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.
Archive for February, 2010
Wet Friday…Cool and Dry Weekend
No Snow This Time
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
Winter Weather Advisory
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
Back To Winter
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
Pleasant Weekend Start…Could be a Stormy Finish
Nice and seasonably mild will be the highlight of our weekend but increasing clouds and the threat of showers and storms will finish off our Sunday. Saturday should be very similar to our Friday with more “in and out” mid- and high level cloud cover. Highs will be in the mid-upper 60s Saturday and should approach 70 for Sunday. There will be the possibility of some fog again by Sunday morning with mostly cloudy skies likely to dominate for the day. A frontal trough will approach late Sunday possibly sparking off a round of scattered showers and a few thunderstorms. The Storm Prediction Center does have Acadiana hatched in for the slight risk of severe storms that may be capable of producing damaging winds and/or hail. Meteorologist Chris Paulsen will have the latest this weekend. Meanwhile, another “interesting” storm system is shaping up for next the Tuesday and Wednesday time-frame with cold arctic air oozing to the south as another quick moving storm system moves in. For most of Acadiana expect another round of cold rains, but farther to the north, significant accumulating snow/mix will be possible across the northern part of the state especially across the I-20 corridor. This system may finish off with a brief flurry especially in northern portions of Acadiana very early Wednesday morning. We are very early in the game to be forecasting much of anything with any accuracy at this time but it should be another interesting week for many southern states again!
Milder Ahead!
Those of you that have been looking for milder temperatures the forecast for the rest of the week into this weekend is just for you! High pressure will begin to shift eastward Thursday gradually allowing for a return flow from the Gulf of Mexico. Temperatures will slowly moderate through Friday…remember the near shore shelf waters of the Gulf of Mexico are in the low-mid 50s so this will help moderate our lows, but will cap our highs, especially closer to the coast with light southerly winds. Mostly sunny skies with some high cirrus clouds are anticipated for our Thursday while a weak disturbance mainly to the south of us will engender more clouds for Friday with a few sprinkles possible, especially closer to the coast. Chance of measurable rain (enough to wet the ground) will be in the 10% range Friday. Highs Friday should reach in the lower 60s with a deeper draw of air from the southern Gulf pushing our temperatures into the upper 60s Saturday under partly sunny skies. Even warmer temperatures are anticipated for Sunday ahead of a cool front that should generate showers and storms by Sunday night. Highs Sunday should top out in the lower 70s. There may be a slight risk of severe storms Sunday evening/night and will update accordingly as we get closer to the event. Slightly cooler weather is expected behind the next front with the next wet weather-maker arriving around next Wednesday. The bottom line though as we segue to milder spring conditions over the next 4-8 weeks is that storm systems will provide for increasing threats for thunderstorms and more than likely a few rounds of severe weather…so each time a front approaches we’ll have to keep an extra eye on the severe weather potential.
Mardi Chill
Our unseasonably cold weather will continue for another 72 hours with a warm-up back to seasonably mild temperatures later this week and into the weekend. Last night’s cold front has reinforced the chill in the air with temperatures dropping nicely through the 40s and the upper 30s this evening. Factor in the wind, wind chills will be about 5 degrees colder so bundle up if you’re heading out for any of the festivities tonight. After a frosty start our Mardi Gras will be sunny and quite cool with temperatures topping out in the lower 50s for the last parades of the day. It appears that Wednesday and Thursday mornings will be frosty but we’ll be able to move the plants back outdoors for Thursday afternoon as highs reach back into the lower 60s. Look for lots of sunshine through Friday but as the weekend approaches weakening fronts and a zonal west to east flow aloft may allow for more clouds and a few showers Saturday with better rain chances possible for next Monday. The bottom line: near term-cold but later in the week a little more spring-like with highs in the 60s through the weekend and perhaps into early next week…we are not quite done iwth winter yet, but at least we’re heading in the right direction for the weekend!
Snow Twice in One Year! Snow Dat!!!
After back to back years with observed snowfall in Acadiana we have gone one better with two snowfalls in one winter. Based on the official records kept in Lafayette this has not occurred since records have been kept going back to 1893. Guess this is what happens when the Saints win the Super Bowl! As expected, the rain briefly turned over to all snow (snow showers) for a few hours this morning leaving a light dusting for most and more to the north. Snowfall totals ranged from a dusting to a half inch along the I-10 parishes to up to 1 inch along the northern Acadiana parishes. Roughly 2-3″ fell across Central Louisiana. So much for “global warming/warning”…or as I prefer to say “climate change”…but that’s the subject of another, more extensive blog entry! For the Mardi Gras weekend expect windy and cold conditions tonight, sunny and a little milder tomorrow with highs in the lower 50s…which is still better than 10 degrees below normal. Fair and chilly conditions are anticipated for Saturday night with mostly sunny and milder conditions expected for Valentine’s Sunday. Highs Sunday will be near 60 but a strong cold front will bang through Sunday night leaving us with a very cold Lundi and Mard Gras. Milder weather is expected finally for later next week. Have a great and safe weekend!
Miserable Winter Rain For Most Of Us!
Soaking wet and raw! That’s the way it will go for much of the night ahead with several inches of rain likely for most of us. Temperatures will likely hover in the mid-upper 30s through the night and much of the day Friday. The National Weather Serviceis maintaining the Winter Weather Advisory through tomorrow morning for northern portions of Acadiana including Allen, Evangeline, and St. Landry Parishes. The rain may mix with some sleet or snow well after midnight across northern Allen, Evangeline and St Landry Parishes with slushy accumulations of less than an inch possible but surface temperatures should stay above the freezing mark so I am not expecting and travel issues locally. Farther north accumulated snow, mainly on grassy areas and trees will be possible toward morning from Central Louisiana northward and eastward. A wet snow accumulation is possible across Rapides and Avoyelles parishes of 1-2″ with locally up to 2-4″ possible in the central and northern part of the Bayou state. Snow totals are forecasted by the NWS in Slidellto reach up to 4-7″ in localized areas across Southwestern Mississippi! Farther south (for the rest of us) expect almost all rain with a brief possible mix as the precipitation diminishes very early Friday morning. At this point we are not anticipating any hazardous travel in Acadiana, but elsewhere in the state could very well be another story. Stay with KATC for the latest as conditions could change. We’ll have a full update at 10pm and live coverage tomorrow morning on Good Morning Acadiana…that’s when it may be interesting!
Latest on our next “Rainy Winter Storm”
Updating Dave’s most excellent and honest blog entry…we are still on course for cold, sloppy rains Thursday into Thursday night. Once again, we are faced with marginal conditions that could generate a rain/snow mix Thursday night with a possible change-over to all snow in the northern most portions of Acadiana before the precipitation ends during the pre-dawn hours of Friday. For this reason the NWS has issued Winter Weather Advisories for Beuaregard, Allen, Evangeline and St Landry Parishes for Thursday night for the possibility of a light slushy accumulation. Temperatures however should stay above the freezing mark at the surface through tomorrow night…but aloft conditions should be cold eneough for snow and/or sleet to mix in with the rain. With that being said cold air to our north and aloft could get entrained into this system, especially if our surface winds stay consistent out of the NE or NNE. Farther to the north a significant accumulating snow may be possible from Alexandria to Baton Rouge while the best target for a good snow will be in SW Mississippi where 2-4″ of snow will be likely with up to 6″ possible there. Winter Storm Watches are posted from Northeast Texas eastward through CenLa into Mississippi including the Baton Rouge Parishes. For most of us the precipitation will start off lightly and sporadic Thursday morning with some sleet quite possible to mix in, then all rain for the balance of the day and then possibly a slow changeover to a wintry mix Thursday night. I am not expect any roadway hazards in Acadiana with this system with the exception of the northern portions of the northern parishes of Acadiana ground temperatures may be too warm. But grassy areas, trees and roof tops may whiten by Friday morning. Most of us along and south of the I-10 corridor should stay almost all rain. But like the last two December snow events (2008 and 2009) we may wake up Friday morning with some folks to the north making snowballs while others just getting to see it on video! Stay tuned for the latest computer model runs and radar trends!
