Thursday, December 24, 2009

A Look into the next couple of weeks....

Now since the rain has passed and we are looking at a chilly Christmas Day in the 40's, I thought I would take a glance into the next couple of weeks and discuss what is ahead of us in the weather world.

Of course we are nearing the end of a very busy month with plenty of rainfall. We are also in the middle of a strong El Nino pattern which typically delivers more rain to the southeast along a Jet pumping in from Mexico and the Western Gulf. We also received our first snow back on December 4 from a Gulf Low that formed near the Texas Coast. This is because the cold canadian air mass is routinely pushing down to the Dixie Line (near Tennessee and Arkansas) during El Nino patterns, and the Gulf Low pull in the cold air into the southeast. Since we are in a strong El Nino, our forecast also shows a continuation of Gulf Lows forming every 4 or 5 days, and models are already putting us close to a rain/snow line as the moisture meets the cold air mass.

Here is when current long range model forecast currently show moisture laden systems impacting our area:
-Sunday (12/27)
-Wednesday (12/31)
-Sunday (1/3/10)*
-Saturday (1/9/10)*
*Anything past 7 days is difficult to be exact, but this gives us an idea of what models are wanting to show.

So the cold air is forecast to be present across the eastern U.S. due to 2 key oscillations going negative. The North Atlantic Oscillation and Arctic Oscillation both will continue to be in the negative going into the New Year. Negative values resemble the ability for cold air to get locked into the nation. So once a Low is formed along the Gulf, the cold air can filter down and produce some snow flurries. No, I'm not saying this is a definite thing for the Pine Belt, but the southeastern states look to be in the discussion for possible snow sightings in the next couple of weeks. Luckily, we've already had a good measure of snowfall!

Also, model consensus continues to predict the El Nino pattern will continue into the Spring, but weakening going into the Summer of 2010.

In Summary:
The same wet pattern will continue to exist into the New Year, and southeastern states have a better than average opportunity for more snowfall in the next few weeks.

Record Montly Rainfall

The rain is near ending here in South Mississippi after an intense afternoon of heavy rain and storms.

Now we can officially look at a record breaking monthly rainfall. We've officially broken the WDAM-TV monthly rainfall total this month with 14.70". *This record goes back to 1986 data records at the station.

Although we've received nothing compared to New Orlean's 25.43" this month!

Live Streaming Titan Radar

Live Titan Radar Stream:

Biggest Threat at this point is heavy rain and possible strong wind. I'm currently watching a cell in Marion/Jeff'Davis County that has the highest potential at this point for damaging wind and hail.

Looks like the showers in front of the main rain line are defeating the instability needed for tornadic activity. The height of the storms right now is very low, and I don't expect a major change. Also, it's lacking, but the better instability for a spin-up looks like the Coastline at this point.

....We'll still keep an eye on things.

Moderate Risk on the Eve

Well I have talked about this for several days now and here we go for a severe day of storms on Christmas Eve.

**Storm Prediction Center in Norman, OK, will upgrade the risk to a Moderate Risk for SE LA and South MS at 10:35am.** This means our atmosphere will continue to be favorable for tornadic supercells forming in advance of the propagating cold front.

A deep 997mb surface Low is present in Eastern TX, which is slightly farther south than expected. This is also why we believe our risk should increase as well. Multiple tornadoes have already been tracked in Louisiana as the line nears the Mississippi River late in the morning. I'm expecting the line to speed up as it crosses into MS with help from the dry cold front propelling it forward. We could also see strong gradient wind out ahead of the cold front. This will not be storm related wind but only pressure gradient wind from the strong gradient induced setup. We could see gust between 25-40mph ahead of the cold front.

Early afternoon, the updraft into any supercell will easily contain a rotating component with the strong storm relative helicity values present. Thermodynamics (instability) is still lacking, but the strong system dynamics have already produced tornadoes this morning. Also along the squall line damaging winds of 55+mph are a concern. So we will be on high alert this afternoon for eyeballing strong supercells approaching our viewing area.

Wednesday, December 23, 2009

Christmas Eve Severe Potential Discussion

Severe weather has broken out in the ArkLaTex region near Shreveport and Texarkana. This is right along the main convergence from the warm air mass overtaking the cooler air mass. But I don't expect our severe weather until tomorrow as the cold front pushes through.

My timing tomorrow looks like 11am to 5pm. I know this window might seem too big for some, but some analysis shows me the potential for the front to move slower than expected. So whats the big deal?

Minimal, but sufficient, instability will be present in South Mississippi from Natchez all the way east towards Greene County and the Coast. The whole state will have plenty of storm relative helicity (rotation in the atmosphere) to go along with the instability. Also, plenty of moisture will be present for heavy rain. So everything seems to mark South Mississippi as the best potential for damaging wind and tornadoes. I'm looking at the area South of Hwy 84 as the geographical line for the highest potential.

A squall line will push across the state parallel to the cold front, and this is where major wind gust can be found. In front of the cold front, discrete supercells can produce isolated tornadoes within the unstable air mass.

My Concerns:
1) The instability has been my concern for the last several days, but I continue to lean on climatology and note the winter season doesn't need much instability to trigger severe events.

2)The timing has been difficult to forecast as well this week. Models are beginning to agree on an early afternoon frontal passage, but some current analysis of the action to our west looks a little slower than anticipated. Some notes have been made that the front could accelerate with the increased drying behind the front as it passes through the state.

Tuesday, December 22, 2009

Tuesday's Discussion

So long to bright sunny days during the next 48 hours. Still the same picture with the cold front on Thursday, but I'll detail tomorrow's forecast first.

Tomorrow most of the rain totals will be found in the Delta and SW portion of MS, but we can still find some scattered showers in the area. The potential is still available for the shower location to record high localized amounts near 1" but a majority of the Pine Belt shouldn't see this.

The cold front looks to barrel through the Pine Belt in the afternoon on Thursday. Instability still looks low ahead of the front. My only concern is to read from climatology and notice most winter season severe weather events occur with low instability parameters. The deepening surface Low in Arkansas/Missouri will create plenty of rotation in the atmosphere so it's a situtation I'll detail more in depth tomorrow. Definitely a situation to keep an eye on.

Rain totals could be near 2" but most should see near 1".

Monday, December 21, 2009

Pre-Christmas Storms

Today was another great day! I really enjoyed capturing the alfa insurance skycam from our Grubbs Ford location in Columbia. Clear skies equals good stuff.

A trough is beginning to move across the county tonight. The West Coast will begin to experience the action of the trough, but we won't see anything till Wednesday and Thursday. This trough is different from the last few systems because the trough will "hook" North once it reaches Arkansas. The surface Low will be in the strengthening phase as the cold front sweeps through the Pine Belt, which is an important factor to notice. So the storm relative helicity (rotation in the atmosphere) variable will be at the moderate-to-high level on Thursday, but the instability (C.A.P.E) value will be low during this frontal passage. What does this mean for the severe weather potential? I'm not impressed at this point for a serious severe weather event on Thursday, but the scenario will require careful watching for any model differences.

When will the rain come? Scattered showers are expected on the fringe of the Pine Belt during the day Wednesday. Then the cold front passage midday Thursday will create heavy showers during the day. Everything looks to be clearing out on Christmas day!

Sunday, December 20, 2009

Record Monthly Rainfall

I mentioned this in yesterday's weather forecast...
Here is the list of the record monthly rainfalls at WDAM-TV since 1986.

1) March 2001: 13.79"
2) June 2004: 13.42"
3) December 2009: 13.07"
4) January 1998: 12.60"
5) May 1987 :12.36"
6) November 1986: 11.90"

Give us 0.73" at the station during these last two weeks of December and we will break a monthly rainfall record.

Sunday's Weather Discussion

Another wonderful day here in the South. Our day started off with some light frost on vegetation and automobiles, but the sun slowly warmed the ground to produce a high over 51 here at WDAM. Tomorrow will be slightly warmer. I'm going with a high near 60, but we will slowly be warming in our high and low temperature leading upto the cold front passage on Thursday.

My big story line in the forecast will begin to focus in on the rain forecast for Wednesday and Thursday. National Weather Service is predicting near 2" for the Pine Belt, which is on track with the latest GFS computer model run.

Yesterday I talked about having widespread showers across the region due isentropic lift along the warm front on Wednesday, but latest model runs have shifted the core lifting zone (area needed for significant rainfall) to our Northwest. So I have lowered the expectations for widespread rain on Wednesday at this point. Although the biggest story will be going into Thursday. Models have slowed a couple hours on the frontal passage. Looks like the cold front will move through around Thursday afternoon at this point. Instability for severe weather will be on the low-end side, but we will keep our eyes open in the next few days for the severe potential.

Christmas forecast still looks like a high near 50. Sky cover is difficult to determine 5 days out....I'm going with mostly cloudy skies

Saturday, December 19, 2009

Beautiful Weekend!

A beautiful weekend with plenty of sunshine to enjoy! I know today was perfect weather for the final shopping Saturday before Christmas (And the roads were extremely busy).

Similar weather will be around for Sunday's daycast. Highs will top out in the mid-50's with lows near 30, but big changes will come again.

On Tuesday I'll expect warmer temperatures to shift in association to a warm front. A good surge of isentropic lift along the warm front Wednesday morning will allow showers to form across the region. Then a cold front will swing through the Pine Belt late Wednesday night and into Thursday morning. The instability looks minimal at this point, but we will be paying close attention to the severe nature of this frontal movement Wednesday night. Models are currently suggesting the upper level jet will weaken as it approaches the area late Wednesday, which is one good sign for avoiding a severe event.

Early Christmas forecast shows mostly clear conditions with a cool high near 50.

Monday, December 14, 2009

Rain and more rain !

A Flash Flood Watch has been issued for our area beginning at noon today and will last through noon Tuesday. Radar is already showing showers and possible thunderstorms moving in from the south and the Watch may have to go into effect earlier than previously thought. Expect rainfall totals to average from 1-3 inches and possibly higher. The ground is already saturated so it will only take a little for some flash flooding issues. Colder and drier weather is forecast by Wednesday and even colder weather may arrive for the weekend. More on that later. Rex

Sunday, December 13, 2009

Rain Again then Cold Air next week...

Tonight the big story is the dense fog advisories throughout the whole southeast. Visibility will be less than a mile through tomorrow morning. So your morning travel could involve some dangerous visibility conditions.

The ground has cooled over the last few days and a moist warm layer of air over the ground has created the abundant fog tonight. But expect the fog to fizzle out mid-to-late morning.

Another warm front will begin to increase more of our rain totals tomorrow. This will likely cause tomorrow to be another cloudy and rainy day. Then late Monday night and into early Tuesday morning a cold front will drift through to provide even more rain. The cold front might have some lightning and thunder embedded in the rain line, but the main front seems on the weaker side. Instability values aren't impressive, and helicity values are extremely low for South Mississippi. Looks like mainly just a rain event.

After the front we will clear out. Temps will drop down into the 50's for daytime and 30's overnight. I've been studying a couple of cold air shots going into the 5 days before Christmas. Looks like a dry cold front could kick through around Saturday and open the door for even colder temps following a second front around the 22nd. GFS has been aggressive on this forecast until today, but it looks like ECMWF is leaning towards a cold direction as well. The Arctic Oscillation is going off-the-charts negative on the 16/17, but the NAO is only slightly negative. So the cold air will be present coming out of Canada, but the air mass might not making it down to South Mississippi.

There is a lot to play out in the next week! Have a good one!


Review of River Stages (12/13)

I'm reviewing river stages around the area after our amazing rain totals from yesterday. Main issues are found at Tallahala Creek, Leaf River, Black Creek, and Chickasawhay for this region.

Tallahala Creek @ Runnelstown: 17.14ft. (Action Stage) Forecast to below Action Stage Monday morning.

Leaf River @ Mclain: 18.78ft. (Flood Stage) Forecast 22ft. through Tuesday afternoon. Dropping below flood stage on Thursday afternoon.

Black Creek @ Brooklyn: 14.45ft (Action Stage) Forecast 20.5ft. (Flood Stage) Sunday evening. Back to Action Stage quickly on Monday morning.

Chickasawhay @ Leakesville: 22.28ft. (Flood Stage) Forecast 26ft. at noon on Monday. Below flood stage on Thursday morning.

Wow! Pascagoula 6.86"

Yesterday and last night was a memorable affair. Nearly another inch fell last night with thunder and lightning embedded in the rain, and this was adding to the nearly 2.50"+ we had already received.

The radar is finally clear of any rain for the remainder of the day, but check out these area rain totals:

Pascagoula: 6.86"
Mobile, AL: 5.53"
New Orleans, LA: 5.45"
Gulfport: 4.82"
HBG: 3.71"
Slidell, LA: 3.46"
PIB: 3.10"
Columbia: 3.09"
Collins: 3.00"
Sumrall: 2.86"
McComb: 2.85"
Prentiss: 2.85"
Mize: 1.89"

Rain will come back into play going into Monday afternoon's forecast, which could easily give us another inch or two.

Saturday, December 12, 2009

Big rain totals! Flooding concerns...

Flooding issues are a big concern now. Yesterday I talked about the opportunity to collect 3"+ in the Pine Belt through next Tuesday, and we have already neared 2" for most of the region.

Here are some totals so far as of 2:30pm:

HBG: 1.90"
PIB: 1.87"
WDAM-TV: 1.73"
Mobile: 1.66"
Pascagoula: 1.13"
Jackson: 0.57"
Meridian: 0.37"

Obviously southeast Mississippi is seeing the bulk of rain today as expected. And it's still raining! Expect the rain to diminish as we go into the overnight period.

Thursday, December 10, 2009

Rain, Rain, Rain

Low temperature tonight is a little difficult to come by with a very cold air mass in place and high clouds streaming in. Normally I would trend a little warmer than model output statistics but I think the models are missing the moisture. It's extremely dry tonight so it's going to be difficult to keep the dry air from holding much energy. Expect the station to drop to near 29 and other areas to be around 30.

Tomorrow will be an interesting day! Starting of partly cloudy then becoming cloudy throughout the day. Precipitation shouldn't come until very late in the day on Friday. I'll leave precip out of my daycast, but the earliest precipitation could be in the form of very fine sleet. NWS is going with sleet/rain forecast late Friday, but I think the lower levels of the atmosphere will be narrowly too warm and melt anything to rain. I'll lean more with the European on the warmer 850 mb temps.

Rain looks to continue throughout the day on Saturday. Chilly rain at first then warming into the 50's by the afternoon.

Wednesday, December 9, 2009

Rainy setup...

Our setup going into the weekend will trend to a troughy pattern across the nation. This will keep us warm and leave room for vertical lift to enhance the rain forecast. This will start by a Gulf Low forming Friday morning near Brownsville, Texas, and sliding into the Pine Belt late Friday night. Rain is expected late Friday night and into Saturday, but it's a little difficult to determine Saturday's evening forecast because we could still have leftover instability behind the Low.

Next another system will run through late on Monday. Showers will go along with this Monday and into early Tuesday.

Not until Next Wednesday will we be back into the "colder" temperatures after the weekend. But we will continue to be in an active pattern oscillating back from mild to cold temperatures. Long range models depict cold air anchoring down in Mississippi for the days leading up to Christmas, but this is two weeks away and hard to determine.

Wrapping up Last Night

Last night most of the severe weather stayed to the North near Meridian and Columbus. Jackson's atmosphere sounding at 6pm last night labeled a good opportunity for severe activity, but Slidell's sounding showed a nice cap keeping convection from growing within thunderstorms. This limited the severe activity South of Hwy 98 because this clearly made a difference in what transpired with the frontal passage. Covington and Jones Counties saw a couple cells move through that knocked down some trees as well as producing golf ball sized hail.

Helicity values were very high last night, which showed decent upper-level rotation in most of the thunderstorms last night, but we were limited by the cap. The cap acts like a bottle top keeping anything from getting out. This is what happened with the rising air.

This was a very unique event to work through last night, but, of course, every event is different and always fun to look research.

A glimpse at Christmas weather!!

Sorry I haven't blogged in awhile but plan on doing much more of it with the upcoming winter!!! The next few days will be cold followed by yet more rain starting sometimes Friday and lasting into Saturday. But what I really am blogging about today is that we are beginning to get a peak at what type of weather that we may have on and around Christmas!! From what I am seeing it just looks plain COLD!!! The weather models are often not accurate so far out but it's looking very interesting to say the least ! Santa may feel right at home here in South Mississippi ! I will continue to blog to each day as we get more data in. Have a great day! Rex

Tuesday, December 8, 2009

Severe Thunderstorm Warnings

JAN issues Severe Thunderstorm Warning for Jones [MS] till Dec 09, 12:15 AM CST

JAN issues Severe Thunderstorm Warning for Covington, Forrest, Jefferson Davis, Lamar, Marion [MS] till Dec 09, 12:15 AM CST

Greatest Threat...hail and wind

Tuesday 11pm Update

Looks like a line will be moving through the Pine Belt near the Midnight hour. No severe thresholds should be achieved by this line, but the potential for 30-40 mph wind is a concern. Hattiesburg/Laurel should see line just after midnight and Columbia will see this in the next 30 minutes.

The majority of the severe weather tonight is continuing to be to our North along the I-20 corridor and North. A couple of tornado warnings skirted near our viewing area, but I'm sure this is good news for most of us. The only storm reports I've heard were some trees down in Central MS.

Tuesday 8pm Update

We are still outside of my "biggest risk" window for our region. From 9pm to midnight things should become more active, but I'm narrowing the location to our Northern and Eastern viewing area. This includes Hattiesburg and North of Hwy 98 that has the highest risk for storm damage heading towards midnight. Even though my window is till midnight, the cold front is still back in LA at this time so we could still be concerned about the instability after the midnight hour.

It's a tricky scenario, but we are looking out the window now and seeing how the atmosphere is evolving in the progression of the cold front.

Busy Tuesday Night

I'm the only one in the weather office tonight so it is tough for me to cover the blog as well. Twitter is my quickest outlet to get information out, but I will update this blog as much as I can throughout the night pending important information.

We've already had two tornado warnings in the viewing area for Simpson County, and the majority of the viewing area is under a Tornado Watch until 2AM. We are under a watch box because the atmosphere can easily rotate any thunderstorm cell.

My main concern will be damaging winds as these thunderstorms pass through because upper levels winds are very strong. These winds could easily be delivered down to the surface.

This sounds like a good night to have the weather radio nearby. Please be safe and email or twitter any comments you have. Thanks!

Monday, December 7, 2009

Tuesday's Severe Weather Threat....

Severe Weather Threat Tuesday...
The instability isn't great, but in the winter we only need a small amount to produce severe storms down here. This means we could see storms cells with towing cumulonimbus capable of strong winds near 50+mph.

I expect the severe risk index to be the highest from Noon to 7pm, and after 7pm any tornadic threat greatly diminishes.

Highest rain totals with the frontal passage will be found in North Mississippi, but we will have the higher severe weather potential. Generally the southern tip a line of storms is the most vulnerable to rotation and higher severity.

Keep track of my twitter account @ WDAMTannerCade and follow this blog for dependable coverage....We'll track anything all night if need be

Saturday, December 5, 2009

Snow Totals and Discussion

Snow Total estimates from the area:

Mt. Olive: 5.0"
Hattiesburg: 2.5"
Laurel: 2.3"
Bassfield: 2.0"
Braxton: 2.0"
Columbia: 2.0"
Moselle: 2.0"
Prentiss: 2.0"
Seminary: 2.0"
Forest: 1.5"
Morton: 1.0"
Heidelberg: 0.5"
Pachuta: 0.4"
The average for the area was about 2.0", but Mt. Olive clearly is the maximum snow fall estimated total at this time from the National Weather Service co-op observer.

Tonight looks like a record cold temperature will be set. Low tonight will fall quickly into the lower 20s and break the old record of 28. This cold night will also do a number on vegetation because a hard freeze will easily kill most plants. If you want to save some plants, then make sure to cover them with a clear bag, but you might still damage since we are already below freezing.

Our forecast for the next several days will now begin to experience a more normal weather pattern. Temperatures will be back to normal with highs in the 60's and lows near 40. Monday should deliver some light showers along a warm front, and Tuesday could incorporate some storms as a cold front passes through. The extended forecast for the end of the week looks "mild" and right on climatology.

Friday, December 4, 2009

Friday Morning...Snow Update

Our conversations about snow are finally about to come to an end. Tonight is the event we've examined all week to distinguish a specific snow forecast, and hopefully you will be blessed with a pleasant white landscape early Saturday morning.

So what are my thoughts now and what has changed in the last 24 hours for this forecast?

The biggest change I have noticed in the last 24 hours is the computer models are trending slightly less in precipitation for Mississippi. National Weather Service also notices this by removing their winter weather watch and only issuing a winter weather advisory for our region. But I don't remember ever saying this was going to be a major snow event anyway. In fact, most of our talks have discussed only light snow, and we are continuing to keep that terminology for tonight's forecast.

After this morning it's nearly pointless to continue looking at the models because our attention is drawn to "nowcasting." Today we will simply be looking out the window to see how the atmosphere is evolving. And we start by noting Houston, TX, is already seeing their expected snowfall this morning with a temperature of 36 degrees. The temp should continue to drop over there for the remainder of the day with even more snow.

We should finally see the system move our way late tonight. I'm going with a window of 9pm to 6am ( 6am looks like a definite cut-off time for anything). In this time period many of us should expect snow flurries...near an inch of light snow for some. Flurries should be plenty wet and melt on contact with the roads.

Have a good day! And regardless of the precip talk...bundle up because it's going to be cold tonight.

Also, now we are beginning to focus more attention on next week's forecast. Rain likely next Monday and Tuesday...I'll have more on next week's forecast this weekend!


Thursday, December 3, 2009

A snow forecast to remember...more snow info.

I don't think we will forget the National Weather Service's updated "Snow Accumulation Probability" map listed through 6am Saturday. The NWS shows a 10% probability line running through Hattiesburg, McComb, Baton Rouge, and East Texas. This 10% isn't just for a snow forecast, but is the percentage that this area could see at least 4 inches of snow accumulation. I highly doubt seeing 4" of snow in the Pine Belt Friday night, but it's incredible to make note of this opportunity on December 5.

With cold arctic air moving south and a Low forming in the Gulf, this is the prime ingredients for a good snow fall in South Mississippi. After 6pm Friday our atmosphere above the ground will be below freezing up through the, moisture rich, snow growth region near 14,000 feet above the ground. Snow fall in South Mississippi is likely from 9pm Friday through 6am Saturday. I expect the roadways to quickly melt the frozen precipitation because the soil temperature is well above freezing right now.

The biggest issue is location. This snow event will form a line across the region, and my best guess has the line running perpendicular to Highway 49 in a SW to NE tangent. The center of this line could be anywhere between Mendenhall and Beaumont.

How much snow? Most will only see near an inch, but isolated locations within the snow line could see near 2 inches (plus some). This means most will see enough to cover vegetation (grass, plants, trees, etc.).

If you have questions going into the Friday night please feel free to send a message on twitter at

Snow likely in the Pine Belt!

As I write this Thursday morning, the question "is it going to snow?" has shifted to "where and how much is it going to snow?".

While models will paint a better picture as the day rolls along, right now it appears many folks in the Pine Belt may be seeing rain turn into snow sometime around 10pm Friday night. As we saw in two significant snows in 2008, pinpointing exactly where the precipitation becomes frozen is the hardest part. You may remember last December, the town of Collins saw a whole lot more snow then Hattiesburg. In January of 2008 there was snow in Sumrall, but just rain right down the road in Purvis.

At this point I think it's safe to say that SOME folks south of I-20 will see snow.

How much you ask? Current predictions are anywhere from a 1/2 inch to 2 inches. If it truly looks like someone is going to get 2 inches of snow you will quickly notice the National Weather Service issue a "Heavy Snow Watch" or "Heavy Snow Warning". And of course here at WDAM we would display that graphically on air immediately.

-Nick Ortego

Wednesday, December 2, 2009

Latest Snow Forecast Update (Wednesday PM)

As we’ve discussed for several days now, a cold arctic blast will punch down to the coast Friday and setup the opportunity for wintry precipitation. Computer models are slowly coming around to picking up on variables to align for snow development.

During my last look at the most recent atmospheric forecast, I detailed a noticeable amount of moisture available in the snow growth region 14,000 ft above the surface to induce the creation of snow. And the evolution of the snow as it falls will maintain a temperature below freezing till about 800 feet above the surface. Slight melting will occur as the precipitation falls in the small layer at the surface (ground), but the warmer layer should be thin enough to meet the threshold for maintaining snowfall. I do expect the warm layer to become increasingly thin as any melting of precipitation will cause the atmosphere to cool, which will help see more white stuff.

In other words, the latest computer models show snow falling after 9pm on Friday and going into the early hours on Saturday morning. A big difference at this point is the location. WRF computer model has the main snow line tracking through Jackson, but the GFS has the snow line tracking right through Hattiesburg. Similar to our snow event back in December 2008, a line of snow will stretch across the state perpendicular to Hwy 49 in a SW to NE direction. Last December, Hattiesburg barely saw any snow while Collins had nearly 3 inches. So location is very important.

How much snow? Well, considering the models are still varying on the location of the snow (see previous paragraph) the amount is still uncertain. Some models depict slightly more than a dusting, but others (GFS) show over an inch. My opinion, I would say some isolated areas will see up to 2 inches, but many folks will experience less than an inch.

The only definite forecast I can give is the potential snow event's snowflake size will be big and wet. After forming in the snow growth region in the atmosphere, the snow parcel will continue to have a wealth of moisture at its disposal. Also, knowing the surface temperature will be above freezing makes me note the snow parcel will slightly melt to give it a “wet” feeling.

Much can change in the next 48 hours going into Friday evening, but hopefully we can all wake up Saturday morning with a beautiful white landscape. I’m sticking with saying “light snow” for Friday night’s forecast until we get closer to the event to help distinguish the exact location of the snow line through the state. But the snow line is still capable of missing our region all together.

Interesting note…The Houston, Texas, area could see a rich snowfall before it reaches Mississippi on Friday.

Snow chances looking better...

(Wednesday - 9:05am) Tuesday morning, there were some early indications that we may see snow here in the Pine Belt Friday night into Saturday, but the majority of models were predicting that there would not be enough moisture to allow it to happen. However, looking at the models Wednesday morning there seems to be a growing shift that snow may fall in the Greater Hattiesburg- Laurel area as we roll into the weekend.

Arctic air is moving in right now and will be here to stay through the weekend. But due to possible cloud cover Friday night, there still is some question on whether or not we will make it down to freezing. The other question mark is the depth and placement of a surface low that will likely develop in the west Gulf and track just south of Mississippi. Wednesday morning there was a majority consensus of models that there will be enough moisture to tap from that surface low to give us some type of frozen precipitation. However, we are still 60+ hours out from this taking place, so there is still a lot of uncertainty.

If all the ingredients come together for wintry weather, we stand the potential to see anywhere from a 1/4 inch to an inch of snow.

Stay tuned to WDAM and for the latest.

-Nick Ortego

Tuesday, December 1, 2009

Cold Air filters into Pine Belt

Possibly the coldest air mass of the season will enter Mississippi by the end of the week.
A strong stream of cold air will drop into South Mississippi Friday, and high temperatures are only expected to be in the upper 40’s going into the weekend. Friday’s overnight forecast involves the potential for snow in the state, but many variables are still uncertain at this time.

Any small variation in the passage of the forecast Low can greatly change a snow forecast for the Southeast. Also, our soil temperature this time of year is still well above freezing, which will make it difficult for any accumulation.

The air mass above the surface will be cold enough Friday night for snow, but variables like the moisture content and upper-air convergence are lacking according to current forecast model runs. The consensus computer forecast does not depict any precipitation Friday or Saturday, but an outlier model does show a line of snow stretching from Houston, Texas, through Central Mississippi and into New England. While snow is unlikely at this time, the News 7 Weather Team will provide you with any future developments.

Today is not the first calendar day for winter, but December first marks the beginning of meteorological winter. The timing of the cold forecast this week is right on schedule with the start of the winter season, which includes December, January, and February.