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Bill Murray

Bill Murray

Bill Murray is the President of The Weather Factory. He is the site's official weather historian and a weekend forecaster. He also anchors the site's severe weather coverage. Bill Murray is the proud holder of National Weather Association Digital Seal #0001 @wxhistorian

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Good News: Storms Weaker, No Warnings For Now

| 1:46 am November 18, 2015


The good news is that our line of storms has weakened in the past 15 minutes and there are now no severe thunderstorm or tornado warnings. The only severe weather warnings are two flash flood watches and one severe thunderstorm warning over Mississippi/Louisiana.

The lightning output on the storms has dramatically lessened over the past hour, indicating they may be running out of fuel.

But having said that, wind shear is still extremely strong and the double s-shaped orientation of the line between Corinth and Tupelo and Starkville indicates that the line is capable of producing damaging winds and spin up tornadoes, like we have seen in Mississippi tonight.

No word on whether the folks at the NWS will extend the tornado watch into Alabama. If current trends continue, perhaps it won’t be needed for North Central Alabama.

Further southwest, storms are quite intense still over southern Louisiana, and these should be able to ride a narrow tongue of unstable air into Southwest Alabama and a watch will probably be required for that part of the area.

Possible Tornado Passing West of Tupelo

| 1:23 am November 18, 2015


A new tornado warning has been issued by the NWS in Memphis for strong rotation NE of Pontotoc, headed toward Sherman, Guntwon, Baldwyn and on toward Booneville in NE Mississippi.

This storm should stay west of the Alabama border and remain on Mississippi.

The line of storms is pushing very slowly east at 15-20 mph. It is going to reach western Alabama’s Lamar and Marion Counties between 2-4 a.m., arriving first in Marion and Lamar Counties.

The rotation in the storm approaching Starkville has weakened and the NWS in Jackson will likely issue a severe thunderstorm warning next on that storm.

While instabilities are slowly decreasing, the wind shear is still very strong over Northeast Mississippi and increasing over Northwest Alabama, so additional spin up tornadoes and damaging winds are possible.

A new tornado watch may be issued for parts of Alabama soon.

Strong Indications of Tornado Heading Toward Starkville, Could Impact Marion/Lamar Soon.

| 1:10 am November 18, 2015


A distinct comma head feature is moving through northeastern Mississippi at this hour.

The thunderstorms associated with this feature have a history of producing possible tornado damage near Carthage around 12:10 a.m.

The possible tornado is north of Louisville and heading in the general direction of Starkville.

It will move toward West Point and Aberdeen and Amory and pass just west of Columbus MS. It could eventually target northern Lamar and western Marion Counties in Alabama. The ETA would be around 2:10-2:25 in northern Lamar County around Sulligent and Hamilton or Guin as early as 2:30-2:45.

It is a good time to be ready to move to a safe shelter in Lamar and Marion Counties on a moment’s notice, especially if you are in a mobile home. If you are in a well constructed home, think low, think inside and and get under something.

Alert your friends in the path in case they don’t have a way to get a warning and might be sleeping.

Mississippi Storms Prompting Warnings, Including Tornado Warnings

| 10:56 pm November 17, 2015


We continue to monitor strong storms tonight over Central Mississippi. They have intensified about 90 minutes ago and prompted tornado warnings.

One set of warnings was located just north of Jackson, in the Canton area. A possible tornado touched down 2 miles south of Edwards in Hinds County, just west of Jackson. It had a possible debris signature and trees are down. That storm is approaching Canton. It appears that it might be at the comma head of a mesoscale convective vortex near Yazoo City. The NWS in Jackson is now tending toward severe thunderstorm warnings on this set of storms, which is a good sign.

A second tornado warned storm was in the Brookhaven area, south of Jackson. Rotation decreased in this storm and the latest warning on this storm.

At 10:55, the NWS in Jackson is issuing a torando warning for Rankin County, which rotation has increased near the Jackson International Airport, around Flowood, east of the city.

Vorticity, or spin and energy in the atmosphere, is being maximized along the flank of the mesoscale convective system as it translates north northeast. That may be because a strong low level jet has been lifting across that area over the past couple of hours, improving upward motion. Inflow into the system appears to be increasing, as evidenced by showers moving north northwest in advance of the system.

At the same time, a narrow funnel of instability continues to translate eastward ahead of the storms, providing the fuel the updrafts need to survive. It appears that wind shear will continue strong, and perhaps even intensify.

SO, it appears that the storms will hold together as they reach the Alabama/Mississippi border between 3-5 a.m. Additional storms will begin to form over areas ahead of the main line and merge with it. These storms will reach Tuscaloosa between 6-8 a.m. and Birmingham between 8-10 a.m. They should reach East Alabama, around Gadsden and Anniston between 11 a.m. and 1 p.m.

Widespread rain and thunderstorms continue behind the front line. The system has slowed its forward progress resulting in heavy rainfall amounts. 2-4 inch amounts are widespread. Wednesday will be a rainy day across Central Alabama, for sure.

Expect another update by 1:30 unless conditions warrant earlier. We will continue monitoring the severe weather situation overnight and have update as necessary.

Operation Weather Watch

| 8:23 pm November 17, 2015

AlabamaWX is in severe weather mode through tomorrow as a dynamic storm system affects a large part of the U.S.

We will be monitoring the situation throughout the night and tomorrow morning with updates as needed.

A line of strong storms extends all along the Mississippi River from St. Louis to Memphis to Natchez MS and on into Louisiana, approaching Lafayette.


Tornado watches cover a wide area from eastern Arkansas and western Tennessee through the Mississippi River Delta region of northeastern Louisiana and Mississippi and into Central Louisiana.

There is currently a severe thunderstorm warning for the area around Natchez MS.

There is just enough instability (500-1,000 j/kg) over the Mississippi Delta to continue to fuel the storm updrafts, with higher instability (1000+ j/kg) lurking across southern Louisiana.

But the main factor in the severe weather is the wind shear. This is a remarkable upper trough, that has produced record low pressures aloft over the West. It is anchored by a bowling ball of an upper level low over the Texas/Oklahoma Panhandles. Rounding the base of the upper low and rotating around its eastern side, winds at 30,000 feet are screaming at 150 mph!

A powerful low level jet is rushing Gulf of Mexico air all the way into the Great Lakes. The evening balloon sounding from ILX (Central Illinois) revealed a precipitable water (PW) value of 1.66 inches. The record value for the date is 1.40 inches! Here is the PW graphic on the right with the very high upper level winds mapped on the left.


The storms are just ahead of the Pacific cold front, which is approaching the Mississippi River.

The storms will continue to be quite strong as they cross Mississippi and they will be approaching Northwest Alabama between 3-5 a.m. They will reach Tuscaloosa around 6-8 a.m. and Birmingham between 8-10 a.m.

Storms could be severe west of US-43 and south of US-80 through the morning hours tomorrow. The best chance for severe weather will be south of a line from Butler to Camden to Fort Deposit to Troy and Dothan through tomorrow afternoon. The main threat will come from damaging winds but an isolated tornado might be possible over Southwest and South Alabama.

Even ahead of the approaching line of storms, winds are quite gusty across Alabama tonight, averaging 15-25 mph and gusting to 35 mph.

The threat will end when the main line of storms passes.

Heavy rain will be a factor with 1.5 inches to 2.5 inches of rain expected on average across Central Alabama. The heaviest amounts will be in the west.

If a Plane Left Dallas for Omaha at 5 and a Plane Left Omaha for Dallas at the Same Time…

| 7:36 pm November 17, 2015


How long would it take?

No, this is a a sixth grade math question, but it is an interesting story tonight, underscoring the impressiveness of the weather system approaching Alabama.

Up where the big jets fly at around 300 millibars constant pressure, or 30,000 feet, winds are screaming at over 150 mph on the front side of the huge trough to our west tonight. The maximum winds extend roughly from the Dallas/Ft. Worth Metroplex to Omaha.

The northbound flight between those two cities would have quite a tailwind! Conversely, the southbound flight would have a heckuva a headwind to contend with.

If an American Airlines MD-80 was flying from DFW to Eppley Airfield in Omaha this afternoon, for a flight that was scheduled to take 1 hour and 45 minutes, how long do you think that flight took today? (Well, of course there is a little padding in that schedule, as the average time is only 1 hour and 19 minutes according to

But today, that MD-80 did it in 1 hour and 8 minutes. The pilot filed a flight plan calling for a speed of 449 knots (516 mph), but the plane achieved groundspeeds of 687 mph as it streaked along in the fast moving river of air.

It left DFW at 5 p.m., and touched down at OMA at 6:08. And that was despite having to take off to the south on runway 18 and turn back to the north!

Here is a graph of the plane’s speed and altitude from late this afternoon.


Of course, there was probably some severe turbulence on the plane’s descent into Omaha. The was a SIGMET (Significant Meteorological Information) advisory in effect along the flight path for severe turbulence between 10,000 and 20,000 feet.


Of course, the flights flying the reverse route told a different story. AA Flight 1286 left Omaha tonight at 6:03 p.m., and still had not made it to DFW as of this writing (7:35 p.m.) despite flying a more direct route. That MD80 has not even been able to go faster that 362 mph. And it has burned a bunch more fuel!