Synopsis – Storm remains unlikely at this time…
– 20% Chance of ‘major’ impacts (6″ or more)
– 40% Chance of ‘minor’ impacts (less than 6″)
– 40% Chance of no impact on Hudson Valley
Detailed Discussion: NERD ALERT!
Ahh…. the joys of tracking and forecasting the dreaded “Bomb Cyclone”. As if the weather isn’t exciting and active enough, we have articles on social media advertising potential imminent doom ????. Instead of scary headlines, let’s talk about where we actually stand at this point.
Our extremely active pattern continues… with bitter air in place across the Hudson Valley and northeast. This arctic air laid the groundwork for a potential major east coast storm this weekend. A piece of energy will dig a DEEP trough into the eastern US. That upper level trough will work to pull the developing surface low pressure up the coast. With such a deep upper level trough, the surface low pressure is expected to undergo ‘Bombogenesis’ (hence the term ‘bomb cyclone’). But the term ‘Bombogenesis’ is actually a meteorological term, that refers to a rapidly intensifying low pressure system, that deepens at least 24mb in 24 hours. Guidance has this storm go from roughly 1000mb Saturday afternoon, to 969mb by 1pm Sunday afternoon… thats 32mb in 24 hours! Storms that intensify that quickly, or “bomb out” are notorious for areas of intense precipitation and strong NE winds.
As Alex highlighted in the first Weekend Storm Buzz discussion, there are a few possibilities with this system. As of late Wednesday night, here are the updated probabilities:
1. 20% chance of MAJOR IMPACT: If the energy building this storm phases earlier and the trough axis becomes negatively tilted… it could still pull the coastal low pressure close enough to the coast to impact us with a substantial nor’easter. Right now the likelihood of this is low, but we cannot rule it out.
2. 40% chance of NO IMPACT: The energies phase later… and the trough axis doesn’t tilt negative… this allows the coastal low pressure to escape further out to sea, and spares the east coast from a significant winter storm. Only portions of the Carolinas and perhaps eastern New England would be impacted.
3. 40% chance of MINOR IMPACT: The energies phase a little later, but still early enough to pull the storm up the coast, close enough to bring a minor event to areas west of I-95… but could have significant impacts right along the coast.
Guidance late on Wednesday was hinting at the storm creeping slightly further west. The image shown here shows the European ensembles from late Wednesday AM, and from late Wednesday afternoon. The trend late in the day was a notable western shift of the low pressure spread on the ensembles. This still would be a negligible event for the Hudson Valley… but if this trend continues, the potential for a significant impact could increase.
This is the “joy” of tracking coastal winter storms. These are very dynamic systems that require patience. The only thing that helps get to the correct answer with these storm setups is TIME. The closer we get to the event, the more uncertainty we can eliminate from the potential storm. We’ll continue to monitor this closely to see if this system has any more westward trends up its sleeve… or if it’s going to be a close call system that stays just off shore.
-Bill