Heavy Snow threat 2/9/11-2/10/11 AR AL MS TN

[ROLLTIDE]

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEMPHIS TN
425 PM CST WED FEB 09 2011

..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..

0415 PM HEAVY SNOW 5 W RIPLEY 34.73N 89.03W
02/09/2011 M4.0 INCH TIPPAH MS PUBLIC

STILL SNOWING.

[ROLLTIDE]

[ROLLTIDE]

Looks like Bart got stuck

[ROLLTIDE]

North AL webcam

http://jdf.waaytv.com/home/homeJ.html

[ROLLTIDE]

Tim C

Snow analysis – 408 pm

Dr. Tim Coleman | 4:11 pm February 9, 2011 | Comments (30)


Snow is moving quickly across Mississippi and into Alabama this afternoon, with reports of light snow as far east as Jasper. Some of the snow along the leading edge is not reaching the ground (see explanation below), but once snow is over a location on radar for 1 hour or so, the atmosphere moistens up and snow begins to fall. We’ll probably start to see light snow here in the BHM metro area between 5 and 6 pm.
The snowstorm approaching Alabama has been stronger than the models had predicted over Arkansas, with some places reporting over 6″ of snow there! So, computer models have to be given less credibility right from the beginning. However, it is close enough now that we can look at observations (radar, surface, satellite, etc.) and see what’s going on to our west and how it’s changing.
The storm won’t be as strong here as it was in Arkansas. The sun came out today in Alabama, warming temperatures into the 40s. Because of this, even once snow reaches the surface, it will take a while for temperatures to drop below freezing due to melting and evaporation of snow. It can happen in 1-2 hours, but this system is moving fast.

The air here is also very dry aloft. Take a look at this morning’s sounding from NWS Calera. The red line is temperature and the green line is dewpoint. The very dry air causes a large spread between dewpoint and temperature. So, once snow gets in here, it will take it a while to saturate the atmosphere and make it to the ground. You may see snow on radar before it falls to the ground.

All that being said, there is a strong upper-level system approaching us, and with the kinds of snow totals we are seeing in Arkansas, there must be some convective snow (like thunderstorms, but along slant) in this system. That could happen here, making snow accumulations vary widely from one spot to another. A convective snow storm produced 4″ of snow in one hour in HSV back on January 9. So, while the overall snow forecast from James in the post above and video (to right) are correct, understand that there may be wild variations. One spot could get 2″, while someone 25 miles away gets 4″.
Bottom line…snow moving in rapidly, but will have to saturate a dry atmosphere before it reaches the ground. Then, due to warm temperatures today, it will take another hour or so to get surface temperatures cold enough for significant accumulation. However, we do expect travel problems early this evening over NW Alabama, spreading SE tonight.

[ROLLTIDE]

.....

Latest on the Wednesday Night Winter Weather

It’s going to be a busy Wednesday night, but the latest bout at winter weather will leave the area as fast as it arrives. We continue to see reason to forecast snow with some accumulations, so let’s get right to business.
First, the map below depicts the latest winter weather information form the National Weather Service. Pink counties represent a Winter Storm Warning through Thursday morning. The cream counties are under a Winter Weather Advisory for the same time. The warning is a higher priority than the advisory, meaning the higher accumulating snowfall amounts are forecast to be in the counties shaded in pink.

This will be a rather quick event tonight. Our timeline is calling for rain moving in during the evening becoming mixed with snow during late evening as temperatures fall. Late evening toward midnight, the rain transitions to all snow in the central counties before ending in the wee hours of the morning, we’re talking around the 4-6am time frame from west to east. The overnight low will be hovering at or below freezing in the northern counties. Counties in the southern portion of our viewing area will likely see this as an entirely cold rain event with lows in the mid-30s.
Before we show the map below, let’s talk about a few caveats. First, snow doesn’t fall in perfect lines. There will be blotches of higher amounts and lower amounts than depicted below. The temperature at the ground coupled with the snowfall rates will determine how much snow will actually stick. Grassy surfaces, elevated surfaces will collect snow first. Roads are typically last to accumulate snowfall. As forecasters, we are now turning away from the models and to the radar, meaning radar trends and observations will be used to determine where the snow is falling and where it’s accumulating. You can help us with this, I’ll let you know how below, keep reading. Ok, here’s the map on our latest accumulation thoughts.

Right now, we continue to forecast a "sweet spot" band set up, which could drop up to 3" somewhere between I-20 and the US-80 corridor as shown in purple. The best chance of accumulating snow will be generally north of the I-85 to US-80 corridor. This all depends on moisture, temperature, and timing. This band could easily shift north or south, east or west, or grow or shrink in area as the event unfolds. Your best source for information during this latest bout of winter weather will be WSFA TV and wsfa.com.
We are forecasting this all to get out of here by daybreak Thursday morning. Roads may be wet with some slick spots, but temperatures will rebound into the low 40s, so most snow should met through the day. Beyond Thursday we’re cool & sunny, with a warming trend into next week.
Please do us a favor. If you see snow, let us know. If you can measure it, let us know. You have many ways to contact us.

[ROLLTIDE]

[ROLLTIDE]

BMX: 12 Nw Hamilton [Marion Co, AL] trained spotter reports SNOW of M1.2 INCH at 06:00 PM CST -- accumulated over the last 3 hours. still snowing heavily.

[ROLLTIDE]

.....

Snow analysis – 550 pm

Dr. Tim Coleman | 5:59 pm February 9, 2011 | Comments (1)

As we mentioned earlier, this storm was stronger than the models anticipated, just like the last one. A weak upper-level trough is located over Arkansas, and as air that is slowed down in that trough speeds up, divergence will occur aloft, pulling air up from below, creating upward motion and precipitation. Also, we are in the right entrance region of an upper level jet maximum (see below). As air tries to adjust to the higher pressure gradient in the jet, it initially flows toward low pressure (farther north). This causes upper divergence in the right entrance region, and more upward motion. So, we have two dynamic processes bringing us upward motion and precipitation over the next 5-8 hours.

As the main area of vertical motion moves over Alabama during the evening hours, expect precipitation to get heavier from west to east. The temperature fell from 47 to 37 degrees in 2 hours at BHM, only due to some sleet and snow falling. The dewpoint is still 24, so the wetbulb is now around freezing, and temperatures in the BHM area will fall to freezing once the heavier snow moves in over the next 2 hours. Bridges could become icy very quickly, so any travel in the BHM area should be done now.
With the heavy amounts coming from some spots in Arkansas and Mississippi (some over 12″ in AR, some over 6″ in MS), there may be some convection involved, so snowfall amounts will vary greatly. The averages James posted earlier are correct, it’s just that one spot may get 2″ while another 5 miles away gets 3″

[ROLLTIDE]

Vincent I love my windshield wipers Webb is still streaming from Jackson MS


http://www.severestudios.com/cgi-bin...t.webb&uid=496

[ROLLTIDE]

Mike W streaming live from North AL

http://www.ustream.tv/channel/mike-w...potter--chaser

[Xanadu]

28 storms guy did a good job. Thanks for posting all of this, Roll. I'm also afraid there might be a little more for us than what the models were showing too. Be careful out there everyone!

[ROLLTIDE]

Terry Sasser

http://www.ustream.tv/channel/TerrySasserLiveStream

[Joe-Nathan]

Looks like Bart got stuck

Dude got stuck!!!

Probably was busy play w/his laptop.