December 21 2022
Wednesday Night Update
The faster weather theme is truly the prime factor in my mind and forecasting now. I may have repeated myself too many times, but I continue to see weather events arriving sooner than models suggest. Now fully in winter mode, that can make a big difference with frozen precipitation and the impact on travel or dare I say schools.
In my last report, I showed the expanded Winter Weather Advisory to Frederick County. I still think Carroll and northern Baltimore in Maryland to York in PA need to pay close attention for brief sleet or snow in the morning. Timing is key!
For the record, I DO NOT want it to. I am in the colder zone and do not want to be hindered from THE BIGGEST school visit I’ve ever had planned in Harford County.
This is going to be a quick report with my text, but a lot of graphics. I feel the pictures tell the story.
It may not look like much now, but that Part 1 is what will be expanding overnight and just able to catch up to some inland cold air.
Part 2 will be a Midwest issue tomorrow, then reach us Friday morning.
My concern is that temperatures are already below freezing inland this evening. Also, the ground is much colder than it was last week. The last few cold days and nights has prepped the ground to get icy… If the ‘stuff’ arrives early enough.
The 36ºF in Hagerstown might be a blip. The surrounding area is below freezing and the region as a whole is under a Winter Weather Advisory for snow in the morning around I-81.
Winter Weather Advisory: EXPANDED TO FREDERICK COUNTY. Also includes Hagerstown and Winchester, VA
Winter Storm Warning: Garrett, Allegheny Counties in Maryland and surrounding higher mountains.
There has been a lot of buzz over this new graphic. My friend/artist Casey and I have worked to improve this (Mt Airy is accurate) and more Profiles on the way.
Western Maryland to Baltimore Expectation on the highway or nearby roads.
Nam 3 Km Thursday 6 AM to 6 AM
This model brings in light precipitation around 6 AM to 7 AM in central Maryland. Steadier snow more likely along and west of I-81.
Notice the initial snow (blue) and icy mix (pink) at the start.
Initial morning mix inland,, changing to all rain. It’s just the first few hours I am concerned with.
Just rain around Baltimore/I-95/and the Bay.
(Another High Resolution Model)
This is the fastest and worst case scenario. This involves Carroll County, the Hereford Zone, and Southern PA.
If you are concerned about travel, we should know if this is on target by sunrise. If so, then I would hold off travel westward until after 10 AM. Most main roads should be OK late morning, even in the Advisory and Warning areas.
Leading edge of precipitation reaching I-70 in central Maryland. This may bump into the colder air and produce a mix of sleet and snow.
I’ve highlighted the freezing line. I have seen temps colder than this already, so some in the freezing zone could be lower.
This shows the precipitation reaching the Pennsylvania line. We will know by this point if this is on target or off time. If so, the Northern Baltimore and Carroll Counties might have some mix precipitation and on the border of freezing.
Whoever starts with a mix may hold that sleet and or snow for a few hours.
Warming and thawing should be evident by this time. Even in icy areas, treated main roads should be passable.
If there is extended snow, it would be in the Northern Frederick Mountains and west to Hagerstown and Cumberland.
By the afternoon, if there is any local icing, it will thaw.
Let’s Focus On The Temperatures, because the snow will be minimal.
The arrival of the arctic air keeps getting sooner.
7 AM to 10 AM Summary
Snow may only last a half hour to up to 2 hours. It’s not the accumulation, it’s the support for wet roads to freeze that is the big story!
The freezing line now reaches the coast by noon, while Baltimore drops to the lower 20s and teens to below zero farther west.
It might be hard to believe this is real, but even if it’s over zealous, it will be getting very cold in a hurry!
This will be painful without question. I expect Wind Chill Advisories for some of the area given these numbers.
Yes, that is -29ºF for McHenry. Barely +3ºF for Baltimore.
This will be ferocious with gusts in metro areas to 40 mph and up to 60 mph in the mountains. I expect there may be some wind advisories and wind chill advisories issued for Friday into Saturday morning.
That’s it for now. I will be up early to see if the ‘stuff’ is advancing in early or not.
In my prior report I answered two common questions about this event. Both will be validated over the next few days.
In short, a storm is low pressure, and a deeper storm has lower numbers of atmospheric pressure we measure in millibars (mb). When a storm gets stronger, the mb are lower numbers, which we say are ‘dropping’.
A Bomb Cyclone is defined as a storm dropping more than 24 mb in 24 hours, or more than 1 mb per hour for a day. See my report here for the maps that prove this.
This is when arctic air arrives and turns wet pavement to ice. We expect temperatures to drop midday Friday. The challenge is if pavement will remain wet as the temps drop, to allow ice to form on roads. Or, will the cold wind evaporate that wet pavement, drying up before it has a chance to freeze.
December 5th Snow In Baltimore And The Start Of Faith In The Flakes FITF
Click to see more and ‘Book’ a visit to your school
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
Atmospheric Memory Suggests Active Winter Storm Pattern Outlook
Winter Outlook 2023 From NOAA Very Different Than Farmers Almanacs
Winter Outlook 2023 Early Look At Snow From Two Farmers Almanacs
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
Winter Weather Folklore Top 20 And More Outlook Signals From Nature For Cold And Snow
