Friday, October 31, 2014

Freeze Watch for Sunday Morning!

By Jay Grymes & Steve Caparotta

WAFB First Alert Quickcast:
- turning much cooler over the weekend
- FREEZE WATCH for the northern half of the viewing area on Sunday morning
- waiting on some rain

The way we see it, there are two weather stories in play for our area. The most immediate is the coming cold snap for the weekend. The other story deals with the “Abnormally Dry” conditions affecting much of the Florida Parishes.

First Up: the coming chill! A dry cold front is working north-to-south through the viewing area leading the way for a cold Canadian air mass. The front slipped through almost unnoticed this afternoon: fortunately, our Trick-or-Treaters will be done with their door-to-door visits before we get a real feel for the northern air mass. But by Saturday’s sunrise, there will be no doubts in anyone’s mind that a ‘real’ autumn has arrived.

We’re calling for Saturday morning lows in the upper 30°s for the Baton Rouge metro area with mid 30°s for many of WAFB’s northern communities -- the coldest morning since mid-April. Although there will be plenty of sunshine on Saturday, it will stay rather cool. We’re looking at highs only in the low 60°s for the Capital City and that means that some neighborhoods north and east of BR may not get out of the 50°s. Add in a northerly breeze and it will certainly be the coolest day of the season thus far.

Don’t forget: set clocks back one hour (you get an extra hour of sleep!) on your way to bed Saturday night. And check the batteries in those smoke alarms and NOAA weather radios too!

It’s colder still for Sunday morning! How about the low to mid 30°s for the Red Stick, with the possibility of a light freeze for some of our northernmost viewers? Say “hello!” to a taste of winter! That forecast has prompted a FREEZE WATCH on Sunday morning for all WAFB communities near and north of the I-12 (the Florida Parishes, Pointe Coupee, West Baton Rouge and SW Mississippi).

Thankfully, we’ll begin a warming trend on Sunday afternoon, with Sunday’s highs in the mid to upper 60°s for most of us. The warm-up continues into the work week, with morning lows getting back into the 50°s and 60°s by mid-week and highs up into the 70°s to even around 80° for many neighborhoods.

So that leaves the “dry” weather over parts of the viewing area as the other weather story. The last two months have been dry ones for a large portion of the viewing area, although certainly not for every WAFB community. The largest two-month rainfall deficits are evident over the Florida Parishes, centered between the I-12 corridor and the LA/MS state line. Some of the largest two-month deficits are reported in central Livingston and central Tangipahoa parish areas, where rain totals since September 1st remain under 4” -- as low as 35% to 50% of normal in some spots. Not quite “drought” just yet, but getting worrisome, especially with regard to wildfire threats.

We still have rain in the forecast for the latter half of next week but admittedly our confidence is a bit lower today than it was yesterday as to when it arrives.

Meanwhile, it’s all quiet across the tropical Atlantic.

Have a great weekend!

Thursday, October 30, 2014

Nice for Halloween, Chilly for the Weekend!

By Jay Grymes & Steve Caparotta

WAFB First Alert Quickcast:

- another cool start for Friday
- downright cold mornings for the weekend
- stays dry into the middle of next week

Yesterday’s front provided very little in the way of measurable rainfall across the region as our extended run of dry fall weather continues.  According to the weekly U.S. Drought Monitor, we are not “in drought” just yet but much of the area along and north of the I-12 corridor is “Abnormally Dry.”  For many farmers, that’s not a bad thing: dry falls make an easier go of the sugarcane harvest.  On the other hand, some hay growers are not seeing the growth that they would like and foresters and land managers are getting a bit concerned about local wildfire threats.  What’s more, we’ve seen some of you breaking out the lawn sprinklers, trying to keep the grass and landscaping happy.  And as of right now, the extended outlook keeps our area dry until next Wednesday.

On the other hand, not everyone is disappointed by the run of dry weather, low humidity and sunshine. 

Yesterday’s front delivered the first of two doses of ‘continental’ air to the region.  After a cool start this morning, it was mid 70°s for most WAFB neighborhoods this afternoon under sunshine.  Plan for another cool start on Halloween morning with sunrise temperatures in the upper 40°s to low 50°s for most WAFB communities under mainly-clear skies.  Sunshine should take us back into the low to mid 70°s but it will be a breezy, if not downright windy, Halloween afternoon.   

For the little ghosts and goblins, the weather cooperates for door-to-door “Trick-or-Treating” -- metro area temperatures on Friday evening will turn cool but not cold, easing from the upper 60°s around 5:30-6:00PM down to the upper 50°s around 8:00-8:30PM.  It will be a little breezy through the evening but costumes with sleeves should be good enough for most of the goblins, with dad carting a light jacket along just in case.

The second dose of continental air arrives Friday evening and you will certainly feel it by Saturday morning.  Many of us will begin Saturday in the upper 30°s -- the coolest morning for Baton Rouge since April 16th.  And for Saturday afternoon, some of WAFB’s more northern neighborhoods may not even make it into the 60°s!  Talk about chilly?  That’s more like what we would expect in January, not late October.

Sunday morning will be even colder, with mid 30°s for metro Baton Rouge and areas north and east of the Capital City flirting with a brief, light freeze -- especially north of the state line.  We’ll call for mid to upper 60°s for most on Sunday afternoon.

Of course, that would be a very early freeze, even for our southwest Mississippi viewers.  For locations along and north of the LA/MS state line, the climatological average “First Fall Freeze” is around mid-November.  For metro Baton Rouge, an easy-to-remember rule-of-thumb is that the “average date” of the first freeze comes around the Thanksgiving holiday.  Although October freezes do occur in SW Mississippi, they aren’t common.  Historical statistics suggest that our Mississippi viewers can expect an October freeze only once every 7 to 10 years, on average.

Into next week, a warming trend sets in as we return to afternoons in the 70°s for Monday through Wednesday, with the next cold front scheduled to arrive on Wednesday.  And since most of us could use a little rain, let’s hope that next week’s front is a little more “productive.”

Monday, October 27, 2014

A Few Showers Possible on Tuesday & Wednesday

By Jay Grymes & Steve Caparotta

WAFB First Alert Quickcast:

- very slight rain chance for Tuesday, 30% chance for Wednesday
- cooler-and-drier for the rest of the week
- T.S. Hanna inland over NE Nicaragua
- keeping tabs on Invest 95L, east of the Leeward Islands

Most of us have only had three significant rainy days over the past 8 weeks or so ... 60-day rain totals for much of the viewing area are running at just 60% to 75% of normal. We’ve enjoyed a prolonged spell of fine autumn weather, but many of us could use a decent soaking now. That said, not everyone needs rain: some of our more southern and coastal viewers would tell you that they have seen more than enough over the past two months.

True, fall tends to be one of the drier periods of the year, especially if we go through the season without any tropical troubles. And no one is “in drought” as yet, but a little rain would be great for many lawns, gardens, streams and bayous, plus it would knock down some of the dust and pollen that’s beginning to give many of you that irritating ‘drip and tickle’ in the back of the throat!

So what about some rain? A modest chance, at most, over the next two days.

A cool front slides through the state on Wednesday, but it’s not packing much of a punch. No threat of any severe weather is a good thing, but no rain will mean no help for dry landscapes and pastures. We’ll go with spotty showers (at best) for Tuesday and then only a 30% rain chance for Wednesday as the front slides by. So most of you won’t get any measurable rain ... and most of those that do get a shower or two will hardly notice any improvement.

What’s more, we’re thinking that if you don’t get any rain over the next two days, you will have to wait until another week -- until next Tuesday and Wednesday -- for the next real chance.

Wednesday’s front will be followed by a cooler-and-drier continental air mass, with highs in the 70°s for the rest of the week and the weekend, and lows dropping as low as the 40°s for some WAFB communities by week’s end. So for outdoor fun for the kids, the weather will cooperate right through the upcoming weekend -- but the plants, trees and shrubs aren’t happy.

In the tropics, the National Hurricane Center (NHC) decided that what were the remnants of T.D. #9 made a big come-back earlier today over the western Caribbean and designated the disturbed weather as T.S. Hanna, the eighth ‘named’ storm of the season. Hanna has already moved inland over the coast of Nicaragua this afternoon, but the NHC maintained ‘her’ at tropical-storm strength through the 4pm Advisory. It seems a near certainty that Hanna will rapidly weaken and is expected to dissipate in 24 hours or less.

The NHC is also watching a large tropical wave to the east of the Lesser Antilles, designating the area of lowest pressure as Invest 95L. Development chances for 95L are set at just 20% over the next five days and the ‘early’ forecast models keep 95L out in the open Atlantic.

Thursday, October 23, 2014

Mild & Dry Through the Weekend

By Jay Grymes & Steve Caparotta

WAFB First Alert Quickcast:

- another very cool start for Friday’s wake-up
- looking good, staying dry for Friday & the weekend
- no ‘tropical’ issues in the Atlantic Basin

Today was yet another in our long run of weather beauties. We started the day off with a Metro Airport low of 49°, tying the season’s low thus far (tied with October 5th). 

And a heads-up: unfortunately, Mother Nature has sent us a deck of high clouds from the west this afternoon. That could be an issue for viewing today’s partial solar eclipse -- between about 5pm and sunset for the WAFB viewing area.

Skies will become mainly-clear again later this evening and overnight with temperatures headed back down into the upper 40°s for the Red Stick. After that “almost chilly” start to the day, tomorrow will turn absolutely gorgeous: mainly sunny and a little warmer with highs for the Capital City in the upper 70°s to around 80°. And the weekend? Highs back into the 80°s with sunny to mostly-sunny skies both days and comfortably low humidity. The LSU Tiger faithful will love the afternoon tailgating weather! 

So how much longer can this high-and-dry pattern continue?

Well, we keep it mostly dry through next week too. Not entirely dry, but rain chances will be very low, with a shower or two possible during the latter half of Tuesday and maybe isolated showers for Wednesday. But that’s just about all that we can expect based on the way things look right now. We’re calling for morning lows in the 50°s and 60°s with highs in the 80°s for Monday through Wednesday. We’ve got a weak cool front trying to make its way into the lower Mississippi Valley early Wednesday, but NWS guidance essentially washes the front off the weather map before it arrives in our area. Even so, the approaching front will signal the arrival of slightly cooler and less humid air at mid-week, taking temperatures down a few degrees by Thursday and likely delivering another run of dry weather through next weekend.

Yes, most of us wouldn’t mind a little rain right about now.

It’s “quiet” in the tropics after yesterday evening’s demise of T.D. #9. We are keeping a watch on a bubble of convective action in the extreme northwestern Caribbean as well as the remnants of #9 which is inland over Mexico near the Yucatan ... but neither of these features shows any pending threat of significant tropical development.

Wednesday, October 22, 2014

A Little Cooler on Thursday & Friday

By Jay Grymes & Steve Caparotta

WAFB First Alert Quickcast:

- northerly flow means slightly cooler and even ‘drier’ air
- looking good through the weekend and into next week
- T.D. #9 headed into the Yucatan tonight

** Reminder **  Much of the U.S. will enjoy a partial eclipse of the sun tomorrow.  For Baton Rouge, the eclipse will begin just after 5pm and peak near 6pm!  Want to watch it with the pros?  Astronomers from the Highland Road Park Observatory and LSU will have equipment for viewing out at BREC’s Soccer Complex on the south end of Burbank Drive.

As for our weather: another beauty today -- we are definitely getting spoiled.  Yes, lots of us could use a shower or two to knock down the pollen and dust, but I think that most of us are quite pleased with our extended run of fair weather.  Today marks nine straight days with mainly sunny skies and highs in the 70°s and 80°s.

Yesterday we talked about a ‘dry’ front passing from north to south through the region, and that is exactly what happened earlier today.  Not only does that front deliver a ‘booster shot’ of low humidity but it sets up a weather situation where many of us will see morning lows near or below 50° for the next few mornings.  By the way, note that the ‘normal high’ for today in Baton Rouge is 79° -- while we can’t say no more ‘hot’ days for 2014, we’ve definitely crossed a ‘climatology’ threshold!

And STILL more great fall weather ahead right through this weekend: mainly sunny each day right through Sunday, comfortably low humidity, cool mornings and mild afternoons in upper 70°s to low 80°s.  For the weekend, LSU Homecoming on Saturday?  Just about perfect.  The Greater Baton Rouge State Fair?  Outstanding.

Our current extended forecast places a very slight chance of a shower or two next Tuesday or early Wednesday when our next front is scheduled to arrive, but even then we are talking about rain chances well under 20%.  Another 10+ days with without any rain?  Very possible.

Late last night, the National Hurricane Center upgraded Invest 93L to T.D. #9, suggesting that #9 would become a tropical storm sometime today.  Well, shearing winds kept T.D. #9 from developing a good convective cloak (wrap-around thunderstorms).  As a result, it looks like #9 will remain a depression as it makes landfall along the Campeche Coast of the Yucatan.  The low-pressure system is expected to cross the landmass and emerge over the western Caribbean by Friday.  At issue is whether the system will still be a depression by then.  Regardless, T.D. #9 offers no threat to Gulf interests within the next 7 days or more.

Monday, October 20, 2014

More Mild & Dry Days Ahead!

WAFB First Alert Quickcast:
- mild-and-dry autumn weather continues

- upper 70°s to low 80°s for highs each day
- watching a broad low pressure area in the southern Gulf
The past several days have served as a textbook explanation of why October is my favorite south Louisiana month (as long as the tropics are behaving) ... and there is much more of this great fall weather ahead for our viewing area.
Our forecast remains rain-free right through the upcoming weekend and the temperatures and humidity will cooperate as well.  Mornings for the Red Stick will see sun-up temperatures in the 50°s with afternoon highs in the upper 70°s to low 80°s -- all along, dew points will remain in the very comfortable range.  Two words come to mind: nearly perfect!

Any weather action over the U.S. during the week will remain to the north.  We’ll get yet another ‘dry’ cold front sliding through the region early Wednesday (what some would call a ‘backdoor’ cold front from the northeast), serving to bolster our run and fair weather and low humidity with a dose of ‘continental’ (Canadian) air.  After Wednesday’s front, surface high pressure over the central U.S. remains in charge through the weekend, with the extended outlook suggesting that another ‘backdoor’ front moves through late Sunday or early Monday.
Our forecast this week calls for mainly sunny skies just about every day.  Right now, it looks like Wednesday’s front will be just too dry to produce more than a few fair-weather clouds on its way by.  Headed into the weekend, we can expect a few more clouds each afternoon, but even then it looks like fair to partly-cloudy skies for the mid-days and afternoons.  No complaints . . .
If you’ve been watching closely, the First Alert team has been mentioning a low pressure mess in and around the southwestern Gulf for several days now.  Currently the National Hurricane Center (NHC) is posting an area in the southern Bay of Campeche with a 50% chance of tropical (or sub-tropical) development in the next two days with those percentages at 60% over the next five days.  There are several features at play here: remnants from what was the East-Pacific’s short-lived T.S. Trudy, moisture surging northwards from the western Caribbean, and a ‘semi-stalled’ front draped SW-to-NE across the southern and central Gulf. 


And it could be more than five days before something actually does develop, if at all.  The majority of our models have the low-pressure blob hanging around the Bay of Campeche and the Yucatan Peninsula for the next 4-5 days.  More importantly for Louisiana interests, if something were to form somewhere over the southern Gulf in the next five to seven days, it would almost certainly move east, becoming more of a problem for Florida (and Cuba) and unlikely to seriously impact the Central Gulf Coast.

So let’s enjoy our local autumn weather . . . and for now, not worry about the tropics.

Thursday, October 16, 2014

Looking Great Through the Weekend!

By Jay Grymes & Steve Caparotta

WAFB First Alert Quickcast:

- a little warmer for Friday & Saturday
- a dry cool front arrives Sunday
- dry all of next week too
- Gonzalo taking aim at Bermuda

Well, our forecast remains on track: fair skies and relatively low humidity will make for comfortable mornings and mild-to-warm afternoons. We’re calling for morning lows in the upper 50°s to low 60°s through the next five to seven days with afternoon highs in the low to mid 80°s. Patchy fog around sunrise could be an issue for some locations over the coming days, but for now we don’t expect any Fog Advisories ... not at least over the next several days.

True, you may need to water the fall garden or that ornamental landscaping, but other than that it’s difficult to complain. The way it looks right now, we will likely remain rain-free this weekend, through the entire upcoming work week and quite possibly through next weekend too!

About the only thing that we’ll have to work on will be the day-to-day temperatures: we’ll tweak them a degree or two here and there, but even those forecast numbers appear to be on pretty solid footing.

Our extended outlook is still calling for a pair of weak cool fronts to push through our viewing area in the short-to-medium range. The first gets through here Saturday but it will be a dry front, knocking back Sunday temperatures a couple of degrees and delivering a booster-shot of low-humidity air. After highs for Baton Rouge in the mid 80°s on Friday and Saturday, Sunday will top out in the low 80°s. A second ‘dry’ front pushes through the WAFB region early Tuesday: once again helping to drop area temperatures a couple of degrees and helping keep humidities comfortably low.

So get set for a prolonged run of fair-sky days, ranging from sunny to partly cloudy, with blue skies the rule rather than the exception.

In the western Atlantic, Gonzalo remains the weather focus as ‘he’ continues on a collision course with Bermuda. If you were with us last night during the 10PM Newscast, we noted how Gonzalo was developing a well-defined eye and that intense convection was wrapping entirely around the center: signs that a new round of intensification was likely. Well, that is exactly what happened and as of this morning, Category 4 Gonzalo became stronger than ever with peak sustained winds near 145 mph. As of 4PM, Gonzalo is still maintaining sustained winds at 145 mph with gusts into the 170s! For the trivia-minded, that makes Gonzalo the hurricane with the highest winds over the Atlantic Basin since Igor, back in September 2010.

Although Gonzalo is expected to weaken before reaching Bermuda, the cyclone will still be a ‘major’ hurricane as it approaches and passes the island-nation. For Bermuda residents, the questions are: “How close will Gonzalo get?” and “How bad will it be?”

Wednesday, October 15, 2014

Staying Nice, A Bit Warmer

By Jay Grymes & Steve Caparotta

WAFB First Alert Quickcast:

- fine autumn weather continues, a little warmer into Saturday
- a dry cold front passes through on Sunday
- looks ‘rain free’ through the next 7+ days

Today was the second superb autumn day for the WAFB viewing area and there are many more on the way.  We will begin a brief and rather modest warming trend tomorrow with afternoon highs for the Baton Rouge metro area returning to the low to mid 80°s for Thursday, Friday and Saturday under fair skies.  And the humidity remains low, so no complaints!

Over the weekend, a reinforcing cold front will be headed our way and slides through the viewing area by late Saturday.  It will be a dry front, with little more than a few fair-weather clouds passing by ahead of the front.  The slightly cooler air behind Saturday’s front will knock temperatures back a few degrees after it passes by -- look for Sunday afternoon highs to top-out around 80° to the low 80°s.  Bottom line: this is going to be a “get outside” weekend, whether it’s to for yard work, a little exercise and fresh air, or just a nice afternoon under fair skies.  Enjoy!

Headed into the next week, we’re calling for more of the good stuff: mainly fair skies for just about the entire work week with yet another dry, cold front sliding through the viewing area on Tuesday.

Although it’s taken half the month, this is the kind of weather that makes October a favorite for so many.  Unlike the stormy frontal weather on Monday, many of our autumn fronts are relatively mild and uneventful – that’s exactly what we’re expecting for the upcoming fronts on Sunday and Tuesday.  These dry fronts often do little more than dropping the temperatures by a few degrees and scrub some of the humidity out of the air, leaving us with mild days with low humidity and cool nights and early mornings.  Think of this weather as a reward for managing the summer season heat and humidity.

In the Atlantic, Gonzalo cranked-up into a Category 4 hurricane this morning, but the 4 p.m. advisory showed a small drop in winds to 125 mph, making it once again a Category 3. However, it's still a very strong and dangerous hurricane. The forecast track still takes a powerful Gonzalo towards Bermuda, with the system currently expected to be a ‘major’ hurricane (Category 3 or 4) as it passes close to the island-nation.  In fact, the official forecast takes Gonzalo just west of Bermuda, putting the island on the most-destructive ‘right side’ of the projected storm track.

Gonzalo is the first hurricane in the Atlantic to reach Category 4 intensity since 2011’s Ophelia, which peaked in strength on the evening of October 1st (local time).  Somewhat ironically, Ophelia’s track was not too unlike the forecasted path for Gonzalo.  But Ophelia passed far enough to the east of Bermuda that the storm had only limited impacts on the island.  Gonzalo may prove to be a much bigger problem.

Monday, October 13, 2014

Autumn Finally Returns!

By Jay Grymes & Steve Caparotta

WAFB First Alert Quickcast:

Several lines of strong to severe t-storms marched through the area late this afternoon and into the early evening hours. In addition to a Tornado Watch that was in effect through most of the afternoon, there were more than a dozen Severe T-Storm Warnings and at least one Tornado Warning. Fortunately, reports of severe weather have been limited, but there were at least a few neighborhoods that saw downed trees and power lines as the storms rolled through.

Here's the REALLY good news -- as the line continues eastward through the lower Mississippi Valley, well begin to enjoy a very pleasant change to our local weather!  Skies should be clearing early Tuesday, with sunrise temps for Tuesday morning down in the 50°s for most WAFB neighborhoods.  Then it’s sunny, cooler and much less humid for Tuesday afternoon, with highs only in the mid 70°s.  Tuesday is likely to be a little breezy at times but we doubt that anyone will complain about the autumn feel to the air.

It looks like just many WAFB viewers along and north of the I-10/12 corridor can expect morning lows in the 40°s for Wednesday’s sun-up, with another beautiful afternoon as highs climb into the upper 70°s to near 80°.  We’ll post the forecast as “fair, mild and dry” right into the weekend with a modest warming trend getting us back to the mid 80°s by week’s end.

We continue to watch two systems in the tropics: Fay and Gonzalo.  After briefly becoming the season’s fifth hurricane yesterday, Fay is losing ‘her’ tropical structure as she heads east over cooler North Atlantic waters.  So it’s “goodbye” to Fay, at least from a threats standpoint.

Gonzalo does not appear that ‘he’ will become a threat to the U.S. mainland or the Bahamas but ‘he’ is still a serious concern for portions of the Lesser Antilles and possibly Bermuda later in the week.  Gonzalo is on target to attain hurricane strength tonight or early tomorrow as ‘he’ passes close to the British and U.S. Virgin Islands and (hopefully) east of Puerto Rico.  The extended forecast for Gonzalo takes him to Category 2 strength and there is still a potential for Gonzalo to briefly reach Category 3 (a ‘major’ hurricane) later this week.

So let’s get through the evening with as little impact as possible, then it’s smooth sailing for the rest of the week!

Friday, October 10, 2014

No Break from the Heat This Weekend

By Jay Grymes & Steve Caparotta

WAFB First Alert Quickcast:
- mornings begin with areas of fog this weekend
- staying warm & humid afternoons for Saturday and Sunday
- 20% to 30% rain chances through the weekend
- vigorous cold front arrives early next week

The forecast can just about be summed up with a single word: “ditto.”

Fog wasn’t quite as widespread nor quite as dense for most earlier this morning compared to the previous two days but we’ll keep “areas of morning fog” in the forecast through the weekend and potentially for Monday’s wake-up too.

The morning fog is the product of the moist Gulf air mass that has been sitting over us since the early part of the week and it’s not going anywhere soon.  You can expect it to persist through the weekend and right through Monday.  That not only means a morning fog potential with wake-up temperatures in the upper 60°s to low 70°s for the next three days but also warm-and-muggy afternoons with highs in the upper 80°s for most WAFB neighborhoods.  And just like we’ve seen the past couple of days, the warm-and-moist air mass will get a boost from the warmer-than-normal afternoons, producing isolated to scattered showers -- with a t-storm here and there -- over the weekend.  We’re currently setting Saturday and Sunday rain chances at about 20% to 30%: mainly the afternoon variety that track from south-to-north.

So when does autumn really return?  You’ll ‘feel’ it making a comeback on Tuesday.

If you watch the progression of weather systems with us over the coming days, you will see a cool front headed our way out of the Southern Plains on Saturday and Sunday.  That will be the first of two fronts headed our way over the next few days. The weekend front gets very close to the WAFB area but all indications are that it will stall and ‘wash-out’ before making it into our viewing area.  While we don’t expect Sunday’s front to make it into our area, it still deserves watching as it could get close enough to enhance the shower and t-storm action for us on Sunday afternoon and evening.   (For now we’ll go with rain chances at about 30% for Sunday but we may end up raising those percentages over the weekend depending on how that front behaves.)

The ‘real’ cold front that will bring back autumn will just be headed into the Central Plains on Sunday.  Based on what we are seeing now, this second cold front will be a relatively fast-mover, sweeping through the Southern Plains late Sunday and early Monday and arriving in the lower Mississippi Valley late Monday.  This will be a “Pacific” front, delivering noticeably cooler and less-humid air but not as serious a chill as we might expect from a true “Canadian” front.

We’ll need to be ready for some active weather as the Pacific front moves through.  Strong to severe t-storms appear likely across portions of the Southern U.S. as the frontal system tracks east; whether that threat will include WAFB parishes and counties is still not certain as yet -- but here’s your heads-up.  It’s looking like the primary severe weather threat will be during the overnight hours (late Monday into early Tuesday), so make sure your NOAA weather radio is ready to go.

Once that front moves through, the weather should quickly improve.  Highs on Tuesday are only expected to reach the mid 70°s for the Red Stick with skies steady clearing through the day.  And for now, at least, we’ve got morning lows in the low 50°s for metro Baton Rouge on Wednesday and Thursday with sunny skies and afternoon highs in the upper 70°s to low 80°s for most of our WAFB communities.

Now that’s more like it.

In the tropics, things are getting a little active after the run of “quiet” days that has followed mid-September’s Edouard.  Invest 99L was upgrades to Sub-Tropical Depression #7 earlier today and appears to headed towards earning the name ‘Fay’ very soon.  Note that this is currently identified as a “sub-tropical” system rather than a “tropical” system. 

Why sub-tropical?  Sub-tropical systems are sometimes defined as hybrids between fully-tropical systems and mid-latitude cyclones (our ‘winter’ storms).  For our purposes, the main difference between tropical and sub-tropical systems is that sub-tropical systems (sub-tropical depressions and sub-tropical storms) are generally a little less intense and less organized.  However, they are often larger than their tropical counterparts with the highest winds and greatest convection extending farther from the center.  In effect, sub-tropical systems tend to be less tightly-wound.  Note that in some cases, sub-tropical systems have transitioned to fully tropical configurations.  Regardless, if they get close enough to the coast, the sub-tropical variety can produce the same destructive impacts as tropical systems, including rain-generated flooding, wind damage, and storm surge.

But s-TD #7 isn’t the only feature getting attention in the Atlantic today.  The National Hurricane Center (NHC) has begun processing Invest 90L, located to the southeast of s-TD #7 and giving it a up to a 30% chance of becoming a tropical cyclone in the next five days.  In addition, there is a healthy-looking tropical wave just to the west of the Cape Verde Islands and it too may earn “invest” status in the next 24-48 hours.

All of this activity is a bit intriguing given that much of the season has been a near-dud for tropical weather enthusiasts.  But the Atlantic waters remain warm and the atmosphere has eased into a somewhat more-supportive structure over the past few days.  What’s more, while the seasonal peak of tropical activity was roughly a month ago (around September 10th), “climatology” suggests a brief secondary peak in Atlantic tropical activity during October. 

Bottom line: “it ain’t over ‘til it’s over” and the Fat Lady hasn’t started to sing just yet.  (And thankfully, we can’t think of any other over-used clich├ęs to use here!)

Have a great weekend!

Thursday, October 9, 2014

Flirting with 90° again on Friday

By Jay Grymes & Steve Caparotta

WAFB First Alert Quickcast:

- warm, humid afternoons continue into the weekend
- 20% to 30% rain chances for Friday thru Sunday
- autumn weather finally returns next week

For the second consecutive morning, our mild-and-muggy morning air resulted in some areas of fog for many WAFB communities during the morning drive -- in some instances, visibility dipped well below one mile. Pockets of locally-dense fog dotted the region with more widespread heavy fog prompting the NWS to issue a DENSE FOG ADVISORY for areas to the east, including our neighbors in Tangipahoa Parish and Pike County, MS. Be ready for more rounds of fog each of the next several mornings as the air mass remains moist right through the weekend and into early next week.

As for the upcoming afternoons, we’ll keep the near-summerlike feel to the air with highs in the upper 80°s to near 90° for Friday and Saturday. Add in the local humidity and many neighborhoods will see peak mid-afternoon Heat Index readings in the low to mid 90°s. For Sunday afternoon, plan on highs in the mid to upper 80°s -- a couple of degrees cooler but still above normal for the first half of October.

We did see a few showers pop up this afternoon -- a pattern that had a bit of the look of a weak sea-breeze front fueled by Gulf moisture and daytime heating. Plan on a return of isolated showers for Friday -- set Friday afternoon and early evening rain chances at about 20%. ‘Live After Five’ and high school football fans will probably be okay … but check your WAFB Weather App to track any late afternoon and early evening showers.

And we’ll go with a 20% to 30% rain chance for both weekend days. All in all, any outdoor plans should be okay for most but be ready to dodge a few showers over the course of the afternoon and early evening. Regardless, any weekend rains should be the ‘passing shower’ variety -- unlikely to last long nor produce much in the way of accumulations.

Our extended outlook continues to show a Pacific cold front arriving in the lower Mississippi Valley next week. If you watch the weather maps in the coming days, you may note a weak cool front approaching from the northwest: this first front will stall and effectively ‘wash out’ to our north and west on Sunday. But behind it will be a stronger cold front and that one does make it through the WAFB viewing area -- right now we’ve got it timed for passage sometime between late Monday and early Tuesday. 

Next week’s front may arrive with sufficient energy to be a bona fide storm-maker, so we’ll have to keep an eye on the situation and prepare for the potential of weather WATCHES and WARNINGS next Monday and Tuesday. However, once the front pushes through, we’ll return to something more like what we expect for the autumn season!

In the tropics, the National Hurricane Center (NHC) is keeping an eye on a tropical wave now labeled as Invest 99L, located several hundred miles to the northeast of Puerto Rico. The environment around 99L should be reasonably favorable in the coming days. As a result, the NHC is posting 99L with a 50-50 chance of becoming a tropical cyclone (depression or tropical storm) during the next two to five days. However, the early guidance keeps 99L out over the open Atlantic: for now at least, a landfall anywhere in the U.S. appears extremely unlikely.