Quiet Locally...Watching the Tropics

By Jay Grymes & Steve Caparotta

Not much change in the outlook through the work week.  If anything, the forecast through the rest of week and into the weekend may be just a tad “drier” than we posted yesterday. 

We did see isolated showers pop-up this afternoon, accompanied by a flash or two of lightning on Titan9 Doppler, mainly along and south of the I-10/12 corridor.  Most or all of those rains will wind-down as we approach sunset; look for mainly fair skies later tonight and extending into Wednesday’s sunrise.

Right now, we’ve got a mainly-dry forecast for Wednesday through Friday and only isolated afternoon showers for the weekend.  Highs will continue to reach the low 90°s through Friday and probably into Saturday  as well -- staying slightly-above normal for most WAFB neighborhoods.  Early morning minimums generally will run around 70° for the ‘Red Stick’ for the rest of the work week and into the weekend. 

Better rain chances return early next week.  For many of you, a little rain wouldn’t hurt one bit!  But don’t count on it, at least not in any significant amounts until next week.  Sure, a handful of lucky communities could see a decent shower in the coming days thanks to our unpredictable, isolated summer-season pop-up showers.  But for most, the continued summer heat and lack of rain is starting to put a real “crunch” on the lawns and gardens.

In the tropics ... a ‘first’ for the 2013 season: two ‘named’ systems spinning at the same time in the Atlantic Basin.

For Gulf interests, the Bay of Campeche likely becomes our tropical focus later this week.  Now labeled “Invest 93L,” the disturbance we pointed-out yesterday in the western Caribbean has continued to show some consolidation today and is expected to move into the SW Gulf over the next two days.  Several models continue to show development later in the week; looks good for “93L” to become INGRID before the weekend.

HUMBERTO has strengthened today but had not reached ‘Category 1’ as of 4:00pm CDT.  The National Hurricane Center (NHC) still calls for additional strengthening with HUMBERTO expected to become a hurricane sometime tonight or early tomorrow.  Although the NHC forecast calls for HUMBERTO to take on a due-west heading over the weekend, at this stage it appears unlikely that ‘he’ will be a threat to U.S. interests.

For the trivia-minded, HUMBERTO looks like ‘he’ will be the first hurricane of the 2013 season.  We’ve mentioned this point frequently of late: as the 8th ‘named’ storm of the season, HUMBERTO will hold the odd distinction of being the farthest we’ve ever gone into the alphabetical list (back to 1950) without a storm reaching hurricane intensity.

And HUMBERTO is still in the running for being the “latest-forming” first hurricane of any season in the satellite era (back thru the 1970s) and the second “latest-forming” hurricane in more than 70 years.  If HUMBERTO makes it past 7:00am Wednesday morning without an upgrade, ‘he’ will set the new record for the modern era.  Prior to 2013, 2002’s GUSTAV was the latest-named hurricane in the Atlantic Basin (since operational satellite-tracking), reaching Category 1 officially at 7:00am on September 11th.

Elsewhere in the basin, GABRIELLE has made a surprise return.  ‘Her’ remnants have slowly moved north over the past several days and as of 4:00am (CDT) this morning, the NHC declared that those remnants had regenerated into a tropical storm.  The NHC expects some limited additional strengthening in the next 12-24 hours as GABRIELLE continues on a generally northward track through Friday, then turns more to the NNE.  The current forecast calls for GABRIELLE to undergo transition from a tropical to a post-tropical system (extra-tropical cyclone) over the weekend, but still deliver tropical-storm force winds to portions of the Canadian Maritime Provinces.

By the way, while the season has been far less eventful than we expected back in early June -- thankfully! -- don’t be fooled into thinking that it has been unusually quiet.  

While long-term statistics for the Atlantic Basin indicate that, on average, there would have been three hurricanes by now, we are still ahead of the game in terms of the number of ‘named’ storms for September 10th.  HUMBERTO (storm No. 8) was ‘named’ Monday, yet NHC statistics show that, on average, only 6 storms are ‘named’ as of September 10th.  Those same long-term stats show that, on average, the 8th ‘named’ storm doesn’t appear until late September.

In addition, the Gulf has been ‘visited’ by ANDREA, BARRY and FERNAND, with the potential for INGRID to pop-up over the weekend.  Four ‘named’ Gulf storms are about average for the Gulf through an entire hurricane season, yet there are roughly 10 weeks to go before season’s end.  But like the basin as a whole, the lack of hurricanes in the Gulf, so far, has been a blessing for all.

Hot, Mainly Dry This Week

By Jay Grymes & Steve Caparotta

Thanks to some afternoon clouds and passing t-showers, most of us dodged the mid 90°s over the weekend. The weekend mornings weren’t bad at all either, with sunrise temps in the upper 60°s to around 70° for many WAFB neighborhoods. Same was true this morning in the metro area. But even with those mild morning starts, daily temps have been running slightly-above normal almost every day this month. In addition, we can expect daily temps to continue to run slightly-above normal through the work week and into the weekend.

At the same time, while we can’t say rain-free, the outlook for the coming 5 to 7 days will be on the “dry” side, with only isolated afternoon rains -- at best -- posted for the daily forecasts through the work week.

We’re not entering drought conditions, but “hit-or-miss” rains over the past several weeks have left some dry spots in the viewing area, especially on the west side of the Mississippi River and for areas close to and north of the LA/MS state line. 

True, rainfall over the immediate Baton Rouge area has been near normal to above normal for the past two weeks. It also has been wetter-than-normal recently over and around St. Mary, northern Terrebonne, Iberia and southern Assumption parishes. But for much of the remaining WAFB viewing area, two-week rains are running at less than 50% of normal. That’s not critical just yet, but with our warmer-than-normal afternoons and plenty of sunshine, soil-water evaporation is likely running at more than 1” per week. So for some of you, it’s time to think about the sprinklers for the lawns and gardens if you haven’t already.

In the tropics, T.S. HUMBERTO continues to churn over the far eastern Atlantic and is expected to reach hurricane strength soon, but as of now HUMBERTO does not look to be a threat for any part of the U.S. mainland.

We've mentioned this before, but as a reminder: HUMBERTO is the 'deepest' into the tropical 'names' list we've ever gone in the Atlantic Basin without a hurricane. That even includes the early "ABLE, BAKER, CHARLIE ..." years, beginning in 1950! The current record-holder for the latest hurricane in the "modern" era is 2002's GUSTAV, which achieved hurricane status at 7AM CDT (1200 UTC) on September 11th of that year.

By "modern era" we mean since the onset of the naming convention in 1950. Yes, earlier hurricane records show an even later "first hurricane" in 1941 (Sep 21) and no hurricanes at all in 1907 and 1914 -- but these records are considered somewhat questionable due to the lack of satellite imagery to monitor the entire basin back then.

The current forecast for 2013's HUMBERTO calls for it to reach 'Category 1' on Tuesday evening. So it looks as though HUMBERTO will just miss setting a new "latest-ever" record for a hurricane.

We’ll be watching for potential tropical development in the southwestern Gulf later in the week. Our in-house RPM, the solid American GFS, and the European ECMWF computer forecast models are all showing something spinning over the Bay of Campeche by or before week’s end. The RPM is showing something as early as Thursday, while the GFS and “Euro” are a day or two slower, but pointing at the same area. There’s nothing to be concerned about right now ... just Mother Nature’s reminder that we are at the mid-point of the Hurricane Season.

And finally, today marks the 48th anniversary of Hurricane Betsy's landfall in southeast Louisiana. Betsy came ashore as a Category 3 hurricane near Grand Isle just before midnight on Sept. 9, 1965. A storm surge of nearly 16 feet was reported near Grand Isle and large sections of New Orleans were flooded by the rising waters. Betsy also produced an 8-foot rise in the Mississippi River all the way up here in Baton Rouge -- likely a combination of the surge and water backing up because it was unable to drain into the Gulf. Betsy was also a big wind storm, with a number of sites reporting gusts well over 100 mph.

A Hot Weekend ... and Tropical Action!

Not a bad way to end the work week -- staying rather warm this Friday evening with just isolated showers in the viewing area – and most of those should be gone by sunset. So enjoy the evening, whether it’s dinner-and-a-movie, a little high school football, or maybe catching this evening’s first “Live After Five” of the fall series!

And summing up your weekend outlook: staying hot and mainly dry! A few WAFB neighborhoods flirted with the mid 90°s today and many of those same areas should get ready for a repeat on Saturday. The calendar says September but it still feels like August!

 

Just like we’ve seen the last several mornings, Saturday will open with mostly-clear skies for the ‘Red Stick’with sunrise temps in the low 70°s. The morning warm-up will be a quick one with readings already close to 90° by noon. Highs will reach the low to mid 90°s for just about everyone under partly cloudy skies, and only a few will get a heat-busting afternoon shower -- we’re going with just a 20% chance of afternoon and early-evening t-showers.

If you are planning on taking in a long run of tailgating fun for LSU’s home opener against Alabama-Birmingham, please take care in the summer heat! Yes, you’ll also need to keep an eye to the skies in the mid and late afternoon for those sneaky showers, but the heat and sun will be the bigger weather issue of the afternoon. In fact, even at game-time (6:00pm), temps around ‘Death Valley’ will still be running close to 90° or so, especially over those parking lots!

And for the Jaguar Nation traveling to Natchitoches for their 6:00pm kick-off, expect it to be even hotter --afternoon highs will reach the upper 90°s on the Northwestern campus! They also have a 20% rain chance for the afternoon and early evening, but if the clouds and showers don’t arrive, kick-off temps at Turpin Stadium could still be in the mid 90°s!

And Sunday for WAFB viewers? Another mainly-clear morning start with sunrise temps in the low 70°s, then becoming just about as hot in the afternoon with spotty showers at best.

We keep the extended forecast warmer-than-normal right through next week too, with metro Baton Rouge morning lows in the low 70°s ... afternoon highs in the low to mid 90°s ... and only spotty-to-isolated mainly-afternoon showers just about all week long.

 

In the tropics, there are no immediate areas of concern but the National Hurricane Center (NHC) is watching four areas. From west to east:

(1) The disturbance in the extreme western Gulf just made it to depression strength -- T.D. #8 -- during the early afternoon, just before beginning its landfall along the Mexican Coast. T.D. #8 will slowly continue to move inland this evening and should rapidly weaken over the next 12 to 24 hours.

 

(2) Remnants of Gabrielle and (3) a broad disturbance northeast of those remnants are both being held in-check by wind shear and nearby “dry” air, keeping the development potential on the low side through the next several days, at least.

(4) A tropical wave roughly midway between Africa and the Lesser Antilles is moving into a region of unfavorable atmospheric conditions, so much so that the NHC gives the low-pressure area virtually no chance of development through the next five days.

 

So there you have it. Enjoy the weekend ... and take care in the heat!

Hot & Humid, A Few Storms into the Weekend

By Jay Grymes & Steve Caparotta

Remember, September is still summer . . . and Mother Nature will be delivering a sure reminder with highs reaching the mid 90°s for many WAFB neighborhoods over the coming days!  In fact, highs are expected to return to the 90°s each day right through the 7-day outlook.  Morning lows for metro Baton Rouge will run in the low 70°s through the 7-day period as well, an indication that moist Gulf air will be in place, with no significant relief in the humidity any time soon.

That means that as the fall season of Live After Five kicks off Friday evening, be ready to deal with some rather warm weather! The good news is that rain chances should be pretty slim as the Baton Rouge Symphony Orchestra takes the stage at 5 PM.

Upper-level ridging remains locked over the nation’s mid-section, placing Louisiana on the southeastern edge of the same high pressure dome that will keep much of the central and northern Plains hot and dry, further extending the drought that has plagued many central and western states this summer.

In addition to warmer-than-normal weather, the upper-air ridging will minimize rain chances for the WAFB viewing area through the weekend and into next week.  We’re posting rain chances through Tuesday at 20% or less each day.

So the recent hit-or-miss rains we’ve seen during the past few days will continue.  That’s leading to a regional situation where some of WAFB neighborhoods are in serious need of a good rain, while adjacent areas are doing just fine.  No doubt, some of you will be running the sprinklers this weekend.

In the tropics, we’ve got a few areas of interest as of Thursday afternoon.

Gabrielle, located near Puerto Rico, was downgraded to a depression earlier today and is really struggling to survive.  ‘She’ is not expected to be around long -- the National Hurricane Center (NHC) has indicated that ‘Gabby’ could be further downgraded to a remnant low at almost any time.

To Gabrielle’s east, a broad area of low pressure is gaining some interest, but regardless of what happens there, it will likely move northward and remain over the open Atlantic.

A ‘Hurricane Hunter’ checked-out the low pressure area in the western Gulf this afternoon but found no evidence of organization.  It offers no threat to the U.S. Gulf Coast, although the NHC is giving this area a 50-50 chance of becoming a depression before it moves inland over northern Mexico during the next couple of days.

And finally, a tropical wave in the eastern Atlantic also has gained the NHC’s interest ... but it is too far out and too poorly organized for our concern at this stage.

Plenty of Heat, A Few Storms Each Day

By Jay Grymes & Steve Caparotta

We mentioned it yesterday and the local outlook looks just about the same through the weekend and possibly right through the next seven days.  Plan on mainly-dry morning starts with sun-up temperatures in the low 70°s around metro Baton Rouge.  The afternoons are likely to remain on the “warm” side of normal into next week, with highs in the low 90°s for most but flirting with the mid 90°s for some locations.

For now, we are calling for mainly-afternoon and early evening showers and occasional storms through the weekend.  Rain probabilities (in other words, areal coverage) each day should be on the order of 20% to 30% or so into early next week.

We’ve got somewhat competing influences driving our day-to-day rain chances through the week and weekend.  At the surface, warm-and-humid Gulf air will be ready to fuel afternoon showers and storms with daytime heating.  Add in a meandering, quasi-stationary front across the Gulf States which will linger over the region for another day or so before dissipating.  These two factors normally would encourage afternoon showers and storms.  At the same time, upper-level ridging centered to our northwest will maintain a northerly upper-air flow over the lower Mississippi Valley.  The ridge -- associated with dry, sinking air -- will act to counter some of the instability promoted by the Gulf air mass and frontal lift. 

However, should a few storms be able to overcome the ridge’s effects (since we will be located on the eastern periphery of the upper-air dome), they could become quite strong.  This is exactly what we experienced on Tuesday afternoon and evening -- isolated pockets of very active thunderstorms, producing frequent lightning and even some hail, moving towards the south and southwest along the eastern edge of the upper-level flow.

As we often remind you, when t-storms are moving from north-to-south, they tend to have cooler-than-normal air in the higher levels.  This cooler air aloft encourages more lightning and hail once a thunderstorm “matures.”   Fortunately, most of Tuesday’s bigger storms were limited in coverage, but if you were under one of them, you certainly knew it!

So far this afternoon (through 4PM), storms have not gained the same strength as what we saw on Tuesday.  But we’ll need to remain alert for a potential repeat over the next few days.

We’re still watching two areas in the tropics: a poorly organized tropical wave near the Yucatan Peninsula and recently upgraded Tropical Depression #7, located just south of Puerto Rico. 

Neither system poses a threat to the central Gulf Coast.

In fact, as of right now, it looks like the Yucatan disturbance will struggle to reach depression strength before it runs out of open-water real estate.  By contrast, the National Hurricane Center (NHC) calls for T.D. #7 to strengthen and become T.S. Gabrielle overnight as the system moves northwest.  The forecast cone for Thursday extends from the eastern Dominican Republic to the western tip of Puerto Rico.  Based on the current model consensus, a moderately strong Gabrielle will move into the western Atlantic but take on a more northerly course, likely passing to the east of the Bahamas and headed towards Bermuda.  At least for the time being, the NHC does not expect T.D. #7 to reach hurricane intensity.

Sct'd T-Storms Each Day This Week

By Jay Grymes & Steve Caparotta

A cool front will continue to sag southward into central Louisiana later today and then stalls over the state. The front likely meanders over and near the Gulf Coast states for the next several days, eventually fizzling out by the weekend. Regardless of where the front is positioned, the WAFB viewing area will remain under the influence of relatively moist-and-unstable Gulf air. 

That means mainly fair but somewhat muggy mornings for metro Baton Rouge, with spotty showers closer to the coast -- much like we’ve seen the past couple of days. Plan on warmer-than-normal and humid afternoons with scattered mainly-afternoon t-showers right into and through the weekend.

Yes, it is September, but summer is far from over yet. 

Don’t be fooled -- September can be a very warm month for the Gulf Coast region. In fact, on average, daytime highs reach the 90⁰s on nearly half of all September days in Baton Rouge. But as we head into the latter half of September, we can often count on that first real feel of autumn -- what some might call the “hallelujah front!” 

Hopefully that first real break in the summer heat is not too far down the road (or calendar, so to speak), but the way the atmosphere is expected to behave over the next seven days or so, that first “welcome to fall” front is certainly not just around the corner.

In the tropics, there are no current threats for the U.S., but the National Hurricane Center (NHC) is watching three areas of interest: (1) an area of disturbed weather near the Yucatan, (2) “Invest 97L” extending from the eastern Caribbean across the Lesser Antilles, and (3) “Invest 98L” located in the far eastern Atlantic. 

The disturbance over the Yucatan has some potential for development in the coming days as it moves westward over the Bay of Campeche, but unless it stalls over the southwestern Gulf, it will likely run out of time before it can “earn a name.” 

Although 97L is currently being held in check by nearby “dry” air, conditions for 97L could become more favorable in the coming days as it moves towards the Greater Antilles (Puerto Rico & Hispaniola). After that, most of the current guidance suggests that 97L may take a more northward turn towards Bermuda. As for 98L, it is simply too far out in the Atlantic to worry about at this time.

As we’ve mentioned many times recently, early-to-mid September is also the “climatological” midpoint of the hurricane season -- statistically, the season peak occurs on or about September 10th. We’ve also noted a number of times about Louisiana’s track record during September: nearly half (about 47%) of all hurricane and tropical storm landfalls since 1900 for the Bayou state have occurred during September. By our count, there have been 17 September hurricane landfalls for Louisiana since 1900, 6 of which were ‘major’ storms. Add to that another two-dozen tropical storms, and you come up with 41 landfalls in 113 seasons.

Consensus among tropical weather experts is that, beginning in the 1995 season, the Atlantic Basin has been experiencing a persistent trend of elevated activity. While we have yet to see a hurricane in the basin this season, we must remain watchful and prepared. Two prime examples are the 2001 and 2002 seasons: neither season saw its first hurricane until September. And how active were those two seasons?

2001 -- 15 ‘named’ storms, 9 hurricanes, 4 ‘majors’

2002 -- 12 ‘named’ storms, 4 hurricanes, 2 ‘majors’ … but maybe more importantly, there were 3 Louisiana landfalls after September 1st: TS Hanna, TS Isidore and Category-1 Lili.

Since the 1995 season (18 seasons total), Louisiana has suffered landfalls on or after September 1st during 8 of those 18 seasons, including multiple hits after August 31st during 2002, 2004, and 2008. Among the more memorable storms in this stretch are 2002’s Lili, 2005’s Rita and 2008’s Gustav and Ike.

Yes, maybe we’ll be lucky this year ... we surely deserve it. But just remember, the season is far from over.

Better Rain Chances Arriving Tuesday

Happy Labor Day! Hopefully most of you have been able to enjoy an extended weekend.

If you were off today and using the time to be outdoors, it wasn’t a bad holiday weather-wise for most. Yep, it was hot and humid, with highs climbing into the low-mid 90°s, but rains have been pretty limited around the area.

However, better rain chances are in the forecast over the next several days as a weak cool front sags into the area from the north. We’ll go with a 40% - 50% chance of showers and t-storms each day from Tuesday into Thursday and highs in the lower 90°s. Unfortunately, it doesn’t look like the front ever makes it through for most of us, meaning hot and humid conditions will stay with us through the week.

By late in the week and into the weekend, the front should become diffuse and high pressure may begin to assert a little more influence on our weather. As a result, we’ll go with slightly lower rain chances from Friday into Sunday – approximately 30% each day.

We’re tracking a few features in the tropics today, but nothing that is of immediate concern to the local area. A tropical wave is moving into the Yucatan Peninsula this afternoon. While it won’t be able to do much while over land, there’s some potential that it could attempt to develop once back over water in the Bay of Campeche by late tomorrow. We’ll keep an eye on it, but for now, it doesn’t look like a major threat.

Farther out, we continue to track an elongated area of disturbed weather located near the Lesser Antilles. This system has been battling some dry air, but conditions could become a little more favorable for development in the next couple of days as it moves into the Caribbean. The National Hurricane Center is currently giving it a 20% chance of development within the next 48 hours, but a 50% chance of development within the next 5 days.

Finally, another rather healthy tropical wave has emerged from the coast of Africa today. While conditions appear somewhat favorable for development, a number of systems in this area recently have tended to struggle. Either way, there’s plenty of time to watch it since it’s in the far eastern Atlantic.

History tells us to remain vigilant this time of year. Check out some of the hurricanes that have impacted south Louisiana from late August into early September (Aug. 26 - Sept. 10).