KATC StormTeam 3 Weather BLOG

Received this press release for NWS Cooperative Observing program.  For more information contact our local National Weather Service at 337-477-5285.  Rob

CoCoRaHS Press Release – March 2010:

CoCoRaHS — National Precipitation Monitoring Network Urgently Needs additional Volunteers to Measure Precipitation in Their Own Backyards!

FORT COLLINS – Ever wonder how much rain fell out of the storm that just passed overhead? Did your mother-in-law on the other side of town get just as wet? Why is the airport so much drier than my house? Wonder no longer. Now, in your very neighborhood, volunteers of all ages and backgrounds are measuring precipitation in their own backyards as part of CoCoRaHS – the Community Collaborative Rain, Hail and Snow Network which as grown to over 15,000 volunteer observers covering every state of the country. More volunteers are urgently needed! It’s fun, easy and only takes five minutes a day.

“We are pleased that this simple backyard monitoring program has become so popular,” said Nolan Doesken, the Colorado State Climatologist at the Colorado Climate Center in Fort Collins, Colorado. “These volunteers are providing scientists around the country with excellent precipitation and hail monitoring statistics for tracking weather patterns and water supplies.”

The CoCoRaHS network engages volunteers of all ages from grade schoolers on up to folks in their 90’s to document the size, intensity, duration and patterns of precipitation by taking simple measurements in their own backyards. Volunteers only need a cylindrical rain gauge, some training and an interest in weather to participate in the program. The specific rain gauges that CoCoRaHS uses are available from several distributors on the network’s website (www.cocorahs.org) for $25 plus shipping. The site also offers on-line training.

Data from CoCoRaHS volunteers are now being routinely viewed and used by many professions and organizations including the National Weather Service, meteorologists, hydrologists, emergency managers, city utilities, insurance adjusters, agribusinesses, engineers, science teachers and many more. Data are used for many applications such as water resource planning, severe storm warnings, teaching earth science, predicting crop yields and for assessing hail damage.
During the month of March 2010, CoCoRaHS is running it’s friendly annual competition among states –”CoCoRaHS March Madness” to see how many new observers can be recruited in each state. If you have a relative, friend or neighbor who is interested in weather, this is a great time to have them become part of the program.

For more information or to volunteer for the CoCoRaHS network, go to http://www.cocorahs.org/. Don’t hesitate in signing-up, you’ll be glad you became part of this important project that is benefiting many across
the nation.

So far, the stable marine layer courtesy of cool shelf waters in the Gulf of Mexico has kept nasty thunderstorm activity at bay across Acadiana throwing a wet blanket on the impressive storm dynamics surrounding us.  It looks like the threat of severe weather should stay to the north or develop to the east of Acadiana this evening, but we’ll keep an eye on things just in case.  A Dense Fog Advisory is in effect once again for the coastal parishes with sea fog possibly an issue farther inland toward daybreak.  After some morning fog Thursday a return to partly to mostly sunny skies is expected for our Thursday.  Temperatures should be as warm as they have been all year long!  Look for highs on Thursday to top out in the mid-upper 70s and if we get past 78, it will be the warmest day of the year!  The same upper level storm system that has brought severe weather to portions of the south Wednesday will usher in cooler air Friday into the weekend.  It  should stay fair to partly cloudy through this weekend with temperatures closer to the upper 60s for highs and mid-upper 40s for lows.  It looks dry through Monday but showers could return to the area for mid-next week.

An active and very strong jet stream will usher another disturbance into the Southern Plains Wednesday allowing for some strong to possibly severe storms from Eastern Texas on northeastward during the afternoon and evening hours.  This system will be most intense primarily in the Arklatex Region but a few hefty storms could get going a little closer to home in Acadiana.  The Storm Prediction Center has most of our area hatched in for a slight risk of severe storms for Wednesday afternoon and evening but where storms initiate will be the question.  Activity for Acadiana should be scattered and not widespread, but because of very strong wind dynamics aloft with a 170mph-200mph jet stream and veering winds with height (clockwise from surface to aloft) any storms that do get going will be capable of producing hail, damaging winds and possibly an isolated tornado.  The risk of this event will increase farther to the north and east of Acadiana, but extra “weather-vigilance” will be the mainstay through tomorrow evening just in case so check with us on air and at katc.com for the latest.  In between, tonight through tomorrow morning, expect mild conditions with areas of fog developing, especially offshore and along the coastal parishes where a Dense Fog Advisory is currently in effect.  After some morning fog, expect partly sunny and warmer conditions with highs pushing into the lower 70s for our Wednesday.  Scattered showers and storms should begin to fire-up across Eastern Texas and/or the Upper Texas Coast early tomorrow afternoon and will rapidly advance east-northeastward during the afternoon and evening.  More stable conditions will move back into Acadiana late Wednesday night with some fog again a possibility by Thursday morning.  Mostly sunny, breezy and warm conditions are anticipated for Thursday with likely the warmest temperatures of the year!  Mid-70s are expected Thursday but a gradual cooling trend is expected into the weekend.  Right now it looks dry through early next week but temperatures will likely stay below normal (50 & 70) Friday through at least next Thursday.

The upper level pattern will be more progressive for the early part of the week bringing a chance for some rain, and eventually some thunderstorms by midweek.  This morning we’ve seen the clouds increasing, but as of late Monday morning, the rains have picked up as well.  A disturbance moving across the area has picked up a bit more moisture than earlier expected, so the coverage of the rain has increased earlier in the day.  Rain chances have been increased to 50% for today and they’ll remain at 60% or better for tonight.

The series of upper level disturbances will continue to parade across the area Tuesday and Wednesday.  It looks like we’ll be between systems during the day tomorrow and rains will pick up again late Tuesday into Wednesday.  A line of storms will develop ahead of the final push of energy Wednesday afternoon and with the jet stream getting very active at the same time, some of those storms could produce damaging winds and/or hail Wednesday afternoon and evening.  Things will quiet down for Thursday and Friday with partly cloudy skies and mild temperatures.  Saturday and Sunday should remain dry, but temperatures will fall back into the 60s during the day with overnight lows in the 40s.

StormTeam3 Meteorologist Dave Baker

Good Morning Acadiana-Weekdays 5-7am

weather@katctv.com

A benign weather pattern will stay with Acadiana for the rest of the week with milder (finally) more seasonable temperatures this weekend.  Chilly conditions will continue during the night time hours with frosty conditions quite possible for Thursday morning.  Highs Thursday will push the upper 50s to lower 60s under wall to wall sunshine.  Sunny conditions and slightly milder temperatures are in the offing Friday after another chilly start in the upper 30s.  This weekend should be fair to partly cloudy with some increased high level, cirrus cloudiness.  Temperatures Saturday should be well into the mid 60s and upper 60s to lower 70s possible for Sunday.  But with a relatively quite pattern and milder temperatures, some late night/early morning fog may be possible this weekend.  The next weather-maker will approach the area Monday.  Long range models are split on the outcome across Acadiana with one camp advertising storms and a dry frontal passage by Monday night with the other stalling the frontal boundary and maintaining some rain chances Tuesday and Wednesday.  For now I’m going with a good chance of storms by late Monday (with perhaps a severe weather element possible) followed by drier but still mild weather into mid-week.  Perhaps we have turned the corner on winter and putting the cold temperatures behind us…let’s hope winter stays in the rear-view mirror!

Your thinking is right!  The winter of 2009-10 had a number of events.  From the earliest measurable snowfall on record in December, to the deep freeze in early January, and the 6th coldest February on record with another measurable snow.  The El Nino pattern was in full swing this winter as system after system rolled up the Texas coast with plenty of rain, clouds, and too many dreary gray days to count.  Even though it is now March, we still can’t seem to shake the cold, or the rain.  I, like many others are anxious for Spring to get here!

Let’s start with temperatures.  Overall the winter was colder than average.  When you take the 90 days of climatological winter (December, January, February), the average temperature is about 53.8 degrees.  This number comes from averaging all of the normal highs and lows for those months.  This winter we finished at 49.0 degrees.  Almost 4 degrees below normal, which is pretty significant for a three month average.  In south Louisiana we don’t have any average highs that are below 60 degrees, but this year we failed to reach a 60 degree high  52 times!  In fact only 26 of the 90 days did we have an above average temperature day!  We dropped below the freezing mark 17 times this winter, compared to only 7 times last winter.  We had almost as many days below freezing this winter as we’ve had for the past three!  There weren’t any breaks this year either.  We’ll go warm, then cold, then warm again in a normal winter.  When I’m talking about breaks, I mean a day where it hits 70 or higher.  Over the past 10 years, we’ve hit 70 degrees about 33 times on average.  This year, only 17.  80 degrees?  Forget about it…last winter we hit 80 once, this year..0!  By the way, February 2010 was tied for the 6th coldest February on record.  Only 2 days were at or above average.  The average temperature was 47.4 degrees, normal is 54.3.  We had 6 days in January where we dropped into the 20s.  The lowest temp of the winter…20 degrees on January 10th, sandwiched in between a pair of 21s on the 9th and the 11th.  And you wonder why everything is brown outside!

Snow…Twice this winter.  December 4th and February 12th.  We’ve had two snows in one winter before, but never three.  I was really hoping to break that record last week, but the snow never came.  December 4th we picked up 0.5″ of snow, and on February 12th we picked up 0.4″.

Rain…Above normal for the winter.  A total of 18.62″, or a little over 3″ above.  We had over 10″ of rain in December, almost 6″ in February.  We caught a break in January with only 2.02″.  Probably because the first 10 days of January were so cold that the air couldn’t hold any moisture!

March is coming in like a lion with the rain, and eventually this afternoon the wind.  It should be cloudy tomorrow, with sunshine returning Wednesday and holding for the rest of the week.  Temperatures aren’t expected to climb to normal until late this weekend when we might hit 70 on Sunday.

StormTeam3 Meteorologist Dave Baker

Good Morning Acadiana-Weekdays 5-7am

weather@katctv.com

Another vigorous storm system will advance toward Acadiana Friday bring clouds and rain.  Look for clouds to increase through the morning hours with rain developing from noon onward.  This system has a very cold upper level core making conditions aloft quite unstable.  Therefore embedded thunder may be possible tomorrow afternoon with even the possibility of some small hail or soft hail (also known as graupel…see the link for a definition) through tomorrow evening.  Our in-house models are showing anywhere from 1/2 to one inch of rain will be likely area-wide with isolated amoounts up to 1.5-2 inches possible if convection (thunder) gets going.  For a meteorologist this is and interesting system…for most of us it’s just plain wet and sloppy.  While this will be just a wet weather system for Acadiana, I wouldn’t be surprised if some snow flurries follow this system as near as southwestern Mississippi into interior portions of Alabama.  Lingering rain showers and drizzle will be likely through much of Friday night but conditions will likely begin to dry toward daybreak Saturday.  Any lingering cloud cover early Saturday will likely burn off by the afternoon or sooner so at least expect a mostly sunny and cool weekend.  Highs will top out Saturday in the low-mid 50s, drop into the mid-30s for Sunday morning, and rise into the upper 50s to near 60 for Sunday afternoon.  Another quick-moving weather system will arrive Monday bringing another shot of chilly rain, and perhaps soaking rains, to Acadiana.  The Monday system will likely turn into another Southeast and Mid-Atlantic snowstorm…no rest of the winter-weary!  At least for Acadiana, milder tempartures will return for later next week.

Snowfall this time around just wasnt’ in the cards.  Predicting that snow will fall is always a tough call.  Predicting when the snow will begin and end is even tougher, and predicting how much snow will fall is one of the most difficult tasks we have here in the WeatherLab.  There are some basic forecasting numbers that we look at that will highlight the possibility of snowfall.  I’ve charted these, and the past three snowfalls with the numbers at those times.  I’ve also included the averages from the previous three model runs that we had to look at prior to the predicted snowfall, and finally the actual observations that show why it didn’t snow.  Honestly, I was bummed that it didn’t snow.  Not because the forecast was wrong, but because the child like excitement had become overwhelming and visions of big fat snowflakes were dancing in my head!

First the explanation of the numbers:

1. Surface Temperature is the temperature right here on the ground.  Less than 37 is best.

2. Freezing Level.  As you go up, this is the height where the temp goes below 32 degrees.

3. Temperature at 850mb.  Pressure drops as you go up.  When you reach a pressure of 850mb, the temp must be below freezing.

4. Temperature at 700mb.  Same concept, just a bit higher up.  Temp needs to be at or below -2 degrees Celsius.

5. Thickness.  This is the distance in meters between a pressure of 1000mb to 500mb, or from just above the surface to about 18000 feet.

6. Below Freezing from the freezing level to 700mb.  Temp must be below 0 degrees Celsius at those heights.

7. Surface Moisture.  Is there moisture in the lowest levels?  Take the temperature and the dewpoint in degrees Celsius.  If the values differ by less than 5 degrees, then the air is moist enough to prevent precip from evaporating.

8. Precipitable Water: Amount of water vapor in the column of air.  The higher the number, the more water available.  This can determine how much precip is received over an area.

Click the image for a larger view.  Notice in the previous three snowfalls, all of the values were there.  In the model data for the prediction, all of the numbers were there, but the surface temperature was on the border line.  Of course after all of the analysis, and looking at the actual numbers that were in place this morning, the temperature, freezing level, and most importantly the Precipitable Water were outside of the guidance.  It was too warm here on the ground, there was too much warm air at the bottom of the atmosphere, and since the moisture dried up, there was no water to make the snow.  It has been a strange winter already…will we get another chance to use this chart??  Stay Tuned.

StormTeam3 Meteorologist Dave Baker

Good Morning Acadiana-Weekdays 5-7am

weather@katctv.com

It looks pretty certain now that another measurable snowfall will occur in Acadiana.  Winter Weather Advisories are posted for most of Acadiana starting this evening and lasting overnight.  Cloudy skies will remain in place today keeping our temperatures at 50 or lower for highs today.  Rain will start later this afternoon and should cover most of Acadiana by the end of the afternoon commute.  The cold rain will change over to snow over Central Louisiana and northern parts of Acadiana during the evening hours, then change over to snow for the I-10 corridor before midnight.  Snow may mix in with rain over southern sections of Acadiana prior to sunrise Wednesday.  The winter weather advisory will cover Allen, Evangeline, St. Landry, Jeff Davis, Acadia, Lafayette, and St. Martin.

Accumulations will be possible mainly on rooftops, cars, and grassy surfaces.  Areas where heavy snowfall occurs may see some slushy accumulation on roadways, especially elevated surfaces.  Most of the area will remain above the freezing point overnight with the exception of the extreme northern parts of Allen, Evangeline, and St. Landry parishes and areas of central Louisiana, where the temperature may drop to 31 or 32 for about a 3 hour period around sunrise.  Those areas may experience some brief freezing of bridges and overpasses.  Otherwise roadways and bridges should remain wet, but not frozen.

As far as accumulations, expect up to 2″ of snowfall to pile up north of US 190.  Up to 1″ of accumulation may occur in areas between I-10 and US 190.  Areas south of I-10 will see less than 1 inch of accumulation, and the region not included in the winter weather advisory will see some snow mixed with rain, but little or no accumulation is expected.

Most of the rain and/or snow will diminish during the mid morning hours.  Sunshine should return by midday and temperatures will climb into the lower 50s for highs.  Below normal temperatures are expected to continue through the week and the weekend.

StormTeam3 Meteorologist Dave Baker

Good Morning Acadiana-Weekdays 5-7am

weather@katctv.com

After a nice break this weekend with temperatures around 70 degrees, it looks like we’ll be back to below normal temperatures for the remainder of this week.  Our cold front last night brought a round of showers and thunderstorms, with some heavy rainfall totals over northern St. Landry and Evangeline parishes, and severe weather was reported in St. Mary Parish with large, damaging hail seen in Franklin!  Another winter storm will be moving across the south bringing a round of cold rain Tuesday night, with a few flurries mixed in toward the end of the event.

Today we should remain cloudy for the most part, although a few welcome peaks of sunshine might get through.  Temperatures will hold in the upper 50s most of the day with the 63 degree high temperature already hit earlier this morning.  Clouds should remain in place overnight as lows will drop back into the lower 40s.  Tuesday will remain cloudy with a slight chance for rain developing late in the afternoon.  Cold rains becoming likely Tuesday night as the winter storm approaches.

This next winter storm will dump heavy, wet snow across northern and central Texas.  Probably not as much snow as the previous system dumped last week, but snows will be falling in roughly the same areas.  Expect mostly a cold rain here in Acadiana.  As the system moves eastward, most of the snow area will erode as it moves toward Louisiana, but some models are pointing at a rain/snow mix around midnight Tuesday/Wednesday across the northern suburbs of Houston, eventually changing to all snow for about an hour or two.  Some of that may move across central Louisiana, and northern parts of Acadiana, but the duration of the snowfall will be much shorter..say, less than an hour.  So I’ve mentioned a brief rain/snow mix right at the tail end of this storm, then all precip will end early Wednesday morning.  No accumulations are expected this time.  Temperatures will remain below normal for the rest of the week and the weekend.  Highs will only reach the mid 50s with lows in the 30s.  Right now it looks like we’ll stay above freezing for the next 7 days.  Hard to believe that it will be March in only a week, and we’re still experiencing temperatures colder than January standards.  Normal highs and lows this week are about 68 and 48, but we’ll be lucky to hit 60 by the weekend!

StormTeam3 Meteorologist Dave Baker

Good Morning Acadiana-Weekdays 5-7am

weather@katctv.com