Severe weather outbreak? December 25-26

[CrazyC83]

Strong wording from NWS New Orleans, who also understands our fears:

694
FXUS64 KLIX 251427
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
827 AM CST TUE DEC 25 2012

.UPDATE...
...SOUNDING DISCUSSION...

WHILE THERE WERE A FEW ISSUES WITH THE FLIGHT THIS MORNING...A
SUCCESSFUL LAUNCH WAS STILL ACHIEVED. THE FLIGHT WAS DELAYED
AROUND 20 MINUTES DUE TO A THUNDERSTORM THAT PASSED OVER THE
STATION IN SLIDELL. ONCE THE SONDE WAS RELEASED IT WAS OBVIOUSLY
EXTREMELY DAMP AND WENT THROUGH A DRY AREA IN WHICH THE SENSOR
LIKELY COOLED RAPIDLY. PURGED ABOUT TWO MINUTES OF DATA AROUND 12K
FEET TO REMOVE THE WET-BULB EFFECT FROM THE SOUNDING.

ALL OF THAT SAID...THE SOUNDING POINTS TO WHAT HAS BEEN EXPECTED
ALL ALONG...A SIGNIFICANT SEVERE WEATHER OUTBREAK. PW VALUES ARE
UP TO AN INCH AND A QUARTER AND ARE LIKELY TO CONTINUE TO RISE.
THE LIFTED INDEX FROM THE SOUNDING WAS -7.5 WHICH SURELY POINTS
TO A HIGH SEVERE THUNDERSTORM POTENTIAL. CAPE IS MORE THAN
SUFFICIENT WITH A VALUE OF OVER 1800 J/KG AND IS LIKELY TO INCREASE
GIVEN THE HIGHER VALUES SHOWN ON THE KLCH SOUNDING. 0-3 KM SHEAR
ON THE ORDER OF 35 KNOTS WAS NOTED IN THE SOUNDING WITH WINDS OUT
OF THE SOUTH AT THE SURFACE QUICKLY SHIFTING TO THE SOUTHWEST AND
WEST. THIS IS PRODUCING STORM RELATIVE HELICITY VALUES AROUND 250
M2/S2 WHICH IS SUFFICIENT TO PRODUCE ROTATING STORMS. WET BULB ZERO
HEIGHTS ARE BELOW 10K FEET AND THE FREEZING LEVEL HEIGHT OF JUST
OVER 10K FEET ARE GOOD INDICATORS THAT LARGE HAIL COULD BE
ENCOUNTERED WITH ANY OF THESE STORMS. SOME LARGE HAIL HAS ALREADY
FALLEN WITH SOME OF THE STORMS TO OUR WEST THIS MORNING.

OVERALL...THE IDEA IS THAT THE ATMOSPHERE IS MORE THAN PRIMED FOR
SEVERE WEATHER TODAY AND IS ONLY LIKELY TO BECOME MORE FAVORABLE
AS WE MOVE INTO THE AFTERNOON HOURS WHERE A LULL IN CONVECTION
COULD ALLOW FOR ADDITIONAL SURFACE HEATING AND DESTABILIZATION OF
THE ATMOSPHERE. IT IS IMPERATIVE THAT ALL INTERESTS IN THE AREA
STAY INFORMED OF THE LATEST WEATHER INFORMATION TODAY...ESPECIALLY
IN LIGHT OF THE FACT THAT THERE WILL BE A SIGNIFICANT NUMBER OF
PEOPLE ON THE ROADWAYS AND AT EVENTS THAT MIGHT TAKE THEM AWAY
FROM THEIR NORMAL MEANS OF RECEIVING WEATHER ALERTS.

&&

[CrazyC83]

1630Z: no upgrade, slight expansion of MDT northwest

[CrazyC83]

Considered an upgrade to High Risk, might still at 20Z.

SPC AC 251619

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1019 AM CST TUE DEC 25 2012

VALID 251630Z - 261200Z

...THERE IS A MDT RISK OF SVR TSTMS SERN TX INTO THE GULF STATES...

...THERE IS A SLGT RISK OF SVR TSTMS CNTRL TX EWD ACROSS THE GULF
COAST STATES TO WRN SC...

A SEVERE WEATHER OUTBREAK IS LIKELY TODAY AND TONIGHT FROM SERN TX
ACROSS THE GULF COAST STATES. STRONG...LONG-TRACKED TORNADOES AND
WIDESPREAD DAMAGING WINDS ARE POSSIBLE.

...SYNOPSIS...
A POWERFUL SHORT WAVE TROUGH /EVIDENT ON 1530Z WV IMAGERY OVER W TX/
IS EXPECTED TO QUICKLY PROGRESS EWD AND BECOME NEGATIVELY TILTED
OVER THE GULF COAST STATES BEFORE REACHING THE TN VALLEY BY 26/12Z.
SIGNIFICANT FORCING FOR ASCENT ATTENDANT TO THE SHORT WAVE WILL
PROMOTE VIGOROUS STORM DEVELOPMENT ACROSS CNTRL TX AND THE GULF
STATES. MEANWHILE...A DUO OF LEAD SHORT WAVES /OVER LA AND ERN TX AS
OF 1530Z/ WILL QUICKLY EJECT NEWD AHEAD OF THE PARENT SYSTEM.

IN THE LOW LEVELS...A TX HILL COUNTRY SURFACE LOW IS EXPECTED TO
DEEPEN AS IT TRAVERSES ACROSS NRN LA/MS AND INTO MIDDLE TN BY THE
END OF THE PERIOD. A COINCIDENT POLEWARD MOVEMENT OF AN EAST-WEST
ORIENTED WARM FRONT ACROSS E CNTRL TX...SRN MS/AL AND THE WRN FL
PANHANDLE WILL OCCUR...BROADENING THE WARM/MOIST SECTOR OVER THE
GULF STATES. MEANWHILE...A SUBTLE N-S SURFACE TROUGH OVER S CNTRL TX
WILL BE REINFORCED AS A COLD FRONT SURGES EWD THROUGH THE SABINE
RIVER VALLEY TODAY AND THE LOWER MS VALLEY...REACHING WRN GA BY
26/12Z.

...ERN TX EWD ACROSS THE GULF COAST STATES...
STRONG/SEVERE ELEVATED THUNDERSTORMS DEVELOPED THIS MORNING ACROSS
PORTIONS OF CNTRL TX AND CNTRL/SRN LA IN RESPONSE TO ISENTROPIC
ASCENT AND ONGOING WAA. AREA VAD WIND PROFILE DATA SHOWS AN INTENSE
LOW LEVEL JET /40-50 KT/ THAT IS FORECAST TO FURTHER INTENSIFY AND
BROADEN TODAY COINCIDENT WITH THE APPROACH OF A STRONG UPPER SYSTEM.
OBSERVED 12Z SOUNDINGS AT FWD AND CRP REFLECTED STEEP MID-LEVEL
LAPSE RATES NEAR 8.2-8.4 C/KM. THESE LAPSE RATES ARE ASSOCIATED WITH
AN EML THAT WILL CONTINUE TO PROMOTE THE DEVELOPMENT OF SUPERCELLS
CAPABLE OF PRODUCING LARGE HAIL OVER ERN TX/WRN LA THIS
MORNING...PARTICULARLY GIVEN STRONG DEEP LAYER SHEAR ATTENDANT TO AN
APPROACHING MID-UPPER JET /90-100 KT 500 MB JET AND 120-130 KT 250
MB/. ADDITIONALLY...USING A MODIFIED 12Z FWD SOUNDING...MINIMAL CINH
REMAINS OVER TX...SUGGESTING CONVECTION IS BECOMING SURFACE-BASED.

DISCRETE SUPERCELLS CAPABLE OF ALL THREATS OF SEVERE WEATHER
/INCLUDING THE POTENTIAL FOR LONG-TRACKED TORNADOES/ MAY BE POSSIBLE
AS THE AFOREMENTIONED MID-UPPER LEVEL JET APPROACHES...SUBSEQUENTLY
STRENGTHENING DEEP LAYER SHEAR PROFILES AND PROMOTING STRONG
ROTATION. VISIBLE IMAGERY SUGGESTS CLEARING MAY OCCUR OVER PORTIONS
OF SE TX...CNTRL/SRN LA/MS/AL...WHERE THE GREATEST POTENTIAL
SURFACE-BASED DESTABILIZATION AND CONSEQUENTLY TORNADIC POTENTIAL
WILL EXIST LATER THIS MORNING INTO THE AFTERNOON. HOWEVER...IMPLIED
SUBSIDENCE /DEMARCATED BY SIGNIFICANT DRYING ON WV IMAGERY OVER THE
WRN GULF/ MAY VERY TEMPORARILY DELAY THE DEVELOPMENT IN DISCRETE
SUPERCELLS ACROSS THE WARM SECTOR UNTIL FORCING FOR ASCENT QUICKLY
ARRIVES WITH THE E TX SHORT WAVE. AS SUCH...THE EXPECTED LIMITED
TEMPORAL THREAT OF DISCRETE CELLS WILL PRECLUDE AN UPGRADE TO HIGH
RISK ATTM...THOUGH THE CATEGORICAL THREAT WILL BE REEVALUATED AT
20Z.

AS THE DAY PROGRESSES...FORCED ASCENT ALONG THE ADVANCING COLD FRONT
WILL RESULT IN QLCS DEVELOPMENT CONTAINING EMBEDDED FAST-MOVING BOW
ECHOES AND POSSIBLE SUPERCELLS/MESO-VORTICES AS IT MOVES EWD ACROSS
LA AND THE SRN HALF OF MS. THE NARROW LINE OF SIGNIFICANT STORMS
/PRIMARILY CAPABLE OF DMGG WINDS/ WILL QUICKLY PROGRESS THROUGH THE
GULF STATES...REACHING WRN GA/THE FL PANHANDLE BY 26/12Z.

..DISPIGNA/COHEN.. 12/25/2012

CLICK TO GET WUUS01 PTSDY1 PRODUCT

NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
CURRENT UTC TIME: 1624Z (11:24AM), RELOAD THIS PAGE TO UPDATE THE TIME

[WeatherGuesser]

Let's not forget the other hazards expected today and tonight:

449 AM CST TUE DEC 25 2012

...BLIZZARD WARNING IN EFFECT FROM 6 PM THIS EVENING TO NOON CST
WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN PADUCAH HAS ISSUED A BLIZZARD
WARNING...WHICH IS IN EFFECT FROM 6 PM THIS EVENING TO NOON CST
WEDNESDAY. THE BLIZZARD WATCH IS NO LONGER IN EFFECT.

* SNOWFALL AMOUNTS: ACROSS SOUTHERN ILLINOIS...THE IMMEDIATE
EVANSVILLE AREA...AND SOUTHWESTWARD ALONG THE OHIO RIVER INTO
THE PURCHASE AREA OF WEST KENTUCKY...8 TO 11 INCHES OF SNOWFALL
IS EXPECTED. OVER SOUTHEAST MISSOURI 4 TO 8 INCHES CAN BE
EXPECTED. SOME LOCALIZED AREAS MAY SEE VERY INTENSE BANDING
WHERE OVER A FOOT OF SNOW WILL BE POSSIBLE.

* WINDS: WINDS TONIGHT WILL INCREASE TO AROUND 25 MPH...WITH
FREQUENT GUSTS FROM 30 TO 40 MPH. THESE STRONG WINDS WILL
PERSIST THROUGH WEDNESDAY MORNING. THE COMBINATION OF THESE
GUSTY WINDS AND THE FALLING SNOW AND POSSIBLY BLOWING SNOW MAY
REDUCE VISIBILITIES TO UNDER A QUARTER MILE AT TIMES.

* TIMING: SNOWS WILL GRADUALLY SPREAD NORTH AND EAST OVER THE
REGION THROUGH THE EVENING. THE HEAVIEST SNOWS AND STRONGEST
WINDS ARE EXPECTED TO DEVELOP BETWEEN MIDNIGHT TO 6 AM
WEDNESDAY. CONDITIONS WILL BEGIN TO IMPROVE BETWEEN 8 AM AND
NOON ON WEDNESDAY.

* IMPACTS: BLIZZARD CONDITIONS ARE EXPECTED. EXPECT TRAVEL TO
BECOME VERY DIFFICULT OR IMPOSSIBLE. BLOWING AND DRIFTING SNOW
COULD MAKE ROADS IMPASSABLE THROUGH MUCH OF THE DAY WEDNESDAY.
WHITEOUT CONDITIONS MAY CREATE A LIFE THREATENING SITUATION FOR
THOSE VENTURING OUTDOORS. BLOWING SNOW MAY CONTINUE INTO
WEDNESDAY AFTERNOON OVER PORTIONS OF THE AREA...SO THE WARNING
MAY NEED TO BE EXTENDED INTO WEDNESDAY AFTERNOON...ESPECIALLY IN
THE EAST.

* OTHER IMPACTS: THE HEAVY WET SNOW AND STRONG WINDS MAY BRING
DOWN SOME TREES AND POWER LINES. IN ADDITION...SHOVELLING HEAVY
WET SNOW HAS CAUSED HEART ATTACKS...BACK PROBLEMS...AND OTHER
ISSUES IN PAST WINTER STORMS.

In the past, these types of events have caused freeway blockages/closures leaving motorists stranded in their vehicles for many hours. This area has snow removal equipment, but not to the extent of more snow prone areas.

[CrazyC83]

Upgrade tomorrow too...

SPC AC 251712

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1112 AM CST TUE DEC 25 2012

VALID 261200Z - 271200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER CENTRAL AND ERN PARTS OF
THE CAROLINAS...

...THERE IS A SLGT RISK OF SVR TSTMS FROM NRN/CENTRAL FL AND SRN GA
NWD INTO SRN VA...

...A SIGNIFICANT SEVERE WEATHER EPISODE IS POSSIBLE ON WEDNESDAY
OVER PARTS OF THE CENTRAL AND ERN CAROLINAS...

...SYNOPSIS...
PROGRESSIVE UPPER FLOW PATTERN IS FORECAST TO CONTINUE TOMORROW AS A
VIGOROUS COLD UPPER LOW /CURRENTLY OVER THE SRN PLAINS/ IS FORECAST
TO MOVE RAPIDLY FROM THE TN VALLEY TO THE SRN MIDDLE ATLANTIC REGION
DURING THE PERIOD. VERY LARGE 12 HR 500 MB HEIGHT FALLS OF 180 M
AND STRONG WINDS ALOFT WILL ACCOMPANY THIS SYSTEM...WITH 90-100 KT
500 MB WINDS AND 60-70 KT FLOW AT 850 MB.

AT THE SURFACE...MODELS INDICATE THAT THE PRIMARY LOW WILL DEVELOP
OVER NRN GA AND DEEPEN AS IT MOVES NEWD EAST OF THE
APPALACHIANS...MOVING ACROSS THE NC PIEDMONT DURING THE LATE
AFTERNOON/EVENING AND CONTINUING ACROSS THE DELMARVA REGION LATER AT
NIGHT. A STRONG COLD FRONT EXTENDING SWD FROM THE LOW WILL SURGE
EWD TOWARD THE ATLANTIC COAST AND SEWD ACROSS THE FL
PENINSULA...MOVING OFFSHORE INTO THE ATLANTIC WATERS OVERNIGHT. A
WARM FRONT EXTENDING FROM THE NC COAST SWWD ACROSS CENTRAL GA WILL
GRADUALLY LIFT NWD...EXTENDING FROM NERN NC INTO THE PIEDMONT BY
LATE AFTERNOON. THESE BOUNDARIES AND SURFACE LOW WILL PROVIDE THE
PRIMARY LOW LEVEL FOCUSING MECHANISMS FOR STRONG/SEVERE THUNDERSTORM
DEVELOPMENT.

...CENTRAL/ERN CAROLINAS...
A STRONG/SEVERE BROKEN QLCS WITH EMBEDDED BOW ECHOES AND POSSIBLE
SUPERCELLS/MESO-VORTICES IS EXPECTED TO BE ONGOING AT THE START OF
THE PERIOD...EXTENDING FROM NRN GA SWD INTO THE GULF OF MEXICO SOUTH
OF THE TLH. AS THE AFOREMENTIONED WARM FRONT LIFTS NWD...LOW LEVEL
MOISTURE WILL INCREASE INLAND WITH LOW/MID 60S F SURFACE DEW POINTS
SPREADING INTO THE WARM SECTOR. ALTHOUGH CLOUDS AND AREAS OF
LIGHTER PRECIPITATION WILL INHIBIT DIABATIC HEATING...THE AIR MASS
IS EXPECTED TO DESTABILIZE WITH MLCAPE REACHING 1000 J/KG IN PARTS
OF THE WARM SECTOR. VERY STRONG DYNAMIC FORCING FOR LARGE SCALE
ASCENT WITHIN THE LEFT EXIT REGION OF THE CYCLONIC UPPER LEVEL JET
WILL OVERSPREAD THE WARM SECTOR DURING THE MORNING. THIS WILL
ENHANCE CONVECTIVE STORM INTENSITY WITHIN THE QLCS AND SUPPORT
ADDITIONAL INITIATION OF DISCRETE CELLS AND CLUSTERS IN THE WEAKLY
CAPPED WARM SECTOR.

VERY STRONG DEEP LAYER SHEAR OF 50-70 KT IN THE LOWEST 6 KM WILL BE
SUPPORTIVE OF UPDRAFT ROTATION AND BOWING SEGMENTS CAPABLE OF
PRODUCING MORE WIDESPREAD DAMAGING WIND GUSTS AND POTENTIAL FOR
TORNADOES ALONG THE QLCS. GIVEN THE VERY STRONG LOW LEVEL SHEAR AND
SRH /200-500 M2 PER S2 FOR RIGHT-MOVING SUPERCELLS/ AND EXPECTED
RAPID STORM MOTION...THERE WILL ALSO BE POTENTIAL FOR SEVERAL
LONG-TRACK STRONG TORNADOES ASSOCIATED WITH ANY DISCRETE PERSISTENT
SUPERCELLS THAT MAY FORM THROUGH THE AFTERNOON AND EARLY EVENING.
THE SEVERE THREAT WILL GRADUALLY END FROM THE WEST AS THE LOW AND
COLD FRONT CONTINUE TO MOVE RAPIDLY NEWD/EWD THROUGH THE EVENING
HOURS.

...GA SWD INTO NRN/CENTRAL FL
A THREAT FOR DAMAGING WIND GUSTS AND ISOLATED HAIL WILL EXTEND SWD
FROM PARTS OF SRN/ERN GA INTO NRN/CENTRAL FL AS THE LINE OF
CONVECTION MOVES EWD DURING THE DAY. THE RISK IS EXPECTED TO
GRADUALLY DIMINISH WITH SWD EXTENT AS THE PRIMARY DYNAMIC FORCING
MOVES EWD/NEWD ACROSS THE CAROLINAS AND MIDDLE ATLANTIC REGION.

..WEISS.. 12/25/2012

CLICK TO GET WUUS02 PTSDY2 PRODUCT

NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z
CURRENT UTC TIME: 1728Z (12:28PM), RELOAD THIS PAGE TO UPDATE THE TIME

[yzerfan]

Weather channel is reporting one fatality from a falling tree in eastern Texas because of this weather event.

[RL3AO]

[CrazyC83]

New watch - likely PDS - coming for LA/MS.

MESOSCALE DISCUSSION 2210
NWS STORM PREDICTION CENTER NORMAN OK
1204 PM CST TUE DEC 25 2012

AREAS AFFECTED...E/SE TX AND CENTRAL/SRN LA

CONCERNING...TORNADO WATCH 692...694...

VALID 251804Z - 251930Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 692...694...CONTINUES.

SUMMARY...TORNADO THREAT WILL CONTINUE TO INCREASE ACROSS SE TX INTO
SWRN AND CENTRAL LA ACROSS WW 694...WITH A TORNADO POTENTIAL ALSO
INTO THE FAR SRN EXTENT OF SVR WW 693.

A NEW TORNADO WATCH WILL BE NEEDED TO REPLACE CURRENT WW 692 PRIOR
TO 19Z...WITH THE POTENTIAL FOR THIS NEW WW TO BE A PDS GIVEN A
SIGNIFICANT INCREASE IN EFFECTIVE SRH THIS AFTERNOON AS THE LLJ
STRENGTHENS ACROSS THE LOWER MS VALLEY.

DISCUSSION...LATE THIS MORNING...THERE HAS BEEN AN INCREASE IN CG
LIGHTNING STRIKES ACROSS SE THROUGH EAST CENTRAL TX TO NWRN LA INVOF
A SURFACE LOW NOW LOCATED IN FAR EAST CENTRAL TX /NEAR JASPER TX/.
THIS LIGHTNING AND SIMILAR INCREASE IN REFLECTIVITIES EXTENDED SSWWD
ALONG A DRY LINE/PACIFIC FRONT THROUGH SE TX/UPPER TX COAST /TO THE
N-SW OF THE HOUSTON METRO AREA/. TSTMS /MAINLY ELEVATED/ ALSO
EXTENDED NEWD OF THE SURFACE LOW INTO NWRN LA. THIS INCREASE IN TSTM
DEVELOPMENT IS LIKELY INDICATIVE OF THE ARRIVAL OF STRONG FORCING
FOR ASCENT WITHIN THE EXIT REGION OF A 90-100 KT MIDLEVEL JET
ACCOMPANYING THE POWERFUL SRN PLAINS SHORTWAVE TROUGH. SUBSEQUENT
AND EXPECTED STRENGTHENING OF A SSWLY LLJ WAS EVIDENT OVER
SWRN-CENTRAL LA PER 17Z LCH WSR-88D VAD SHOWING 60 KT AT 1 KM AGL.
THE STRONG VERTICALLY VEERING WINDS HAVE GREATLY ENHANCED THE
EFFECTIVE SRH VALUES UP TO 400-600 M2/S2 TO SUPPORT AN INCREASED
TORNADO THREAT...EXPECTED TO SPREAD EWD THIS AFTERNOON INTO THE SRN
PART OF THE LOWER MS VALLEY...WITHIN THE WARM SECTOR.

LATE MORNING SURFACE ANALYSES SHOWED THE LOW HAS CONTINUED TO DEEPEN
AND AT 17Z WAS LOCATED INVOF JASPER TX. A WARM FRONT HAS MOVED
STEADILY NWD AND EXTENDED EWD THROUGH CENTRAL LA...SRN MS /N OF
KMCB/...TO THE N OF KMOB AND INTO THE WRN FL PANHANDLE. GIVEN THE
LOCATION OF THE WARM FRONT...THE SRN EXTENT OF SVR WATCH 693 WILL
ALSO HAVE A TORNADO POTENTIAL AS STORMS WILL BE SFC-BASED OR NEAR
SFC-BASED.

MEANWHILE...THE WARM FRONT HAS MOVED N OF WW 692...THOUGH THE WARM
SECTOR ACROSS THIS WW HAS ONLY SLOWLY DESTABILIZED THUS FAR DUE TO
THE MIXING RELATED DECREASE IN THE DEWPOINTS. 18Z SLIDELL SPECIAL
SOUNDING INDICATED AN INVERSION LOCATED BETWEEN 700-800 MB AND THIS
SHOULD CONTINUE TO INHIBIT DEEPER CU DEVELOPMENT UNTIL THE ARRIVAL
OF GREATER ASCENT WITH THE EXIT REGION OF THE IMMEDIATELY UPSTREAM
MIDLEVEL JET. SOME VEERING OF LOW LEVEL WINDS ACROSS SWRN LA SHOULD
ADVECT RICHER MOISTURE INTO SERN LA/SRN MS SUPPORTING STRONGER
DESTABILIZATION TO SUPPORT AN ENVIRONMENT FAVORABLE FOR
SUSTAINED...DEEP UPDRAFTS.

..PETERS/EDWARDS.. 12/25/2012


ATTN...WFO...MOB...JAN...LIX...LCH...SHV...HGX...

LAT...LON 28859514 29869488 31269374 31809285 31679156 31618920
31578843 30318844 29628962 29139007 29119092 28929128
29139235 29169380 28859514

[WeatherGuesser]

http://i44.photobucket.com/albums/f38/RL3AO/00120klch.png

994.12 KB (1,017,974 bytes) ????

[RL3AO]

http://i44.photobucket.com/albums/f38/RL3AO/00120klch.png

994.12 KB (1,017,974 bytes) ????

Wow. And photobucket cut it down from 1.45 MB. I'll have to see if I can save as jpg from gibson ridge.

[CrazyC83]

I'm guessing the probs on the next watch will be 80/70 for tornadoes. Last PDS watch? April 14 of this year. That tells you how quiet things have been.

[CrazyC83]

SVR Watch 693 likely to be replaced by a Tornado Watch (or a northern extension of Tornado Watch 695 coming).

MESOSCALE DISCUSSION 2212
NWS STORM PREDICTION CENTER NORMAN OK
1223 PM CST TUE DEC 25 2012

AREAS AFFECTED...NERN TX INTO NRN MS

CONCERNING...SEVERE THUNDERSTORM WATCH 693...

VALID 251823Z - 251930Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 693
CONTINUES.

SUMMARY...SEVERE CONVECTIVE WIND GUSTS AND LARGE HAIL WILL CONTINUE
AS THE PRIMARY THREATS ACROSS THE WW AREA AS A QLCS PROGRESSES EWD.
AREAS IN THE WAKE OF THE QLCS MAY BE CLEARED FROM THE WW.
MEANWHILE...SUFFICIENT SURFACE-BASED DESTABILIZATION HAS OCCURRED
ACROSS THE SRN PORTION OF THE WW SUCH THAT A TORNADO THREAT EXISTS
/REF MD 2210/. A TORNADO WW WILL BE NEEDED DOWNSTREAM ACROSS
PORTIONS OF MS.

DISCUSSION...A QLCS HAS FORMED RAPIDLY IN RESPONSE TO STRONG FORCING
FOR ASCENT...WITH THE LEADING EDGE CLEARLY DEMARCATED ON 18Z WV
IMAGERY ACROSS E TX. AS THE WARM SECTOR CONTINUES TO EXPAND AND
CONVECTION BECOMES NEAR SURFACE-BASED...A COINCIDENT STRENGTHENING
OF DEEP LAYER WINDS WILL AID IN INCREASING DAMAGING WIND GUSTS
ACROSS THE WW AREA. RECENT SURFACE OBSERVATIONS ACROSS NRN LA
REFLECT GUSTS TO NEAR 50 MPH WITH THE PRIMARY LINE OF CONVECTION.
MEANWHILE...TORNADIC POTENTIAL IS INCREASING ACROSS SRN PORTIONS OF
THE WW /REF MCD 2210/...WITH A STRONG COUPLET RECENTLY NOTED OVER
VERNON PARISH JUST S OF SVR WW 693.

..DISPIGNA.. 12/25/2012


ATTN...WFO...JAN...LIX...LZK...LCH...SHV...

LAT...LON 31439254 31379312 32029312 32769295 33069309 33469121
32479101 31929118 31169162 31499220 31439254

[WeatherGuesser]

Wow. And photobucket cut it down from 1.45 MB. I'll have to see if I can save as jpg from gibson ridge.

I can't remember, but I usually flop'em over to IrfanView and compress them there to about 70% or less.

[CrazyC83]

PDS Tornado Watch 695 just issued, per tweet from NWS New Orleans.

[CrazyC83]

Probs are 80/70.

SEL5

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 695
NWS STORM PREDICTION CENTER NORMAN OK
1255 PM CST TUE DEC 25 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

SOUTHWESTERN AND WEST-CENTRAL ALABAMA
EASTERN AND SOUTHEASTERN LOUISIANA
CENTRAL AND SOUTHERN MISSISSIPPI
COASTAL WATERS

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 1255 PM UNTIL
800 PM CST.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

DESTRUCTIVE TORNADOES...LARGE HAIL TO 1.5 INCHES IN DIAMETER...
THUNDERSTORM WIND GUSTS TO 75 MPH...AND DANGEROUS LIGHTNING ARE
POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 125 STATUTE
MILES EAST AND WEST OF A LINE FROM 25 MILES SOUTHWEST OF
BOOTHVILLE LOUISIANA TO 40 MILES NORTHEAST OF JACKSON
MISSISSIPPI. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 692. WATCH NUMBER 692 WILL NOT BE IN EFFECT AFTER
1255 PM CST. CONTINUE...WW 693...WW 694...

DISCUSSION...WARM SECTOR SPREADING INLAND ACROSS WW AREA WILL BECOME
INCREASINGLY JUXTAPOSED WITH STRENGTHENING DEEP SHEAR AND ENLARGED
LOW-LEVEL HODOGRAPHS. MCS MOVING EWD INTO THIS REGIME WILL
ENCOUNTER MLCAPE 500-1500 J/KG...WITH EFFECTIVE SRH MAXIMIZED NEAR
WARM FRONT AT 400-600 J/KG. ANY RELATIVELY SUSTAINED/DISCRETE
SUPERCELLS WILL OFFER RISK OF LONG-TRACKED/DAMAGING TORNADOES.
DAMAGING GUSTS AND OCNL TORNADOES ARE ALSO LIKELY FROM QLCS/LEW/BOW
STRUCTURES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 65 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 24040.


...EDWARDS

[CrazyC83]

ABC 33/40 about to go live at 2 pm CST.

[CrazyC83]

NWS Jackson: wind gust at their office to 72 mph

[CrazyC83]

No upgrade. Only changes are cutting back in areas where the front has passed.

[CrazyC83]

SPC AC 251950

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0150 PM CST TUE DEC 25 2012

VALID 252000Z - 261200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF SRN/ERN
LA...CENTRAL/SRN MS...ANS WEST CENTRAL/SWRN AL...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LOWER MS AND TN
VALLEYS EWD INTO THE SERN STATES...

...A SEVERE WEATHER OUTBREAK CONTINUING ACROSS THE GULF COAST
STATES...

LITTLE CHANGES NEEDED TO THE PREVIOUS OUTLOOK...EXCEPT TO CLEAR WRN
PART OF THE OUTLOOK AREA AS THE LINE OF SEVERE STORMS MOVES EWD
ACROSS PARTS OF LA AND EXTREME SERN TX.

SURFACE LOW CURRENTLY OVER WEST CENTRAL LA IS EXPECTED TO MOVE NEWD
TOWARD THE TN VALLEY TONIGHT...AS A WARM FRONT ACROSS SRN PARTS OF
MS AND AL LIFTS NWD. 19Z SURFACE MESOANALYSIS SHOWS LARGE PRESSURE
FALLS CONCENTRATING JUST NORTH OF THE WARM FRONT FROM NERN LA INTO
WEST CENTRAL MS/SERN AR...SUGGESTING THE LOW LEVEL JET MAY BE
STRENGTHENING ALONG THE AXIS OF THE MS RIVER. THE AIR MASS SOUTH OF
THE WARM FRONT IS CHARACTERIZED BY TEMPERATURES IN THE 70S AND DEW
POINTS IN THE 60S...ALTHOUGH A SMALL DECREASE IN DEW POINT VALUES
HAS BEEN NOTED OVER THE PAST FEW HOURS AS VERTICAL MIXING OCCURS.
OBJECTIVE ANALYSES INDICATE SUFFICIENT INSTABILITY WITH MLCAPE
AROUND 1000 J/KG TO SUPPORT SEVERE STORMS GIVEN STRONG DEEP LAYER
SHEAR /EFFECTIVE SHEAR OF 50-60 KT/.

LATEST RADAR REFLECTIVITY AND NLDN DATA INDICATE NEW CONVECTIVE
STORMS DEVELOPING IN THE WARM SECTOR OVER SOUTH CENTRAL/SERN LA INTO
SRN MS AHEAD OF THE FRONTAL QLCS. THE STRONG DEEP LAYER SHEAR WILL
PROMOTE DEVELOPMENT OF SUPERCELL STRUCTURES...EMBEDDED WITHIN
BOWS/LEWPS ALONG THE QLCS AND WITH DISCRETE CELLS AND CLUSTERS IN
THE WARM SECTOR. DAMAGING WIND GUSTS AND TORNADOES WILL BE THE
PRIMARY SEVERE THREATS...INCLUDING POTENTIAL FOR A FEW LONG-TRACK
STRONG TORNADOES WITH ANY PERSISTENT SUPERCELL THAT DEVELOPS.

12Z MODEL CONSENSUS INCLUDING CONVECTION-ALLOWING MODEL SOLUTIONS
SHOW A BOWING QLCS ACCELERATING EWD/ENEWD ACROSS THE LOWER MS VALLEY
THIS AFTERNOON AND EVENING WITH THE SEVERE THREAT LIKELY CONTINUING
DURING THE OVERNIGHT HOURS...REACHING AS FAR EAST AS GA AND POSSIBLY
WRN SC BY THE END OF THE PERIOD.

..WEISS.. 12/25/2012

[CrazyC83]

New watch. Probs are 50/40.

SEL6

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 696
NWS STORM PREDICTION CENTER NORMAN OK
245 PM CST TUE DEC 25 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

SOUTHERN ALABAMA
WESTERN TO CENTRAL FLORIDA PANHANDLE
COASTAL WATERS

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 245 PM UNTIL
1000 PM CST.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 20 MILES NORTHWEST OF
PENSACOLA FLORIDA TO 25 MILES EAST SOUTHEAST OF MARIANNA FLORIDA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU6).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 693...WW 694...WW 695...

DISCUSSION...POTENTIAL IS INCREASING FOR A FEW TORNADOES INITIALLY
FOR CELLS MOVING NNEWD OFF GULF...PER SPC MESOSCALE DISCUSSION
2215...THEN FOR ACTIVITY DEVELOPING LATE AFTN INTO EVENING AHEAD OF
MCS NOW CROSSING LOWER DELTA REGION. AIR MASS S OF SFC WARM FRONT
-- NOW EVIDENT OVER EXTREME SERN AL AND MOVING SLOWLY NWD -- WILL BE
CHARACTERIZED BY WEAK MLCINH...55-65 KT EFFECTIVE SHEAR MAGNITUDE
AND 250-400 J/KG EFFECTIVE SRH IN SUPPORT OF SUPERCELL POTENTIAL.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 22035.


...EDWARDS