Thoughts on remnant low

[ncweatherwizard]

First of all, why is this not a) classified as a tropical depression or b) why was the former Nicholas considered a tropical storm? The low pressure we are observing looks better than some of the images from when Nicholas was weakening to a remnant low. In any case, this is interesting. The low pressure center is moving slowly west-northwest this morning, but I find it amazing that it is holding together under extreme 25kt to even some 30kt shear. On second thought, the center is not as badly exposed as the clouds on the north side of the system which is taking a beating. Dry air is going to hang around for awhile, it seems. Dominant high pressure is in control of the eastern US; (which I happen to like, since temperatures will be well into the 80s this weekend.) therefore, the trough over the Atlantic has nowhere to go.

As usual we have a difficult situation to deal with to determine what will happen, because the setups are so dynamic in November. But with an unusually dominant ridge in control of the US, I imagine that thet the trough to which the remnant Nicholas is connected will slowly dissipate over several days; all the time, the low pressure will drift toward the US coast under the ridge. Note that the next trough should not approach the East Coast until around Thursday---that's five days. Looks to me like a similar situation to 2002 Kyle, except movement will likely be more distinct in one direction, than that storm's looping path.[/i]

[wxman57]

You have to remember that this is a cold-core low, not a tropical system. Cold core lows THRIVE on wind shear. Therefore it's easy to remain intact. As for classifying it as a TS now, there are two reasons not to. First, it isn't tropical. Second, just because Nicholas was called a TS when it looked worse than this, doesn't mean THIS low should be called a TS. Nicholas should have been downgraded days before it was.

So right now it's just an old frontal low that is separating (has separated) from the front. It's associated with a large upper low, so shear will probably remain high for another day or so.

[Steve H.]

Yeah, I agree with the motion you suggest, probably 275/280 right now. The low center is impressive IMO considering the environment, but since its hybrid or even cold core in nature, it can handle it. Think the models may be too far south and fast given the setup of the ridge. Still think as the axis of the ridge comes to the mid-Atlantic and gets 'over' the low, conditions will improve for some development. Should see shower activity increase during the next 24 hours, and all it will take is some warmer water to spark T'storm activity. There is some warm water a few degrees further west and if the low depens some more tonight it should tap moisture and warmth from the south, pulling it into its circulation. This is still TBD, but this is an unusual setup for November 1st.....well....not that unusual

[wxman57]

As for the motion, you're following a small vortex that is rotating counter-clockwise around a large upper low. It is traveling WNW now, but it's nearing the top of the mid/upper low so it shoudl turn W then SW soon. It's the main upper low you need to monitor for movement, and it's moving SW.

[ncweatherwizard]

You have to remember that this is a cold-core low, not a tropical system. Cold core lows THRIVE on wind shear. Therefore it's easy to remain intact. As for classifying it as a TS now, there are two reasons not to. First, it isn't tropical. Second, just because Nicholas was called a TS when it looked worse than this, doesn't mean THIS low should be called a TS. Nicholas should have been downgraded days before it was.

So right now it's just an old frontal low that is separating (has separated) from the front. It's associated with a large upper low, so shear will probably remain high for another day or so.

I agree with you. My mistake. Makes sense now that I take time to actually think about it and look at everything. Trough=attached ULL=cold core system=no-brainer... You also mentioned to Steve a SW movement overall, which I am having difficulty in locating that movement, for I continue to see a movement just north of west for now, with seems to be a wobble to the south lately, which is what I base the WNW movement on. Bottom line: ridge will get it soon.