Wednesday, January 30, 2008

12 comments:
HOW HAPPY WILL YOUR FRIDAY BE?

Uncertainty abounds in the latest round of winter weather set to affect the Mid-Atlantic Thursday night into Friday. High pressure settling into place for the next 2 days will allow overnight temperatures to refreeze the ground and make all surfaces quite cold as the next storm system approaches from the Tennessee Valley. Overnight Thursday into Friday it seems likely that west of I-95 in Maryland will see several hours of freezing rain. Rapid arrival of the storm will allow low level cold air to hang tough into the early morning Friday, and will take until well after sunrise for the southeast and easterly flow to scour out that cold air. However, low dewpoints also mean the potential for a delayed start of precip, which for those hoping to get school delayed, could be a "mixed" blessing, no weather puns intended.


Since many of you come to this site for the "inside scoop" on weather events like this one, here's the breakdown: A tricky call for school districts in central Maryland. Baltimore County especially will face a challenging decision for several reasons:
- There will be ice accretion in roughly two-thirds of the county, north and west of a line from Fork to Towson to Catonsville, enough to disrupt morning traffic only. South and west of a line from White Marsh to Glen Burnie, expect a brief period of freezing rain overnight turning to all rain. If your commute keeps you along or east of 95, icing will be minimal.
- All frozen precip will change over to rain by 10 AM, with exception of far N and W, such as Hereford Zone and obviously into the more rural counties like Carroll and Frederick.
- Despite this changeover likelihood, the issue becomes... will it occur quickly enough (say by 8AM) so as to let a 2 hour delay stand. We all know that if a school system announces the call at 5:30, they can't wait until 8AM to change it, because by then buses would already be rolling to pickup high school students.

- My theory on the logistics of this (based on witnessing similar situations in Feb 2005), is that any decision to upgrade a 2 hour delay to a closing really has to be made by 6:30-7:00 AM. While it may still be icing throughout the area (except for east of 95)...I fully expect temperatures to warm above 32 by mid morning SO THAT were buses to start rolling at 8AM...things theoretically would be fine.
- The problem with this whole setup is the call to stick with a 2 hour delay will have to be made on a HOPE that the forecast pans out as projected. The danger is that if warming to well above 32 has not occured by 8AM, the whole area remains a disastrously treacherous commute right at the critical time of 8 to 9 AM, only to clear up perfectly at 10.


For simplicity sake, let's hope that:
1. In eastern areas (the immediate Baltimore Metro area) Any freezing rain/sleet quickly turns to rain just in time to let school systems feel confident the 2 hour delay call was a good one.
2. in central and western areas (Carroll County on west)...the weather forecast at least makes it easy for schools to make a sensible call that won't cause political or parental consternation.


What do I think will happen?
Honestly, I can see Baltimore County closing the Hereford Zone, (or perhaps allowing them a 2 hour delay) and leaving everyone else with a 1 hour delay. I say this because I sense we'll have a later start time, (5AM instead of after midnight) limiting how much can fall and freeze. The city may not even have a delay. Carroll, Frederick and west-ward are facing a significant ice storm that could result in .25" or greater, and strong winds behind the storm are going to knock down trees and powerlines. They're going to heed the call and close outright in my opinion. From Howard County on south, expect mostly rain and nothing in the way of delays or closings, sorry Anne Arundel, PG and Montco, you'll have to sit out this one. Harford County likely ends up with a 2 hour delay. Will be interesting to see what the morning brings, so goodnight all!

Friday, January 25, 2008

8 comments:
IN MARKING PERIOD GRADE MODE UNTIL MONDAY

Sorry for not being able to post recently, what little brainpower is left in the evenings this week has been diverted to preparing quarterly grades. Sometime during the weekend, I hope to post an overview of what's lurking for February. I see the potential for a little surprise snow Saturday, and some computer models are having trouble resolving the development of a possible rogue coastal on Sunday. At least there wasn't much Mid-Atlantic weather to talk about this past week. But as we head into February, I foresee some "weather whiplash" coming up, with wild swings in temperature and storm types. Feel free to post any questions you have about the upcoming pattern and I will answer this weekend as time permits.