Oklahoma Severe Weather Discussion - March 2011

[venture]

This thread will be used to discussion upcoming/ongoing severe weather events through the month of March. These events can include both spring-like and winter-like events as we are in the transition into Spring. This initial post will contain information, images, and links that can be used at any time. Images posted later through the thread may or may not be accurate on the day you are viewing them (check the post comments). Information contained in this thread should not be used as an alternative to weather radios, media, or other means of getting weather warnings/advisories.

Norman & Tulsa County Warning Area Maps

Tornado Warning | Tornado Watch | Severe Thunderstorm Warning | Severe Thunderstorm Watch | Blizzard Warning | Red Flag Warning | Fire Warning | Winter Storm Warning | Winter Storm Watch | Freezing Rain Advisory | Heavy Snow Warning | Winter Weather Advisory | Severe Weather Statement | Special Weather Statement | Hazardous Weather Outlook | Fire Weather Watch
Other Color Meanings: http://www.weather.gov/wwamap-prd/faq.php

NEXRAD Radar Mosaic


Visible Satellite Image (will appear blank overnight)


Oklahoma Mesonet Current Conditions


Useful Links
COD Weather Analysis Page: http://weather.cod.edu/analysis/
NWS Norman Enhanced Page: http://www.srh.noaa.gov/oun/enhanced.php
Storm Prediction Center: http://www.spc.noaa.gov/
Oklahoma Mesonet: http://www.mesonet.org/
West Texas Mesonet: http://www.mesonet.ttu.edu/
Oklahoma Fire Weather: http://www.srh.noaa.gov/oun/?n=fireweather
Oklahoma Road Conditions: http://www.dps.state.ok.us/cgi-bin/weathermap.cgi
Severe Weather Values Reference Guide: http://weatherspotter.net/index11.php -or- http://www.theweatherprediction.com/severe/indices/
TwisterData Model Page: http://www.twisterdata.com/
Earl Barker's Central US Model Page: http://128.121.193.153/central_models.htm
NSSL WRF Model: http://www.nssl.noaa.gov/wrf/
NSSL 4KM WRF Model Forecast Soundings: http://www.nssl.noaa.gov/wrf/sdg/

[Thunder]

Thank you for starting another lovely topic discussion on here.

[Jesseda]

so any news on these storms that are suppose to be coming? is it a hail chance etc.. love ventures updates, i check here before the news channels now

[venture]

Eh I guess we are close enough, so I'll move the discussion over here.



MESOSCALE DISCUSSION 0121
NWS STORM PREDICTION CENTER NORMAN OK
0710 PM CST WED FEB 23 2011

AREAS AFFECTED...NERN OK...SWRN MO...SERN KS

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 240110Z - 240345Z

SCATTERED THUNDERSTORMS...SOME POSSIBLY STRONG...WILL CONTINUE TO
DEVELOP AND MOVE E-NEWD ACROSS PORTIONS OF NERN OK AND SERN KS INTO
SWRN MO THROUGH MID-EVENING. A WW WILL NOT BE NEEDED.

A SLOWLY MOVING COLD FRONT WILL CONTINUE TO CROSS PORTIONS OF SERN
KS AND NERN OK THROUGH MID EVENING. A ZONE OF ELEVATED INSTABILITY
/MUCAPE VALUES AOA 500 J/KG PER 00Z RUC ANALYSIS/ WILL CONTINUE TO
COMBINE WITH FRONTAL CONVERGENCE TO SUPPORT CONVECTIVE INITIATION
ALONG AND IMMEDIATELY AHEAD OF THE FRONT. THE CONVECTION IS FORECAST
TO BEGIN TO SPREAD INTO SWRN MO AFTER 02Z. EFFECTIVE BULK WIND SHEAR
MAGNITUDES OF 50-55 KT WILL PROMOTE MARGINAL STORM ORGANIZATION AND
THE THREAT FOR STRONG STORMS. AN ISOLATED SEVERE THUNDERSTORM
CAPABLE OF PRODUCING LARGE HAIL CANNOT BE ENTIRELY RULED OUT.
HOWEVER...THE LACK OF GREATER INSTABILITY OR STRONGER DEEP-LAYER
FORCING WILL PRECLUDE A MORE ROBUST CONVECTIVE THREAT...AND A WW
WILL NOT BE NEEDED.

..COHEN.. 02/24/2011

[Easy180]

So it looks like nothing really to worry about...I mean how much damage can hail do right?

[Thunder]

So it looks like nothing really to worry about...I mean how much damage can hail do right?

Hail can crack open your skull.

[Thunder]

Just saw a short story on KOCO about the cities and tornado sirens. Got me thinking how the cities spend thousands to warn their hearing taxpayers all the while they let their deaf taxpayers die. Something to think about.

(Btw, I don't think Mick will ever care. lol)

[bandnerd]

Just saw a short story on KOCO about the cities and tornado sirens. Got me thinking how the cities spend thousands to warn their hearing taxpayers all the while they let their deaf taxpayers die. Something to think about.

(Btw, I don't think Mick will ever care. lol)

What kind of system would you propose? They also interrupt tv shows with the information. I wonder what the statistics are on deaf people who die in tornadoes? What about stupid people that ignore the sirens/tv interruptions?

[Dustin]

Freaky storm... I just heard the loudest thunder I think I have ever heard in my 20 years of living in this state. The power went out and now 5 minutes later, complete silence....

[venture]

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 12
NWS STORM PREDICTION CENTER NORMAN OK
410 AM CST THU FEB 24 2011

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

SOUTHERN AND WESTERN OKLAHOMA
WEST CENTRAL AND NORTHWEST TEXAS

EFFECTIVE THIS THURSDAY MORNING FROM 410 AM UNTIL 1100 AM CST.

WIDELY SCATTERED DAMAGING WINDS TO 70 MPH
WIDELY SCATTERED LARGE HAIL TO 2.0 INCHES IN DIAMETER

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES NORTH OF
BIG SPRING TEXAS TO 40 MILES SOUTH OF CHANDLER OKLAHOMA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU2).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

DISCUSSION...TSTMS EXPECTED TO INCREASE OVER W CNTRL AND NW TX
THROUGH LATER THIS MORNING AS SMALL SCALE IMPULSE AHEAD OF LARGER
SCALE UPR TROUGH NOW OVER NM CONTINUES NE AND FURTHER INTERACTS WITH
WRN EDGE OF PW AXIS. CLOUD-LAYER WIND PROFILES AND STEEP MID-LVL
LAPSE RATES SUGGEST A THREAT FOR SVR HAIL WITH LONGER-LIVED UPDRAFTS

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM
MOTION VECTOR 24035.

[venture]

MESOSCALE DISCUSSION 0123
NWS STORM PREDICTION CENTER NORMAN OK
0747 AM CST THU FEB 24 2011

AREAS AFFECTED...NWRN TX THROUGH SW AND CNTRL OK

CONCERNING...SEVERE THUNDERSTORM WATCH 12...

VALID 241347Z - 241545Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 12
CONTINUES.

SOME THREAT FOR HAIL AND ISOLATED STRONG WIND GUSTS WILL CONTINUE
FOR THE NEXT COUPLE HOURS FROM NWRN TX INTO CNTRL OK.

DEEPER ASCENT ASSOCIATED WITH NEWD EJECTING LEAD SHORTWAVE TROUGH
HAS OVERSPREAD NWRN TX THROUGH OK. THIS HAS RESULTED IN A
SIGNIFICANT INCREASE IN THUNDERSTORM COVERAGE ALONG AND JUST EAST OF
EWD ADVANCING PACIFIC FRONT FROM NWRN TX INTO SWRN OK AS WELL AS
ALONG AND NORTH OF SWD ADVANCING POLAR FRONT ACROSS CNTRL THROUGH
NERN OK. THE 12Z NORMAN RAOB SHOWS 1500 J/KG MUCAPE AND A LAYER OF 7
C/KM LAPSE RATES BETWEEN 700-500 MB...BUT WITH WEAKER LAPSE RATES
ABOVE 500 MB. LATEST OBJECTIVE ANALYSIS INDICATES A NARROW CORRIDOR
OF MODERATE INSTABILITY REMAINING FROM NWRN TX INTO CNTRL OK.
POTENTIAL STILL EXISTS FOR A FEW CELLS TO PRODUCE HAIL AND ISOLATED
STRONG WIND GUSTS...BUT THREAT IS BECOMING INCREASINGLY MARGINAL AS
THE MORE UNSTABLE PORTION OF WARM SECTOR IS OVERTURNED.

..DIAL.. 02/24/2011

[venture]

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0400 AM CST THU FEB 24 2011

VALID 271200Z - 041200Z

...DISCUSSION...
ANOTHER STRONG STORM SYSTEM IS FORECAST TO AFFECT PORTIONS OF THE PLAINS AND MS VALLEY ON SUN/D4 WITH A PROBABLE SEVERE WEATHER OUTBREAK.

THE ECMWF AS WELL AS THE MAJORITY OF MREF MEMBERS ARE IN GOOD AGREEMENT WITH THE POSITION OF THE MEAN UPPER TROUGH OVER THE SWRN U.S...AND RESPECTABLY CLOSE WITH THE LOCATION OF THE UPPER LOW CENTERED SOMEWHERE BETWEEN THE LOWER CO RIVER VALLEY AND CNTRL AZ BY 12Z SUN. AS THE TROUGH CONTINUES INTO THE CNTRL/SRN PLAINS BY 00Z...AND TO THE MS RIVER BY 12Z MON...MREF MEMBERS ARE SHOWING A SLOW AND FAST CLUSTERING OF SOLUTIONS...THE SLOWEST OF WHICH MATCHES WELL WITH THE ECMWF SOLUTION...WHICH IS TYPICALLY THE PREFERRED MODEL.

USING THE SLOWER SOLUTIONS...A STRONG LOW PRESSURE CENTER IS FORECAST TO BE ACROSS KS OR POSSIBLY NWRN OK AT 00Z. BY THEN...A BROAD SLY FETCH OFF THE GULF OF MEXICO WILL HAVE RESULTED IN MID 60S F BOUNDARY LAYER DEWPOINTS NWD INTO OK AND AR...WITH NEAR 60 F DEWPOINTS POSSIBLY INTO SERN KS AND SRN MO. FORECAST SOUNDINGS ACROSS THE WARM SECTOR INDICATE CAPPING DURING THE DAY BUT STORM SHOULD ERUPT ALONG THE DRYLINE/COLD FRONT BY LATE AFTERNOON...AND PERHAPS ALONG THE RETREATING WARM FROM KS INTO MO AND SRN IL. ALTHOUGH PRECISE STORM MODE IS DIFFICULT TO DISCERN AT THIS TIME...STRONG SHEAR PROFILES AND MODERATE INSTABILITY WILL LIKELY FAVOR SUPERCELLS AND BOWING STRUCTURES CAPABLE OF TORNADOES...DAMAGING WINDS AND LARGE HAIL.

THE SEVERE THREAT WILL LIKELY PERSIST INTO MON/D5 BUT TO A LESSER EXTENT ACROSS PORTIONS OF THE SE...TN AND OH VALLEYS...BUT PREDICTABILITY BECOMES TOO LOW FOR ANY AREAS.

..JEWELL.. 02/24/2011

[venture]

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1254 AM CST SAT FEB 26 2011

VALID 271200Z - 281200Z

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SRN PLAINS...ARKLATEX
TO LOWER OH VALLEY REGION...

...SYNOPSIS...
UPPER-AIR PATTERN FCST TO REMAIN QUASI-ZONAL ACROSS MOST OF CONUS...PRIMARY PERTURBATION BEING STG SHORTWAVE TROUGH AND EMBEDDED LOW LOCATED OVER NRN CA AS OF 26/05Z. THIS FEATURE IS FCST TO DIG SSEWD THEN TURN EWD ACROSS LOWER CO RIVER VALLEY AREA NEAR START OF PERIOD. GIVEN SLIGHTLY LAGGED UPSTREAM PATTERN OF HEIGHT FALLS AND RUN-TO-RUN TRENDS IN PROGS...WILL MAINTAIN EARLY-PERIOD FCST CLOSER TO CONSISTENTLY SLOWER ECMWF POSITION...AS OPPOSED TO FASTER OPERATIONAL SPECTRAL...WITH 500-MB CYCLONE POSITIONED OVER LAS-EED AREA AT START OF PERIOD. THIS ALSO RESEMBLES ETA MEMBERS OF SREF. TROUGH IS FCST TO ASSUME PRONOUNCED POSITIVE TILT EARLY IN PERIOD AND DEVOLVE TO OPEN WAVE...MOVING EWD TO AXIS FROM CENTRAL HIGH PLAINS TO S-CENTRAL/SWRN NM BY 28/00Z. TROUGH THEN SHOULD MOVE EWD BY 28/12Z TO NEAR KS/MO BORDER...SERN OK...AND N-CENTRAL TX...BY WHICH TIME ECMWF ACCELERATES SYSTEM INTO SREF MEAN POSITION.

AT SFC...LEE TROUGHING OVER CO LATE DAY-1 SHOULD CONSOLIDATE RAPIDLY INTO STG SFC CYCLONE THERE BY ABOUT 27/18Z AS UPPER WAVE APCHS...WITH WARM FRONT EWD ACROSS PORTIONS KS/MO. SFC LOW THEN SHOULD PIVOT SEWD/EWD OVER SRN KS DURING AFTERNOON/EVENING. SFC LOW PRESSURE THEN SHOULD BECOME ELONGATED SW-NE ALONG SFC FRONTAL ZONE BY END OF PERIOD...WITH NEWER CENTER POSSIBLE OVER LOWER MI AND ORIGINAL LOW OVER MO OR IL. COLD FRONT TRAILING SFC LOW WILL MOVE EWD FROM CENTRAL/SRN ROCKIES ACROSS OK AND MOST OF TX BY 28/12Z. DRYLINE SHOULD MOVE EWD ACROSS PORTIONS CENTRAL/N-CENTRAL TX AND CENTRAL/ERN OK DURING AFTERNOON/EVENING...INTERSECTING FRONTAL ZONE NEAR S-CENTRAL/SERN KS SFC LOW.

...SRN PLAINS...ARKLATEX TO LOWER OH VALLEY REGION...
MOST CONCENTRATED AND SIGNIFICANT SVR THREAT IS FCST DURING EVENING/OVERNIGHT HOURS IN AND NEAR OZARKS...WITH MORE CONDITIONAL SVR RISK BEGINNING AS EARLY AS MID-LATE AFTERNOON AND AS FAR W AS CENTRAL/ERN PORTIONS OF KS/OK. BULK OF SVR EVENTS SHOULD BE DAMAGING WIND...ALTHOUGH A FEW STG TORNADOES AND LARGE/DAMAGING HAIL ALSO ARE POSSIBLE.

INITIAL/DIURNAL CONVECTIVE DEVELOPMENT...AND TSTM COVERAGE THROUGH AROUND 28/00Z...REMAIN RATHER UNCERTAIN/CONDITIONAL...AS AREAS ALONG AND E OF DRYLINE OVER SRN KS...NE TX AND OK SHOULD BE CAPPED FOR MOST OF AFTERNOON BENEATH ELEVATED MIXED-LAYER AIR. ISOLATED SVR TSTMS ARE POSSIBLE...WHICH COULD INCLUDE SUPERCELLS.

EXPECT MAJOR INCREASE IN CONVECTIVE COVERAGE DURING 28/00Z-28/06Z AS LIFT STRENGTHENS ON ALL SCALES...AND STRONGER FORCING IMPINGES UPON PROGRESSIVELY MORE MOIST LOW-LEVEL AIR MASS. KINEMATIC ENVIRONMENT WILL BECOME MORE FAVORABLE WITH TIME DURING AFTERNOON/EVENING AS STRENGTHENING FLOW AND ASCENT ALOFT SPREADS OVER PROGRESSIVELY MOISTENING WARM SECTOR E OF DRYLINE. LEFT-EXIT REGION OF INTENSIFYING...SOMEWHAT CYCLONICALLY CURVED...125-150 KT 250-MB JET WILL BE SPREADING ACROSS MUCH OF OK...KS...OZARKS AND INTO LOWER OH VALLEY REGION DURING LATTER HALF OF PERIOD. MEANWHILE...EXPECT BROAD AREA OF 60-80 KT 500-MB WINDS TO SPREAD OVER SVR RISK AREAS
DURING EVENING AND OVERNIGHT...CONTRIBUTING TO FAVORABLE DEEP-LAYER SHEAR...E.G. EFFECTIVE SHEAR MAGNITUDES 50-60 KT IN MANY FCST SOUNDINGS. LOW-LEVEL HODOGRAPHS ALSO WILL ENLARGE CONSIDERABLY AFTER 00Z FROM ERN OK THROUGH PORTIONS AR/MO/SRN IL/WRN KY/WRN TN...WITH 0-1 KM SRH 250-400 J/KG UNDER 45-60 KT LLJ. MEANWHILE...60S F SFC DEW POINTS SHOULD BECOME COMMON OVER MOIST SECTOR AND S OF ABOUT I-70 OVERNIGHT...CONTRIBUTING TO SFC-BASED PARCELS WITH MLCAPE IN 500-1500 J/KG RANGE.

THOUGH SUBSTANTIAL SVR OUTBREAK IS POSSIBLE...A FEW FACTORS PRECLUDE MORE SPECIFIC CORRIDOR OF GREATER PROBABILITIES ATTM. IN ADDITION TO TIMING/LOCATION OF INITIATION...EVOLUTION OF CONVECTIVE MODE REMAINS HIGHLY UNCLEAR THIS FAR IN ADVANCE. ANY RELATIVELY DISCRETE SUPERCELLS THAT CAN FORM IN SUCH FAST AMBIENT FLOW MAY TRAVEL LONG DISTANCES WITH TORNADO POTENTIAL...WHILE DAMAGING QLCS DEVELOPMENT WITH BOWS/LEWPS APPEARS LIKELY AT SOME POINT OVERNIGHT. SWD BACKBUILDING OF OVERNIGHT CONVECTION ALSO IS LIKELY...AFFECTING LOWER MS VALLEY REGION...THOUGH CAPPING WILL MAKE THIS RISK MORE CONDITIONAL WITH SWD EXTENT TOWARD GULF.

..EDWARDS.. 02/26/2011

[venture]

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CST SAT FEB 26 2011

VALID 271200Z - 281200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF EASTERN OK/MUCH OF AR/SOUTHERN MO/SOUTHERN IL/FAR SOUTHWEST INDIANA/WESTERN KY/WESTERN TN/NORTHERN MS...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SOUTHERN PLAINS TO THE LOWER/MIDDLE MS VALLEY AND LOWER OH VALLEY...

...SYNOPSIS...
CLOSED UPPER LOW CURRENTLY CENTERED OVER CA IS EXPECTED TO OPEN/SHIFT EASTWARD OVER AZ/NM DURING THE DAY ON SUNDAY...AND TAKE ON MORE OF A NEUTRAL/SLIGHT NEGATIVE TILT AS IT REACHES THE SOUTHERN PLAINS/OZARKS LATE SUNDAY NIGHT. A REGIONAL OUTBREAK OF SEVERE TSTMS...INCLUDING THE POSSIBILITY OF WIDESPREAD DAMAGING WINDS/STRONG TORNADOES...SEEMS PROBABLE LATE SUNDAY AFTERNOON AND ESPECIALLY SUNDAY NIGHT.

...SOUTHERN PLAINS/ARKLATEX/OZARKS/MID-SOUTH/LOWER OH VALLEY...
THE POSSIBILITY OF WIDESPREAD DAMAGING WINDS AND TORNADOES /INCLUDING SOME STRONG/...IN ADDITION TO AN INITIAL BOUT OF LARGE HAIL...WILL BEGIN LATE SUNDAY AFTERNOON...AND CONTINUE WELL THROUGH THE NIGHT/EARLY MORNING HOURS OF MONDAY ACROSS PORTIONS OF THE OZARKS/MID-SOUTH TO MIDDLE MS VALLEY/LOWER OH VALLEY.

INITIAL/DIURNAL DEEP CONVECTIVE COVERAGE IS A STILL A BIT UNCERTAIN ALONG THE DRYLINE ACROSS OK/NORTH TX/FAR SOUTHERN KS DURING THE DAYLIGHT HOURS...AS MUCH OF THE WARM SECTOR SHOULD REMAIN CAPPED BENEATH AN ELEVATED MIXED LAYER. NONETHELESS...CURRENT THINKING IS THAT AT LEAST AN ISOLATED INITIAL THREAT FOR SEVERE TSTMS WILL DEVELOP BY SUNSET...WITH INITIALLY ISOLATED SUPERCELLS CAPABLE OF LARGE HAIL AND A TORNADO THREAT ACROSS PORTIONS OF OK/FAR NORTH TX AND PERHAPS FAR SOUTHERN KS.

OTHERWISE...A SEASONALLY MOIST LOW LEVEL AIRMASS...GENERALLY CHARACTERIZED BY LOWER 60S F SURFACE DEWPOINTS...WILL BECOME ESTABLISHED WITHIN A RELATIVELY BROAD WARM SECTOR ACROSS THE REGION DURING THE AFTERNOON/NIGHT. A CONSIDERABLE INCREASE IN DEEP CONVECTIVE COVERAGE/INTENSITY IS ANTICIPATED THROUGH THE EVENING...AS LARGE SCALE FORCING FOR ASCENT/DEEP TROPOSPHERIC WIND FIELD DRAMATICALLY INCREASE ATTENDANT TO THE ADVANCING UPPER TROUGH/POLAR JET. WITH DEEP LAYER SHEAR ON THE ORDER OF 50-70 KT...SUFFICIENT INSTABILITY ON THE ORDER OF 750-1250 J/KG MLCAPE WILL SUPPORT A POTENTIALLY WIDESPREAD SEVERE THREAT. GIVEN STRONG LOW LEVEL SRH AS AIDED BY A STRENGTHENING 60+ KT LOW LEVEL JET...A MIXED CONVECTIVE MODE INCLUDING QUASI-LINEAR BOWING SEGMENTS/LINE-LEADING SEMI-DISCRETE SUPERCELLS WILL BE CAPABLE OF WIDESPREAD DAMAGING WINDS/STRONG TORNADOES...AS THE SEVERE THREAT CONTINUES WELL INTO THE EARLY MORNING HOURS OF MONDAY TOWARD THE MIDDLE/LOWER MS AND TN/LOWER OH RIVER VALLEYS.

..GUYER.. 02/26/2011

[venture]

Storm chances today will be contingent on the cap breaking ahead of the dryline. One the dryline is passed a certain location, expect very wind and dry conditions. Fire weather is a major concern today.



DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1030 AM CST SUN FEB 27 2011

VALID 271630Z - 281200Z

...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON INTO TONIGHT FROM
AR NEWD TO THE LOWER OH VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS FROM SRN KS...NRN AND ERN
OK...AND NE TX NEWD INTO THE OH VALLEY...

...MID SOUTH/LOWER OH VALLEY THIS AFTERNOON THROUGH TONIGHT...
THE AXIS OF RICHEST LOW-LEVEL MOISTURE EXTENDS NEWD FROM SE TX TO NW
MS AND ERN AR...ALONG THE LLJ AXIS. CONTINUED NWD/NEWD EXPANSION OF
THE WARM SECTOR AND SOME SURFACE HEATING IN CLOUD BREAKS WILL RESULT
IN SUFFICIENT DESTABILIZATION /MLCAPE OF 1000-1500 J PER KG/ FOR
SEVERE STORMS IN THE WARM SECTOR BY MID-LATE AFTERNOON. VERTICAL
SHEAR PROFILES WILL BE FAVORABLE FOR SUPERCELLS WITH EFFECTIVE BULK
SHEAR IN EXCESS OF 50 KT AND EFFECTIVE SRH AOA 300 M2/S2.

THE PRIMARY CONCERNS THIS AREA DURING THE AFTERNOON WILL BE A FOCUS
FOR STORM INITIATION...THE INFLUENCE OF CLOUDS ON SURFACE
HEATING...AND EWD EXPANSION OF THE ELEVATED MIXED LAYER/CAP.
ASSUMING A FEW STORMS CAN FORM THIS AFTERNOON FROM NE AR INTO WRN
TN...THE ENVIRONMENT WILL BE FAVORABLE FOR TORNADIC SUPERCELLS...AND
THE POTENTIAL FOR A STRONG TORNADO OR TWO. OTHERWISE...AN INCREASE
IN THUNDERSTORMS IS EXPECTED OVERNIGHT IN ADVANCE OF THE EJECTING
MIDLEVEL TROUGH AND ALONG THE LLJ CORRIDOR...ALONG/IN ADVANCE OF THE
COLD FRONT MOVING EWD FROM OK ACROSS AR. THE PRE-FRONTAL CONVECTION
MAY CONTAIN SUPERCELLS WITH A CONTINUED TORNADO RISK OVERNIGHT INTO
THE LOWER OH VALLEY...WHILE A MORE LINEAR CONVECTIVE MODE IS
EXPECTED TO EVOLVE ALONG THE COLD FRONT BY 09-12Z. DAMAGING WINDS
WILL BE THE MAIN THREAT WITH THE FRONTAL CONVECTIVE BAND...THOUGH
QLCS TORNADOES WILL ALSO BE POSSIBLE.

...KS/OK BORDER THIS EVENING INTO NRN MO/IL OVERNIGHT...
THE INITIAL LEE CYCLONE IN SE CO WILL DEVELOP EWD ALONG THE KS/OK
BORDER THIS EVENING INTO EARLY TONIGHT IN RESPONSE TO THE MIDLEVEL
SHORTWAVE TROUGH THAT WILL EJECT ENEWD OVER THE SRN HIGH PLAINS.
SLY FLOW INDUCED BY THE LEE CYCLONE HAS RESULTED IN AN INCREASE IN
LOW-LEVEL MOISTURE IN THE WARM SECTOR INTO OK...WITH BOUNDARY LAYER
DEWPOINTS EXPECTED TO HOLD IN THE LOW 60S THROUGH THE AFTERNOON.
SURFACE HEATING WILL BE INHIBITED BY LOW STRATUS AND A SEPARATE BELT
OF MID-HIGH CLOUDS NOW OVERSPREADING THE ERN TX PANHANDLE/NW TX AND
WRN OK. HOWEVER...CLEARING FROM THE W IS EXPECTED OVER THE DRYLINE
AND TRIPLE POINT BY ABOUT 21Z...AND THIS SURFACE HEATING WILL
CORRESPOND WITH INCREASING LOW-LEVEL ASCENT AND LOCAL WEAKENING OF
CONVECTIVE INHIBITION. THUS...AT LEAST ISOLATED THUNDERSTORM
DEVELOPMENT IS EXPECTED IN THE 22-00Z TIME FRAME NEAR THE TRIPLE
POINT INVOF THE KS/OK BORDER...W OF I-35.

A COMBINATION OF 7-8 C/KM MIDLEVEL LAPSE RATES ABOVE BOUNDARY LAYER
DEWPOINTS OF 58-62 F...AND AFTERNOON SURFACE TEMPERATURES IN THE LOW
70S...WILL SUPPORT MLCAPE NEAR 1500 J/KG. EFFECTIVE BULK SHEAR OF
50-70 KT WILL FAVOR SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL...AND
A COUPLE OF TORNADOES WILL BE POSSIBLE BEFORE STORMS CROSS INTO THE
COOL AIR N OF THE WARM FRONT. OTHERWISE... ELEVATED THUNDERSTORMS
WILL EXPAND NEWD ACROSS SRN AND ERN KS INTO MO AND IL OVERNIGHT IN
ADVANCE OF THE SURFACE LOW...WITH A CONTINUED RISK FOR LARGE HAIL.

[venture]

MESOSCALE DISCUSSION 0149
NWS STORM PREDICTION CENTER NORMAN OK
0212 PM CST SUN FEB 27 2011

AREAS AFFECTED...NRN OK...SERN KS...SWRN MO

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 272012Z - 272145Z

LEADING EDGE OF STEEPER LOW LEVEL LAPSE RATE PLUME IS
DEVELOPING/SPREADING EWD ACROSS THE TX/OK PANHANDLE REGION INTO WRN
OK. THIS IS AFFIRMED IN THE LATEST DIAGNOSTIC DATA WHERE DRY
ADIABATIC LAPSE RATES ARE NOTED AT LEAST THROUGH 3KM.
ADDITIONALLY...VIS IMAGERY INDICATES BOUNDARY LAYER CU FIELD IS
DEVELOPING FROM THE OK PANHANDLE...SEWD ALONG THE OK/TX BORDER TO
NEAR I-40. AS THIS CU FIELD APPROACHES A MORE MOIST/UNSTABLE
AIRMASS DOWNSTREAM IT APPEARS THUNDERSTORMS SHOULD EVOLVE ACROSS THE
WARM SECTOR OVER NWRN OK. SUPERCELLS ARE CERTAINLY POSSIBLE GIVEN
THE VERY STRONG SHEAR AND ISOLATED TORNADOES CAN BE EXPECTED.
TORNADO WATCH MAY BE WARRANTED IN THE NEXT FEW HOURS TO ACCOUNT FOR
THIS EVOLVING THREAT.

..DARROW.. 02/27/2011


ATTN...WFO...SGF...TSA...ICT...OUN...

[Thunder]

Nothing for the metro. I'm not gonna look forward to it, since it is so windy, the storms will only be pushed together into a line racing E/NE.

When is the next time for tornado chances?

[venture]

Ww 21 tornado ks ok 272050z - 280300z
axis..40 statute miles north and south of line..
35ssw avk/alva ok/ - 25ese cnu/chanute ks/ ..aviation coords.. 35nm n/s /47e gag - 24nne osw/ hail surface and aloft..2 inches. Wind gusts..60 knots.
Max tops to 450. Mean storm motion vector 25040.

Lat...lon 36889891 38119505 36959505 35729891

Update...



URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 21
NWS STORM PREDICTION CENTER NORMAN OK
250 PM CST SUN FEB 27 2011

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

SMALL PART OF SOUTH CENTRAL AND SOUTHEAST KANSAS
NORTH CENTRAL OKLAHOMA

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 250 PM UNTIL 900
PM CST.

SEVERAL TORNADOES
WIDELY SCATTERED DAMAGING WINDS
ISOLATED WIND GUSTS TO 70 MPH POSSIBLE
SCATTERED LARGE HAIL
ISOLATED HAIL TO 2.0 INCHES IN DIAMETER POSSIBLE

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 40 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 35 MILES SOUTH SOUTHWEST OF
ALVA OKLAHOMA TO 25 MILES EAST SOUTHEAST OF CHANUTE KANSAS. FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU1).

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 20...

DISCUSSION...VISIBLE IMAGERY SHOWS DEEPENING CUMULUS NEAR AND E OF
THE TRIPLE POINT ACROSS N CENTRAL OK. A SEPARATE BAND OF HIGH-BASED
CUMULUS IN NW OK DEMARCATES THE STRONG DRY SURGE AND SUGGESTS AN
INCREASE IN LOW-LEVEL CONVERGENCE/ASCENT NEAR THE TRIPLE POINT IN
THE NEXT COUPLE OF HOURS. NOW THAT SURFACE TEMPERATURES HAVE WARMED
INTO THE 70S...THE CAP IS WEAKENING AND THUNDERSTORM DEVELOPMENT
APPEARS PROBABLE BY 22-23Z. STRONG DEEP-LAYER SHEAR AND MLCAPE
APPROACHING 1500 J/KG WILL SUPPORT SUPERCELLS CAPABLE OF PRODUCING
LARGE HAIL. A COUPLE OF TORNADOES WILL BE POSSIBLE GIVEN 0-1 KM SRH
AOA 200 M2/S2 AND THE POTENTIAL FOR STORMS TO MOVE NEAR/ALONG THE
SURFACE WARM FRONT THIS EVENING.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
450. MEAN STORM MOTION VECTOR 25040.


TORNADO WATCH PROBABILITIES FOR WT 0021
NWS STORM PREDICTION CENTER NORMAN OK
0250 PM CST SUN FEB 27 2011

WT 0021
PROBABILITY TABLE:
PROB OF 2 OR MORE TORNADOES : 40%
PROB OF 1 OR MORE STRONG /F2-F5/ TORNADOES : 20%
PROB OF 10 OR MORE SEVERE WIND EVENTS : 30%
PROB OF 1 OR MORE WIND EVENTS >= 65 KNOTS : 30%
PROB OF 10 OR MORE SEVERE HAIL EVENTS : 50%
PROB OF 1 OR MORE HAIL EVENTS >= 2 INCHES : 30%
PROB OF 6 OR MORE COMBINED SEVERE HAIL/WIND EVENTS : 70%

&&
ATTRIBUTE TABLE:
MAX HAIL /INCHES/ : 2.0
MAX WIND GUSTS SURFACE /KNOTS/ : 60
MAX TOPS /X 100 FEET/ : 450
MEAN STORM MOTION VECTOR /DEGREES AND KNOTS/ : 25040
PARTICULARLY DANGEROUS SITUATION : NO

[venture]

Nothing for the metro. I'm not gonna look forward to it, since it is so windy, the storms will only be pushed together into a line racing E/NE.

When is the next time for tornado chances?

There is still a chance for storms today until the dryline passes. The cap though is pretty stout today. And yes...storm movement will be very vest, but that doesn't mean things will go linear right away. Just typical early spring storms that will move 40-60 mph. Chaseable stuff really doesn't happen until late April anyway.

[venture]

Cells rapidly going up in Western OK at this point. Main cells are near Buffalo and Harmon with additional development near Woodward, Roll and Fort Supply.

CU field is developing south to near Sayre along I-40 at this time so development seems probably anywhere north of I-40 in Western OK.

[Thunder]

Is that a potential development far southwest I see on the radar? Or just a bunch of birds or giant fans?

[venture]

Is that a potential development far southwest I see on the radar? Or just a bunch of birds or giant fans?

Dryline is through most of SW Oklahoma at this point. Anything on radar in that portion of the start will either be dust or smoke from wild fires.

There is developing CU ahead of the dyline from Central OK south which will need to be watched. If anything does fire up, it will likely end up going severe pretty fast with the very high instability in the area right now.

[venture]

Bulletin - eas activation requested
tornado warning
national weather service norman ok
545 pm cst sun feb 27 2011

the national weather service in norman has issued a

* tornado warning for...
Northeastern kay county in northern oklahoma...

* until 615 pm cst

* at 545 pm cst...national weather service radar indicated a severe
thunderstorm capable of producing a tornado 5 miles northwest of
newkirk...moving east at 55 mph.

* locations in the warning include chilocco...newkirk and peckham.

[Thunder]

The first tornado of the year and its in another county. *sighs*

[bandnerd]

The first tornado of the year and its in another county. *sighs*

Well, Mother Nature has 77 Oklahoma counties to choose from, and since all counties in our state are prone to tornadic weather, the chances weren't really in our favor.

I, on the other hand, am fine with it. I'd be happy to get some more rain, though. I think we all would.