The Weather Centre: 04/14/12

Saturday, April 14, 2012

Damage Reports

Damage has been reported in Mustang, Oklahoma. More to come.
This updates as we get more reports right here on this post.

Particularly Dangerous Situation Tornado Watch #171

SEL1

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 171
NWS STORM PREDICTION CENTER NORMAN OK
630 PM CDT SAT APR 14 2012

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

CENTRAL AND SOUTHEAST NEBRASKA

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 630 PM
UNTIL 200 AM CDT.

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

DESTRUCTIVE TORNADOES...LARGE HAIL TO 2 INCHES IN DIAMETER...
THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE
POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 15 MILES WEST OF KEARNEY
NEBRASKA TO 40 MILES SOUTH OF OMAHA NEBRASKA. 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 166...WW 167...WW
169...WW 170...

DISCUSSION...SURFACE LOW N OF GLD WILL DEVELOP NEWD INTO CNTRL NEB
TONIGHT WITH AN ASSOCIATED WARM FRONT/OUTFLOW BOUNDARY LIFTING NWD
THROUGH S-CNTRL/SERN NEB. THE RETREAT OF THIS BOUNDARY WILL
COINCIDE WITH THE WRN EXTENSION OF A 50+ KT SLY LLJ WHICH WILL
ENHANCED VERTICAL SHEAR AND AIR MASS DESTABILIZATION. AS
SUCH...ENVIRONMENT IS EXPECTED TO REMAIN SUPPORTIVE OF SUPERCELLS
CAPABLE OF TORNADOES /SOME SIGNIFICANT/ AND LARGE HAIL.

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 24035.

...MEAD

Developing Tornado May Plow into Pretty Prairie, Kansas

693
WFUS53 KICT 142331
TORICT
KSC095-155-150015-
/O.NEW.KICT.TO.W.0019.120414T2331Z-120415T0015Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE WICHITA KS
631 PM CDT SAT APR 14 2012

THE NATIONAL WEATHER SERVICE IN WICHITA HAS ISSUED A

* TORNADO WARNING FOR...
NORTHERN KINGMAN COUNTY IN SOUTH CENTRAL KANSAS...
SOUTHEASTERN RENO COUNTY IN SOUTH CENTRAL KANSAS...

* UNTIL 715 PM CDT

* AT 625 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
TORNADO WAS LOCATED 9 MILES NORTH OF ZENDA...AND MOVING NORTHEAST
AT 40 MPH.

HAZARD...DEVELOPING TORNADO AND GOLF BALL SIZE HAIL.

SOURCE...RADAR INDICATED ROTATION.

IMPACT...SIGNIFICANT HOUSE AND BUILDING DAMAGE POSSIBLE. MOBILE
HOMES COMPLETELY DESTROYED IF HIT. SOME TREES UPROOTED OR
SNAPPED. VEHICLES WILL LIKELY BE THROWN BY TORNADIC WINDS.

* LOCATIONS IMPACTED INCLUDE...
KINGMAN...PRETTY PRAIRIE...PARTRIDGE...KINGMAN AIRPORT AND MT
VERNON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

THIS STORM HAS A HISTORY OF PRODUCING BRIEF FUNNEL CLOUDS AND STRONG
ROTATION. A NEW TORNADO MAY DEVELOP AT ANY TIME.

&&

LAT...LON 3805 9808 3782 9770 3748 9820 3757 9837
TIME...MOT...LOC 2330Z 224DEG 35KT 3760 9819

TORNADO...RADAR INDICATED
HAIL...1.75IN

Significant Tornado May Hit Salina, Kansas

999
WFUS53 KICT 142319
TORICT
KSC169-150000-
/O.NEW.KICT.TO.W.0018.120414T2319Z-120415T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE WICHITA KS
619 PM CDT SAT APR 14 2012

THE NATIONAL WEATHER SERVICE IN WICHITA HAS ISSUED A

* TORNADO WARNING FOR...
SALINE COUNTY IN CENTRAL KANSAS...

* UNTIL 700 PM CDT

* AT 615 PM CDT...A CONFIRMED LARGE AND EXTREMELY DANGEROUS TORNADO
WAS LOCATED 7 MILES SOUTH OF BROOKVILLE...AND MOVING NORTHEAST AT
35 MPH.

THIS IS A PARTICULARLY DANGEROUS SITUATION.

HAZARD...DAMAGING TORNADO.

SOURCE...LAW ENFORCEMENT CONFIRMED TORNADO.

IMPACT...MAJOR HOUSE AND BUILDING DAMAGE LIKELY AND COMPLETE
DESTRUCTION POSSIBLE. NUMEROUS TREES SNAPPED. MAJOR POWER
OUTAGES IN PATH OF TORNADO HIGHLY LIKELY. SOME ROADS
POSSIBLY BLOCKED BY TORNADO DEBRIS. COMPLETE DESTRUCTION
OF VEHICLES LIKELY.

* LOCATIONS IMPACTED INCLUDE...
SALINA...BROOKVILLE...SMOLAN...ASSARIA...GYPSUM...NEW CAMBRIA AND
SALINA AIRPORT.

THIS INCLUDES INTERSTATE 70 BETWEEN MILE MARKERS 241 AND 266. THIS
INCLUDES INTERSTATE 135 BETWEEN MILE MARKERS 79 AND 95.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS TORNADO WARNING REPLACES THE PREVIOUS TORNADO WARNING THAT WAS
IN EFFECT FOR SALINE COUNTY.

TO REPEAT...A LARGE...EXTREMELY DANGEROUS AND POTENTIALLY DEADLY
TORNADO IS ON THE GROUND. TO PROTECT YOUR LIFE...TAKE COVER NOW. MOVE
TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID
WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE
CLOSEST SUBSTANTIAL SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 3895 9737 3893 9737 3892 9738 3887 9736
3872 9737 3861 9767 3861 9787 3866 9793
3875 9793 3896 9779
TIME...MOT...LOC 2319Z 226DEG 29KT 3870 9779

TORNADO...OBSERVED
TORNADO DAMAGE THREAT...SIGNIFICANT
HAIL...1.75IN

PDS Tornado Warning for Salina, Kansas

Large and Extremely Dangerous Tornado on Ground- SW of Salina, KS

999
WWUS53 KICT 142307
SVSICT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE WICHITA KS
607 PM CDT SAT APR 14 2012

KSC053-113-169-142330-
/O.CON.KICT.TO.W.0016.000000T0000Z-120414T2330Z/
SALINE KS-MCPHERSON KS-ELLSWORTH KS-
607 PM CDT SAT APR 14 2012

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN ELLSWORTH...
NORTHWESTERN MCPHERSON AND SOUTHWESTERN SALINE COUNTIES UNTIL 630 PM
CDT...

AT 606 PM CDT...A CONFIRMED LARGE AND EXTREMELY DANGEROUS TORNADO WAS
LOCATED 6 MILES NORTHWEST OF MARQUETTE...AND MOVING NORTHEAST AT 35
MPH.

THIS IS A PARTICULARLY DANGEROUS SITUATION.

HAZARD...DAMAGING TORNADO.

SOURCE...LAW ENFORCEMENT CONFIRMED TORNADO.

IMPACT...MAJOR HOUSE AND BUILDING DAMAGE LIKELY AND COMPLETE
DESTRUCTION POSSIBLE. NUMEROUS TREES SNAPPED. MAJOR POWER
OUTAGES IN PATH OF TORNADO HIGHLY LIKELY. SOME ROADS
POSSIBLY BLOCKED BY TORNADO DEBRIS. COMPLETE DESTRUCTION OF
VEHICLES LIKELY.

LOCATIONS IMPACTED INCLUDE...
LINDSBORG.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPEAT...A LARGE...EXTREMELY DANGEROUS AND POTENTIALLY DEADLY
TORNADO IS ON THE GROUND. TO PROTECT YOUR LIFE...TAKE COVER NOW. MOVE
TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID
WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE
CLOSEST SUBSTANTIAL SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 3856 9765 3848 9792 3852 9793 3853 9819
3878 9782
TIME...MOT...LOC 2307Z 225DEG 31KT 3863 9788

TORNADO...OBSERVED
TORNADO DAMAGE THREAT...SIGNIFICANT
HAIL...2.50IN

$$

--

NWS Warnings Provided by AllisonHouse.com

Particularly Dangerous Situation Tornado Watch #170

A PDS tornado watch has been issued for North Oklahoma and much of Kansas.

Tornadoes are likely, as the nighttime part of the storms are expected to be more tornadic.
Here are the probabilities.
I am on my phone, so I apologize if the probabilities are hard to read.

Hazard Tornadoes EF2+ Tornadoes
Likelihood High Moderate
Severe Wind 65 kt+ Wind
Moderate Moderate
Severe Hail 2"+ Hail
High Moderate

Moderate Risk of Severe Weather Tomorrow

Probability of severe weather

A moderate risk of severe weather has been issued for Wisconsin. As of now, it appears that the main cause of severe weather is to be wind damage, with this quote from the SPC's outlook:

...SYNOPSIS...
A POWERFUL UPPER TROUGH WILL MOVE EWD OUT OF THE PLAINS AND INTO THE
MS VALLEY DURING THE DAY...WITH A 100+ KT MID LEVEL JET STREAK
EXTENDING FROM ROUGHLY ERN KS INTO SRN WI BY 00Z. AT THE SURFACE...A
DEEP AREA OF LOW PRESSURE WILL MOVE FROM SD/NEB INTO SRN MN...WITH A
COLD FRONT TRAILING ALONG THE MN/WI BORDER EXTENDING SWD ACROSS ERN
IA AND INTO ERN TX. AHEAD OF THE FRONT...STRONG SLY FLOW WILL RESULT
IN AMPLE MOISTURE AND INSTABILITY FOR THUNDERSTORMS...WITH BOUNDARY
LAYER DEWPOINTS NEAR 60 AS FAR N AS NRN WI. THE PROGRESSIVE NATURE
OF THIS TROUGH AND INTENSE WIND FIELDS SUGGEST SIGNIFICANT WIND
DAMAGE POTENTIAL...AS WELL AS A FEW TORNADOES OVER THE UPPER MS
VALLEY.
FARTHER S ALONG THE COLD FRONT...CONDITIONS WILL ALSO BE FAVORABLE
FOR EPISODES OF DAMAGING WINDS WITH A LINES OF STORMS ALONG THE
FRONT...MAINLY FROM TX INTO AR.

This will be the same piece of energy currently making for a potentially deadly tornado outbreak today, so this should be closely watched.

Particularly Dangerous Situation Tornado Watch #166

A Particularly Dangerous Situation, or PDS, Tornado Watch has been issued for southeast Nebraska.
This watch is valid until 7:00 PM CDT.

Strong thunderstorms are developing in the watch area amidst shear and instability.

I am very concerned about this watch, with a 'High' probability of strong tornadoes (EF 2+).

Andrew

11:30 AM CDT SPC Outlook Update

Overall severe weather threat

Risk of tornado within 25 miles of any point

In the most recent Storm Prediction Center outlook update, the 45% tornado risk area was pulled south, indicating a shift towards more tornadoes in Kansas.

This remains as dangerous a situation as ever, and I ask all of you to stay vigilant throughout the night.

Keep up to date on the latest severe weather updates by 'liking' our Facebook page at www.facebook.com/TheWeatherCentre

Particularly Dangerous Situation Tornado Watch #165

A Particularly Dangerous Situation, or PDS, tornado watch has been issued for north Oklahoma and central Kansas.

Probabilities in the above graphic indicate a 'High' likelihood of tornadoes, even a high likelihood of EF2+ tornadoes. Thunderstorms are erupting in central Kansas. With instability and rotation in place, expect these storms to go supercellular, if they are not already.

This watch expires at 6:00 PM CDT.

Repeat: This is a PDS Tornado Watch, meaning that these storms may threaten life and property. Plan accordingly.

Mesoscale Discussion #521

A mesoscale discussion has been issued by the Storm Prediction Center over North Texas, the Oklahoma panhandle, and southwest Kansas as towering cumulus clouds appear to be signaling the start of today's convection.
With the dryline only a little ways away from this mesoscale discussion, and dew points/instability rapidly rising in and to the east of this discussion, any convection that does start up will quickly become strong/severe and may have some rotation as a jet streak progresses eastward.

Andrew

8:00 AM CDT Updated SPC Outlook

The Storm Prediction Center extended the High risk to cover much of the Plains, as convection looks to be coming along easier than first thought.
The main risks remain tornadoes and large hail before storms turn more linear and it turns to a damaging wind threat.
Expect main convection to occur in the afternoon.

-Andrew

Significant Tornado Outbreak Expected Today

Overall Outlook

Chance of a tornado within 25 miles of any point

There is a 45% chance of tornadoes within any given point today in central and eastern Nebraska as a strong storm system's winds combine with the wind field of a warm front to initiate tornadic thunderstorms and supercells. Further south, there remains a 30% chance for tornadoes, just slightly lower, but still very high where tornadoes can be anticipated.

The latest sounding from OUN (Norman, Oklahoma) indicates some pretty stunning things. First, we have over 3000 j/kg of instability- a lot of instability to work with. The Supercell index is over 16, which is very high. Even more concerning is in the bottom right, where analogues to previous soundings are matched against this one. From that, 9 other soundings matched up with this one, two of them described as 'Significant' supercells. Using the bottom pink wording, one can deduce that there would theoretically be a 62% chance for a tornado if the sounding could predict the future.

A strong, amplified 300mb jet stream will be pushing eastward, adding a lot of energy to the system responsible for this event. The system will be up near Nebraska. Increasing the system strength increases the surrounding wind field, thus increasing rotation and instability potentials. The storms will begin when the dryline begins to shift east to try and escape the oncoming cold front from the west (which will not happen). With up to 3000 j/kg of instability and over 3 on the EHI index, expect storms that form to quickly become tornadic.

Initiation, or the initial occurrence, of these storms has been sort of a gray area in recent days. Here is the latest initiation graphic from the National Severe Storms Laboratory (NSSL)'s personal WRF model.

I have circled the area where the strongest storms are expected to be at 7:00 PM CDT tonight. Now, this is what I see as the initialization of strong to severe storms. But see below's actual initiation graphic.

Actual initialization is expected in west or central Oklahoma around 4-5 PM CDT, as the dryline edges east and the cold front moves even faster east than the dry line is.
Here is my tornado graphic.

Blue: Low risk for tornadoes
Dark blue: Moderate risk- a few weak tornadoes
Purple: Substantial risk- many weak-moderate tornadoes
Green: Dangerous risk- several strong tornadoes expected

Andrew

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