A Big Alabama Temperature Contrast

December 3, 2005, 2:37 pm
Posted by J.B. Elliott in Weather Discussions
Rating: 0/5   Votes : 0
How about this for a big temperature contrast across Alabama at 2 o'clock on this Saturday afternoon:

Fort Payne 37
Gadsden 41
Birmingham 61
Tuscaloosa 69
Montgomery 71
Mobile 76

Warm air is streaming north from the Gulf of Mexico.

Some colder air still trapped in the deep valleys of Northeast Alabama.
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Posted by  
on December 3, 2005, 2:54 pm
That's amazing. I'm in Decatur today and it's a 5D day in Decatur: damp, drizzly, dank, dark, and damp. It's hard to imagine that such warm, moist air is pushing up into the southern part of the state. I sometimes wonder what it was like 100 years ago when the lack of communication and technology would have made it impossible to know what was about to happen...

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Posted by  
on December 3, 2005, 8:06 pm
You say severe weather tonight????? Where is the update? What is going on? No update from abc3340 in quite a while. Someone clue me in.

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Posted by  
on December 3, 2005, 4:53 pm
hey .. you know what?

Im.. ah.. not buying it today.

I think NOAA is wrong.. I think Peters (as usual) is wrong

Im going to sleep and Im not turining on my NOAA radio.. and im going to have a peaceful night....



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Posted by  
on December 3, 2005, 5:57 pm
I don't know a lot about weather. So why do you say that Scott?

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Posted by  
on December 3, 2005, 10:39 pm
hey i dunno about you but with the weather in alabama you need to expect the unexpected...i keep intouch with all the local weather stations because usually wvua's weather comes on about 3 mins before abc3340 so i see them both and wvua said that the tornado watch is out till 5am and tuscaloosa is expected to be added to it but they did say in the early morning hours just hope and pray that the main storms ride the front and are not as strong as the predict tornadoes are nothing to ignore and straight line winds can do alot of damage as well.. all the ingrediats are coming together with the dew points and all i just pray for you and me and everyone else here in bama that we get through this one again with no damage and everyone has a peacefull night ...."may there be angels wrapped around us all tonight into tomorrow to protect us from the weather that could happen"

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Posted by Brett  
on December 3, 2005, 6:07 pm
Brian and Bill both know what they are talking about. The parameters are there with plenty of shear in place across NW Alabama and instability building in given 60 degree dewpoints already encompassing much of MS and WRN/SWRN Alabama at this time. The main focus of severe weather will be North of 59/20 and West of 65 where the best instability coupled with lift will combine later tonight into the early morning hours. We could deal with some descent hail with the front as it comes through Central Alabama later tomorrow afternoon.

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Posted by John T.  
on December 3, 2005, 7:06 pm
A.J. this is going to be one of those nights that depends on where the warm front passes by & where you live. Again, severe weather feeds off of temp. about 63* or so plus, Dewpoint about the same, wind direction & speed and strength of storm system. A good bit of this could come together just like Brent mentioned. If you have a weather radio keep it on just in case. Keep tuned to the blog or tv. Its one of those "you never know" situations. Trust me Bill & Brian know what they are looking at. You can watch the weather on the news and see things are changing now just like they said. We will probable have a watch of some type issued by the S.P.C. later on for SOME part al AL..

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Posted by Brent  
on December 3, 2005, 7:07 pm
Don't let your guard down folks... I had a low of 29.1 this morning and it's 60 degrees right now(2 hours after dark in December). Warm front is surging northward... I don't think there will be a major severe weather outbreak, but areas northwest of I-20/59 need to stay alert...

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Posted by Jason  
on December 3, 2005, 7:31 pm
SPC has lowered the threat tonight for most of the previously warned area only NW Alabama under a slight risk for tonight, but that just the day one outlook the main risk looks to be from midnight to 5am according to the HWO

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Posted by Brandon  
on December 3, 2005, 7:39 pm
Strong thunderstorms now developing in Tennessee things are starting to pop now. There has been a mesoscale discussion about issuing a watch for Tennessee

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Posted by jeff  
on December 3, 2005, 7:46 pm
Can anyone help me? I am flying out of Birmingham tommorrow at 2:30pm. I am hoping that severe storms will not be a problem then so my flight will not be late and I can catch my connection in Atlanta. Anyone have an idea of how it is going to be then. Thanks for all the help

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Posted by  
on December 3, 2005, 7:56 pm
ok yall......

i have been gone most of the day, and when i have been here my home has been like a zoo of wild animals. i have NO IDEA what is going on lately with the weather. normally i pay attention to this. can someone please clue me in? I would muchly appreciate it -am in central AL - can i be in deep sleep?

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Posted by Brent  
on December 3, 2005, 8:19 pm
Central Alabama should be fine overnight... it looks like the storms may not even reach NW Alabama until around daybreak, so it'll be even later for areas farther south and east.

Looks wet for the flight Jeff... don't know about severe weather, but be prepared for delays(especially at Atlanta).

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Posted by  
on December 3, 2005, 8:24 pm
Thanks Brent!! I haven't slept much at all this week, between my 9 month old teething and my husband's cell phone goes off at all hours of the night (his job is 24/7) and I am exhausted. I tend to stay awake during severe weather so if I need to put my boys in a safe place, I can. Everyone, have a great night. I am crashing :-)

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Posted by Jason  
on December 3, 2005, 8:38 pm
The warm air still hasn't made it to Cherokee County. Temp 43 Dewpoint 37

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Posted by John T.  
on December 3, 2005, 8:55 pm
Actually the way I look at things is no news is good news as of now. Its the weekend. They have lives of their own also. If it was getting bad we would have heard from one of them. Temp. in H'town 66*, DP 61*. Windy.

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Posted by Greg  
on December 3, 2005, 8:58 pm
Talking about some blown forcast. I thought it was going to be 10-18 degrees this upcoming week with flurries. WOW.... time to start paying more attention to the NWS instead of all this discussion

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Posted by Jason  
on December 3, 2005, 9:11 pm
I think Greg and Scott are just reaching out for attention.

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Posted by Evil  
on December 3, 2005, 9:25 pm
Rome, GA was reporting snow and 1/2 mile vis. early this morning. Snow. Not light snow or flurries. Snow.

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Posted by Brent  
on December 3, 2005, 9:29 pm
Yes... there was some snow in North Georgia, though I'm skeptical it occurred at Rome(though I did see the observation). It was mainly at elevations above 2,500 feet. Whatever happened there was no accumulation.

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Posted by Brent  
on December 3, 2005, 9:32 pm
Correction... no snow report in Rome this morning. "Unknown precip" at 6:53am EST.

http://www.srh.noaa.gov/data/obhistory/KRMG.html



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Posted by Pmott  
on December 3, 2005, 9:38 pm
Big storms fireing over northwestern Mississippi and southern Arkansas. No warnigs at the time, but a band of thunderstorms looks to be forming

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Posted by Greg  
on December 3, 2005, 10:05 pm
no snow.. no nothing... blown forcast. who cares about rome, ga. We are in Birmingham , not Rome, Georgia

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Posted by  
on December 3, 2005, 10:11 pm
Greg, Snow was never forecast for today or any part of this weekend. Flurries have been mentioned as an outside chance for Monday and James said he was planning to watch the storms later in the week for the possibility of freezing rain. As for the 18 degrees, that's forecast as a potential for mid-week. Read carefully and you'll see that. Another thing to remember about this forecast, it covers a HUGE area of the state and the numbers are always averages.

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Posted by Jason  
on December 3, 2005, 10:13 pm
tornado watch for w, nw albama

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Posted by John T.  
on December 3, 2005, 10:14 pm
Snow was never forecasted. As for as no nothing? We have had plenty of weather. As far as teens...next week has not gotten here. James has allready stated if clouds hang touch we will probably just see low to mid 20s. If clear, we could see the teens. Either way its gonna be cold. Allready has been where I'm at.

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Posted by  
on December 3, 2005, 10:16 pm
How come info is so scant here on the weekends? B/C during the week, the info is SOOOO good and SO frequently updated. Anyone know why info seems to be so lacking on weekends?

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Posted by  
on December 3, 2005, 10:19 pm
Well andy , many of us are trying to get caught up with family life...Ia m here now and plan on being here for a short bit longer...Did you get my email?
I will go ahead and post some of the watches and radar immages...

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Posted by John T.  
on December 3, 2005, 10:24 pm
The way I see it I'm sure James and the rest have lives with there families on the weekend just like everyone else. Just because we have nothing going on outside the weather may not mean they don't. I can understand & respect that when there is no current bad weather in progress for US, that they don't post a statement every other hour. I'm know if we were under the gun they would be all over it.

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Posted by Pmott  
on December 3, 2005, 10:30 pm
First tornado warning of the night for Calhoun, and Bradley counties in southern Arkansas. Another intrestering developing suppercell over northern Mississippi south of main band.

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Posted by  
on December 3, 2005, 10:48 pm
Don't misunderstand my question. I understand perfectly people having families. I guess the question was more of a weather office staffing question for ABC3340.

LOL I understand you guys have families and so do JB and James. Just thought they had a different crew updating the forum on the weekends. You guys know how it works better than me. I just wasn't sure.

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Posted by  
on December 3, 2005, 11:00 pm
Well, just as we have figured, sorry Scott, maybe you should turn that NOAA weather radio on… We have the storms starting to fire along the boundary of the warm from that has moved up out of the gulf. Here is a link to one of my favorite sites and it will give you a complete breakdown from Cape values, to Helicity values and as well gives you radar images. .
http://www.spc.noaa.gov/exper/mesoanalysis/s1/index2.html

Here is a link that you can see some of the Lightning output:

http://www.wallysweather.com/index.php?config=&forecast=pass&pass=l
ightning

Here are some of the local reports:
CULLMAN MOCLDY Temp. 61 Dew point 54 RH. 77 wind S10 Pressure 29.88R

BIRMINGHAM CLOUDY Temp. 64 Dew Point 61 RH 89 wind S13 Pressure 29.93R

TUSCALOOSA CLOUDY Temp. 64 Dew Point 61 RH 89 Wind S12 Pressure 29.90R

So as you can see, we are starting to get some of those Dew Points that will allow the atmosphere to become unstable and support some storms this evening. But it will be early morning hours.

This may be a little out there for some of you, but here is the Current Skew T Plot for Shelby Co AL (EET-72230)

http://weather.unisys.com/upper_air/skew/skew_KEET.html

A sounding comprises a vertical picture of the atmosphere which is a helpful tool in determining the stability of the atmosphere, type of precipitation, and maximum temperature. Pressure levels are shown on the left side of the sounding corresponding to horizontal lines across the diagram. Temperature (in degrees Celsius) is shown at the bottom of the diagram, with temperatures lines running diagonally (or skewed) across the diagram. Also provided is mixing ratio information, plotted wind barbs, and many thermodynamic variables (see below for a list).

LCL Lifting Condensation Level - Height at which a parcel of air becomes saturated when it is lifted dry adiabatically.

CCL Convective Condensation Level - Height at which a parcel of air, if heated sufficiently from below, will rise adiabatically until condensation occurs. It is the height of the base of cumuliform clouds which are or would be produced by thermal convection solely from surface heating. Severe weather usually occurs when the CCL is at or below 770 millibars.

LFC Level of Free Convection - The height at which a parcel of air lifted dry adiabatically until saturated, and saturated adiabatically thereafter would first become warmer than the surrounding air, and then continues to rise until it becomes colder than the surrounding air. Severe weather usually occurs when the LFC is at or below 650 millibars.

FL Freezing Level - Height at which temperature is at freezing.
WBO Wet Bulb Zero Height - Height where wet bulb reaches zero. Generally, if the wet bulb zero height ranges between 7,000-9,000 feet, large hail, damaging winds, and tornadoes are possible. At the Gulf Coast, the range must be between 9,000-10,500 feet for damaging winds and hail to occur.

EL Equilibrium Level - Height where the temperature of a buoyantly rising parcel of air again becomes equal to the temperature of the surrounding air. Usually, if thunderstorm echo heights are above this equilibrium level, it is referred to as 'Over-Shooting Tops' and is a precursor to severe weather.

KI K-Index - Stability index useful in predicting non-frontal thunderstorm situations. Relationship of K-Index to probability of thunderstorms: K 15-20: < 19%, K 21-25: 20-39%, K 26-30: 40-59%, K 31-35: 60-9%, K 36-40: 80-89%, K >40: >90%.

LI Lifted Index - This index helps predict overall atmospheric stability. Lifted Index guidelines: +3 to +1: slightly unstable, supports showers, +1 to -1: unstable, supports showers and isolated T-storms, -1 to -3: moderately unstable, supports widespread T-storms, -3 to -6: very unstable, supports severe T-storms, <-6: extremely unstable, supports widespread severe weather.

SSI Showalter Index - A stability index similar to the Lifted Index, but values are typically not as low for severe weather. Generally, an index of +3 to +1 supports T-storms and <-3 supports severe weather.

SI Sweat Index - Stability index indicating severe T-storms and tornado potential.

CTI Cross Totals Index - This index determines the horizontal transport of unstable air. A value in excess of 25 is needed for strong T-storms.

VTI Vertical Totals Index - This index determines the vertical transport of unstable air. Values in excess of 25 are needed for strong T-storms.

TTI Total Totals Index - This index determines the potential for T-storms and is very helpful in diagnosing the difference between weak and strong T-storms. The relationship between the TTI and Thunderstorm Acitivity is as follows: 44 - Spotty, usually light thunderstorm. 46 - Spotty, usually moderate thunderstorm. 48 - Usually heavy thunderstorm. 50 - Usually heavy thunderstorm with hail possible. 52 - Usually heavy thunderstorm with a tornado possible. 56 - Heavy thunderstorm with tornadoes likely.

EPA Positive Area - Positive area denotes the buoyancy of the atmosphere. The higher the positive area, the more buoyant energy available. Values in excess of 500J/KG support T-storms, values between 1000 and 3000 J/KG support T-storm development with moderate shear.

PW Precipitable Water - The amount of water that would be found in a column of air above the surface. Comparing sounding values indicates the amount of water available for rain or snowfall potential.

TH Tropopause Height - Height where the tropopause begins, or the temperature curve warms. The location of a tropopause height helps determine severe T-storm potential. If T-storm echo tops exceed tropopause height, severe weather is likely.

STC Convective Temperature - The surface temperature that must be reached to begin formation of convective clouds by solar heating of the surface air layer.

HSZ Hail Size - The size that hail may reach given the state of atmospheric updrafts. This is based on the calculation of critical updraft speed which determines the size of hailstones that can stay aloft for a given updraft speed.

STC Richardson Shear Index - This value indicates how turbulent the flow is. Low RI numbers are associated with fast moving systems in an environment that has strong shear. Small RI numbers support greater shear.

Well that is the lesson for tonight..Keep your ears open and we sill see what we get as the night progresses...

Rusty (IWIWAM)







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Posted by  
on December 3, 2005, 11:19 pm
here is a radar of the current warnning area in Arkansas.

http://beta.abc3340.com/externalwebsite.hrb?website=http://www.sr
h.noaa.gov/radar/latest/DS.p19r0/si.kbmx.shtml

Here is the formal warning for ARKANSAS
http://iwin.nws.noaa.gov/iwin/us/tornado.html

and here is the current weather conditions in greenville Mississippi, which is in the direct path of this storm....71 °F ... Humidity: 78% Dew Point: 64 °F ..

Now lets compare that to BIrminghams current conditions:
65°in Birmingham
Humidity: 86%
Dew Point: 61°F

so , as you can se, we are not that different in terms of temperature and dewpoints... and actually our Dewpoint has been going up over the past hours... We are not out of the woods, so everyone keep out a close eye, and stay safe...Great Job ABC3340 Iknow yall will keep us updated....

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Posted by John T.  
on December 3, 2005, 11:40 pm
I understand where you are coming from Andy. I figure John is staffing the office like he normally does on the weekends. Because of all the dang football games they have not been able to have there regular news yet. I figure the others are watching else where from laptops. They will have us covered buddy. Did NOT mean if my statement sounded rude or anything. Just giving my thinking.

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