Friday, April 17, 2015

Looks Wet Again for Saturday

April 17th Quickcast: 
- rains likely for Saturday morning 
- Flash Flood Watch extended through Saturday evening 
Believe it or not, I have had one person today tell me that they have not had enough rain this week and would like more. 
For the rest of us, today’s dry spell was greatly appreciated.  Not only did we see some welcomed sunshine, but the lack of rain almost everywhere allowed areas dealing with standing water to drain.  In addition, the lack of rain was helpful along our area rivers.  While the lower Tangipahoa River is experiencing some minor flood issues, it currently appears that no other local river gaging sites (except those on the Mississippi) will reach flood with this run of wet days.
However, that does not mean that we are done with the rain just yet.  While this evening will remain mainly-dry (I can’t rule out a spotty shower or two), most of us will be dealing with another round of rains by Saturday morning.  A large disturbance currently over central Texas -- where it has prompted Watches and Warnings -- is headed our way and should begin impacting the WAFB area in the early morning hours.  We’re expecting showers and t-storms as the stormy weather tracks from west-to-east across our region with the rains potentially extending into mid-day and the early afternoon.
Here is the satellite/radar composite as of 8:00pm Friday:
The threat of additional rain is enough to prompt the NWS to continue the Flash Flood Watch (FFW) into Saturday evening for all of south Louisiana.  In addition, as of this afternoon, the NWS has expanded the FFW to now include all areas across the Florida Parishes north of the I-12 corridor: up until today, those areas and our SW Mississippi viewers were not included in the FFW.
According to the NWS Storm Prediction Center (SPC), there will be a “Slight Risk” for severe weather on Saturday, mainly in the form of high winds and hail.  Although unlikely, tornadic storms cannot be ruled out, especially during the first half of the day.  While most of us will see 1" of rain or less, isolated totals of 2” or more will be possible.
Set Saturday’s rain chances at 80% for the entire day, although the most widespread action looks to occur during the morning and mid-day.  (With some luck, we could get a break from the rains by the mid to late afternoon hours.)  We’ll start the day in the upper 60°s around the Red Stick, with the daytime high topping out in the upper 70°s.
Here are the RPM PrecisionCast and the Hi-Resolution Rapid Refresh (HRRR) radar depictions estimated for 8:00am Saturday as of 8:00pm Friday:
For Sunday, we’ll back the rain chances down to the 30% to 50% range, although the SPC is still maintaining a “Slight Risk” for severe weather given the moist-and-unstable Gulf air that will remain in place.
But then finally, some good news for all of us … well, good news for all except for those that really think that they need more rain.  A spring cold front should push through the lower Mississippi Valley early Monday.  That front should sweep the humid Gulf air out of the area, at least for a few days, and mark the onset of a run of drier weather. 
For now, we’ll keep things dry through Wednesday, with scattered rains returning for the end of the work week.

Thursday, April 16, 2015

Can't Get a Break from the Wet Spell!

April 16th First Alert Quickcast:
- showers & t-storms likely on Friday & Saturday
- Flash Flood Watch continues
Well, let’s start with the good news of the day: most WAFB communities stayed dry into the afternoon and as of 3PM there were no Warnings issued anywhere in the region and no reports of storm-related damage.
Unfortunately, the rain started moving into the western half of the viewing area -- including metro Baton Rouge -- just in time to add to the trials of our typical evening commute.  Those drive-home rains were accompanied by a few rumbles of thunder in some spots but thankfully no severe storms.
The Flash Flood Watch continues for much of the WAFB viewing area through Friday at 7:00pm.  At the same time, a Flash Flood Watch has been issued for communities on the west side of the Atchafalaya Basin through 1:00pm Friday … and I suspect that we may see that Watch extended later in the day too.  In fact, I’m really expecting both Watches to be extended into Saturday.
The rain should subside a bit later into the evening and overnight, but we’ll keep isolated-to-scattered rains in the overnight and early-morning forecast.  Expect a Friday morning low in the mid to upper 60°s for the Red Stick, with patchy fog for the morning drive too.
Unfortunately, Friday and Saturday are currently shaping up to be even wetter than today -- we’re going with rain likely for both days with those percentages running at 70% to 80%.  And with those higher rain chances will also come a slight increase in a severe-weather threat, especially for Saturday.  The main threats from severe storms will be damaging winds, but as we saw yesterday, large hail is in the severe weather mix too.  Although the chances are very low, we cannot completely rule out a tornado touchdown in the region either.
So when does this extended run of wet weather end? 
For the time being, I’m still carrying a 50-50 chance of rain for Sunday.  The real question here is about how long does it take for an upper-level “closed low” currently over the Rockies to move off to the east.  The current thinking is that the upper low remains a factor for our weather through Sunday, pushing a cold front through the lower Mississippi Valley early Monday.  Were that low to start moving east sooner, we might be able to salvage Sunday.
However, the way it looks now, we’ll have to wait until Monday afternoon for some rain relief!
In the meantime, we could see another 2” to 4” of rain -- with some locally-higher totals -- between now and Sunday.  That virtually guarantees more nuisance flooding and standing water ... and will require that we watch our area rivers closely through the weekend.

Tuesday, April 14, 2015

Flash Flood Watch Extended Through Wednesday

By Jay Grymes & Steve Caparotta

April 15th First Alert Quickcast:

- Flash Flood Watch extended into Wednesday for much of the WAFB viewing area
- a bit of a break in the rains tonight
- NWS forecast still suggesting another 3” to 6” of rain between now and the weekend!

What a mess!  The rains got into the viewing area sooner this morning than we expected and they came with a vengeance -- prompting one of the most widespread arrays of Flash Flood and Areal Flood Warnings that we’ve seen in a long, long time.  Thankfully, as we ease into the late afternoon and evening, those Warnings have been allowed to expire.

Radar estimates are showing an extensive area of more than 3.0” of rain for today - - focused across WAFB communities to the south of metro Baton Rouge.  Those big rain totals are highlighted by a bull’s-eye of roughly 5.0” to 6.0” or more along and near the Iberville/Ascension parish line. 

Thanks to our viewers, we’ve received numerous photos of street flooding throughout the WAFB viewing area with reports of water in homes in some locations south of the Baton Rouge metro area.  Those living along and north of the I-10/12 corridor have been far more fortunate today, with radar showing most of these areas with roughly 1.0” to 1.5” for the day.

Thankfully, we should get a break from the heavy rains over the next 18-24 hours.  We’re going with isolated showers for most of the viewing area overnight and scattered rains for Wednesday.  Rain totals for just about everyone should be less than one inch for Wednesday, with many coming in at well under one-half-inch for the day.

Unfortunately, our Thursday and Friday outlooks return to a “rain likely forecast” ... and it doesn’t get a whole lot better for the weekend either.  Our two main extended-range forecast models -- the American ‘GFS’ and the European ‘ECMWF’ -- are both indicating that the much of our area could see another 3.0” to 5.0” of rain between tonight and Sunday evening, with isolated higher totals.

Now ... let’s factor in the radar estimates and raingage reports since last Friday.  They show as much as 6.0” to 8.0” has fallen across portions of WAFB’s southern parish zones already with some radar bull’s eyes topping an estimated ten inches of rain in the Iberville/Ascension area.  Add in the forecast for the coming five days and we could be dealing with some serious high-water problems, especially for areas already pounded by heavy rains over the past five days.

We’ll keep an eye on the Florida Parish rivers too.  So far, with the heaviest rains to the south, we don’t anticipate any serious river flooding -- for the Amite, Comite, Tickfaw and Tangipahoa -- even with the “wet” five-day forecast.   Rains have generally been under two inches across the upper parts of these river basins, thus far.  However, one or more of these rivers could climb out of its banks should the forecasted rains come in one big dousing.

Monday, April 13, 2015

Flash Flood Watch into Tuesday

By Jay Grymes & Steve Caparotta

April 13th WAFB First Alert Quickcast:

- FLASH FLOOD WATCH remains in effect for much of the WAFB viewing area
- “wet” pattern persists just about all week

The NWS tweaked the coverage of the FLASH FLOOD WATCH early this morning, adding several of WAFB’s parishes to the mix early this morning.  The WATCH currently remains in effect for the majority of the viewing area through Tuesday evening, and we would not be surprised to see the WATCH extended into the week given our “rain likely” forecast for Tuesday, Wednesday and Thursday.

Today was a veritable “Tale of Two Cities” in terms of our weather: a wet and gloomy start to Monday but some sunshine and even a soft breeze for the afternoon to make up for the morning.  Unfortunately, the good stuff doesn’t last long …

Clouds will be on the return overnight with spotty to isolated showers likely for Tuesday’s morning commute.  But fog may even be a bigger player for the morning drive, at least in some locations.  We’ll start the day in the upper 60°s to near 70° for the Capital City.  Tuesday’s highs will top-out in the upper 70°s for many of us as a cloudy and wet day takes shape -- we’re going with rain chances at 80% for Tuesday.  While it may not be an all-day rain, the current set-up looks very wet through the middle of the day with the rains settling down by the evening.

Sadly, “wet” is the operative word over the next several days, at least. We're posting rain chances at 70% for Wednesday and Thursday and still at 50% to 60% for Friday.  Even the weekend outlook currently includes scattered showers and t-storms for both days.  Our temperature forecasts through the week call for highs in the upper 70°s to low 80°s with morning minimums in the 60°s -- that means daily average temperatures near- to above-normal each day.

That run of rainy days also means a threat of nuisance flooding and may even cause some issues on local bayous and rivers.  Two of our popular long-range forecast tools -- the American GFS and the European models -- are indicating widespread rain totals of 4” to 5” or more between now and next Sunday evening.

For the time being, we are not too concerned about a severe weather threat over the coming days, but even that will need close watching as waves of rain move through the region this week.

Friday, April 10, 2015

More Rain This Weekend

By Jay Grymes & Steve Caparotta

April 10th WAFB First Alert Quickcast:

- scattered rains into the evening
- more rain this weekend

The rains arrived in the afternoon as expected, washing-out hopes for “Live After Five” and making for an added headache for the Friday evening drive home. The weather turned a bit active in the Baton Rouge metro area a little after 1:00pm with a Severe T-Storm Warning posted for an area east of downtown Baton Rouge. Fortunately, however, the action subsided a bit into the later afternoon hours but we are still keenly watching another wave of rains heading this way from the southwestern parishes.

The cold front responsible for this afternoon’s weather will slide south of metro Baton Rouge this evening but then stall near/along the coast overnight and into Saturday morning. We’ll feel the wind shift and see temps drop into the low to mid 60°s across much of the WAFB viewing area. However, with the front in close proximity through the night, we will keep isolated showers in the overnight and early morning forecast for most of the WAFB area, with scattered rains possible along the coast.

So for many of us, Saturday will start out without rain. There may be some pockets of fog, especially near waterbodies and in those usual suspect spots, but we think that the air will be a little too dry for widespread fog issues -- with the possible exception of the coastal margins. But through the day, the front will begin a northward retreat as a warm front, allowing a return of moist-and-unstable Gulf air into the area and resulting in a return of scattered-to-likely showers and t-storms by the afternoon and early evening.

And for the time being, we’re keeping rain chances in the “scattered-to-likely” categories for Sunday too -- all in all, a relatively wet weekend outlook. We’ve got highs for Saturday and Sunday running around 80° to the low 80°s for both days.

Look for two-day rain totals over the weekend on the order of about 1” on average for the area, with locally higher and lower totals. We’re not particularly concerned about a severe weather outbreak on either day, although we can’t rule out one or two warnings over the weekend given the nature of the unstable air that will be in place.

The outlook for next week doesn’t seem to get much drier either. Our extended guidance is showing a series of passing disturbances through the week including two frontal passages: one around mid-week and another closer to the end of the work week. That all adds up to a continued “unsettled” weather pattern that keeps things damp-to-wet into Friday.

Not everyone gets rain every day, but over the course of the next seven days we could easily see widespread rain totals of 3” to 4” with locally-higher totals based on the current extended-range guidance from the NWS Weather Prediction Center.

So stay dry .. get outside when you can .. and enjoy the weekend!

Wednesday, April 8, 2015

Better Rain Chances Ahead

By Jay Grymes & Steve Caparotta

April 8th First Alert Quickcast:

- isolated afternoon showers for Thursday
- showers & t-storms for Friday afternoon and evening
- scattered-to-likely rains for Saturday & Sunday

A very warm afternoon for the viewing area under partly cloudy skies -- in fact, Baton Rouge Metro Airport’s high of 87° today ties the all-time record for this date, a record that has stood since 1907 -- 108 years.

We did see a few specks of rain on regional Doppler radar during the afternoon but what did bubble-up in the afternoon died-out quickly ... and we’ll stay with partly cloudy skies through the evening and into the overnight hours. By Thursday’s sun-up, expect partly-to-mostly cloudy skies with some patchy fog with low temperatures in the upper 60°s to near 70°. We’re expecting a little more wind in the morning, and that should keep us from the widespread dense fog that many encountered during the past couple of mornings.

For Thursday afternoon, we’re calling for a sun/cloud mix with rain chances at around 20% or so and highs again in the mid to upper 80°s for the metro area. Then into Thursday night through early Friday it will be another round of partly-to-mostly cloudy with some patchy wake-up fog.

Unfortunately, the Friday afternoon and evening forecast hasn’t improved. We’re still anticipating the arrival of a cold front during the latter half of the day, bringing showers and t-storms to the area -- complete with a “Slight Risk” for severe storms. That’s NOT what “Live After Five” fans want to hear. 

And there’s not a lot of good news for the weekend either. Friday’s cold front is expected to stall near the coast, then begin a retreat to the north as a warm front on Saturday. With that, we’re staying with “rain likely” for Saturday. What’s more, we’ve got scattered showers and t-storms for Sunday too. The only bright spot in this wet forecast is that neither Saturday nor Sunday shape-up to be all-day rains … but you’ll need to keep an eye on the live radar on your WAFB Weather App and schedule your outside time accordingly.

Into next week, we’ll still carry scattered rains in the forecast for Monday, Tuesday and Wednesday.

Tuesday, April 7, 2015

Mainly Dry Again for Wednesday

By Jay Grymes & Steve Caparotta

April 7th First Alert Quickcast:

- areas of fog return for Wednesday morning
- mainly dry for Wednesday
- rain likely for Friday & the weekend

We started the day with areas of fog, with a Dense Fog Advisory in effect during the morning for a number of parishes. The fog and low clouds were somewhat slow to clear through the morning, but by the afternoon we had shifted to partly cloudy skies with highs in the 80°s with very little showing up on Doppler radar.

Our Wednesday forecast calls for a near repeat of Tuesday’s weather: areas of fog for the morning, becoming dense in some areas and potentially prompting another round of Advisories. Then it’s back to the mid to upper 80°s for Wednesday afternoon with spotty showers, at best. 

You’ve probably noticed a bit of a muggy feel to the air. Our dew point temperatures have been running in the mid and upper 60°s since Tuesday and are likely to stay there for the next few days as flow off the Gulf has added low-level moisture to the air. While dew points in the 60°s may not be truly “summerlike,” they are well above normal for early April -- average dew points at this time of year are in the mid to upper 50°s.

For Thursday, we’ll up the rain chances to 20% to 30% for the afternoon, so most WAFB neighborhoods remain dry as highs again return to the mid 80°s. But after that, our guidance is pointing to a run of “wet” days extending from Friday right into next week.

A cold front arrives on Friday, with showers and t-storms likely by the afternoon. It’s still early, but we’ll want to keep watch for the potential for a few strong to severe storms on Friday too.

Unfortunately, rather than simply sweep through the region and leave us with a cooler and less-humid weekend, our guidance is suggesting that the front slows, stalls and then retreats to the north as a warm front: that’s a recipe for a wet Saturday and Sunday.

To add to the wet forecast, the meandering front will get some added help from eastbound disturbances. Of the three days, Friday appears to be the most active in terms of storms but most WAFB communities are likely to deal with showers and a few storms for all three days. For the time being, Saturday and Sunday don’t appear to be all-day washouts … but it’s too early to try and nail down the timing of wet and dry spells through the weekend.

In fact, we’re keeping scattered-to-likely rains in the Monday forecast with isolated-to-scattered rains in our Tuesday outlook. Given the forecasted wet spell, the NWS Weather Prediction Center is calling for 1” to 3” of rain by Tuesday for the WAFB viewing area, with the larger totals more likely north of the I-10/12 corridor.