October Hurricane Update
By Justin Drabick
PHILADELPHIA (CBS) – The 2012 hurricane season has been active with now 18 named storms. With the peak of hurricane season long gone, climatology shows another little spike in activity in October. This year is no different, as Tropical Storm Sandy developed on Monday along with Tropical Depression #19. All eyes will be on Sandy over the next several days as an East Coast impact is possible late in the weekend or next week.
The storm is currently stuck over the Caribbean, where it is gaining strength and expected to become a hurricane. There are a few things in the atmosphere that will play a role in the track of the storm. A blocking weather pattern exists, which doesn’t allow for big changes to occur in the weather pattern. Typically during autumn, we have faster moving patterns due to rapid changes in the jet stream. Low pressure over the northern Atlantic, high pressure over the Northeast, and low pressure over the Midwest are causing the blocking pattern.
A huge player in the track outcome will be the low pressure or jet stream trough over the Midwest. If the trough moves fast enough to the East Coast, it will help push out Sandy farther offshore. If the blocking pattern remains strong with the high pressure holding over the Northeast, then the trough would slow down allowing for Sandy to track closer to the East Coast. Both scenarios are possible at this time. Then you have to deal with the interaction of the trough and Sandy. As the trough (energy) meets up with what’s left of Sandy, a large non-tropical low pressure system (nor’easter) will develop. So, the location of that interaction needs to be watched as well. If Sandy remains offshore some showers and breezy conditions are still possible on Sunday, from the jet stream tough moving through the region.
Most — but not all — of the latest forecast and hurricane model guidance push Sandy a little farther offshore. As a meteorologist, I look for consistency in the model guidance runs, so you still need another day or two to get a clearer idea where the storm is headed. Forecast model guidance is terrible at handling tropical systems in the mid-latitudes.
No matter what the outcome, cool temperatures will return for next week, with highs well below average as we head into Halloween.
Stay with CBS 3 for the latest forecasts.