Severe weather outbreak? April 2 - MDT risk

[CrazyC83]

MESOSCALE DISCUSSION 0371
NWS STORM PREDICTION CENTER NORMAN OK
0204 PM CDT THU APR 02 2009

AREAS AFFECTED...PARTS OF MIDDLE TN...W CNTRL KY AND ADJACENT AREAS
OF SRN IL/IND

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 021904Z - 022100Z

TRENDS ARE BEING MONITORED FOR AN INCREASING SEVERE THREAT AND THE
POSSIBILITY OF A WW.

SCATTERED CONVECTIVE DEVELOPMENT IS ALREADY UNDERWAY AS FAR NORTH AS
THE LOWER OHIO VALLEY...SUPPORTED BY AN INITIAL AREA OF MID-LEVEL
FORCING EMANATING FROM THE MUCH STRONGER UPSTREAM SHORT WAVE TROUGH.
WHILE THIS FORCING DEVELOPS EAST NORTHEASTWARD THROUGH THE LOWER
OHIO VALLEY AND WEAKENS THIS AFTERNOON...THE EXIT REGION OF THE
PRIMARY MID-LEVEL JET STREAK IS PROGGED TO GRADUALLY NOSE THROUGH
WESTERN TENNESSEE AND KENTUCKY. DESPITE THE TENDENCY FOR BACKING
WINDS ALOFT...FROM SOUTHWESTERLY TO SOUTHERLY...STRENGTHENING
SOUTHEASTERLY LOW-LEVEL FLOW...AHEAD OF THE DEEPENING SURFACE
CYCLONE MIGRATING ACROSS ARKANSAS...IS EXPECTED TO CONTRIBUTE TO AN
INCREASINGLY FAVORABLE ENVIRONMENT FOR SUPERCELLS ACROSS MUCH OF
WEST CENTRAL KENTUCKY BY THE 21-23Z TIME FRAME. BOUNDARY LAYER
DESTABILIZATION IS ONGOING ACROSS THIS REGION...WITH FURTHER
DESTABILIZATION LIKELY AS SURFACE DEW POINTS APPROACH THE LOWER 60S.
ISOLATED TORNADOES WILL BE POSSIBLE...IN ADDITION TO THE RISK FOR
LARGE HAIL/LOCALLY DAMAGING WIND GUSTS.

..KERR.. 04/02/2009


ATTN...WFO...LMK...OHX...IND...PAH...MEG...

LAT...LON 37698864 38518782 38838595 37758526 36238580 36128648
36208777 36908858 37698864

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HUNTSVILLE AL
207 PM CDT THU APR 2 2009

THE NATIONAL WEATHER SERVICE IN HUNTSVILLE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
NORTHEAST COLBERT COUNTY IN NORTHWEST ALABAMA...
EASTERN LAUDERDALE COUNTY IN NORTHWEST ALABAMA...

* UNTIL 230 PM CDT

* AT 203 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR
LEIGHTON...MOVING NORTHEAST AT 35 MPH. ANOTHER SEVERE THUNDERSTORM
WAS LOCATED JUST NORTH OF ST. FLORIAN IN LAUDERDALE COUNTY.

* LOCATIONS IMPACTED INCLUDE...
FORD CITY...SAINT FLORIAN...
KILLEN...ST. FLORIAN...
CENTER STAR...ELGIN...
ROGERSVILLE...
KINGTOWN...LEXINGTON...

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOBILE AL
159 PM CDT THU APR 2 2009

THE NATIONAL WEATHER SERVICE IN MOBILE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
SOUTHEASTERN ESCAMBIA COUNTY IN NORTHWEST FLORIDA...
THIS INCLUDES THE CITY OF PENSACOLA...
OKALOOSA COUNTY IN NORTHWEST FLORIDA...
THIS INCLUDES THE CITIES OF...FORT WALTON BEACH...DESTIN...
CRESTVIEW...
SOUTHERN SANTA ROSA COUNTY IN NORTHWEST FLORIDA...
THIS INCLUDES THE CITY OF NAVARRE...

* UNTIL 245 PM CDT

* AT 154 PM CDT...THE NATIONAL WEATHER SERVICE INDICATED A LINE OF
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DESTRUCTIVE WINDS OVER 70 MPH. THESE STORMS WERE ALONG A LINE
EXTENDING FROM MILTON NEAR WHITING FIELD TO GULF BREEZE TO 24 MILES
SOUTHWEST OF PENSACOLA NAVAL BASE...MOVING NORTHEAST AT 60 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
HAROLD BY 205 PM CDT...
GULF BREEZE...WEST PENSACOLA...WARRINGTON AND MYRTLE GROVE BY 210
PM CDT...
PENSACOLA REGIONAL A/P...GOULDING...FERRY PASS AND BRENT BY 215 PM
CDT...
MILLIGAN BY 220 PM CDT...

[Bunkertor]

-double post edit-

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
212 PM CDT THU APR 2 2009

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A

* TORNADO WARNING FOR...
SOUTHERN HARRISON COUNTY IN SOUTHERN MISSISSIPPI...
THIS INCLUDES THE CITIES OF...LONG BEACH...GULFPORT...BILOXI...
SOUTHWESTERN JACKSON COUNTY IN SOUTHERN MISSISSIPPI...
THIS INCLUDES THE CITIES OF...ST. MARTIN...OCEAN SPRINGS...

* UNTIL 245 PM CDT

* AT 210 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A TORNADO NEAR
BAY ST LOUIS...MOVING NORTHEAST AT 50 MPH.

* THE TORNADO WILL BE NEAR...
BILOXI BY 225 PM CDT...
ST. MARTIN BY 230 PM CDT...
OCEAN SPRINGS AND 8 MILES NORTHWEST OF GULF PARK ESTATES BY 235 PM
CDT...

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING
QUARTER SIZE HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS.

[CrazyC83]

Could we see a back-building of storms behind the line? It is rapidly clearing out over Louisiana and SW Mississippi, and it is still only 2:15 pm there.

[Brent]

Maybe today should have been a HIGH RISK day...

No way, this isn't even close to a moderate risk yet. I'm not impressed at all so far.

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NASHVILLE TN
217 PM CDT THU APR 2 2009

THE NATIONAL WEATHER SERVICE IN NASHVILLE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
DICKSON COUNTY IN MIDDLE TENNESSEE...
THIS INCLUDES THE CITY OF DICKSON...
NORTH CENTRAL HICKMAN COUNTY IN MIDDLE TENNESSEE...

* UNTIL 245 PM CDT

* AT 215 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM. THIS STORM WAS LOCATED 9 MILES SOUTHWEST OF
DICKSON...AND MOVING NORTHEAST AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
DICKSON AND BURNS BY 230 PM CDT...

[Bunkertor]

There are loads of Cells popping up in the FL panhandle area.

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE JACKSON MS
216 PM CDT THU APR 2 2009

THE NATIONAL WEATHER SERVICE IN JACKSON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
CLARKE COUNTY IN EAST CENTRAL MISSISSIPPI...
THIS INCLUDES THE CITY OF QUITMAN...

* UNTIL 315 PM CDT

* AT 217 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
FROM 6 MILES NORTHWEST OF STONEWALL TO GOODWATER...OR ALONG A LINE
EXTENDING FROM 14 MILES NORTHWEST OF QUITMAN TO 10 MILES SOUTHWEST
OF QUITMAN...AND MOVING EAST AT 35 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
DE SOTO AND QUITMAN BY 230 PM CDT...
SABLE BY 235 PM CDT...
SYKES AND MIDDLETON BY 245 PM CDT...
CRANDALL BY 250 PM CDT...
SNELL BY 255 PM CDT...

[Dave]

TVS W/SW of Nashville TN, watching for possible warning.

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
220 PM CDT THU APR 2 2009

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
GREENE COUNTY IN WEST CENTRAL ALABAMA...
THIS INCLUDES THE CITY OF EUTAW...
SOUTHERN PICKENS COUNTY IN WEST CENTRAL ALABAMA...
THIS INCLUDES THE CITY OF ALICEVILLE...
NORTHERN SUMTER COUNTY IN WEST CENTRAL ALABAMA...
THIS INCLUDES THE CITY OF LIVINGSTON...

* UNTIL 300 PM CDT

* AT 220 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING NICKEL SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM 20 MILES WEST OF PANOLA TO 13
MILES WEST OF BOYD...OR ALONG A LINE EXTENDING FROM 26 MILES
SOUTHWEST OF PICKENSVILLE TO 14 MILES NORTHWEST OF CUBA...AND
MOVING EAST AT 45 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
EMELLE AND BOYD BY 235 PM CDT...
WEST UNION BY 240 PM CDT...
MEMPHIS...THE UNIVERSITY OF WEST ALABAMA...LIVINGSTON AND PANOLA BY
245 PM CDT...
BLUFFPORT...GAINESVILLE AND EPES BY 250 PM CDT...

THIS INCLUDES
AND INTERSTATE 20 EXIT NUMBERS 32 THROUGH 79.

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MEMPHIS TN
220 PM CDT THU APR 2 2009

THE NATIONAL WEATHER SERVICE IN MEMPHIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
TISHOMINGO COUNTY IN NORTHEAST MISSISSIPPI...

* UNTIL 300 PM CDT

* AT 220 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED 7 MILES
WEST OF TISHOMINGO...OR 10 MILES WEST OF TISHOMINGO STATE PARK...
AND MOVING NORTHEAST AT 40 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
MIDWAY...IUKA AND JCOLEMAN STATE PARK. THIS WARNING ALSO INCLUDES
BAY SPRINGS LAKE.

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
221 PM CDT THU APR 2 2009

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
WEST CENTRAL MARION COUNTY IN NORTHWEST ALABAMA...
THIS INCLUDES THE CITY OF HAMILTON...
LAMAR COUNTY IN WEST CENTRAL ALABAMA...
THIS INCLUDES THE CITIES OF...VERNON...SULLIGENT...

* UNTIL 300 PM CDT

* AT 221 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM 18 MILES NORTHWEST OF BEDFORD
TO 17 MILES SOUTHWEST OF BEDFORD...OR ALONG A LINE EXTENDING FROM
AMORY TO COLUMBUS AFB...AND MOVING EAST AT 35 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
BEDFORD BY 245 PM CDT...
DETROIT BY 250 PM CDT...
CREWS...VERNON...SULLIGENT AND LAMAR COUNTY AIRPORT BY 255 PM
CDT...
BEAVERTON BY 300 PM CDT...

[Ed Mahmoud]

Maybe today should have been a HIGH RISK day...

So far, the MDT hasn't verified, but QLCS situations often lead to tornadoes as well...

Have they gone HIGH RISK for hail or derechoes in the recent past, ie, HIGH RISK w/o a hatched tornado area?


Just curious.

[RL3AO]

Interesting blog post from yesterday that seems to be on the money so far.
----

Now that we are closer to tomorrow's threat, we can hone in a little more than I did the other day. First off, check the first map below which shows SPC's risk areas for tomorrow. We still have a lead shortwave which veers winds in its wake tomorrow, and keeps the low level jet a little on the weaker side, though probably not as weak as last week's system saw initially. Still though, despite the veered LLJ, the surface winds look to have a more southerly component, which would give a decent 0-1 km shear vector, which for a tornado outbreak is the most important shear layer. I agree with SPC's moderate risk, but despite robust moisture and more than sufficient instability progged, you can color me skeptical on this being a "major outbreak" of tornadoes. I will preface this comment though by saying that if you live in the risk area, be ready! This stuff can be tricky and you don't want to be caught downplaying an event that has any potential to turn out serious.

But I will look to the past some here. The second map below is the progged 500 mb map for tomorrow afternoon. Note the strong, but sharp, and already trying to tilt negatively, shortwave headig toward the South. My reason for some skepticism is that such a pattern looks conducive for storms to fire early, and with stronger forcing due to tilt of trough, we get many storms that can more easily cluster together rather than discrete storms which in a sheared environment can be more of a tornadic problem. If you look at historical data, many (but to be fair, not all) of the big outbreaks in the south occurred with a trough that had a larger base and / or was actually more of a positive tilt variety. Why? Well, since the South almost always has a lot more moisture to work with, positive tilt means forcing isn't as strong, but still strong enough for isolated / discrete storms to fire. The third map below is from 4/7/06, which was one such major outbreak, but I could provide other examples.

In any case, as mentioned, I agree a moderate risk is warranted. I don't see it being a high risk day, or at least verifying as one at this time, and think the tornado threat will be confined mostly to initial storms in western half of moderate risk area, and then become mostly a wind / hail threat rather quickly, with spin-up tornadoes mixed in the clusters still a possibility. We're still 24 hours away though, so small scale details can still change, so stay tuned! Maps referred to above follow:

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE JACKSON MS
224 PM CDT THU APR 2 2009

THE NATIONAL WEATHER SERVICE IN JACKSON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
SOUTHEASTERN CLAY COUNTY IN NORTHEAST MISSISSIPPI...
LOWNDES COUNTY IN NORTHEAST MISSISSIPPI...
THIS INCLUDES THE CITIES OF...COLUMBUS AFB...COLUMBUS...

* UNTIL 330 PM CDT

* AT 224 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING NICKEL SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM 6 MILES WEST OF WAVERLY TO 17
MILES SOUTH OF CRAWFORD...OR ALONG A LINE EXTENDING FROM WEST POINT
TO 17 MILES NORTHEAST OF PRESTON...AND MOVING NORTHEAST AT 40 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
BENT OAK BY 230 PM CDT...
WAVERLY BY 235 PM CDT...
COLUMBUS AFB BY 240 PM CDT...
KOLOLA SPRINGS AND COLUMBUS BY 245 PM CDT...
STEENS AND CALEDONIA BY 255 PM CDT...

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MOBILE AL
225 PM CDT THU APR 2 2009

THE NATIONAL WEATHER SERVICE IN MOBILE HAS ISSUED A

* TORNADO WARNING FOR...
SOUTHEASTERN ESCAMBIA COUNTY IN NORTHWEST FLORIDA...
THIS INCLUDES THE CITY OF PENSACOLA...
SOUTHERN OKALOOSA COUNTY IN NORTHWEST FLORIDA...
THIS INCLUDES THE CITIES OF...FORT WALTON BEACH...DESTIN...
SOUTHEASTERN SANTA ROSA COUNTY IN NORTHWEST FLORIDA...
THIS INCLUDES THE CITY OF NAVARRE...

* UNTIL 315 PM CDT

* AT 219 PM CDT...THE NATIONAL WEATHER SERVICE INDICATED A
DEVELOPING CIRCUALTION THUNDERSTORM CAPABLE OF PRODUCING A
TORNADO 6 MILES SOUTHWEST OF PENSACOLA NAVAL BASE...OR ABOUT 12
MILES SOUTHWEST OF PENSACOLA...MOVING NORTHEAST AT 65 MPH.

* THE TORNADO WILL BE NEAR...
ORIOLE BEACH BY 230 PM CDT...

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TALLAHASSEE FL
228 PM CDT THU APR 2 2009

THE NATIONAL WEATHER SERVICE IN TALLAHASSEE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
WESTERN HOLMES COUNTY IN THE PANHANDLE OF FLORIDA...
WALTON COUNTY IN THE PANHANDLE OF FLORIDA...
THIS INCLUDES THE CITIES OF...SANTA ROSA BEACH...DE FUNIAK
SPRINGS...

* UNTIL 315 PM CDT

* AT 224 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING GOLF BALL SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS
LOCATED 28 MILES NORTHWEST OF SANTA ROSA BEACH...AND MOVING EAST AT
55 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
DE FUNIAK SPRINGS BY 300 PM CDT...

THERE HAVE BEEN NUMEROUS REPORTS OF GOLF BALL SIZE HAIL ALONG THE TRACK
OF THIS STORM ACROSS THE WESTERN FLORIDA PANHANDLE.

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PADUCAH KY
228 PM CDT THU APR 2 2009

THE NATIONAL WEATHER SERVICE IN PADUCAH HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
WESTERN CALLOWAY COUNTY IN WESTERN KENTUCKY...
EASTERN GRAVES COUNTY IN WESTERN KENTUCKY...
MARSHALL COUNTY IN WESTERN KENTUCKY...

* UNTIL 300 PM CDT

* AT 225 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR
MAYFIELD...AND MOVING NORTH AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
7 MILES WEST OF CALVERT CITY BY 300 PM CDT...