April 27, 2012 - Moderate Risk - Kansas/Missouri

[CrazyC83]

Decided to start a new topic on today. As much as my thoughts are with everyone lost and affected last year, we might see an outbreak (not as large, but significant) today in an area untouched by last year's Super Outbreak.

Had to include the year to avoid confusion.

SPC AC 271613

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1113 AM CDT FRI APR 27 2012

VALID 271630Z - 281200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER CENTRAL/ERN KS INTO WRN
MO...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS INTO
THE LOWER MO VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS FROM NERN GA INTO SC...

...KS/WRN MO AREA...
WATER VAPOR IMAGERY INDICATES AN INTENSE UPPER VORTICITY MAX OVER
EXTREME NWRN KS. THIS SYSTEM IS EXPECTED TO MOVE ENEWD AND THEN
NEWD OVER THE MO RIVER VALLEY AND WEAKEN TONIGHT AS THE PRIMARY
UPPER LOW OVER DEVELOPS OVER THE NRN ROCKIES...AND PROVIDE STRONG
DYNAMIC FORCING FOR ASCENT. AT THE SURFACE...A CO-LOCATED DEEP LOW
OVER EXTREME NWRN KS IS FORECAST TO MOVE EWD INTO CENTRAL KS THIS
AFTERNOON...CONTINUING TOWARD NWRN MO TONIGHT. A WARM FRONT
EXTENDING ESEWD FROM THE LOW WILL SLOWLY LIFT NWD AS EXTENSIVE
CLOUDS OVER CENTRAL/ERN KS WILL BE SLOW TO DIMINISH. A DRY LINE
ARCING SWD FROM THE LOW ACROSS WRN OK WILL SURGE EWD ACROSS SRN KS
AND OK THIS AFTERNOON IN RESPONSE TO INCREASING DEEP LAYER WESTERLY
FLOW ON THE SRN PERIPHERY OF THE UPPER SYSTEM.

A NARROW LINE OF CONVECTION IS CURRENTLY INDICATED BY VISIBLE
SATELLITE AND RADAR FROM NEAR HLC SWD TO EAST OF DDC...WITH BREAKS
IN CLOUD COVER NOTED IMMEDIATELY IN ADVANCE OF THE CONVECTIVE LINE.
STRONGER HEATING WILL ALSO OCCUR OVER MUCH OF OK WHERE FEWER CLOUDS
ARE PRESENT...AND AS MOISTURE SPREADS NWD IN ASSOCIATION WITH THE
WARM FRONT...SURFACE DEWPOINTS IN THE LOW/MID 60S WILL BECOME MORE
COMMON OVER PARTS OF CENTRAL/ERN KS INTO WEST CENTRAL/SWRN MO BY
LATER THIS AFTERNOON AND EVENING. 12Z REGIONAL RAOBS EXHIBIT STEEP
MID LEVEL LAPSE RATES WHICH WILL ENHANCE INSTABILITY...WITH MLCAPE
REACHING 1500-2000 J/KG. HOWEVER...THE ASSOCIATED EML WILL LIKELY
CAP DEVELOPMENT OF SURFACE BASED STORMS OVER MUCH OF OK...WITH
PRIMARY TSTM ACTIVITY SPREADING ACROSS PARTS OF KS INTO MO.
FAVORABLE DEEP LAYER SHEAR /40-50 KT OVER THE LOWEST 6 KM/ WILL
PROMOTE DEVELOPMENT OF SUPERCELLS...AND SUFFICIENT LOW LEVEL
SHEAR/SRH COUPLED WITH LOW LCL HEIGHTS SUGGEST POTENTIAL FOR
TORNADIC SUPERCELLS TO DEVELOP...ESPECIALLY ALONG/NEAR THE WARM
FRONT WHERE A FEW STRONG TORNADOES WILL BE POSSIBLE. VERY LARGE
HAIL AND DAMAGING WIND GUSTS WILL ALSO BE POSSIBLE AS STORMS
PROGRESS EWD INTO WRN MO BY EVENING. THE ACTIVITY IS EXPECTED TO
GRADUALLY WEAKEN AFTER 03Z AS DIURNAL BOUNDARY LAYER COOLING OCCURS.


...NERN GA INTO SC...
RELATIVELY FEW CLOUDS WILL ALLOW STRONG HEATING TO OCCUR THIS
AFTERNOON AS A COLD FRONT SETTLES SWD ACROSS THE AREA. SURFACE DEW
POINTS NEAR 60F WILL PERMIT DEVELOPMENT OF STEEP LOW LEVEL LAPSE
RATES IN THE PRE-CONVECTIVE ENVIRONMENT. MODEL GUIDANCE IS
CONSISTENT INDICATING STORMS WILL DEVELOP IN A CORRIDOR FROM THE SRN
APPALACHIANS ACROSS SC THIS AFTERNOON AS A WEAK PERTURBATION IN THE
MID/UPPER LEVEL FLOW TRAVERSES THE REGION. WINDS ALOFT/DEEP LAYER
SHEAR WILL BE SUFFICIENTLY STRONG TO SUPPORT ORGANIZED MULTI-CELL
CONVECTION...WITH STRONGER CELLS CAPABLE OF PRODUCING LARGE HAIL AND
STRONG WIND GUSTS. THE SEVERE THREAT IS EXPECTED TO DIMINISH AFTER
SUNSET.

..WEISS/MOSIER.. 04/27/2012

CLICK TO GET WUUS01 PTSDY1 PRODUCT

NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
CURRENT UTC TIME: 1850Z (2:50PM), RELOAD THIS PAGE TO UPDATE THE TIME

[cycloneye]

Graphic that shows the Moderate Risk area.



Uploaded with imageshack.us

[CrazyC83]

MESOSCALE DISCUSSION 0605
NWS STORM PREDICTION CENTER NORMAN OK
0129 PM CDT FRI APR 27 2012

AREAS AFFECTED...N-CNTRL TO SERN KS

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 271829Z - 272000Z

SEVERE THREAT IS STILL EXPECTED TO INCREASE THIS AFTERNOON...BUT
APPEARS TO BE DELAYED IN TIMING AS TSTM INITIATION IN S-CNTRL KS HAS
BEEN CURTAILED BY STRONG SUBSIDENCE. WITH STRONGER HEATING NOW
OCCURRING AHEAD OF THE DRYLINE...CONVECTION WILL GROW ACROSS N-CNTRL
KS AND EVENTUALLY DEVELOP S/SEWD TOWARDS SERN KS. A TORNADO WATCH
WILL LIKELY BE ISSUED BETWEEN 19-21Z.

SUBSTANTIAL DRYING NOTED IN WATER VAPOR IMAGERY HAS SPREAD ACROSS
S-CNTRL KS WITH LARGE-SCALE SUBSIDENCE S OF THE COMPACT SHORT WAVE
IMPULSE OVER NWRN KS. THIS APPEARS TO BE THE PRIMARY LIMITING FACTOR
SUPPRESSING TSTM DEVELOPMENT THUS FAR S OF THE IMMEDIATE VICINITY OF
THE TRIPLE POINT /LOCATED AROUND 30 S HLC AT 18Z/. WITH INDIVIDUAL
CELL MOTIONS SHIFTING N/NEWD OF THE SURFACE WARM FRONT THAT ARCED
SEWD INTO SERN KS...CONVECTION THUS FAR HAS STRUGGLED TO REACH
SEVERE INTENSITY. 12Z CONVECTION-ALLOWING WRF AND RECENT HRRR RUNS
SUGGEST THAT CONVECTION MAY REMAIN TIED ALONG AND JUST N OF THE WARM
FRONT IN THE LOBE OF ASCENT ASSOCIATED WITH THE SHORT WAVE IMPULSE.
STILL...WITH A 50 MILE WIDE AREA OF STRONGER HEATING OCCURRING
BETWEEN THE DRYLINE AND REMNANT STRATUS DECK IN CNTRL KS...THIS
SHOULD PROVE FAVORABLE FOR SUSTAINING DEVELOPMENT OF A FEW
SUPERCELLS WITH ATTENDANT LARGE HAIL/TORNADO THREATS.

[CrazyC83]

Probs are 50/30.

SEL4

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 194
NWS STORM PREDICTION CENTER NORMAN OK
215 PM CDT FRI APR 27 2012

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

CENTRAL AND EASTERN KANSAS

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 215 PM UNTIL 900
PM CDT.

TORNADOES...HAIL TO 3 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 85 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH OF CONCORDIA
KANSAS TO 50 MILES SOUTH SOUTHWEST OF CHANUTE KANSAS. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU4).

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.

DISCUSSION...STORMS ARE EXPECTED TO CONTINUE DEVELOPING ALONG THE
DRY LINE OVER CENTRAL KS IN RESPONSE TO INCREASING FORCING FROM A
STRONG VORTICITY MAX MOVING OVER WRN KS. HEATING IN ADVANCE OF THE
DRY LINE OVER CENTRAL INTO SOUTH CENTRAL KS IS CONTINUING TO
DESTABILIZE THE AIR MASS AND WEAKEN THE CAP...WITH RADAR AND VISIBLE
SATELLITE SHOWING EARLY STAGES OF DEEPENING CONVECTION. CURRENT
STRONG/SEVERE STORMS OVER NORTH CENTRAL KS WILL MOVE NEWD TOWARD
NERN KS...WHILE OTHER STORMS ARE EXPECTED TO INTENSIFY OVER SOUTH
CENTRAL/SERN KS. VAD AND WIND PROFILER DATA SUPPORT SUPERCELL
FORMATION WITH POTENTIAL FOR VERY LARGE HAIL...TORNADOES...AND
DAMAGING WIND GUSTS FROM STRONGER CELLS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 22035.


...WEISS

[wx247]

Keeping an eye on the situation from SW MO. Definitely looks like it could get rough, especially north of me.

[Fyzn94]

Tornado-warned supercell S of Concordia...