster than shown here. While the models are expected to arrive around midday, I would plan for mid to late morning.

We start with the view of the Mid-Atlantic and then take a closer look at the high-resolution NAM 3 km model and key time frames.

Larger view: Sunday morning to Monday evening

ECMWF model

• Blue = snow
• Pink = freezing rain
• Green = rain

Please note this will develop throughout the day and transition to full rain overnight, ending on Monday morning. The next route will see a lot of rain on Monday night.

6 Hour Model Summaries

ECMWF model 1:00 p.m. to 7:00 p.m

GFS Model 1:00 p.m. to 7:00 p.m

Take a closer look at the NAM 3km model

7 a.m. temperatures

Deep freezer area with enough support to start the day.

7 a.m. to midnight

Rain/snow often arrives 1 to 2 hours earlier than indicated.

Snapshots

Midday radar

Midday temperatures

Afternoon

3pm radar

3 p.m. temperatures

Sunday evening

10pm radar

10 p.m. temperatures

Road travel profile

This is between 8am and 6pm

Long term forecast

From this morning

Wednesday afternoon to Friday afternoon

This round of rain will be followed by colder air and mountain snow. The subtle instability is not visible, but there will be energy to produce severe weather east of the mountains.

LONGER RANGE PROSPECTS

Focus on the jet stream because the surface storm charts are not reliable at this distance…

After the rain and warming, a shot of very cold air arrives late next week. This will dominate the eastern US through the end of next weekend.

Sunday morning

The coldest air is expected to end the weekend. Parts of Florida may experience temperatures below freezing.

7 day forecast

Sunday will be the most complex day, with ice and snow in the mountains and rain in the evening in metropolitan areas.

Next week it will be warmer and it will rain. Not only will it rain, but just a few showers for a few days.

The colder end of the week may bring severe weather.

Subscribe to email notifications

FITF equipment on offer

In case you missed that

The Faith In The Flakes December 5th Origin story

In case you missed it:

Snow report from November 22nd

WINTER OUTLOOK

My winter outlook report

Please share your thoughts and pictures/videos of the best weather or just stay in touch via social media.

Plan for a weather-dependent stem assembly

Severe weather: Storm Smart in October and next spring

Winter weather FITF (Faith in the Flakes): November to March

Click here to see more and submit an inquiry for your school.

THANK YOU VERY MUCH:

Baltimore Magazine Readers’ Choice The Best of Baltimore

Maryland Trek 11, Day 7, completed Saturday, August 10th

We’ve raised OVER $104,000 for Just In Power Kids – AND we’re still raising more

The annual event: Hike and bike 329 miles in 7 days between Wisp Summit and Ocean City.

Every day we honor a child and their family’s cancer journey.

The fundraising is intended for Just In Power Kids: funding free holistic programs. I have never taken a dime and never will. It’s all up to our nonprofit.

Click here or on the image to donate:

REPEATING MY MESSAGE ON THE TOPIC OF LEGEND

I understand that there are some spelling and grammatical errors, as well as occasional other errors. I take responsibility for my mistakes and even the computer errors I may miss. I’ve made a few public statements over the years, but if you’re new here you may have missed it: I have dyslexia and found out about it in my sophomore year at Cornell University. However, that didn’t stop me from getting my degree in meteorology and being the first to receive the AMS CBM in the Baltimore/Washington area.

One of my professors told me that I had made it this far without knowing it and that I shouldn’t let it be a crutch for the future. That was Mark Wysocki, and he was absolutely right! I miss my mistakes when proofreading myself. The automatic spell checker on my computer sometimes misses the mark and makes the problem worse. I can also make mistakes in forecasting. Nobody is perfect at predicting the future. All maps and information are correct. The “wordy” stuff can get sticky.

There was no editor to review my work when writing and have it ready to ship in a newsworthy time frame. Barbara Werner is a member of the web team that helps me maintain this website. She has made it her mission to correct typos when available. That could be AFTER you read this. I accept that and perhaps prove that what you read is really mine… It’s part of my charm. #FITF