Update on Hurricane Late Next Week

It continues to look very likely that a hurricane, and a strong one at that, will develop in the Atlantic over the next few days and move toward the United States. The various model solutions are still somewhat at odds as to where the hurricane might make landfall in the U.S., but today's model runs have shown a significant southerly shift to the track. The GFS, which has been locked in on an east coast landfall for several straight runs, is now falling more in line with what the Euro (ECMWF) has been hinting at all along, in a track through the Florida Straits, or perhaps even farther south.

The latest NAM run from this evening (0z Friday) shows a strong upper-level trough across the eastern U.S., a pattern that has been consistent over the past few weeks. The trough will weaken later in the period, but could still be enough to keep the hurricane tracking westerly rather than northwesterly.

The dominant subtropical ridge will likely not have the steering effect it typically does this time of year, taking the hurricane up the east coast across Hatteras. This could all change, but it seems the most likely scenario will be a southerly track of the hurricane across the Greater Antilles, with a landfall along the Gulf coast. We'll see what future runs look like. ZD

Smoky air could affect central Virginia again Thursday

The large wildfire that continues to burn in Southeast Virginia (primarily affecting the Suffolk area) in the Great Dismal Swamp may spread its boggy scent and smoky air northward as far as the DC Metro Area today with a persistent southerly wind. This fire was started by lightning on August 4th, and has since burned more than 6000 acres. Air Quality today will be at Code Orange in the areas highlighted in grey on this map:

Closer to the fire, though, Code Red air quality may occur today with smoke producing visibilities below a mile and making breathing extremely difficult for people living near the fire.

Here is the latest official wildfire report on the Lateral West Fire from the USDA Forest Service Active Fire Mapping Program:

Fire Information Report for Lateral West
Wildland Fire Incident
Report Date: 17-AUG-11

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Burnt Area:	6,007 Acres (1% increase from yesterday)
Location:	Suffolk City County, VA (Nine miles southeast of Suffolk, VA)
Cause:	Lightning
Incident Team Type:	IMT Type D
Team Leader:	Michael Quesinberry
Containment Status:	10% contained)
Expected Containment:	Unknown
Fuels:	Pockets of brush and grass regrowth along with large a amount of dead and downed fuel from the 2008 fire is fueling this fire. Fire is slowly spreading into drought stressed hardwood fuels (Model 10)aHigh 3059561.00 403

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Fire report information is based on the Incident Status Summary (ICS-209) database.

If you smell or see the smoke today, post your report on our CBS 6 Storm Team Facebook Page Wall by clicking here.
Stay with CBS6, we'll keep you ahead of the storm.
--Meteorologist Carrie Rose

Could an end-of-August hurricane head for the U.S.?

Looking into the next two weeks toward the end of August, there has been indication over the last several weather computer model runs that a tropical system may move from the Atlantic through places like the Dominican Republic, Haiti and Cuba before heading toward southern Florida by August 27th (and riding inland up toward Virginia as a weakening cyclone by the 29th?). As weather forecasters right now in the CBS 6 Storm Team, we'll keep looking at each new data set from the model runs to check for "consistency" of the hurricane's existence, track, and timing. We'll also look at a suite of models for comparison to see if the various potential scenarios look similar. This far in advance if we continue to see consistency of this potential hurricane, then we can have higher confidence in the storm affecting the U.S. the last few days of August. Here is just one (GFS 06Z model run today) representation of that potential hurricane on Saturday, August 27th:

What you see there over Florida will likely in reality be different by the time we get there...but it's definitely something to which we as forecasters are already paying close attention.

Based on tropical cyclone climatology in the Atlantic Basin, you can see that late August into September is when we typically see most of our tropical activity. We are also past-due (statistically speaking) for our first hurricane of the season (See Table 1 below), which in an average season would have occurred by August 10th. As of this blog posting, we are through Tropical Storm Gert, our 7th named storm of the 2011 season (all storms of which have remained below Hurricane status).
Table 1: Progress of the average Atlantic season (1966-2009). Date upon which the following number of events would normally have occurred.

The point of formation for this potential late-August hurricane looks to be in the central or western Atlantic, which is a statistically active formation region of the Basin during that time of year:
Sea surface temperatures continue to remain highly favorable through the Atlantic, Caribbean, and Gulf regions, so no matter which way this system goes, it will encounter ample fuel for development and strengthening. Upper-level winds will continue to be our primary concern, as has been the case with every storm so far this season. Tropical Storms in many cases were inhibited from reaching Hurricane strength because of even the slightest shear. We'll need a low-wind-shear environment for this storm to get its act together.

You can learn about Virginia's long record of brushes or hits by tropical cyclones by clicking here.
Stay with CBS6, we'll keep you ahead of the storm.
--Meteorologist Carrie Rose