Rule #1 of forecasting snow in our area…Colder air never moves in as quick as the models say. I’ve been forecasting now for ~6 years and I have never found that rule to be wrong. This has important implications for the Thursday morning snow as the colder air will still be working its way south. Areas in elevation have the advantage, and the further south you are the less likely you are to see accumulation (it may change over, but it’s still above freezing).
Winter Weather Advisories more most of northern Maryland. Cecil, extreme western Allegany, and Garrett Counties have winter storm warnings
Northern areas, I think everyone sees some accumulation. Rain becomes snow 3AM – 5AM, and it could be heavy at times. In the cities & South/East (pink area), rain changes to snow after 6AM. Colder surfaces may get some small accumulations, but don’t expect much – 1″ would be your best case scenario, a dusting would be more likely. Farther south and east, this is a rain event that may end as a few flakes.
Rain moves in before midnight, but temperatures will still be well above freezing. The rain could have some moderate to heavy pockets at times. The changeover to snow won’t take place until well after midnight. Temperatures at midnight will be in the 40s, but will continue to fall. By 6AM, much of northern Maryland will be at or below freezing, while southern Maryland will be in the 30s to around 40. Southern Delmarva will likely hold in the upper 40s/near 50 until about 6AM, as the low will track almost directly over our area, before quickly plummeting into the 30s. The precipitation wraps up and moves out from 8AM to noon. Additional snow showers or flurries are possible through the remainder of the day.
Here’s futurecast from one computer model. Remember it’s just one model so don’t look at specifics, just the general idea, but I think it has a decent handle on the snow for tomorrow.
And here’s the temperature forecast from midnight to 10AM from one of the very high resolution models.
In addition to the snow, it will be windy tomorrow. Winds: NW 15 – 25 G 40 MPH. As temperatures fall, wind chills will too. Wind chills will be in the 20s during the morning, and most likely fall into the teens during the evening as temperatures fall into the 20s area wide.
The snow could fall heavy at times, so expect visibility issues during the morning commute. The last two days have had temperatures in the 60s and 70s, and pavement temperatures are in the 60s and 70s across the entire state. Most roads, especially primary roads, will just be wet. Across northern Maryland where the heavier totals are expected, I would expect some slushy roads, and use caution if traveling in these areas.
FRIDAY MORNING ISSUES
Temperatures will fall well into the 20s and teens by Friday morning. Any spots that don’t dry up during Thursday afternoon could turn to ice by Friday morning. I wouldn’t be surprised to see some delays for ice on Friday morning as a result.
Here’s the NWS forecast lows for Friday morning.
That’s the way everything looks right now.