Climatologically speaking, the prime-time weeks for major hurricane threats in the Gulf of Mexico are generally from the last week of August through the first week of October.  Based on the current and future weather pattern it appears that two of those weeks will be crossed out for Acadiana with no major storm threats expected through the Labor Day Weekend.  That leaves the 3 week period from mid-September onward that climatology dictates we will see more big storms.

The pattern will likely change however with models indicating a deep easterly flow developing across the Caribbean and into the Gulf.  While the models do not show any major overt storm development in the 10-14 day time frame, it does not mean that we won’t have any threats.   I would expect the pattern  to shift to more tropical genesis near the Caribbean by the second week of September all the while as robust disturbances continue to roll off the African coast.

In the near tern, unfortunately major Hurricane Earl’s forecast track issued by the National Hurricane Center has shifted a little farther to the west today putting the Mid-Atlantic U.S. to New England and the Canadian Maritimes at greater risk for damaging conditions later this week.  Hurricane watches for the North Carolina Coast have been issued with the 400pm update today.

Meanwhile Fiona is very close on the heals of Earl and may become a victim of the Fujiwhara Effect that makes Earl the dominant storm while Fiona or the future remnants fighting to survive and possibly “dumb-belling” north and northeastward keeping Fiona well away from land.  In addition to more hostile upper winds, cooler water upwelled from Earl should keep Fiona a marginal tropical storm over the next several days.

We’ll be watching Earl for our East Coast friends but we will be at least able to enjoy the extended weekend without any tropical worries close to home.

We are now at that time of year when the tropics ramp up quickly as robust tropical waves that come off of the African Coast, near the Cape Verde Islands, have increased potential for hurricane development. 

Danielle was the first this year with another candidate looking to become “Earl” before the week is done. 

All indicators for an active tropical season remain present, including very warm ocean temperatures, lower than normal tropical surface pressures, and favorable upper level winds associated with La Nina. 

There remain two “wild cards” as we have mentioned over the last several weeks…dry Saharan air with dust has been a storm “mitigator” over the last several weeks, and probably has had impact on Danielle today.  This dust should become less of a factor over the next week or two as more regular and wetter waves traverse the southern Saharan Desert.

The second wild card: upper level lows, that present interupting shear, have also inhibited some development so far this summer.  These upper lows have been theorized to be more robust and numerous in hotter summers. 

There is no indication one way or another whether these features will continue to be a factor as we head into the heart of hurricane season.

Factoring all the variables, it is still expected that on average we will likely be talking about 1-2 tropical systems per week through at least the second week of October.  How many of these systems will threaten the Gulf of Mexico and the East Coast of the U.S. remains to be seen.

In the near term and closer to home, deep tropical moisture will be pooling along a decaying frontal boundary in the Western Gulf of Mexico through the end of the week.  This moisture should bring higher rain chances and the threat of soaking rains back to Acadiana just in time for the weekend.

 As expected over the weekend this remnant system persisted across the interior portions of the Gulf States and then dropped back to the south with the circulation getting back out over open Gulf water late Sunday night.

Hurricane Hunters flew this system Monday afternoon just south of Mobile, Alabama.  The reconnaissance plane found broad low pressure, like last week, but disorganized thunderstorm activity near the center, like last week.  This time around upper level conditions are a little more favorable for development through Tuesday prior to the circulation making landfall over Eastern Louisiana Tuesday afternoon.  If thunderstorms cluster near the center of circulation later tonight it will likely become an “official” tropical system

Based on upper level conditions and broad lower surface pressures this system is very close to being a depression and may become one at any time through tomorrow.  If the system is upgraded, tropical storm warnings would probably be issued for portions of Louisiana through the Alabama coast.

The bottom line with this system is that it will be a major rain-maker with rainfalls of 3-5″ likely around this system and up to 8-10″ possible near where the center of circulation travels through mid-week.  Rainfall totals will likely be directly correlated to the speed, or lack of, this exhibits over the next few days.  Most computer models earlier today indicated the greatest threat of flooding rains will be in the eastern part of the state Tuesday and then the central part of the state Tuesday night into Wednesday. 

More recent computer model runs this evening are much more robust with rainfall totals in Acadiana with  3-5″  possible through Thursday with isolated spots receiving possibly more than double depending ultimately where the center of circulation goes and how quickly it moves.  Stay with KATC and katc.com for the latest information.

Interestingly enough, some of the models actually intensify the low as it drifts westward across the Louisiana coast during the Tuesday/Wednesday time-frame.  While this is rather unusual, other poorly organized remnant systems sealed in an almost purely tropical environment have done this in the past with previous systems actually slowly strengthening over land, and near water, across the Yucatan, Florida, North Carolina and Texas…most memorable being Tropical Storm Allison in 2001. 

The bottom line for us in Acadiana is that we may see better rain chances and something a little more for mid-next week.  Meandering systems almost always make for “forecast busts” so stay with KATC and katc.com for the latest over the weekend…

Our in house high resolution computer model, FutureCast, shows modest surface development to a tropical depression or weak tropical storm status Wednesday into Thursday as this system moves westward and then possibly northward. 

The bottom line: expect a good soaking, perhaps some blustery winds, and perhaps a named tropical system knocking on Acadiana’s door by Thursday so stay with KATC and katc.com for the latest.

Experts continue to indicate there is plenty of oil still in the Gulf but natural processes are likely getting a foothold on weathering and naturally dispersing the oil now that the leak has been capped.  This also argues that the response to the spill has likely made some progress too.

The Gulf of Mexico contains 660 quadrillion gallons of water…thats 660,000,000,000,000,000 gallons!  By comparison given the highest estimates of 200 million gallons of oil spilled in the Gulf would account for less than 1 billionth of the entire volume of the Gulf.  These numbers make it seem better for the Gulf, but the question however is how will a few parts per billion (or much, much more in concentrated areas) affect the basic bio-processes/ecosytems and how that will manifest further up in the food chain?  Time will tell.

Bonnie is moving smartly to the west-northwest but should slow somewhat along with a gradual turn to the northwest Saturday.  This may provide some opportunity for the system to strengthen back to tropical storm status. 

Conversely, some of the latest tropical models weaken the system back to a tropical wave prior to landfall Saturday night/Sunday morning over eastern-most Louisiana or southern Mississippi. 

It appears that the main tropical threats from Bonnie will be confined east of Acadaina but there may be the threat of heavy tropical showers and storms spreading westward into the area mainly Sunday…so that is what we will be on the look out for.  Storm surge issues and damaging winds are not expected for the Acadiana area. 

The remnant moisture from Bonnie may linger Monday and Tuesday across the area keeping the chance of some flooding with us until drier weather moves back into the area mid-late next week.  Stay with KATC online or on the air for the latest this weekend…

The Threat Index is derived through utilization of information gathered from the National Hurricane Center, tracking the Global Madden-Jullian Oscilliation, all global and tropical weather models and current satellite and observational trends.

With a 60% chance of the Caribbean disturbance developing into a tropical cyclone, the risk of a depression appears “moderately high” over the next 48 hours and a potential tropical storm assessed at a “moderate” risk, near 40%.  Hurricane Hunters are scheduled to probe this system Wednesday. 

Look for updates on this product daily on KATC.  Rob

Temperatures have averaged more than 4 degrees above normal over the last couple of months with the main culprit being steamy overnight/morning lows that have averaged nearly 5-6 degrees above normal.  This can partially be attributed to above normal Gulf and Atlantic sea surface temperatures and seasonal variability of a drier than normal spring that has spilled into the summer months.

The bottom line for most of us in Acadiana is that our cooling/electric bills will be higher than normal for June.   July temperatures have been running closer to normal thanks in part to more shower and thunderstorm activity through the third week of the month.

La Nina is anomalous cooling of water temperatures across the equatorial Eastern Pacific which allows for lighter winds and less shear across the Caribbean and portions of the Atlantic Basin.  Less shear over these areas often lead to more storms and more intense hurricanes.  This means that the hurricane forecast projections of a very active season by NOAA and Colorado State will likely verify considering both forecast projections factored generally neutral conditions in the Pacific. 

In the near term, it appears that the recent active tropical pattern across the Caribbean and Gulf will be quieter through the next week, but expect the pattern to ramp up dramatically as we head into the first few weeks of August.  In fact, I wouldn’t be surprised if we will be talking about one or two tropical systems every week from mid-August through the first week of October…but for now, enjoy the quiet it won’t last for more than a few more weeks.