December 19 2022

Monday Evening Update

We are now within 3 days of the start of this storm for us on the East coast, and it is starting to come together with higher confidence. At this point, if you continue to follow my updates I hope to guide you for what I see with consistency and trends.  I want to do things a little different in this report. First, some quick notes and answering the most common questions I’ve been getting.  Then a look at the model maps below will help support my answers. Also, a very interesting Meteogram that shows how the snow projections from one model have changed each day since last Thursday.

Here is what jumped out to me today:

Quick Take: This large storm will bring our region mostly rain at the start, despite some inland mix.  The main event for us will be Friday as the arctic air moves in.  This may be late morning to midday, and catch up to the moisture for two important factors:

1. This may end with a slushy mix or snow
2. Flash Freeze: Enough moisture could be left over as the arctic air arrives!

The latest models seem to speed up the arrival, which falls in line with many events I have shared with you over the last few months.  We should hedge our bets on the faster time frame with this.

I feel good about these ideas, but the specific timing is still hard to pin down this early. Here is an example why: 

If we can plot the leading edge of arctic air now (Monday) and miss the exact speed by just 1 mph, then it would be off by 24 miles each day. So by Friday afternoon, it could be 90 to 100 miles off. If this was moving at roughly 20 mph, that 100 miles could make the difference of five hours sooner or later.

The latest models have sped up the arrival of the arctic air to late Friday morning.  It still may have some fine tuning that is best to start working on within 2 days of the event. 

Popular Questions I’ve Been Getting

Will my plane be delayed?

In my experience, the holiday travel is congested enough to cause problems. This storm will affect a large part of the Eastern US.  It’s best to prepare for a delay regardless of the rain, wind, or snow in your travel airport.  Flights can get delayed due to the weather in some other location holding up the connection. 

What is a Flash Freeze?

This is when arctic air arrives and turns wet pavement to ice.  

I realized last week we had a freezing rain event, but the ground was just warm enough to stay wet.  Since then we have had a lot of nights below freezing to chill the ground.  It can freeze faster now. 

Can we really get this? We often hear about a Flash Freeze that does not materialize.

The models below are showing temperatures dropping quickly from the 50s to below freezing, perhaps the 20s within two hours.  Also, there will be moisture left over, with the GFS showing a few hours of potential snow while in the freeze.

Let’s take a look…

Jet Stream

Wednesday Morning To Christmas Sunday Night

Snapshot 1 PM

The White Circle is the Closed Upper Level Low. This will pass through Pittsburgh and Buffalo. It will push the arctic air through our region, but the debate is whether there will be moisture left or not.

Often with this set up, we get the arctic air as the rain ends.  In this case, it looks like we could get this to catch up for a few hours.

Surface Weather Animation

7 AM Thu to 7 PM Fri

I am starting with the European Model, since it has been the most consistent.

Snapshot at 1 PM

I need to emphasize, this is faster that the previous model runs. This has the arctic front reaching east of Philadelphia by 1 PM.

Closer Look

There is not a lot of moisture but it does show some snow in the cold air for 1 to 3 hours. It may not accumulate much in metro areas, but could be enough to keep the roads wet as the deep freeze arrives.

Winds At 1 PM

Yes, the winds will be strong and help to dry out roads (if not raining or snowing).

Steady winds 15 to 25 mph, with gusts 30 to 40 mph.

Temperatures Forecast: Tracking  From Morning

(readings on the thermometer NOT Wind Chill)

10 AM

WOW! 

• McHenry = 12ºF
• Baltimore = 53ºF
• Ocean City = 57ºF

1 PM

• McHenry = 5ºF
• Baltimore = 34ºF
• 20s just west and north of the Beltway
• Ocean City = 52ºF

4 PM

• McHenry = 1ºF
• Baltimore = 30ºF
• Ocean City = 39ºF

Let’s Compare to the GFS Model 

I want to reinforce that this model as recently as last night was delaying the cold air until the evening. It is now sooner and keeps more moisture around in the cold air.  It is a worst case scenario, but still a bump from before. I want to see consistency or the ECMWF Model to trend this way before I bite.  

However, most weather apps use this model, so this may reflect what you have been seeing.

10 AM Friday 

• McHenry = 10ºF
• Baltimore = 53ºF
• Ocean City = 55ºF

1 PM Friday

Surface Weather

Front moves East of the Chesapeake Bay with a wintry mix (pink) from Baltimore to Cecil County.

Sleet (orange) and Snow (blue) extend from the western suburbs to western Maryland mountains. This supports a few hours of precipitation in the freezing air!

Temperatures 1 PM

• McHenry = 5ºF
• Baltimore = 28ºF *Freeze arriving a few hours faster than the ECMWF Model
• Ocean City = 57ºF
• *Freeze on the doorstep of Philadelphia 

4 PM Friday

Surface Weather

This supports snow showers and flurries through metro Baltimore and within 50 miles in all directions, at least for the 1 PM to 4 PM time fame.   This may NOT amount to much accumulation, but maybe enough to keep roads wet as the cold air catches up.  That is the concern for the Flash Freeze, and the GFS Model makes it look more likely.

Temperatures at 4 PM

• McHenry = -1ºF
• Baltimore = 23ºF
• Ocean City = 35ºF *Most of Delmarva and metro Philadelphia the Deep Freeze

Christmas Weekend: VERY COLD

I am just showing Saturday Morning, but this is like to repeat for Christmas Day as well. 

Baltimore reaches the mid Teens, with Ocean City and coastal areas in the Mid 20s.

This is now showing up in the 7-day Forecast which will be updated in my Tuesday morning report.

Snow Meteogram: Model Time Adjustment 

I thought this meteogram was good to share now. Here is a look at the Snowfall forecast for Baltimore on all ECWMF Model Runs since last Thursday (from top to bottom).

Remember when many were talking about a big snowstorm and I was hesitant, because I don’t trust modeling one week away. Also, I NEVER give snow totals more than 3 days away. This is why! You almost have to laugh at the adjustment, but it does prove the Chaos Theory, and how missing small details can lead to big changes farther out in time. 

Additional Notes On All Winter Storms

From my perspective, this is the protocol I follow and I hope it helps as I dive into the updates and expectations. 

1. Never promise snow a week or more ahead of time. I carefully choose my words with possibility and model guidance trends. I did show this event a week and a day ahead of time, with the caveat that it will be during high holiday travel and worth extra attention. 
2. Never flip a forecast based on one model run. Especially with this still being 5+ days away, there are a lot of small details that can be missed by computer guidance. Or a small shift early can lead to a 200 mile move of a snow line a week away.
3. I continue to ‘look’ at guidance and share it with you to identify trends. These trends help to show which model is consistent or if there is new information that will trend the timing or temperatures to be adjusted.
4. Any snow or ice forecasting is more realistic within 72 hours (3 days) of the event. Until then it is not worth guessing.
5. A large storm regardless of snow, ice, or rain locally, can still have wide ranging impacts for travel ahead of a holiday. 

Faith in the Flakes Gear

What is Faith in the Flakes?

It began with my son in 2009

December 5th Snow In Baltimore And The Start Of Faith In The Flakes FITF

SNOWSTIX – Available Now

STEM Assemblies/In School Fields Trips Are Back

Click to see more and ‘Book’ a visit to your school

My Winter Outlook: Not A Typical La Niña!

I see many factors to support colder influence with multiple systems. Early and later in winter. Check it out.

Winter Outlook 2023 For Snow Not Typical La Niña Plus Polar Vortex Disruption

Also See The Winter Outlook Series:

Atmospheric Memory Suggests Active Winter Storm Pattern Outlook

Winter Outlook 2023 From NOAA Very Different Than Farmers Almanacs

Farmer’s Almanac Comparison

Winter Outlook 2023 Early Look At Snow From Two Farmers Almanacs

Triple Dip La Niña Winter

Winter Outlook 2023 La Niña Triple Dip Expectations

CONNECTION TO WINTER?

If you want a snowy winter, this is what you might want to look for in the rest of the tropical season. (You might be seeing a lot of commercial snow removal people out this Winter).

Record August For No Named Tropical Storms: Closer Look At Snow Following

Wooly Bear Caterpillars

Winter Weather Outlook From The Wooly Bear Caterpillar

Persimmon Seeds

Winter Weather Outlook: Persimmon Seeds And Snow Folklore

Click to see Top 20 and MORE

Winter Weather Folklore Top 20 And More Outlook Signals From Nature For Cold And Snow

Normals And Records: Maryland and Baltimore Climate History

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

• Facebook: Justin Berk, Meteorologist

• Twitter: @JustinWeather

• Instagram: justinweather