SOUTH MISSISSIPPI (WLOX) - Storm developing in the Atlantic?
continue to try to develop an area of low pressure off the east coast of Florida, north of the Bahamas, by the middle of next week.
put out a Special Tropical Weather Outlook on Sunday morning. Their outlook stated, "A non-tropical area of low pressure is expected to form north of the Bahamas later this week. This system could gradually acquire some subtropical characteristics by Thursday or Friday as it moves slowly northward." The National Hurricane Center gave this area of low pressure a low (near 0%) chance of forming over next 48 hours and a low (30%) chance of forming over the next 5 days.
The main things I want to know, and I'm sure a lot of folks would agree, are how strong will this area of low pressure become and where will it go? One thing is for sure... this is a forecast with quite a bit of uncertainty. Sure the computer models all agree that a low will form, but they are not agreeing on low pressure strength, track, or even what day the area low pressure could form. Below is my extended discussion:
Where will it go?
As of Sunday morning, a blocking ridge of high pressure remains parked over the eastern US, centered near North Carolina and ridging southwestward into Texas. While the center of that high will gradually move east into the open Atlantic through this week, it will still continue to ridge over the southeast US. Why am I talking about high pressure? Well, it can give a clue as to the potential path a storm would take IF one were to develop.
The area of low pressure that may develop around Wednesday of next week near the Bahamas wouldn't have very far north of the Bahamas to go before its path was stopped or at least greatly slowed by that previously mentioned blocking high pressure. This could mean a system that is just sitting in the same spot near eastern Florida for several days into late this week and perhaps next weekend.
The GFS (Global Forecast System) model does exactly this... keeping the low nearly stationary on Thursday and then gradually turning it westward toward the east coast near southern Georgia on Friday into Saturday. On the other hand, the European Model takes the low northward on Friday into Saturday toward North Carolina and then farther northward up the east coast into the following week... this seems less likely given the previously mentioned strong ridge of high pressure.
How strong will it be?
Two factors for storm strength... sea surface temperatures and wind shear. Warm temperatures and weak wind shear both favor tropical development. And as of Sunday, there is strong wind shear near the north Bahamas. The wind shear forecast by midweek does, however, become more favorable for tropical development along the east coast. Also, water temperatures off the east coast of Florida are in the mid 70s and lower 80s which is marginally favorable for tropical development. Will it reach the strength to become 2015's first named (tropical or not) storm (Ana)? Surely, it's far too early to tell due to the high uncertainty. But, my bet is on probably not based off of the latest information. The European model keeps the low weaker... and that's a solution that I'm siding with for now.
With the current set up of a persistent upper level ridge, it seems more likely that surface high pressure across the southeast will block the northward motion of that area of low pressure (similar to Sunday morning's GFS forecast). Neither of the models show any significant weather impacts to south MS.. but folks in eastern FL, GA, SC, NC could see a potential rain/wind threat. The interaction of that low pressure and high pressure would surely cause increased winds and waves around next Wednesday for folks along the east coast.
Food for thought:
The beginning of hurricane season is less than one month away. Tropical climatology tells us that very few named storms form before July, let alone before June. But,
that it's not impossible (TS Alberto: 5/19/2012, Sub-TS Andrea: 5/9/2007).