2009 Severe Weather thread

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
450 PM EDT SUN MAY 3 2009

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
FANNIN COUNTY IN NORTH CENTRAL GEORGIA
NORTHERN GILMER COUNTY IN NORTH CENTRAL GEORGIA

* UNTIL 530 PM EDT

* AT 450 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZED HAIL...AND
DAMAGING WINDS UP TO 60 MPH. THIS STORM WAS LOCATED NEAR
ELLIJAY...MOVING EAST AT 30 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO BLUE
RIDGE AND MORGANTON.

[Dave]

CLEBURNE AL-CALHOUN AL-CHEROKEE AL-
356 PM CDT SUN MAY 3 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 415 PM CDT FOR
SOUTHEASTERN CHEROKEE...EXTREME NORTHEASTERN CALHOUN AND NORTH
CENTRAL CLEBURNE COUNTIES...

AT 356 PM CDT...A TORNADO WAS REPORTED. THIS TORNADO WAS LOCATED
NEAR BORDEN SPRINGS...OR 9 MILES EAST OF PIEDMONT...MOVING NORTHEAST
AT 30 MPH.

THE TORNADO WILL BE NEAR...
RURAL SOUTHEASTERN CHEROKEE COUNTY AT 410 PM CDT

[Dave]

Have to leave for awhile, someone else pick it up if needed.

[Brent]

Tornado threat seems to have decreased significantly and the derecho seems to have weakened somewhat(though it still looks like an intense squall line). It's almost here, less than 20 minutes probably.

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
411 PM CDT SUN MAY 3 2009

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
NORTHERN CHAMBERS COUNTY IN EAST CENTRAL ALABAMA...
THIS INCLUDES THE CITY OF STROUD...
SOUTHEASTERN CLEBURNE COUNTY IN EAST CENTRAL ALABAMA...
RANDOLPH COUNTY IN EAST CENTRAL ALABAMA...
THIS INCLUDES THE CITIES OF...WEDOWEE...ROANOKE...

* UNTIL 445 PM CDT

* AT 411 PM CDT...THE NATIONAL WEATHER SERVICE DETECTED A LINE OF
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DESTRUCTIVE WINDS IN
EXCESS OF 70 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
FROM RANBURNE TO PENTON...OR ALONG A LINE EXTENDING FROM 13 MILES
SOUTHEAST OF HEFLIN TO 10 MILES WEST OF STROUD...AND MOVING EAST AT
35 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO RED
LEVEL...FRUITHURST...ABERNATHY...CRYSTAL LAKE...MUSCADINE...WHITE
PLAINS...WELCH AND POST OAK FORKS

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING WIDESPREAD WIND DAMAGE ACROSS
ALL OF CENTRAL ALABAMA. TREES DOWN AND STRUCTURAL DAMAGE HAS BEEN
COMMON WITH THE LINE. THIS IS AN EXTREMELY DANGEROUS SITUATION. SEEK
SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS!

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 500 PM CDT SUNDAY
AFTERNOON FOR EASTERN ALABAMA.

[Brent]

Not bad at all here at least at my location. Not much wind at all.

[JonathanBelles]

Atlanta about to be hit hard.

[Ed Mahmoud]

Tomorrow still a potentially interesting day in North Texas and Southern Oklahoma






Both NAM and GFS soundings show a good potential for severe, but also show a warm nose at 700 mb that may be hard to break, and limit coverage of storms South of the warm front.

[Dave]

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
205 PM EDT MON MAY 4 2009

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* TORNADO WARNING FOR...
NORTHERN WASHINGTON COUNTY IN EAST CENTRAL GEORGIA

* UNTIL 230 PM EDT

* AT 205 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 7 MILES WEST OF
SANDERSVILLE...MOVING NORTHEAST AT 25 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
WARTHEN.

[Dave]

WASHINGTON GA-JEFFERSON GA-GLASCOCK GA-
244 PM EDT MON MAY 4 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 315 PM EDT FOR SOUTH
CENTRAL GLASCOCK...WEST CENTRAL JEFFERSON AND NORTHEASTERN WASHINGTON
COUNTIES...

AT 244 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO. THIS TORNADO WAS LOCATED NEAR DOWNS...MOVING
NORTHEAST AT 25 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
GRANGE...EDGEHILL AND STAPLETONS CROSSROADS.

[Ed Mahmoud]

NAM shows some precip in DFW area between 7pm and 1 am tomorrow, and the sounding looks fairly reasonable for severe, with a touch less of a 700 mb warm nose that would surpress storm formation

[somethingfunny]

Good morning, Dallas-Fort Worth!

DISCUSSION... /ISSUED 418 AM CDT TUE MAY 5 2009/
LOOKS LIKE ANOTHER ROUND OF ACTIVE WEATHER TODAY AND TONIGHT AS
FAST WEST/NORTHWEST FLOW ALOFT PATTERN CONTINUES. SOUTHERLY FLOW
IS INTENSIFYING JUST ABOVE THE SURFACE...AND IS BRINGING A WARM
FRONT NORTH INTO THE REGION. WARM FRONT WILL REACH THE I-20
CORRIDOR BY NOON...AND EVENTUALLY STALL IN THE NORTHERN ZONES THIS
EVENING. VERY MOIST AIRMASS...CHARACTERIZED BY DEWPOINTS NEAR
70...WILL RESULT IN MODERATE INSTABILITY IN THE WARM SECTOR. SHEAR
PROFILES WILL BE ENHANCED ALONG AND NORTH OF I-20 NEAR THE FRONT.
ALL THE USUAL SUSPECTS ARE IN PLAY FOR A POTENTIALLY SIGNIFICANT
SEVERE WX EVENT FOR THE NORTHERN HALF OF THE CWA THIS EVENING.

A FIRST SHORTWAVE WILL MOVE ACROSS OKLAHOMA THIS MORNING AND EARLY
AFTERNOON...RESULTING IN A ROUND OF ELEVATED CONVECTION IN
OKLAHOMA...WHICH SHOULD BUILD SOUTHEAST AND AFFECT PRIMARILY THE
NORTHERN ZONES ALONG AND NORTH OF RETREATING WARM FRONT.

BY THIS EVENING...LOW LEVEL JET INTENSIFIES...AND BACKED FLOW IN
THE VICINITY OF FRONT WILL CREATE IMPRESSIVE CURVED HODOGRAPHS.
LCLS WILL BE LOW WITH CAPES OF 1000-2000 J/KG. SECOND SHORTWAVE
WILL MOVE DOWN THE RED RIVER VALLEY THIS EVENING...WITH SUPERCELL
CONVECTION LIKELY FIRING IN THE NW ZONES NEAR STALLED FRONT BEFORE
SUNSET. HIGHEST TORNADO POTENTIAL WILL BE ACROSS THE NW/N ZONES
THIS EVENING...WHILE STORMS REMAIN DISCRETE. NORTH TEXAS WILL BE
PLACED IN A LEFT EXIT REGION OF UPPER LEVEL JET...WHICH IS OFTEN A
GOOD SIGN THAT CONVECTION WILL GROW UPSCALE INTO AN MCS. MCS
MOTION WILL BE SOUTHEASTERLY...AND FAVORABLE SHEAR/INSTABILITY
SUGGESTS A BOW ECHO/WIND EVENT MAY EVOLVE FROM THE METROPLEX TO
THE ATHENS AREA. THIS SCENARIO IS MODELED BY THE 4KM WRF...AND
THUS HAVE EXPANDED POPS FARTHER SOUTH THAN NAM/GFS INDICATE...
SINCE THEY OFTEN STRUGGLE WITH MCS MOTION.

WITH THE COMBINATION OF 2 ROUNDS OF CONVECTION OVER THE NORTHEAST
ZONES AND ALREADY SATURATED GROUND FROM RECENT RAIN...FEEL IT IS
PRUDENT TO HIGHLIGHT THESE ZONES IN A FLASH FLOOD WATCH. WHILE THE
HEAVY RAIN POTENTIAL LOOKS LESS IMPRESSIVE THAN THE LAST COUPLE
EVENTS...THERE IS STILL A RISK OF TRAINING ECHOES NEAR FRONT.

CONVECTION WILL MOVE EAST...WITH PERHAPS SOME LINGERING STORMS OVER
THE NORTHEAST WEDNESDAY MORNING. SOUTHWEST FLOW IN THE LOW LEVELS
WILL BRING IN MUCH WARMER AIR FROM WEST TEXAS...WHICH SHOULD SERVE
TO DEPLETE PWATS AND RESULT IN WARMER TEMPS WEDNESDAY AND THURSDAY.
MODELS INDICATE AIRMASS WILL REMAIN UNSTABLE...BUT WESTERLY FLOW
ALOFT WILL ALSO STRENGTHEN CAP.

ANOTHER COLD FRONT WILL MOVE INTO NORTH TEXAS FRIDAY...AND WILL
PHASE POPS BACK INTO THE FORECAST OVER THE WEEKEND. MOST OF THE
CONVECTION WILL AGAIN BE NORTH OF I-20...WHERE BETTER DYNAMICS
WILL ASSIST IN ERODING CAP.

TR.92

[Ed Mahmoud]

[somethingfunny]

Something similar to this is right across the street from my place of work, and I use it frequently, to avoid problems like that!


Although it still runs a risk of this .......


I calculate the risk of large hail to be significantly higher than that of a tornado or downburst.

BTW....Ed, are you still in Wichita Falls? Storms are already popping in southwestern Oklahoma.

[Ed Mahmoud]

Back in Houston. Missed the flood, did see pea sized hail in a late evening t-storm Tuesday.

[Ed Mahmoud]

Dallas area will have to overcome a bit of a warm nose at 750 mb for the thunderstorms to really fire per GFS forecast 7 pm skew-T, but if storms can initiate, boatloads of instability and helicity, and a forecast EHI of 4.3



Partly sunny here in Houston, and it looks like clouds are mixing out South of the warm front to allow near maximum mid-day insolation.



Judging by the local obs, the somewhat diffuse front, which separates air in the 70s and dewpoints in the low 70s or high 60s from air in the upper 60s with dewpoints in the low 60s (Farenheit) is through Corsicana and Hillsborough, but not yet to the DFW metroplex.

[Ed Mahmoud]

NWS in Fort Worth to launch special sounding at 2 pm CDT to evaluate cap strength and severe probabilities.


This is the 14th anniversary of the Fort Worth softball sized hail storm.

[Bunkertor]

NWS in Fort Worth to launch special sounding at 2 pm CDT to evaluate cap strength and severe probabilities.

Hey Ed where did you get that info from ?

[Ed Mahmoud]

18Z RUC shows a supercell forming somewhere between Abilene and Fort Worth. NWS Fort Worth-Dallas has seen the 21Z RUC already, and discounted it because it didn't initialize well. Maybe they meant the 18Z RUC, because it isn't 21Z yet.


So, maybe this is from the run discounted, but a mega-scary forecast sounding...

[Ed Mahmoud]

NWS in Fort Worth to launch special sounding at 2 pm CDT to evaluate cap strength and severe probabilities.

Hey Ed where did you get that info from ?

I work until I get bored, I read local NWS office discussions and HPC discussions, look at PSU e-Wall model page and Northern Illinois University model skew-T generator page.

Then I start working again.

[RL3AO]

NWS in Fort Worth to launch special sounding at 2 pm CDT to evaluate cap strength and severe probabilities.

Hey Ed where did you get that info from ?

LARGE HAIL AND DAMAGING
OUTFLOW WINDS APPEAR TO BE A MORE COMMON THREAT FOR THIS EVENING
AND OVERNIGHT...WITH DAMAGING WINDS LOOKING LIKELY WITH ANY MCS
THAT MOVES ACRS THE CWA THIS EVENING. 19Z SOUNDING WILL BE SENT UP
TO EVALUATE CAP STRENGTH. CAVANAUGH

http://kamala.cod.edu/offs/KFWD/0905051725.fxus64.html