KATC StormTeam 3 Weather BLOG

…will make for a tricky forecast over the next couple of days…well come to think of it’s been tricky ever since the June/July heat wave busted early this month. An unusual frontal boundary will stay in the vicinity of south-central Louisiana over the next several days while disturbances in the northwest flow aloft will likely ignite scattered showers and thunderstorms.  Where the storms take up residence is the question de jour.  In addition, there are hints of drying and warming aloft which makes an argument for lowering the rain chances.  So the forecast is certainly fraught with hedges but we’ll go with a little more dull sunshine tomorrow, with the chance of scattered daytime showers and storms, and put the most favored areas for seeing storms along the coastal parishes and/or offshore.  Thunderstorm activity however,  could certainly dictate where the frontal boundary will go and a shift 20 miles to the north or 20 miles farther to the south would make big differences in the forecast.  The models are coming in even drier for Friday but we haven’t bought into that quite yet…we’ll see how successive model runs look through this evening.  This weekend should be a typical July/August weekend with partly cloudy, hot and humid conditions along with the chance of scattered mainly daytime heating induced showers and thunderstorms.  Next week looks more interesting as our first real slug of tropical moisture will push into the Gulf of Mexico from the Caribbean with the moisture likely to add to our rain chances by mid-next week.  Rob

A moist and unstable atmosphere will stay with us through Wednesday while a frontal trough combined with plenty of upper level support will keep showers and thunderstorms in the area overnight through Wednesday.  Afternoon model runs have been keying in on a pretty good chance of storms redeveloping overnight toward daybreak with a stormy start to our Wednesday morning commute quite possible…so allow a little extra time to get where you are going tomorrow.  Locally very heavy downpours will be possible leading to localized street flooding with some storms capable of producing gusty winds and the possibility of small hail.  It wouldn’t surprising if we have a stormy morning through the midday hours with quieter conditions and some limited sunshine during the afternoon  We’ll probably see a little more sunshine Thursday but with a nearly stationary frontal boundary and disturbances rolling in from the northwest we’ll likely keep near or above normal rain chances with us for Thursday, Friday and into the weekend.  Interestingly enough, it looks like there will be plenty of enhanced thunderstorm activity through mid-next week more than likely easing many of our drought issues…the question of “when this rainy pattern may quit?” will likely be creeping into our conversations sooner than later!  Rob

We’ve been watching Tropical Disturbance 97L since the end of last week.  Yesterday it crossed the Leeward Islands and today it’s south of Puerto Rico.  So far all it has generated is some heavy rain and some gusty winds over the islands.  Even today there is a good flare up of storms, but wind shear in the area is still way to strong for this to develop.  The track continues to take this westward toward the Dominican Republic.

Another area worth watching today is a little closer to home.  Over the Bahamas a tropical wave has been producing numerous showers and thunderstorms.  This wave will continue to drift toward the northwest.  A couple of models have picked up on this wave, possibly having it acquire tropical characteristics later this week off of the coast of North Carolina.  After that most models show this disturbance rocketing northeast, following the general upper level pattern that has kept a trough over the east coast, blocking any systems from having much impact. 

Activity, or at least suspected activity should be on the increase over the next several weeks.  The peak of the hurricane season is only about 6 weeks away.  August and September normally have more than half of the annual tropical activity.  I did take a look back at the last 30 years, and only 9 times have we not had a 1st named storm by July 21st.  Funny thing is, seven of those seasons are between 1980 and 1992.  This was during the “low activity” cycle that lasted from 1970-1994.  The current 20-25 year “high activity” cycle we’re in started in 1995.  Scientists have mapped out other “natural” cycles of increased or decreased activity in the past.  Other notable “highs” lasted from 1940-1965, and 1875-1900.  Significant “lows” were from 1855-1874 and 1901-1924.

Closer to home, with a ridge over the west and a trough in the east, the upper level pattern will continue to drive disturbances in from our northwest.  One in particular was generating quite a bit of rain over Oklahoma, Arkansas, and Texas early this morning.  This will drift southward and may bring us some rain later this afternoon.  A front will drift to central Louisiana by Thursday and stall.  Another front is indicated later this weekend that might bring another shot of dry air by Sunday.  Two cold fronts in July???  Are you kidding me???  –Baker

It appears that our short-lived break from the humidy will be just that…as southerly breezes from the Gulf of Mexico have returned.  Scattered daytime showers and storms will stay in the forecast through the rest of the week and the weekend with chances varying each and every day depending on the timing of upper atmospheric perturbations that will continue to ride in a northwest flow aloft.  It appears that we may see a few weak disturbances Tuesday but a stronger series of disturbances appear on the docket for Wednesday…so rain chances for Wednesday afternoon and evening are higher than that of Tuesday.  The upper trough over the Southeast U.S. responsible for our northwest flow aloft appears to continue through early next week but timing these disturbances are quite difficult.  So the bottom line is expect storms at some point during the next several days with some activity persisting past dark on a few nights.  Away from the storms it will be typical July weather with highs ranging mostly in the upper 80s to lower 90s over the next few days.  We could see slightly hotter conditions on Friday, perhaps Saturday, as drier more stable air briefly moves in.  The humidity unfortunately will modify and stay near typical July levels while overnight lows moderate back into the mid-70s.  Rob

A very unusual cool front moved through the area over the weekend bringing slightly cooler air and lower humidities for much of Sunday and the early part of today.  Sunday’s high was only 88 degrees, 3 degrees cooler than normal, and with full sunshine most of the day!  Early this morning lows were right around 70 degrees here in Lafayette.  New Iberia and Baton Rouge dropped to 69 for a while, and Hattiesburg, Mississippi was down to a pleasant 63!!!  Temps in the 60s in July doesn’t happen very often, and the record low for today is 66.  I looked back at the past 10 years, and we only hit the 60s in July 3 times.  July 1 and 2 of 2008 (69 & 68) and July 20, 2004 (69).

Our front was still draped across the northen Gulf of Mexico south of Louisiana to near Houston and then northwestward to Dallas.  An upper level disturbance was generating some storms in Texas, but those are weakening this morning.  The front will lift northward today allowing the humidity levels to rise again, and normal summer like conditions will prevail again for most of the week.  Another front will drop southward over Texas by the mid week and our chances for storms will increase again Wednesday and Thursday.  Temperatures should be near normal for most of the week and the weekend.

The tropical wave we were watching over the weekend is holding on as it moves toward the Windward Islands.  There is still less than a 30% chance for development today.  As the wave moves westward, the upper level conditions become more unfavorable for development.  Right now it looks like it will drift over the Caribbean by tomorrow.  We’ll continue to monitor this wave, and the rest of the tropical Atlantic stays quiet!

The dry air kicked in behind yesterday’s front and made it a comfortable day across the state today. Too bad it won’t last. Monday the dry air stays with us most of the day but in the evening, southerly winds return and the front that’s out in the Gulf begins to retreat back to the north. That will put us back on the humid side of the boundary and rain chances increase toward the middle part of the week. It was nice to, at least briefly, get some clear sunny skies.

In the tropics, a tropical wave near the Windward Islands is being monitored but upper level winds are expected to become less favorable for the low to strengthen. Otherwise, it stays quiet as we head into the end of July.

Enjoy your week!

Storms moved into Acadiana and parked prompting a flood warning for Lafayette parish. Youngsville and Broussard got the heaviest rain today, the same areas that flooded yesterday so in the past couple of days at least 6 inches of rain fell in south Lafayette. Washington also got about 3 inches by radar rainfall estimates. Breaux Bridge and New Iberia also had torrential rain with rates about 3 inches per hour. All of this because of a boundry between humid and dry air pushing south. Sunday the front may stall just offshore putting us on the dry side of the boundary Monday. Rain chances look to go down for a couple of days before increasing.

Updates to the on-going forecast include the latest on our waffling rain chances.  Today the global, large scale computer models continue to call for excellent rain chances tomorrow and Sunday while our in house Futurecast model, which is generally a more robust model with respect to cool fronts is pushing most activity offshore and back into Texas this weekend.  The quagmire de jour remains that a northwest flow aloft behind a deep upper trough will continue this weekend.  In this type of pattern we are vulnerable to mesoconvective complexes that develop in the High Plains and then race southward in the flow.  Even though our temperatures and dew points will drop to below normal levels this weekend, don’t be surprised if a couple of hefty storms roll through, especially Saturday night into early Sunday (but I would favor SE Texas more so than Louisiana at this point).  The global models pick up nicely on this feature but the Futurecast only hints at it…so we’ll go with a blend tonight (and as I write this the latest global model run is coming in drier).  The bottom line forecast…as of now…will be partly to mostly sunny conditions across most of Acadiana Saturday, except along the coast where clouds will persist longer.  Most of the storms should stay offshore with some back-building along the coastal parishes for tomorrow afternoon possible.  Scattered storms will be possible Saturday night into early Sunday with the window of opportunity previously discussed…and timing these events is always difficult so we could be off by a good 6-12 hours.  More clouds and the chance of storms will be possible Sunday.  The best part about this weekend will be that highs should be limited in the upper 80s to lower 90s tomorrow and mid-upper 80s Sunday while overnight lows drop into the upper 60s by Sunday morning…and relative humidity should get more comfortable through Sunday.  It will be interesting to see how this weekend plays out…not the “same-old-same old”!  Enjoy and have a good weekend!  Rob

The line of storms over northern Louisiana lost its punch very early this morning .  There were a few showers over the northern Acadiana parishes before sunrise, but most were light.  There was a concentration of storms over the coastline and the near shore waters, but most of that is moving offshore and weakening.  There is another complex of storms over northeast Texas heading southeast, this line also seems to be weakening at this hour, but it should help to generate more storms in the unstable air later this afternoon.  With daytime heating, normal afternoon storms should develop, and the outflow boundary from the Texas storms should lend a hand too.

Our front is still heading this way.  Saturday looks to be partly cloudy, but storms will become more likely later in the afternoon as the front gets closer.  Storms may be likely again overnight Saturday into Sunday.  Drier air will move in late Sunday, and Monday and Tuesday look pleasant with sunshine and lower humidity levels.

Our tropical wave over the mid-Atlantic looks better organized again today.  This has been an “on again, off again” thing for the past few days.  The National Hurricane Center says there is less than a 30% chance for this to develop.  We will keep watching it over the weekend, but not a concern at this time.  Waters of the Gulf, Caribbean, and the rest of the Atlantic are quiet and should remain that way over the weekend.  Have a great Saturday and Sunday!–Baker

The big mesoconvective complex entering the northern part of the state has forced us to raise the rain chances by tomorrow morning…this will probably through a monkey-wrench into the previous forecast and blog entry!  This thunderstorm complex may ultimately stabilize our atmosphere for the midday hours Friday knocking down the rain chances somewhat for the midday hours and perhaps also mitigating the slight severe weather risk…stay tuned for GMA with an update from Dave dark and early at 500am…Rob