KATC StormTeam 3 Weather BLOG

A strengthening low pressure system in the western Gulf of Mexico this evening will advance northeastward Saturday and head toward the Florida Panhandle Saturday afternoon.  Breezy conditions with period of rain will be likely through Saturday afternoon with activity likely to taper off Saturday night.  Rough conditions offshore have been reported this afternoon with sustained winds as high as 35-40kts with gusts to near 60kts.  Additional strong storms that develop this evening and tomorrow will insure that very rough conditions will continue through Saturday.  Meanwhile inland most of the precipitation will stay as rain with general accumulations through Saturday evening in the 1-2″ range but isolated amounts to 3″ will be possible for St Mary Parish.  Heavier rains and the slight risk of severe weather with this system may clip extreme Southeastern Louisiana and head toward the Florida Panhandle.  Most of the rain generated in Acadiana through Saturday will be driven by the upper level low that is guiding this system.  The upper low won’t clear the area until Sunday morning.  So after the rains end there will likely be lingering drizzle/mist and perhaps some fog into Saturday night.  Lingering cloud cover Sunday morning should yield to partial clearing and some sun Sunday afternoon.  Temperatures will stay in the upper 40s to lower 50s through Saturday evening dropping into the low-mid 40s for Sunday morning.  Milder conditions are possible for Sunday afternoon with highs in the upper 50s to near 60.  Spring-like conditions with mostly sunny skies are anticipated for Monday and Tuesday of next week with highs pushing into the mid-upper 60s.  The next weather-maker will arrive for next Wednesday likely producing a round of thunderstorms.  Even warmer temperatures should follow late next week into the weekend with highs pushing into the low-mid 70s!  Another round of even healthier (possibly severe)  storms may follow for next Sunday.  As we start to see the warmer temperatures ahead of frontal troughs over the next few weeks the risk of severe weather will increase with each system.  Normally our spring severe weather season begins in the latter part of February, but given this El Nino winter pattern it is not unusual to have more frequent severe weather events starting as early as late January.  At least for this weekend it will just be a rain event.  Have a great weekend and Geaux Saints!  Rob

After the devastating earthquake in Haiti this week, some are asking about the potential for a tsunami heading toward the United States including the Gulf Coast.  Of course, here in Acadiana we are too familiar with storm surge flooding due to hurricanes.  The majority of us living in Cameron, Vermilion, Iberia, and St. Mary parishes are familiar now with the elevation of our homes.   A difference of just a foot or two of storm surge can mean the difference between no damage and total loss.  Storm surge is much easier to predict than the height of a tsunami.  First, there is no storm surge unless we have a tropical system.  Tropical systems are watched on satellite and radar for days or weeks prior to the threat of surge.  More than 90% of tropical systems in the Atlantic Basin occur between June 1st and November 30th, hurricane season.  Also, we have a considerable amount of data from past tropical systems and how their track, speed, and strength have impacted our area.

Tsunamis on the other hand are generated by earthquakes, volcanoes, or massive landslides.  These are generally unpredictable events.  Sure, we can determine if a volcano is getting more active, and we have sensing equipment across the globe to monitor earthquake activity, but the actual time and location of the next event is a mystery.  Areas of the globe that are more prone to seismic activity have preparations in place as we do for hurricanes.  In developed countries such as the United States and Japan, major earthquakes of 6.0 or higher have occurred, but because of building codes, and preparation by locals, damage and injuries can be held down.  Unfortunately, many of the worlds’ countries that are in seismic zones are poor, such as Haiti.  Countries impacted by the 2004 Sumatra earthquake and tsunami were also poor and undeveloped.  Although China isn’t considered to be a third world country, the earthquake in the Sichuan Province in 2008 killed more than 70,000 people.  Much of it due to the proximity of the earthquake to populated areas, poor construction of buildings, and the infrastructure collapse preventing search and aid workers to get into the mountainous region.

So after the Haitian earthquake Tuesday, one of the first things I looked up was the U.S. Geological Survey or USGS.  Their website monitors earthquake activity across the country and the world.  They are also linked to the Tsunami Warning Center in Hawaii that watches deep water gauges around the world.  The Tsunami Warning Center is responsible for issuing statements, watches, and warnings for potential tsunamis following seismic events.  A Local Tsunami Watch was posted for some time across islands of the Caribbean.  One sensor in the Dominican Republic measured a 12cm (0.4 ft) wave, and another sensor in the central Caribbean measured a 1cm (0.03 ft) wave.  After those reports, the watch was dropped.

The Caribbean, especially an area from eastern Cuba through Jamaica, Haiti, the Dominican Republic, Puerto Rico, the Virgin Islands, down the chain of the Leeward and Windward Islands are seismically active.  Also the northern coast of South America and much of Central America experience earthquakes frequently.  Since these areas are fairly close to us and the Caribbean Sea is connected to the Gulf of Mexico, is there a significant threat to Louisiana for a tsunami?  The answer is “No”.  Although, as we like to say in the news biz, “It could happen anytime!”, the likelihood of a tsunami event is very, I mean VERY small. 

According to a publication prepared by the USGS and NOAA for the National Tsunami Hazard Mitigation Program, there have been no recorded tsunamis impacting Louisiana in the last 300 years.  In fact, out of over 2600 tsunami events recorded for the United States and its territories, only 3% of those events occurred outside of the Pacific Basin!  Of that 3%, only 1 event produced a recordable tsunami along the Gulf Coast.  It occurred in Texas after a 7.5 magnitude earthquake centered between the Dominican Republic and Puerto Rico in October of 1918.  This quake was centered about 300 miles east of this week’s quake in Haiti.  The height was less than 1 cm.  Compare that with storm surges of Rita (457cm or 15 Feet) or Ike (518cm or 17 Feet).  The Atlantic coast has a hand full of events, but almost all of those were generated by local quakes, not Caribbean quakes.  There are no reported deaths from a tsunami along the Atlantic or Gulf Coasts. 

Earthquakes can occur within the Gulf of Mexico.  Only quakes measuring 7.0 or higher in the Gulf can prompt a tsunami watch.  The quake would probably have to be 8.0 or higher for a Gulf-Wide tsunami.  A local earthquake or an asteroid impact in the Gulf could also generate a tsunami.  Areas east of the Rocky Mountains are more likely to experience a major earthquake thanks to many fault lines such as the New Madrid Fault that stretches from St. Louis to Memphis.  Some of most powerful earthquakes in U.S. history have occurred there.  Some larger than most California quakes.  Three of those quakes occurred in 1811 and 1812 and are believed to be in the 8.0-8.5 range.  Scientists believe there is a 10% chance for a similar quake (7.0 or stronger) to strike along that fault line in the next 50 years, and up to a 40% chance for a quake 6.0 or higher to strike.  There have been at least three magnitude 6.0 or higher quakes in the New Madrid Zone, and six magnitude 5.0 or higher in the past 100 years.  The most recent was a 5.4 in April of 2008!  The New Madrid Fault Zone produces about 150-200 quakes a year, most too small to feel.

Like the Haitian quake this week, historical tsunamis in the Caribbean have been localized.  Deaths have occurred from tsunamis in Haiti, Jamaica, Cuba, Dominican Republic, and Puerto Rico and the Virgin Islands.  The quakes occurred near these areas, and the tsunamis were produced within seconds or minutes.  There was simply no time to escape the waves and even less time to warn people of the danger.

StormTeam3 Meteorologist Dave Baker

Good Morning Acadiana-Weekdays 5-7am

weather@katctv.com

After nine straight mornings with sub-freezing temperatures in Acadiana a moderating temperature trend is expected while a storm system begins to develop in the Gulf tomorrow and Friday.  High and mid-level clouds should keep our temperatures in the upper 30s to lower 40s tonight with highs Thursday approaching the lower 60s under mostly cloudy skies.  An upper level disturbance in Texas is helping to induce the cloudiness this evening and will continue to do so Thursday.  Underneath these mid-level clouds there will be the possibility of a few sprinkles Thursday afternoon and evening but our best rain chances will likely hold-off until Friday night and Saturday as a stronger disturbace in the SW US helps to deepen surface low pressure in the Gulf.  The track of this storm system will put the low south of the Louisiana coast by Saturday morning trekking toward the northeastern Gulf Sunday.  This path should keep the heavier showers and storms well offshore or to the east of us with mostly light to moderate rain in-store for Acadiana.  Expect lots is clouds and breezy easterly winds on Friday with increasing rain chances developing late in the day or into the evening.  Periods of rain are a good bet  for Saturday.  Rain totals should be no higher than 1-2″ other than in St Mary Parish where isolated higher amounts will be possible.  Portions of Southeastern Louisiana could see a fair bit more depending on the track of the storm and its associated precipitation field.  So expect on and off rain with lots of clouds and maybe some fog Saturday (while your watching the Saints game!) with clearing conditions likely for Sunday.  It should be partly sunny and milder early next week with highs pushing into the mid-60s.  The next storm system will likely present a good chance of healthier thunderstorms Wednesday with the following weather system bringing the threat of stormy weather back to the area for following weekend.

Warmer temperatures are with us this morning as light southerly winds continue ahead of a weak cold front moving across the area.  Most of the region except the extreme northern part of Acadiana is actually at or just above the freezing point!  Tiny amounts of moisture that are available have produced a bit of ground fog here and there with visibilities dropping to about a mile for a period of time, but conditions will improve rapidly as the front moves through.  Sunshine, with light winds and dry air will warm temps into the low 50s today and mid 50s tomorrow.  A light freeze is planned for tonight as lows will drop to 28-29 over northern Acadiana, 30-31 along I-10, and 32-33 closer to the coast.

Farther down the road a vigorous storm system will develop to our southwest.  A deep trough in the upper levels will develop over the western states and move east across Texas.  At the surface, a low pressure area will generate over the lower tip of Texas and progress East-Northeastward across the Gulf of Mexico.  Right now it appears the surface feature will remain over the waters, but the upper level part of this system will drift across central Louisiana.  Expect cloud cover to develop Thursday, with rain developing Thursday night.  Good rain chances for Friday, Friday night, and Saturday are expected with 1-2 inches of rain possible over the area.  Heavier amounts will be over the Gulf, with the chances for severe weather offshore.  Small hail may be possible in thunderstorms in the coastal parishes late Friday as the colder upper level part of the system moves through.  Most rain should end by Saturday afternoon.  Clouds will remain for most of the day Sunday, and sunshine will return for Monday.  Temperatures over the weekend will be in the 50s for highs and 40s for lows, with more normal conditions early next week with highs back in the 60s.

After seven sub-freezing mornings a slow moderating temperature trend will continue this week not before a couple of more light-moderate freezes tonight and for Tuesday night.  High pressure will continue to dominate through Wednesday allowing for mostly sunny and seasonably cool temperatures Tuesday and Wednesday.  Another hefty storm will be developing in the western Gulf of Mexico Thursday into Friday resulting in a good soaking for Acadiana late Friday, Friday night into early Saturday.  This storm will likely generate strong to severe storms in the Gulf along with the possibility of gale conditions.  Although there may be some embedded storms with the rain for Acadiana at this point it appears that the severe weather threat will stay offshore.  With that being said however, the upper low driving this system will be quite cold so there may be the threat of embedded hail with some convective rain cells Friday night into Saturday.  Although it is early in the “pre-game” for the system later this week but 2-3″ of rain is the preliminary call for rain totals between Friday and Saturday.  Good news is that milder conditions will likely follow this system into early next week, but the bad news is that a pattern with an active sub-tropical jet stream more typical of an “El Nino” will likely resume later this month…setting the stage for more wetness and shots at severe weather into February.

As expected arctic air will stay entrenched across the region through the weekend with lows for Saturday and Sunday morning in the upper teens to lower 20s.  Wind chills will again be in the 8-14 degree range Saturday morning but winds will be less of an issue for Saturday night into Sunday morning.  Sunny skies will make it feel a little better this weekend with highs in the upper 30s Saturday and mid-40s Sunday.  One more hard freeze is in the offing for Monday morning then a gradual moderating trend is expected through the middle part of next week.  It looks to get on the wet and stormy side later next week as the long range models have been consistent in indicating a whopper of a storm in the Gulf for the 15th.  So next week we will say goodbye to the arctic air and say hello again to an active weather pattern.

No major changes to the ongoing forecast other than the amount of cloud cover that we are going to see tomorrow.  After some brief clear tonight high clouds will invade with an upper trough approaching from the northwest.  These high clouds will not only be thick enough to dull the sun, but may take any meager solar heating away from us Friday.  Therefore there is a chance that temperatures may not got much above freezing tomorrow…and if so it will only be a few degrees.  So there is the possibility that instead of staying below freezing for 12-15 hours we could see sub-freezing temperatures for more than 36 hours straight.  This will certainly lead to pipe-busting issues for some folks who aren’t properly prepared for this arctic outbreak.  You may recall the arctic outbreak just before Christmas 1989…temperatures during this outbreak stayed below freezing for more than 72 hours with lows on successive nights at 15, 9 and 11 degrees (22nd-24th).  We shouldn’t be that cold with this outbreak but some records will be threatened, especially Saturday morning.  The record for tomorrow morning is 21 in 1942 (should be safe), 21 in 1962 for Saturday (in jeopardy) and14 for Sunday (should be safe).  Stay with KATC and katc.com for the latest on the big chill.

Acadiana is still on track for the the coldest weather since early February 1996 with relatively mild temperatures and some patchy rain early Thursday yielding to drier air and plummeting readings tomorrow evening.  There should be no local travel problems Thursday as any residual moisture from the early rains will dry up and evaporate well before the colder temperatures arrive.  This arctic outbreak will likely keep our temperatures near or below freezing for most of Friday, Saturday and Sunday with just a few hours each day with temperatures above the freezing zone.  Highs Friday will be confined to the mid-upper 30s with limited sun by high clouds.  Saturday we’ll be no warmer than the mid-30s under full sun while sunshine continues for Sunday with only a modest warm-up into the low-mid 40s.  Overnight lows will be in the bitter upper teens to lower 20s Friday night and Saturday night with some nasty wind chills mixed in Thuursday and Friday nights.  Wind chills Friday morning will be in the upper teens while Saturday morning chills could be as low as the lower teens or even single digits.  There are no indications that there will be any travel problems associated with any precipitation with this arctic outbreak as any moisture on the ground will be evaporating with the wind and very dry air.  With that being said, roadways over water Saturday night into Sunday morning could accrete some ice if some “arctic sea smoke” develops…especially over the Atchafalaya Basin.  Arctic Sea Smoke is a condensation fog that develops over relatively warmer water when the air is very cold and still.  This is famous weather triple misnomer as in our case develops in Louisiana (not in the arctic), it’s not on the sea (in the swamp) and it’s not smoke-it’s a condensation cloud/fog.  It will likely make for some very interesting images come Sunday morning with light winds and daybreak temperatures in the teens…photo buffs this is your calling!  But dress warmly and be careful.

After a freezing and frosty Wednesday morning we’ll see a nice warm-up for Wednesday afternoon as mostly sunny skies works in concert with a developing southeasterly wind.  High and some mid-clouds will begin to invade late Wednesday with clouds thickening Wednesday night keeping our temperatures in the lower 40s.  A vigorous storm system in the Northern Rockies will race southeastward through the next 24 hours allowing for patchy light rain to develop for Thursday morning.  It appears that there will be little or no threat of any kind of wintry weather with this system as the precipitation should initiate below the freezing layer aloft.  The rain should be light in nature but more moderate rainfall rates may be possible through Thursday mid-morning.  The rain will depart the area well before the arctic air begins to settle in but do expect windy and much colder conditions to return for late Thursday night into Friday morning.  Temperatures should drop into the low-mid 20s for Friday morning while wind chills will likely drop into the teens.  Arctic air-masses are like molasses when the spill into the region and it appears that the coldest air will arrive Friday night into Saturday.  This should put our lows Friday night/Saturday morning near 20 (plus or minus a few degrees) with wind chills likely in the lower teens or single digits for Saturday morning.  It will likely be even colder Saturday night/Sunday morning without any wind with lows likely to approach the mid-upper teens.  Daytime highs will stay in the 30s both Friday and Saturday and if high clouds linger on Friday we may not make it much above freezing Friday afternoon.  This could become quite problematic for frozen pipe issues as we will likely see a 72 hour period where only a few hours will be above freezing.  The good news is that the long range outlook calls for much milder weather the second into the third week of the month…hopefully this will be the coldest weather we see all winter!

Well it looks like we’ll see cold weather similar to the 1996 freeze where we hit the teens three morning in a row.  As cold Canadian air moves southward Thursday, our temperatures will plummet to near 20 by Friday morning.  There will be rain late Wednesday night through the afternoon hours Thursday.  There is a hint that the rain may change over to snow for a short time.  Right now it looks like any snowfall will be light, and occurring while the surface temperature is still just above freezing.  As the temperature drops below 32, all precip will have ended.  The air mass is very cold and dry, so I’m expecting the roadways to dry up well before moisture would have a chance to freeze on the roads.  There may be a few isolated slick spots, but not expecting much.  We’ll be keeping a close watch for any changes. 

I talked briefly yesterday here in the blog about past cold spells in Acadiana.  I had a few graphics detailing the freezes on Good Morning Acadiana early Tuesday.  Here is some of the information in graphical form for your viewing pleasure.

Here are the computer model forecast lows for Friday, Saturday, and Sunday mornings.

Protect the plants, pipes, and pets.  Get prepared today and tomorrow because Thursday will be quite wet!

StormTeam3 Meteorologist Dave Baker

Good Morning Acadiana-Weekdays 5-7am

weather@katctv.com