Possible Storms: 12/19/11 - 12/21/11

[wxchaser420]

Best looking system since November. Doesn't look too intimidating right now with less than 65degree Tds but definatly an East TX and LA type thing with maybe some gulf coast action.

[ROLLTIDE]

Jan

THIS WILL BE A HIGH SHEAR/LOW INSTABILITY EVENT GIVEN THE STRONG JET DYNAMICS...AND MIXED LAYER CAPE GENERALLY LESS THAN 500 J/KG. STRONG FORCING AND SHEAR WILL HELP OVERCOME THE MEAGER INSTABILITY TO SUPPORT THE RISK FOR SEVERE THUNDERSTORMS... PARTICULARLY IF THE ASSOCIATED TSTM SYSTEM MOVES THROUGH THE FORECAST AREA DURING THE AFTERNOON AT TIME OF PEAK HEATING...AS LIMITED AS THAT MAY BE IN LATE DECEMBER. WILL CONTINUE TO MENTION THE POSSIBILITY OF SEVERE WEATHER IN THE PRODUCTS.

[ROLLTIDE]

...

Dec 19, 2011 0700 UTC Day 2 Convective Outlook
Updated: Mon Dec 19 07:03:09 UTC 2011 (Print Version)
Probabilistic to Categorical Outlook Conversion Table
Categorical Probabilistic

Population Cities CWAs Interstates Counties ARTCC FEMA Regions
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe weather within 25 miles of a point. (More Info)
Forecast Discussion

SPC AC 190700

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CST MON DEC 19 2011

VALID 201200Z - 211200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE LOWER MS
VALLEY AREA...

..SYNOPSIS...

SPLIT FLOW SYNOPTIC REGIME WILL PERSIST THROUGH DAY 2. CUTOFF LOW
OVER AZ HAS BEGUN TO ACCELERATE ENEWD AS OF SUNDAY EVENING IN
RESPONSE TO UPSTREAM VORT MAX DROPPING SWD THROUGH THE PACIFIC NW.
THE UPPER LOW WILL BE OVER THE CNTRL/SRN PLAINS EARLY TUESDAY THEN
INTO THE MID MS AND OH VALLEYS TUESDAY NIGHT ACCOMPANIED BY A SFC
LOW. TRAILING COLD FRONT WILL ADVANCE THROUGH THE LOWER MS AND TN
VALLEYS.

...LOWER MS VALLEY THROUGH A PORTION OF THE GULF COAST STATES...

STRONG MIGRATORY SLY LLJ WILL ADVECT PARTIALLY MODIFIED GULF AIR
WITH LOW 60S DEWPOINTS INTO THE GULF COASTAL STATES PRE-FRONTAL WARM
SECTOR WITH 50S LIKELY FARTHER NORTH INTO THE TN VALLEY. LIKELIHOOD
OF WIDESPREAD CLOUDS AND MODEST LAPSE RATES SHOULD LIMIT MLCAPE TO
GENERALLY AOB 500 J/KG WITH GREATEST INSTABILITY EXPECTED OVER SRN
HALF OF THE GULF COAST STATES. BASED ON FORECAST TRACK OF EJECTING
SHORTWAVE TROUGH...TENDENCY WILL BE FOR LLJ AND STRONGER FORCING TO
SHIFT NEWD INTO THE TN AND OH VALLEYS WHERE BOUNDARY LAYER
DESTABILIZATION WILL SHOULD BE MORE LIMITED. BANDS OF STORMS WILL BE
ONGOING ALONG WARM CONVEYOR EARLY TUESDAY FROM ERN TX INTO THE LOWER
MS VALLEY. ACTIVITY WILL PERSIST INTO TUESDAY AFTERNOON WITHIN
WEAKLY CAPPED SECTOR OVER THE LOWER MS VALLEY WHERE GREATER INFLUX
OF MOISTURE WILL PROMOTE A BETTER CHANCE FOR SURFACE BASED STORMS.
LARGEST HODOGRAPHS SHOULD DEVELOP FROM NRN PORTIONS OF THE LOWER MS
VALLEY AND TN AND OH VALLEYS TUESDAY AFTERNOON AND NIGHT...SOMEWHAT
REMOVED FROM THE GREATER INSTABILITY. AT THIS TIME IT APPEARS THE
BEST SHEAR/INSTABILITY PARAMETER SPACE AND BEST CHANCE FOR SEVERE
STORMS MAY TRANSPIRE IN CORRIDOR FROM CNTRL/NRN MS INTO SWRN TN AND
NWRN AL. PRIMARY THREATS WILL BE ISOLATED DAMAGING WIND ALONG WITH A
CONDITIONAL THREAT FOR ISOLATED TORNADOES.

..DIAL.. 12/19/2011

CLICK TO GET WUUS02 PTSDY2 PRODUCT

[Joe-Nathan]

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF THE NORTHWEST
GULF OF MEXICO...CENTRAL LOUISIANA...SOUTH CENTRAL LOUISIANA...
SOUTHWEST LOUISIANA...WEST CENTRAL LOUISIANA AND SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

TONIGHT...WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS WILL MOVE THROUGH
THE AREA TONIGHT ALONG AND AHEAD OF AN ADVANCING COLD FRONT. A FEW
OF THESE SHOWERS HAVE THE POTENTIAL TO BE STRONG WITH STRAIGHT
LINE WINDS BEING THE PRIMARY THREAT. AN ISOLATED TORNADO CANNOT BE
RULED OUT.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

TUESDAY...SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH MUCH OF THE DAY
TUESDAY IN ASSOCIATION WITH AN ADVANCING COLD FRONT. A FEW OF
THESE THUNDERSTORMS MAY BE STRONG WITH STRAIGHT LINE WINDS BEING
THE PRIMARY THREAT. AN ISOLATED TORNADO CANNOT BE RULED OUT.

THURSDAY...ANOTHER COLD FRONT IS FORECAST TO MOVE THROUGH THE AREA
ON THURSDAY BRINGING WIDESPREAD SHOWERS TO THE AREA. NO SEVERE
WEATHER IS EXPECTED AT THIS TIME.

[Joe-Nathan]

DAY 1 CONVECTIVE OUTLOOK CORR 1
NWS STORM PREDICTION CENTER NORMAN OK
0113 AM CST MON DEC 19 2011

VALID 191200Z - 201200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS CNTRL AND EAST TX...

CORRECTED FOR TYPOS IN THE FIRST AND LAST PARAGRAPHS

...CNTRL AND EAST TX...
AN UPPER-LEVEL LOW IN SE AZ WILL MOVE QUICKLY EAST TO NEWD ACROSS
WEST TX TODAY. TO THE EAST OF THE SYSTEM...A 45 TO 60 KT LOW-LEVEL
JET WILL STRENGTHEN...RAPIDLY TRANSPORTING MOISTURE NWD INTO CNTRL
TX THIS AFTERNOON. SFC-BASED THUNDERSTORM DEVELOPMENT IS FORECAST
THIS AFTERNOON ALONG THE WRN EDGE OF THE MOIST AXIS WHERE A LINE OF
THUNDERSTORMS IS LIKELY TO ORGANIZE AND MOVE EWD ACROSS THE I-35
CORRIDOR FROM NEAR DALLAS/FORTH WORTH SWD TO NEAR BRYAN-COLLEGE
STATION. THIS LINE SHOULD PERSIST EWD ACROSS THE SLIGHT RISK AREA
EVENTUALLY AFFECTING THE HOUSTON AREA DURING THE EVENING.

AS THE UPPER-LEVEL LOW MOVES OUT INTO THE SRN PLAINS...A 65 TO 80 KT
MID-LEVEL JET IN THE BASE OF THE TROUGH WILL CREATE STRONG DEEP
LAYER SHEAR PROFILES ACROSS THE SLIGHT RISK AREA. FORECAST SOUNDINGS
ALONG THE I-35 CORRIDOR AT 00Z SHOW 0-6 KM SHEAR VALUES IN THE 55 TO
65 KT RANGE. IN ADDITION...SFC DEWPOINTS MAY REACH THE LOWER 60S F
AS FAR NORTH AS DALLAS WITH UPPER 60S F LOCATED ALONG THE MIDDLE TX
COAST WHERE MODERATE INSTABILITY IS FORECAST. THIS ENVIRONMENT
SHOULD SUPPORT SEVERE STORMS WITH THE GREATEST POTENTIAL ACROSS THE
NRN HALF OF THE SLIGHT RISK AREA WHERE THUNDERSTORM DEVELOPMENT IS
MOST CERTAIN. AS THUNDERSTORMS INITIATE...SUPERCELL DEVELOPMENT WILL
BE POSSIBLE ACROSS THE WRN PART OF THE SLIGHT RISK AREA WHILE THE
CONVECTION REMAINS DISCRETE. AS STORMS INCREASE IN COVERAGE AND A
LINE ORGANIZES...A WIND DAMAGE THREAT MAY DEVELOP WITH THE GREATEST
POTENTIAL ACROSS THE CNTRL AND ERN PART OF THE SLIGHT RISK AREA. THE
MAGNITUDE OF THE SEVERE THREAT SHOULD DEPEND ON UPON HOW MUCH
DESTABILIZATION TAKES PLACE IN CNTRL AND EAST TX THIS AFTERNOON.
ALTHOUGH THE SRN END OF THE LINE SHOULD AFFECT THE HOUSTON AREA THIS
EVENING...LARGE-SCALE ASCENT WILL BE QUITE WEAK IN SE TX SUGGESTING
THE SEVERE THREAT COULD BE MORE ISOLATED THERE.

...NW TX/SW OK...
SCATTERED THUNDERSTORMS SHOULD BE ONGOING ACROSS WEST AND NORTHWEST
TX AT DAYBREAK. THIS ACTIVITY SHOULD BE FOCUSED ALONG THE NWRN EDGE
OF THE LOW-LEVEL JET AND ALONG THE LEADING EDGE OF LARGE-SCALE
ASCENT ASSOCIATED WITH AN APPROACHING UPPER-LEVEL LOW. FORECAST
SOUNDINGS ACROSS WEST AND NORTHWEST TX THIS MORNING SHOW SOME CAPE
IN THE 700 TO 500 MB LAYER WITH INSTABILITY INCREASING AS THE AIR
MASS WARMS THIS AFTERNOON. THIS ALONG WITH STEEP MID-LEVEL LAPSE
RATES SHOULD BE ENOUGH FOR AN ISOLATED HAIL THREAT AS CONVECTION
INITIATES JUST AHEAD OF THE UPPER-LEVEL LOW. THE HAIL THREAT APPEARS
MOST LIKELY TO AFFECT NW TX AND SW OK AS STORMS MOVE NEWD ACROSS THE
REGION LATE THIS AFTERNOON. THE POTENTIAL FOR HAIL IS EXPECTED TO
REMAIN MARGINAL WITH A 5 PERCENT HAIL PROBABILITY SUFFICIENT TO
COVER THE THREAT.

..BROYLES/DEAN.. 12/19/2011

[Joe-Nathan]

MESOSCALE DISCUSSION 2379
NWS STORM PREDICTION CENTER NORMAN OK
0258 PM CST MON DEC 19 2011

AREAS AFFECTED...CNTRL TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 192058Z - 192300Z

A CONDITIONAL THREAT OF SEVERE THUNDERSTORMS IS GRADUALLY INCREASING
ACROSS PORTIONS OF CNTRL TO E CNTRL TX...AND TRENDS WILL CONTINUE TO
BE MONITORED FOR A POSSIBLE WATCH LATER TODAY.

RADAR CONTINUES TO SHOW A N/S BAND OF SHALLOW CONVECTIVE SHOWER FROM
WRN OK INTO TX...JUST W OF THE I-35 CORRIDOR. NO LIGHTNING HAS BEEN
OBSERVED WITH THIS ACTIVITY DUE TO RELATIVELY POOR LOW LEVEL LAPSE
RATES PROFILES. THE 20 Z FWD SOUNDING DID INDICATE ELEVATED CAPE ON
THE ORDER OF 600 J/KG WITH A LARGE HODOGRAPH...ALTHOUGH MUCH OF THE
LOWER PORTION IS BEING MADE INEFFECTIVE DUE TO A RELATIVELY STABLE
BOUNDARY LAYER THIS FAR N.

TO THE S...A NARROW AXIS OF LOW TO MID 60S F DEWPOINTS AS WELL AS
WARMER SURFACE TEMPERATURES EXISTED FROM THE CNTRL TX COAST TOWARD
AUSTIN. HERE...RADAR HAS SHOWN SOME INCREASE IN REFLECTIVITIES
ASSOCIATED WITH SLOWLY GROWING WARM SECTOR CONVECTION. A LIGHTNING
STRIKE WAS RECENTLY NOTED WITH ACTIVITY S OF FT. WORTH.

CONTINUED FORCING ALONG THE COLD FRONT...AS WELL AS SOME FURTHER
DESTABILIZATION...MAY EVENTUALLY RESULT IN A FEW STRONG TO SEVERE
THUNDERSTORMS LATER TODAY. ALTHOUGH CELLS MAY FORM IN A LINEAR
FASHION ALONG THE FRONT...SHEAR PROFILES WILL FAVOR AN EVOLUTION
INTO SUPERCELLS...POSSIBLY IN A MERGED LINE...AND AN ISOLATED
TORNADO MAY OCCUR GIVEN SUCH STRONG LOW LEVEL SHEAR. ANY SUPERCELL
WILL ALSO BE CAPABLE OF HAIL AND LOCALLY DAMAGING WIND GUSTS. ONE
NEGATIVE FOR COVERAGE OF SEVERE WILL BE RELATIVELY MERIDIONAL STORM
MOTIONS WHICH WILL TEND TO MOVE THE STORMS AWAY FROM THE BETTER
INSTABILITY.

..JEWELL.. 12/19/2011


ATTN...WFO...SHV...HGX...FWD...EWX...

LAT...LON 32119533 30789556 30139602 29679686 29649758 30049795
31129769 32179747 32829732 33309672 33349587 33149546
32639531 32119533

[dkmac]

15% tomorrow for NE MS and NW AL:

SPC AC 191650

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1050 AM CST MON DEC 19 2011

VALID 201200Z - 211200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF MS/AL/TN...

A LEAD SHORTWAVE TROUGH CURRENTLY OVER WEST TX WILL TRACK EASTWARD
AND ACROSS THE LOWER MS VALLEY TUESDAY MORNING. THIS SYSTEM WILL
BRING WIDESPREAD CLOUDS AND PRECIPITATION TO PORTIONS OF AR/MS/TN.
STRONG SOUTHERLY LOW LEVEL WINDS THROUGH THE DAY WILL ALSO HELP TO
BEGIN TRANSPORTING GULF MOISTURE NORTHWARD INTO THE REGION. BRIEF
SHORTWAVE RIDGING IS LIKELY THROUGH THE EARLY AFTERNOON...BEFORE THE
NEXT AND STRONGER UPPER IMPULSE APPROACHES AFTER DARK. COOLING MID
LEVEL TEMPERATURES AND DEWPOINTS IN THE UPPER 50S/LOWER 60S WILL
RESULT IN AT LEAST MARGINAL CAPE VALUES OVER PORTIONS OF MS/AL/TN
WHERE FAVORABLE LOW LEVEL AND DEEP LAYER VERTICAL SHEAR WILL
CO-EXIST. ISOLATED STRONG OR EVEN SUPERCELL STORMS WILL BE POSSIBLE
TUESDAY EVENING-NIGHT OVER THIS AREA WITH A RISK OF HAIL...GUSTY
WINDS...OR A BRIEF TORNADO. THE LACK OF A MORE ROBUST RETURN OF
RICH GULF MOISTURE IS THE MAIN LIMITING FACTOR FOR THIS SEVERE
WEATHER THREAT.

..HART.. 12/19/2011

[Joe-Nathan]

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF THE NORTHWEST
GULF OF MEXICO...CENTRAL LOUISIANA...SOUTH CENTRAL LOUISIANA...
SOUTHWEST LOUISIANA...WEST CENTRAL LOUISIANA AND SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT
A LINE OF SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE AREA
TODAY IN ASSOCIATION WITH A COLD FRONT. A FEW OF THESE STORMS
COULD BE STRONG WITH GUSTY STRAIGHT LINE WINDS. AN ISOLATED
TORNADO CANNOT BE RULED OUT. THE GREATEST THREAT WILL BE ACROSS
NORTHERN AND WESTERN PORTIONS OF THE AREA.


.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THURSDAY...SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP DURING
THE DAY THURSDAY BUT SHOULD COME TO AN END BY THURSDAY EVENING. NO
SEVERE WEATHER IS EXPECTED WITH THIS EVENT AT THIS TIME.

SATURDAY...A COLD FRONT IS EXPECTED TO PUSH THROUGH THE AREA ON
SATURDAY. NO SEVERE WEATHER IS EXPECTED WITH THIS EVENT AT THIS
TIME.

[Joe-Nathan]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LAKE CHARLES LA
729 AM CST TUE DEC 20 2011

THE NATIONAL WEATHER SERVICE IN LAKE CHARLES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
CENTRAL BEAUREGARD PARISH IN SOUTHWEST LOUISIANA...
THIS INCLUDES...SINGER...DRY CREEK...DE RIDDER...

* UNTIL 830 AM CST

* AT 728 AM CST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
SEVERE THUNDERSTORM...CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
OF 60 MPH...OVER SINGER...MOVING EAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
DE RIDDER BY 745 AM CST...
TULLA BY 750 AM CST...
DRY CREEK BY 815 AM CST...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS IN EXCESS OF 60 MPH
..AND HEAVY RAIN. STAY INDOORS
AWAY FROM WINDOWS.



PLEASE REPORT SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE AT
337-477-5285 EXTENSION 1.

LAT...LON 3088 9306 3060 9304 3060 9313 3057 9314
3059 9347 3080 9343 3088 9309
TIME...MOT...LOC 1328Z 261DEG 22KT 3072 9340

[Joe-Nathan]

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAKE CHARLES LA
849 AM CST TUE DEC 20 2011

.TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON

.DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE.

..REMARKS..

0825 AM TSTM WND DMG DEQUINCY 30.45N 93.44W
12/20/2011 CALCASIEU LA PUBLIC

PUBLIC REPORTED ROOF BLOWN OFF WEST WING OF PATIENT CARE
FACILITY OF DEQUINCY MEMORIAL HOSPITAL. CALLED HOSPITAL
AND DAMAGE WAS CONFIRMED BY HOSPITAL EMPLOYEE.

[Joe-Nathan]

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAKE CHARLES LA
849 AM CST TUE DEC 20 2011

.TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON

.DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE.

..REMARKS..

NOW CONFIRMED AS EF1 TORNADO (PRELIM):

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE LAKE CHARLES LA
1026 AM CST TUE DEC 20 2011

.TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON

.DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE.

..REMARKS..

0825 AM TORNADO ENE DEQUINCY 30.45N 93.44W
12/20/2011 F1 CALCASIEU LA NWS STORM SURVEY

PUBLIC REPORTED ROOF BLOWN OFF WEST WING OF PATIENT CARE
FACILITY OF DEQUINCY MEMORIAL HOSPITAL. CALLED HOSPITAL
AND DAMAGE WAS CONFIRMED BY HOSPITAL EMPLOYEE. FROM STORM
SURVEY THERE IS A DAMAGE PATH STRETCHING FROM .25 MILE SW
OF THE HOSPITAL TO .5 MILE NE OF HOSPITAL WITH MOSTLY
JUST DOWNED TREES AND A FEW POWER LINES. ROOF WAS BLOWN
OFF AND DAMAGED THREE CARS IN PARKING LOT.

[ROLLTIDE]

...

Mesoscale Discussion 2382

< Previous MD

MESOSCALE DISCUSSION 2382 NWS STORM PREDICTION CENTER NORMAN OK 1125 AM CST TUE DEC 20 2011 AREAS AFFECTED...CNTRL AND SRN LA...SRN MS CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 201725Z - 201930Z ISOLATED SEVERE STORMS MAY OCCUR LATER THIS AFTERNOON OVER CNTRL AND ERN LA AS WELL AS CNTRL/SRN MS. A WATCH IS NOT EXPECTED TO BE NECESSARY AT THIS TIME. A LINE OF STORMS CONTINUES TO PUSH SLOWLY EWD ACROSS LA...ASSOCIATED WITH A WEAK COLD FRONT. THESE STORMS ARE NOT CURRENTLY SEVERE...BUT MAY EVOLVE OVER THE NEXT SEVERAL HOURS. SWLY LOW LEVEL FLOW WILL CONTINUE THROUGHOUT THE DAY...AS THE PRIMARY UPPER TROUGH AND SURFACE LOW MOVE NEWD ACROSS OK/AR/MO. AS THE LATEST SURFACE ANALYSIS SHOWS...RICHER LOW LEVEL MOISTURE IS GRADUALLY MOVING INLAND ACROSS LA AND SRN MS...WITH SOLID 64 TO 67 F DEWPOINTS NOTED AT 17Z. FURTHER...VISIBLE IMAGERY SHOWS CLEARING NOW TAKING PLACE...WITH TEMPERATURES RISING INTO THE MIDDLE 70S F. ALTHOUGH LAPSE RATE PROFILES FROM THE LOW TO MID LEVELS ARE RELATIVELY POOR...CONTINUED HEATING WILL YIELD SOME FURTHER DESTABILIZATION. WITH FAVORABLE DEEP LAYER SHEAR IN PLACE...THIS WILL LIKELY HAVE THE EFFECT OF STRENGTHENING A FEW STORMS...WITH A POSSIBILITY OF A WIND AND ISOLATED TORNADO THREAT DEVELOPING. ANY TORNADO THAT MAY OCCUR WOULD LIKELY BE BRIEF AND WEAK. ..JEWELL.. 12/20/2011 ATTN...WFO...MOB...JAN...LIX...LCH...SHV...

[dkmac]

N.O. NWS

ON THURSDAY...AN UPPER TROUGH MOVING THROUGH TEXAS WILL RESULT IN
A SURFACE LOW DEVELOPING ON THE TAIL END OF THE FRONT OVER THE
WESTERN GULF. THIS LOW WILL MOVE QUICKLY NORTHEASTWARD ALONG THE
STALLED BOUNDARY AND WILL RESULT IN WIDESPREAD SHOWERS AND
THUNDERSTORMS AS IT MOVES THROUGH THE REGION. HAVE BUMPED POPS UP
TO THE 80 TO 90 PERCENT RANGE ACROSS THE ENTIRE AREA FOR THURSDAY.
THERE WILL ALSO BE A SLIGHT RISK OF SEVERE WEATHER AS THE LOW
MOVES THROUGH THE AREA. WHILE THUNDERSTORMS ARE EXPECTED TO REMAIN
ELEVATED AT FIRST...AT LEAST A PORTION OF THE LOCAL FORECAST
AREA...PROBABLY THE EASTERN HALF OR THIRD OF THE AREA...WILL BE
LOCATED IN THE WARM SECTOR AS THIS LOW MOVES NORTHEASTWARD INTO
THE MIDDLE MISSISSIPPI VALLEY. THIS SHOULD ALLOW SOME OF THE
THUNDERSTORMS TO BECOME SURFACE BASED AS THE AIR MASS BECOMES MORE
UNSTABLE.

WITH SOUTHEASTERLY FLOW AT THE SURFACE TRANSITIONING TO
MODERATE/STRONG SOUTHWESTERLY FLOW ALOFT...STORM RELATIVE HELICITY
IS FORECAST TO BE NEAR OR ABOVE 200 M2/S2. LIFT ALSO WON/T BE A
PROBLEM WITH THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET
STREAK MOVING THROUGH THE AREA AND THE ADDED FORCING OF THE
SURFACE LOW/FRONT. THE LIMITING FACTOR APPEARS TO BE INSTABILITY
WITH CAPE VALUES FORECAST TO PEAK IN THE 500 TO 800 J/KG RANGE AND
LI VALUES ONLY SLIGHTLY NEGATIVE.

DESPITE THE LIMITED INSTABILITY...A FEW STRONG TO SEVERE STORMS
WILL BE POSSIBLE. THE MAIN THREAT WILL BE STRONG/DAMAGING STRAIGHT
LINE WINDS...BUT GIVEN THE SHEAR PROFILE...AN ISOLATED TORNADO OR
TWO WILL ALSO BE POSSIBLE.

[ROLLTIDE]

Live streaming very possible tomorrow

[ROLLTIDE]

Live Tracker for Thursday

">

[ROLLTIDE]

Mesoscale Discussion 2387

< Previous MD

MESOSCALE DISCUSSION 2387 NWS STORM PREDICTION CENTER NORMAN OK 0411 AM CST THU DEC 22 2011 AREAS AFFECTED...SRN/CENTRAL LA AND SRN/CENTRAL MS CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY VALID 221011Z - 221045Z A TORNADO WATCH ISSUANCE IS LIKELY FOR SRN/CENTRAL LA INTO PARTS OF SRN/CENTRAL MS WITH THE SEVERE WEATHER THREAT BECOMING A CONCERN AROUND OR BY DAYBREAK OVER SWRN LA. A DEVELOPING NNE-SSW ORIENTED SQUALL LINE /WITH EMBEDDED LEWPS AND BOW STRUCTURES/ WILL ADVANCE FAIRLY QUICKLY EWD AND SHOULD REACH MCB-LFT AREAS BY 15Z AND INTO PIB TO NEW ORLEANS METRO BY 18Z. DAMAGING WINDS AND ISOLATED TORNADOES WILL BE THE PRIMARY THREATS. SATELLITE IMAGERY SHOWED A DIFFLUENT FLOW REGIME UNDERWAY ACROSS MUCH OF CENTRAL/E TX...DOWNSTREAM OF A PROGRESSIVE SHORTWAVE TROUGH CURRENTLY MOVING ENEWD THROUGH THE TX BIG BEND REGION. THIS TROUGH HAS BECOME NEUTRALLY ORIENTED...WITH A NEGATIVE TILT EXPECTED THIS MORNING AS THE TROUGH AXIS REACHES E TX/LA BY 18Z. THIS EVOLUTION WILL SUPPORT AN INCREASE IN LARGE SCALE ASCENT ACROSS THE DISCUSSION AREA...AND A RESPONSE IN LOWER TROPOSPHERIC MASS FIELDS IS ALREADY UNDERWAY WITH FURTHER STRENGTHENING OF A SLY LLJ EXPECTED INTO THE LOWER MS VALLEY. SURFACE ANALYSES DURING THE LAST SEVERAL HOURS HAVE SHOWN A WARM FRONT ADVANCING NWD...AND AT 0945Z THIS BOUNDARY WAS LIKELY LOCATED ALONG OR JUST OFFSHORE OF SERN TX/SWRN LA GIVEN A SELY COMPONENT OF OFFSHORE OBS. A SECOND SURFACE TROUGH EXTENDED FROM EXTREME SERN TX NEWD INTO SRN MS TO CENTRAL AL...WITH MODELS SUGGESTING THIS LATTER BOUNDARY BECOMES THE PRIMARY SYNOPTIC WARM FRONT TODAY. SURFACE OBSERVATIONS ACROSS CENTRAL-SERN TX AND MESO-ANALYSES INDICATED A COLD POOL WAS SUPPORTING A FORWARD PROPAGATING LINE OF TSTMS ACROSS E TX TO OFF THE UPPER TX COAST AS OF 10Z. A SQUALL LINE IS EXPECTED TO EVOLVE FROM THIS LINE OF TSTMS AS LARGE SCALE ASCENT STRENGTHENS ATOP LOW LEVEL WAA. BACKED SURFACE WINDS /SELY COMPONENT/ ACROSS SRN LA TO SRN MS WILL ENHANCE LOW LEVEL SHEAR TO SUPPORT A TORNADO THREAT ACROSS THE WARM SECTOR AS IT SPREADS INLAND THIS MORNING AND EMBEDDED WITHIN THE SQUALL LINE. ..PETERS.. 12/22/2011

[dkmac]

Tornado Watch:

[h=3]Tornado Watch[/h]
TORNADO WATCH OUTLINE UPDATE FOR WT 898NWS STORM PREDICTION CENTER NORMAN OK435 AM CST THU DEC 22 2011TORNADO WATCH 898 IS IN EFFECT UNTIL 100 PM CST FOR THE FOLLOWING LOCATIONSLAC001-003-005-007-009-019-023-025-029-033-037-039-045-047-051-053-055-057-063-065-071-077-079-089-091-093-095-097-099-101-103-105-107-109-113-117-121-125-221900-/O.NEW.KWNS.TO.A.0898.111222T1035Z-111222T1900Z/LA. LOUISIANA PARISHES INCLUDED AREACADIA ALLEN ASCENSIONASSUMPTION AVOYELLES CALCASIEUCAMERON CATAHOULA CONCORDIAEAST BATON ROUGE EAST FELICIANA EVANGELINEIBERIA IBERVILLE JEFFERSONJEFFERSON DAVIS LAFAYETTE LAFOURCHELIVINGSTON MADISON ORLEANSPOINTE COUPEE RAPIDES ST. CHARLESST. HELENA ST. JAMES ST. JOHN THE BAPTISTST. LANDRY ST. MARTIN ST. MARYST. TAMMANY TANGIPAHOA TENSASTERREBONNE VERMILION WASHINGTONWEST BATON ROUGE WEST FELICIANA$$

[dkmac]

BULLETIN - IMMEDIATE BROADCAST REQUESTED
   TORNADO WATCH OUTLINE UPDATE FOR WT 898
   NWS STORM PREDICTION CENTER NORMAN OK
   435 AM CST THU DEC 22 2011
   
   TORNADO WATCH 898 IS IN EFFECT UNTIL 100 PM CST FOR THE
    FOLLOWING LOCATIONS
   
   LAC001-003-005-007-009-019-023-025-029-033-037-039-045-047-051-
   053-055-057-063-065-071-077-079-089-091-093-095-097-099-101-103-
   105-107-109-113-117-121-125-221900-
   /O.NEW.KWNS.TO.A.0898.111222T1035Z-111222T1900Z/
   
   LA 
   .    LOUISIANA PARISHES INCLUDED ARE
   
   ACADIA               ALLEN               ASCENSION           
   ASSUMPTION           AVOYELLES           CALCASIEU           
   CAMERON              CATAHOULA           CONCORDIA           
   EAST BATON ROUGE     EAST FELICIANA      EVANGELINE          
   IBERIA               IBERVILLE           JEFFERSON           
   JEFFERSON DAVIS      LAFAYETTE           LAFOURCHE           
   LIVINGSTON           MADISON             ORLEANS             
   POINTE COUPEE        RAPIDES             ST. CHARLES         
   ST. HELENA           ST. JAMES           ST. JOHN THE BAPTIST
   ST. LANDRY           ST. MARTIN          ST. MARY            
   ST. TAMMANY          TANGIPAHOA          TENSAS              
   TERREBONNE           VERMILION           WASHINGTON          
   WEST BATON ROUGE     WEST FELICIANA      
   
   
   MSC001-005-007-015-019-021-023-025-029-031-035-037-049-051-061-
   063-065-067-069-073-075-077-079-085-087-089-091-097-099-101-103-
   105-109-113-121-123-127-129-147-149-155-157-159-163-221900-
   /O.NEW.KWNS.TO.A.0898.111222T1035Z-111222T1900Z/
   
   MS 
   .    MISSISSIPPI COUNTIES INCLUDED ARE
   
   ADAMS                AMITE               ATTALA              
   CARROLL              CHOCTAW             CLAIBORNE           
   CLARKE               CLAY                COPIAH              
   COVINGTON            FORREST             FRANKLIN            
   HINDS                HOLMES              JASPER              
   JEFFERSON            JEFFERSON DAVIS     JONES               
   KEMPER               LAMAR               LAUDERDALE          
   LAWRENCE             LEAKE               LINCOLN             
   LOWNDES              MADISON             MARION              
   MONTGOMERY           NESHOBA             NEWTON              
   NOXUBEE              OKTIBBEHA           PEARL RIVER         
   PIKE                 RANKIN              SCOTT               
   SIMPSON              SMITH               WALTHALL            
   WARREN               WEBSTER             WILKINSON           
   WINSTON              YAZOO               
   
   
   GMZ432-435-452-455-530-550-221900-
   /O.NEW.KWNS.TO.A.0898.111222T1035Z-111222T1900Z/
   
   CW 
   
   .    ADJACENT COASTAL WATERS INCLUDED ARE
   
   CALCASIEU LAKE 
   
   VERMILLION BAY 
   
   COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM 
   
   COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY
   LA OUT 20 NM 
   
   LAKE PONTCHARTRAIN AND LAKE MAUREPAS 
   
   COASTAL WATERS FROM PORT FOURCHON LA TO LOWER ATCHAFALAYA RIVER
   LA OUT 20 NM 
   
   ATTN...WFO...LCH...LIX...JAN... 

[Joe-Nathan]

Glad I did not go hunting today.

[ROLLTIDE]

http://www.hardcoreweather.com/blog.php