final update Tuesday Feb 1 Midnight
As I write this the radar shows my area receiving mixed precip (freezing rain), but as I look outside it is only rain. It does appear that with the delay in the precip reaching the area the cold air was given more time to erode prior to the precip. To be honest, since this means less or no ice at all, I am not complaining that my forecast was not 100%. I do not at all like ice. Had the precip come in earlier as originally thought, we would have had a layer of ice. BUT ... for those North of Baltimore, especially in Northern Harford Co and along the PA/MD line, you still could see some ice, so be careful.
The concern with this rain is minor flooding. For many, the storm drains are covered by the snow pack, and the rain on top of the snow, with rising temps, will only produce more liquid in need of a run off which is more then likely blocked.
Onward .... As I have been mentioning for some time now I am tracking the potential storm this weekend and mid next week. It is still too far off for much certainty, but, at this early date here is how I see the weekend storm (I am not at all going to talk about the other storm which is over a week away):
1. The potential for snow exists, but currently the model data moves the Low up the coast in such away as it brings the warm Southern air into our area, meaning another rain event for us.
2. But, I do see the chance for snow later Saturday as the Low pushes to our North and the wrap around cold air enters the precip, turning it to snow or mixed precip.
More to come in the following days. I will keep the Weather Phone updated as necessary.
update Tuesday Feb 1 afternoon
We are under a Freezing Rain advisory for this evening.
We are in the lull I had talked about with the bulk of the moisture moving in after dinner. That is when the precip will fall as freezing rain through Midnight, and for those North, through Wednesday morning before turning to all rain Wednesday.
I am still watching the possibility of snow this weekend, and I noticed the NWS has just now upped their snow percentage to 60% (a big jump from the previous forecast). Maybe they read my posts (just kidding).
I will keep the Weather Phone updated and will have another update later tonight.
update Monday Jan 31 Midnight
So far so good according to my last post and forecast. The precip primarily held off until later in the evening as I mentioned yesterday. Over night we can expect light precip in the form of sleet and ice pellets to linger through the morning rush hour. There will be a lull in the action Tuesday afternoon before the "main" portion of the storm comes through around dinner time or later. This precip will be sleet and later freezing rain as the warm air over runs the cold air in place. We could see up to 0.5 inches of ice, mainly around Harford Co and along the MD/PA line. By Wednesday morning we should be experiencing all rain.
As I have mentioned, we need to be cautious as any shift in the Low or delay in eroding the cold air will mean a greater build up of ice. I am leaning toward a more cold solution for two reasons: the models typically erode cold air too fast; and the layer of snow over the area should keep us colder longer then the models are saying as they are not taking this layer into account. So I do agree with the 0.5 estimate for ice.
To make matters worse, come Wednesday we could experience winds in the 30+ mph, not good for those trees and power lines still with ice on them. I am concerned about the Tuesday rush hours (plural) as well as widespread power outages.
As I have been mentioning these past days, I am still following the potential for another storm this weekend and then again mid next week. It is too far out for much detail at this time, so this is all I will say at the moment.
I will keep the Weather Phone updated.
update Sunday Jan 30 Midnight
I have been reviewing the data, etc and I really don't have much to add from my last post. The timing may be delayed a bit, so we may not see precip until later Monday evening, but I would still keep in mind that the weather will be turning anytime after dinner Monday.
Snow accumulations should be light, maybe an inch or so, more toward PA. Ice accumulations could be around 0.3 or more inches. The ice accumulation will depend on how long the precip lasts before the change to rain, and as I mentioned earlier, it is not easy to move cold air out of the region, especially with a snow cover on the ground. On Tuesday afternoon there could be a lull in the precip, but know it will start up again later in the afternoon Tues.
I am expecting at least an advisory to be issued later Monday. I will keep the Weather Phone updated.
update Sunday Jan 30 Noon
As much as can be it appears the storm this week is taking shape. From all indications we will have a mixed precip mess, with the upside being not a lot of snow accumulation, while the downside is ice accumulation.
TIMING & PRECIP
1. Monday around dinner time (for Central MD. NOTE: Southern MD will see precip sooner and a turn over to rain sooner. Not a major issue there. Northern Balt Co and Harford Co will see precip a bit later and stay frozen longer. This holds true for all I say in this post) we will start to see snow falling. This should be light snow with minimal accumulation.
2. Tuesday around rush hour (7:00 or so) the snow will begin to turn over to sleet and ice pellets. This will last through the midday before any turn over to rain. Those along the PA / MD border may never see rain.
3. Wednesday should be rain with a chance for a turn over to snow late Wednesday night (no major accumulation)
CAUTIONS
I will most likely be tweaking this later today and Monday as to timing and accumulation rates, but let this serve as an outline.
1. Cold air is not easy to move out of the area, so precip type and timing will be a challenge to pin point
2. Any shift in the Low or timing will change what happens
3. Bottom line: Monday night into Wednesday be prepared for periods of mixed precip
4. With icing I am concerned about power outages and the Tuesday morning commute
ONWARD
Winter is not yet over for us. As I mentioned earlier I am tracking the possibility of a coastal storm this weekend (maybe Friday night into Saturday) and then another strong storm potential the following week (8 - 12). Fun times!!
I will be updating again late tonight. I would not be surprised to see at least an advisory issued by the NWS by tomorrow morning. I will keep the Weather Phone (443-470-9804) updated.
update Saturday Jan 29 evening
Just a quick update, keeping in mind that this far out things tend to change. But right now it is looking more and more like this may move to the North and West. The positive is less snow (for those snow haters), yet the negative is a longer period of icing possible. There is also a chance for this to end in rain later Wednesday. So a complicated forecast only getting more complicated. And to be honest, a slight - and I mean slight - shift of the Low will change things dramatically. The other factor is the cold air and it's propensity to stay longer than the models tend to show. So, definitely tricky.
Now, for the next part of this - are you ready - stay seated - there is the potential for another coastal storm next weekend!! Yup, Winter is not yet done with us. So I will now be keeping you all posted on both storms ....
original post Sat. Jan 29 morning
I hope most if not all of you now have power restored so you can focus on the beauty around us! It is not often that snow lingers here in Central MD.
Ok, on to the next system (as I have been following since the 15th). This is just a quick update as we are still too far out to know with any certainty what will happen, and even though we just had a decent snowfall, this Winter is still one where most (not all) storms will miss us to the North and West, giving us mainly mixed precip storms (as we have seen). So I am still leery on long-range forecasting for this Winter.
TIMING
Looks like most of us will see light snowfall on Tuesday (Southern MD to see a mix) with little accumulation. The bulk of the storm will hit us Tuesday night into Wednesday.
DYNAMICS
We are dealing with a couple dynamics which will influence what happens here. The track of the Low on Wednesday will determine if we get snow (6 or more inches) or if we get mixed precip or an actual ice storm. Currently the model data shows the Low just to the West of us, giving us mixed precip. The NAO is trending positive, which typically means a Westerly track for the Low, but, there could be a High system to our North which should block (damming) the cold air over our area. So timing is an issue as to the placement of the High and the Low.
Keep in mind that a High spins clockwise while the Low counterclockwise. This is important, for the position of each system will effect the air temps and position of the Low. If you can visualize a High to our North spinning clockwise and a Low moving toward it, the position and spin of the High will push the Low. Depending on the locations, the Low could be pushed further to the West as it gets caught in the spin. So the position and timing of the High will effect the position of the Low. As the Low moves near us and spins counterclockwise, depending on it's position it will either spin up warm Southern air (into the dammed cold air) or spin up moisture from the Atlantic (into the dammed cold air). The first scenario gives us mixed precip, while the latter brings us snow. I say all this to help demonstrate not only some of the dynamics of the weather, but also to show how forecasting this far out can be tricky (but fun!).
I will update again throughout the weekend, maybe later today, but definitely Sunday morning.
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Updated: 5:28 AM GMT on February 02, 2011
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