Friday, July 3, 2015

Scattered Storms Return for the Holiday Weekend

By Jay Grymes & Steve Caparotta

July 3rd WAFB First Alert Quickcast:

- back to scattered afternoon t-storms for the independence Day weekend
- drier and a little warmer for next week

Happy 4th to you and yours!

We doubt that anyone is complaining about our back-to-back dry days, thanks to high pressure at the mid and upper levels putting the clamps on afternoon thundershower development.

Unfortunately, the “lid” comes off the atmosphere over the weekend and we return to scattered afternoon showers and t-storms for both Saturday and Sunday. In fact, we’re leaning towards “rain likely” for Saturday (rain chances at 50% to 60% for Saturday afternoon), and there is a potential for a few strong to severe storms in the WAFB area over the two-day span.

The upper-level high (a mid/upper-air ridge, the “lid” on the pot) that put the brakes on afternoon rains yesterday and today will give ground over the weekend. That will let our moist and unstable Gulf air do its thing: build mid-day and afternoon showers and storms without an inhibitor to slow their vertical growth. Neither day will result in all-day rains for your backyard, but we expect a pretty active radar depiction for both afternoons as individual t-storms build, move and subside through the day. If you’ve got outdoor plans on either day, make sure that you have an indoor or under-cover option ready to go.

After muggy morning starts in the low to mid 70°s for both Saturday and Sunday around metro Baton Rouge, look for temperatures to climb into the upper 80°s to around 90° before the clouds and rains knock the temperatures back through the afternoon.

As for the Saturday evening “Fireworks on the Levee,” we expect the rains to have dissipated by showtime, but we could still have isolated rains in the area as late as 7:00 or even 8:00pm. We’re thinking that temperatures for the 9:00pm showtime will be in the upper 70°s to low 80°s on the levee.

Into next week, the ridge returns, taking rain chances back down into the ”isolated” category for just about every day next week -- yep, too bad the ridge had to retreat during the weekend. With the drier pattern in the forecast for next week, plan for muggy morning sunrises in the low to mid 70°s for most WAFB communities, with highs in the low 90°s just about every day.

Thursday, July 2, 2015

Mainly Dry Again for Friday

By Jay Grymes & Steve Caparotta

July 2nd WAFB First Alert Quickcast:
- hot, breezy and mostly dry for Friday
- scattered showers & t-storms expected for both weekend days

Okay, our “mainly dry” forecast for today took a big hit in a number of neighborhoods before 7:00am thanks to a band of mainly-light showers draped over the viewing area. Those showers fizzled out by or before mid-morning and the gray cloud deck had largely thinned before lunchtime. With the thinning clouds, mid-day and afternoon sunshine took temperatures into the 90°s for the afternoon.

Even as late as 3:00pm this afternoon, Doppler was “all clear” across the WAFB viewing area. A rogue, spotty shower or two might pop-up during the late afternoon or early evening, but we expect that just about everyone stays dry into the evening and overnight too.

Our Friday forecast calls for another mainly-dry day like today … with the big exception being no morning showers like some of us experienced this morning. After a muggy Friday morning start in the low to mid 70°s for many WAFB communities, we’ll climb once again into the low 90°s for Friday afternoon, with spotty showers, at best. Add in the afternoon humidity and that low 90° reading will ‘feel like’ 100° or more at the peak of the afternoon heat. Then it’s a warm and dry Friday evening and mostly fair skies into the night.

Out mostly-dry Thursday and Friday are courtesy of a western U.S. upper-air ridge building just a bit farther east. That ridge has pushed drier and slightly warmer air into the middle levels over the Bayou State -- and that serves as a rain-cloud inhibitor.

Unfortunately, the dry spell doesn’t hold through the weekend. The ridge softens and retreats westward allowing our locally-unstable air a better chance to build vertically during the afternoons: bigger afternoon cumulus clouds usually means more rain-clouds and better rain coverage. We’re still not too concerned about any kind of severe weather threat for either Saturday or Sunday, but we’ll go with rain chances at 40% to 50% or so for both days. Of course, with those elevated rain chances, we can’t rule out one or two strong storms on either afternoon.

So be ready to dodge the rains during both afternoons. We don’t anticipate all-day rains in either case and not everyone gets wet each day … but have a plan to get out of the weather should storms roll through your neighborhood. The good news is that we expect Saturday’s mainly-afternoon rains to be out of the way for Saturday evening’s fireworks and festivities.

Headed into next week, upper-level ridging builds back over the area, knocking rain chances back to around 20% to 30% for just about every afternoon. (Too bad that isn’t the cast for the weekend, eh?)

Tuesday, June 30, 2015

Scattered T-Storms Again on Wednesday

By Jay Grymes & Steve Caparotta

June 30th WAFB First Alert Quickcast:

- scattered afternoon showers & t-storms return for Wednesday
- isolated rains for Thursday & Friday
- back to a summer routine for the July 4th weekend

Looking for WAFB’s Weather App?  Find it here:
- Apple users click here:
- Android users click here:
.. or text WEATHERAPP to 99009 …

And for yet another day, some fairly strong t-storms rocked parts of the viewing area.  Unlike last night’s late-night storms and the action last Tuesday and Wednesday, these storms were not out of the north and northeast.  However, they were still quite energetic and lightning-laden, fueled by our very most and unstable Gulf air.  What’s more, they got an additional boost from a pair of features working together: a sea-breeze-like wave heading inland and what appears to be a broad-but-weak non-tropical disturbance moving to the west-northwest over the western Gulf.

Bottom line: a very active middle of the afternoon for metro Baton Rouge and western Livingston Parish, sections of the Felicianas and points west including parts of Pointe Coupee, Avoyelles and St. Landry parishes.  Once again, the most noteworthy aspect of these storms was the lightning - - which is credited with power outages and even one or more fires.  But we can’t ignore the reports of small hail from WAFB viewers as well as locally-heavy downpours that produced more rounds of street flooding.

The action will wind down into the evening and most of us will stay dry through the overnight and early morning hours on Wednesday.  We could see a few showers down near the coast for Wednesday’s sunrise, but the morning commute for metro BR should be a dry one for just about everyone.  Plan for a muggy, partly-to-mostly cloudy start to Wednesday with morning temperatures in the mid 70°s.

For Wednesday afternoon, here they come again: 50% rain chance with highs getting up to around 90° before the rains arrive. 

The weather gets much quieter for Thursday and Friday, with rain chances for both days currently posted at 20% or less.  Both days start off in the mid 70°s for the Red Stick and afternoon highs reach the low 90°s for most, with a few neighborhoods potentially sneaking into the mid 90°s.

And into the Fourth of July weekend, we return to something fairly typical for this time of year: morning starts in the low to mid 70°s for the metro area, afternoon highs in the low 90°s, and scattered mainly-afternoon t-showers for both days.

Friday, June 26, 2015

More Rain This Weekend

By Jay Grymes & Steve Caparotta

June 26th WAFB First Alert Quickcast:

- weekend cool front still on the forecast board

Today was yet another afternoon with scattered showers and storms … but the action was less substantial than what we saw on Thursday and nothing at all like the big boomers and excessive rains of Tuesday and Wednesday.  Today was something more “normal” for a summer day in the viewing area.

There is a change coming this weekend in the form of a summer cool front.  We can’t call summer fronts “rare” but they certainly aren’t very common.  During the winter and spring, we can expect to see five or six frontal passages -- sometimes even more -- each month, on average.  By comparison, during the summer season, that number drops to something closer to an average of one or two passages per month.  And often, our summer fronts don’t push all the way through the area: they stall near or along the coast and sit there until they fizzle-out.

That is precisely what we are expecting this weekend: a cool front will slide south out of the U.S. Plains and reach the WAFB area by Saturday afternoon and evening.  Then it simply stalls along or near the coast for the remainder of the weekend.

If that front would continue southward and move out over the Gulf, we would get a nice change in our weather.  A completed frontal passage would deliver slightly cooler temperatures and, even more welcomed, a big drop in our local humidity.  (90° afternoons don’t feel so bad if the air is less humid).  Unfortunately, our guidance is suggesting that the weekend front will stall somewhere along or near the coast late Saturday and then linger there into Monday before dissipating.

Fronts usually mean rain in the local forecast no matter what time of year.  So our weekend cool front will be a focus for rains on Saturday afternoon and evening -- by adding extra lift to our typical hot, humid and unstable sub-tropical Gulf air.  Then, with the front lingering near the coast into Sunday, we’ll keep “rain likely” in the overnight and morning forecast for our viewing area.

In the spring, a frontal set-up like this could mean some nasty weather and another round of potentially large rain totals.  Fortunately, summer fronts along the Gulf Coast tend to be less energetic than their winter and spring counterparts.  That said, we’ll still get showers and storms with this frontal boundary and we can’t rule out a few strong to severe storms as it settles over the area.  But with the front over the area at night rather than during the heat of the day, the threat for severe storms is reduced somewhat.

The rains will continue into Sunday morning, but rains on Saturday afternoon and into the overnight hours will take a big bite out of the local atmosphere’s storm energy, with rains winding down as we head towards Sunday mid-day and afternoon.  We’re not ready to say “rain free” for Sunday afternoon, but it’s looking like isolated showers with the majority of WAFB neighborhoods staying dry into Sunday afternoon and early evening.  In addition, clouds and morning rains on Sunday will slow the daytime warm-up, with just about all of us topping out in the 80°s for Sunday afternoon.

So how “cool” will it get?  Most viewers in the coastal parishes will get little or no relief from the humidity, which means not much change in terms of morning lows on Sunday and Monday.  For the northern half of the viewing area, if the front can make its way as far south as the coastal zone, at least some communities north of the I-10/12 corridor could slip into the upper 60°s on one or both mornings. 

We’ll go with morning minimums on both days close to 70° for metro Baton Rouge: not much of a change but at least a couple of degrees cooler -- and a little less humid -- than the past several days.

As for next week, our current extended outlook calls for a return to our traditional summer routine at least through mid-week: morning lows in the low to mid 70°s, most afternoons climbing to 90° or more, and scattered mainly-afternoon showers and storms just about every day.

How about the tropics?  Dead quiet.  While there are a few tropical waves running in the easterly tropical flow (and that is normal), none of them show any potential for development.

Eyes to the skies on Saturday afternoon … but here’s hoping that you get to enjoy the weekend!

Wednesday, June 17, 2015

Hot & Humid, Isolated Showers

By Jay Grymes & Steve Caparotta

June 17th WAFB First Alert Quickcast:

- ‘Bill’ continues chugging northward
- summer heat, humidity and afternoon showers locally

Tropical Depression Bill continues moving steadily to the north and is still expected to begin a turn to the northeast over the next 24 hours. Bill has been quite the rainmaker for parts of Texas -- sadly, in some places that really didn’t need more rain. 

For most of Louisiana, however, Bill failed to leave much of a calling card. While there have been some pockets of 1” to 2” rains over the western parishes, and even T-Storm Warnings in the northwestern part of the state, most of the Bayou State saw little in the way of noteworthy weather. Thank you for that favor, Bill!

We should note that while Bill’s landfall was roughly 170 miles southwest of Cameron Parish, the Lake Charles NWS office has reported multiple locations in that parish with sustained winds of 40 mph or more -- tropical-storm strength. And the NHC’s wind field projection during Bill’s peak strength suggested that tropical-storm winds could indeed reach into the westernmost portions of Cameron Parish. So technically, does this confirm a tropical-storm impact by Bill on the Bayou State? It will be interesting down the road to see how the NOAA tropical experts evaluate it.

Meanwhile, weatherwise for us, it’s shaping up for a steady dose of typical summer weather for the central Gulf Coast right into the weekend. The line-up reads like this: morning lows in the low to mid 70°s, afternoon highs in the low 90°s, and a steady influx of humid Gulf air that keeps dew points in the 70°s. That will mean afternoon Heat Index readings topping out in the upper 90°s for many WAFB neighborhoods, with occasional readings at 100° or more. 

Be extra careful in the heat, especially if you are spending time under direct sunshine. And please remember the pets too!

Rains chances will run in the 20% to 30% range for Thursday and Friday and probably right through the weekend. As we’ve mentioned over the past few days, the upper-air ridge centered over the Southeast U.S. that steered Bill away from us also kept rain chances in our area on the lower end (isolated at best) over the past couple of days. That ridge is likely to shrink a bit and shift a little eastward over the next couple of days, allowing for ever-so-slightly higher chances for afternoon showers on Friday and Saturday. But even then, we’re talking 30%, which is still at or below normal for mid to late June.

As we head into Sunday and next week, models are indicating the development of upper-air ridging over the Desert Southwest, putting us under the influence of dry, northwesterly flow at the mid- and upper-levels. That should keep rain chances in the 20% to 30% range for Sunday and Monday, and possibly right through the middle of the upcoming work week.

So it’s summer heat-and-humidity for the end of the work week and the weekend, with the occasional passing shower that might be welcomed as a nice mid-afternoon heat-breaker.

And in the tropics, the NHC notes four tropical waves over the Atlantic Basin, with a fifth about to move off the western coast of Africa, but none show any significant signs for potential development, at least not in the next three to five days.

Tuesday, June 16, 2015

Bill Moving Inland...Hot, Humid Locally

By Jay Grymes & Steve Caparotta

June 16th WAFB First Alert Quickcast:

T.S. Bill moving inland over Texas
- muggy mornings followed by hot-and-humid afternoons will be the rule locally

T.S. Bill made landfall along Matagorda Island along the central Texas Gulf Coast just prior to the lunch hour today.  Peak sustained winds at landfall were estimated at a respectable 60 mph with higher gusts, making Bill a formidable tropical storm as he headed inland.

After making landfall, Bill stalled and meandered along the coast for several hours.  By 3:00pm, however, it looked as though Bill had begun slowly moving again to the North to NNW, and the 4:00pm NHC Advisory indicated that Bill had begun weakening with sustained winds at 50 mph.

The tropical forecast keeps Bill well to our west through mid week.  ‘His’ impacts in Louisiana will be periodic rains for the western parishes, but even there most rain totals through week’s end will come in at around an inch or less.  And for us in WAFB-land?  Very little in the way of a Bill weather signature other than a breezy couple of days.

For Texas and Oklahoma, however, it’s another round of very soggy weather.  The forecast from the NWS Weather Prediction Center (WPC) indicates a swath of 4” to 8” rains extending from the coast into the middle of the Red River Valley (where they just endured record-setting rains).  And that’s where Bill will likely have ‘his’ biggest effect: prolonging the high water along the Red River is it passed through northwestern and into central Louisiana.

What Bill does give WAFB viewers is a quick refresher course that tropical systems can bubble-up fairly quickly over the Gulf.  Texas coastal residents had only 36 to 48 hours to prep for this system: would you have been ready for a couple of days without power had Bill taken a turn to the northeast and beat a hasty path in our direction?  Bill serves as a reminder to make sure that you, your family and your business have “tropical game plans” in place and that you are ready to go.

Meanwhile, we’ll get an extended run of relatively dry weather through the week and weekend.  A high-pressure ridge centered over the southeast U.S. appears ready to remains in place into next week.  That same ridge is the key steering agent accounting for Bill’s forecast path, with the western margin of that ridge extending across the Bayou State and into East Texas.

While the ridge won’t fully deter afternoon showers from popping up in our viewing area, it will be a persistent inhibitor to raincloud formation through the coming weekend.  We’re posting regional rain chances in the 20% to 30% range for most WAFB communities right into next week. 

Less cloud cover means more sunshine and that adds to the usual daytime heating.  In the meantime, our low-level flow will continue to come off the Gulf, keeping the air humid.  With dew points in the 70°s, we can expect morning minimums to stay in the low to mid 70°s right through the next seven days for the Red Stick.  And that moist air will combine with daytime highs in the low to mid 90°s to push peak daily Heat Index readings up to near or even above 100°!

So, enjoy the drier weather spell … but be extra careful in the summer heat!

Monday, June 15, 2015

Tropical Rains for Texas...Minimal Impacts Locally

By Jay Grymes & Steve Caparotta

June 15th WAFB First Alert Quickcast:
- much attention on the western Gulf and Invest 91L

- much attention on the western Gulf and Invest 91L
- declining rain chances locally over the next few days

Yes, a good deal of attention this weekend and today was focused -- and remains focused -- on the tropical disturbance in the western Gulf - Invest 91L.  Assessment of Hurricane Hunter data earlier in the day by the national Hurricane Center (NHC) pros indicated that the disturbance has yet to achieve the complete structure to be classified as a tropical cyclone (either a tropical depression or a tropical storm) - - however, there is little doubt that the system is awfully close as of this afternoon. 

Why not a tropical storm as yet?  The NHC stated that a clearly-defined low-pressure center has yet to sufficiently consolidate to earn cyclone classification, although there is ample evidence of tropical-storm force winds in the region.  Another Hurricane Hunter aircraft is scheduled to visit the disturbance this evening, and we suspect that it will collect the evidence needed for upgrade to Tropical Storm Bill. 

Virtually every major tropical forecasting model takes this system into the Texas Coast and then northward into the Southern Plains -- bad news for the already-flooded Red River region but good news for the Bayou State.  Parts of Louisiana could receive some east-side wrap-around rainbands from the tropical system over the several days but it appears as though the main storm energy misses us.

Note that there are Coast Flood Advisories - - and Warnings - - either already in effect or anticipated for Louisiana, but most of this is a result of the steady southeasterly winds that have been impacting the region and are expected to continue.  However, winds along the central and western Louisiana coast are likely to show additional increases due to the larger-scale flow around the tropical system as it continues along a northwesterly track into Texas.

For most of us, however, we can expect a turn to a slightly drier regime over the next couple of days or so.  High pressure ridging, centered over the southeastern U.S. will serve as a modest inhibitor for our afternoon thundershowers -- not fully shutting off the afternoon rains but keeping them in the 20% to 30% range for our viewing area for the next three days.

The “muggies” will stay with us all week long.  While we may see a little less in the form of rain coverage, moist Gulf air will remain in place all week long.  Look for afternoon highs in the 90°s each day, with morning starts in the low to mid 70°s for most WAFB neighborhoods - - and upper 70°s at sunrise for the more southern parishes.

So here we are, only two weeks into the Hurricane Season and we could have our second ‘named’ storm?  What happened to the forecast for below-average storm numbers?  It’s still on the table, but we admit that the average date of the second ‘named’ storm in the Atlantic is August 1st!