Apr. 6-14 Plains/MW/OV/GL Severe Weather, SPC Risk Level: Day 1-3 Slight Risk - Forecasts & OBS Options

[jdrenken]

Again...the Northern segment is why this thread has been extended.

Attached thumbnail(s)

 

[jdrenken]

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1226 PM CDT THU APR 12 2012

VALID 131200Z - 141200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM FAR NWRN TX INTO THE MID
MO RIVER VALLEY...

...SYNOPSIS...
A MEAN TROUGH WILL EXIST OVER THE WRN U.S. WITH A LEAD SHORTWAVE
EJECTING NEWD ACROSS THE NRN PLAINS AND INTO THE UPPER MS VALLEY
DURING THE DAY. THIS WILL LEAD TO BRIEFLY RISING HEIGHTS ALOFT OVER
THE CNTRL AND SRN PLAINS DURING THE DAY...IN ADVANCE OF THE MAIN
TROUGH WHICH WILL EMERGE INTO OK AND NM BY SAT MORNING.

AT THE SURFACE...A LOW WILL MOVE FROM CNTRL SD AT 12Z NWD ACROSS ND
WITH THE EJECTING WAVE...WITH FRONT TRAILING SWD FROM ERN NEB INTO
NRN KS AND DRY AIR BEHIND. THIS BOUNDARY WILL WASH OUT OVER CNTRL
KS...MERGING WITH A DRYLINE THAT WILL EXTEND SWWD INTO NWRN TX BY
AFTERNOON.

A VERY UNSTABLE AIR MASS WILL EXIST S AND E OF THESE BOUNDARIES WITH
DAYTIME HEATING AND DEWPOINTS MAINLY IN THE 60-64 F RANGE.

OVERNIGHT...THE INFLUENCE OF THE UPPER TROUGH WILL BEGIN TO AFFECT
PORTIONS OF THE CNTRL PLAINS...WITH DEEPENING LOW PRESSURE OVER
CNTRL NEB AND KS...AND AN INCREASING SWLY LOW LEVEL JET.

...NW TX AND WRN OK INTO SRN KS...
A LARGE AREA OF LOW LEVEL WARM ADVECTION WILL EXTEND FROM MN INTO
ERN OK AND NRN AR FRI MORNING IN ASSOCIATION WITH THE NRN PLAINS
TROUGH. THIS DEEP ZONE OF FORCING WILL BE ACCOMPANIED BY RAIN AND
EMBEDDED THUNDERSTORMS. SOME OF THESE STORMS MAY BE CAPABLE OF
HAIL...ALTHOUGH MUCH OF IT SHOULD BE NON-SEVERE.

LATER IN THE DAY...THE THREAT FOR DIURNAL ACTIVITY ALONG THE DRYLINE
IS UNCLEAR. WITH SELY FLOW RETURNING ACROSS THE WARM SECTOR...AND
NEUTRAL FORCING ALOFT...LOW LEVEL CONVERGENCE WILL BE SUBTLE. AS
SUCH...MUCH OF THE WARM SECTOR IS EXPECTED TO HAVE A WEAK CAPPING
INVERSION DUE TO RELATIVELY COOL BOUNDARY LAYER TEMPERATURES AWAY
FROM THE DRYLINE ITSELF. EARLY ACTIVITY OVER ERN OK INTO SWRN MO MAY
LEAVE RESIDUAL BOUNDARIES THAT COULD ACT AS A FOCUS FOR DAYTIME
ACTIVITY. IF THIS OCCURS...THERE WOULD BE A THREAT OF ISOLATED
SUPERCELLS THERE WITH HAIL AND A TORNADO OR TWO.

ALONG THE DRYLINE...HEATING WILL ERODE CIN COMPLETELY...AND AT LEAST
ISOLATED STORMS ARE LIKELY AS A RESULT. WITH PLENTY OF INSTABILITY
AND A FAVORABLE HODOGRAPH...SUPERCELLS WOULD BE THE STORM MODE WITH
VERY LARGE HAIL AND A FEW TORNADOES PERSISTING FROM LATE AFTERNOON
INTO THE EARLY EVENING.

...NERN KS...SERN NEB...NWRN MO LATE EVENING AND OVERNIGHT...
WITH INCREASING SLY LOW LEVEL FLOW OVERNIGHT...MOISTURE AND
INSTABILITY SHOULD RETURN RAPIDLY NWD ACROSS KS AND INTO NEB BY SAT
MORNING. SOME MODELS INDICATE THAT CONVECTIVE INHIBITION MAY REMAIN
LIMITED OVER ERN KS...SERN NEB...NWRN MO AND SWRN IA. THUS...FORCING
FROM WARM ADVECTION SHOULD BE SUFFICIENT TO INITIATE NOCTURNAL
STORMS CAPABLE MAINLY OF LARGE HAIL. CONDITIONALLY...HAIL COULD BE
VERY LARGE WITH AMPLE SHEAR AND COOL PROFILES ALOFT.

..JEWELL.. 04/12/2012

[jdrenken]

MESOSCALE DISCUSSION 0498
NWS STORM PREDICTION CENTER NORMAN OK
0124 PM CDT THU APR 12 2012

AREAS AFFECTED...NERN CO...SWRN NEB THROUGH WRN KS

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 121824Z - 122030Z

ISOLATED SUPERCELLS ARE EXPECTED TO INITIATE BY 20Z OVER NERN CO.
ACTIVITY WILL THEN DEVELOP INTO SWRN NEB AND WRN KS THIS EVENING.
PRIMARY THREATS WILL BE VERY LARGE HAIL AND ISOLATED TORNADOES.

EARLY THIS AFTERNOON A DRYLINE EXTENDS SWD THROUGH ERN CO FROM A
WEAK SFC LOW IN NERN CO. A WARM FRONT/DIFFERENTIAL HEATING BOUNDARY
STRETCHED FROM NERN CO SEWD THROUGH WRN KS. A NE-SW ORIENTED
BOUNDARY WITH DEVELOPING CUMULUS WAS INDICATED JUST WEST OF AKRON.
LOW CLOUDS ARE MIXING OUT SOUTH AND WEST OF THE WARM FRONT ALLOWING
FOR DESTABILIZATION WITHIN THE MOIST WARM SECTOR. THE CAPPING
INVERSION WILL ERODE NEXT COUPLE HOURS PROMOTED BY SFC HEATING AND
MIXING AS WELL AS DEEPER FORCING FOR ASCENT ACCOMPANYING A NEWD
EJECTING SHORTWAVE TROUGH THAT WILL INTERACT WITH WRN FRINGE OF
MOIST AXIS. HIGH BASED STORMS MAY SOON DEVELOP IN THE DRIER AIR OVER
NE CO ALONG THE NE-SW BOUNDARY. DEEP LAYER VERTICAL SHEAR OF 40-50
KT WILL SUPPORT SUPERCELLS. OTHER STORMS MAY DEVELOP FARTHER EWD
ALONG DRYLINE...AND AS THEY MOVE THROUGH THE MOIST AXIS THEY WILL
ENCOUNTER SOMEWHAT LOWER LCLS AND INCREASINGLY FAVORABLE HODOGRAPHS
ASSOCIATED WITH STRENGTHENING LLJ. STORMS MAY EVENTUALLY INTERACT
WITH THE NW-SE ORIENTED WARM FRONT FROM EXTREME NE CO...SWRN NEB
INTO WRN KS WHERE 0-1 KM STORM RELATIVE HELICITY WILL BE MAXIMIZED
THIS EVENING.

..DIAL.. 04/12/2012

[jdrenken]

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 157
NWS STORM PREDICTION CENTER NORMAN OK
1250 PM MDT THU APR 12 2012

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

EASTERN COLORADO
WESTERN KANSAS
SOUTHWEST NEBRASKA

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 1250 PM UNTIL
800 PM MDT.

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 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 50 MILES NORTHWEST OF IMPERIAL
NEBRASKA TO 45 MILES EAST SOUTHEAST OF LAMAR COLORADO. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU7).

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...THUNDERSTORMS ARE EXPECTED TO INTENSIFY THIS AFTERNOON
OVER EASTERN CO AND TRACK EASTWARD INTO WESTERN KS/SOUTHWEST NEB.
THIS REGION IS WITHIN A CORRIDOR OF MODERATE CAPE AND STEEP LAPSE
RATES...ALONG WITH FAVORABLE LOW LEVEL AND DEEP LAYER SHEAR. STORMS
ARE FORECAST TO QUICKLY BECOME SUPERCELLULAR WITH A RISK OF VERY
LARGE HAIL AND A FEW TORNADOES. INCREASING WIND FIELDS THROUGH THE
LATE AFTERNOON AND EVENING WOULD SUPPORT A RISK OF STRONG TORNADOES.

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
450. MEAN STORM MOTION VECTOR 27030.

...HART

[jdrenken]

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH OUTLINE UPDATE FOR WT 157
NWS STORM PREDICTION CENTER NORMAN OK
1250 PM MDT THU APR 12 2012

TORNADO WATCH 157 IS IN EFFECT UNTIL 800 PM MDT FOR THE
FOLLOWING LOCATIONS

COC017-061-063-075-095-099-115-121-125-130200-
/O.NEW.KWNS.TO.A.0157.120412T1850Z-120413T0200Z/

CO
. COLORADO COUNTIES INCLUDED ARE

CHEYENNE KIOWA KIT CARSON
LOGAN PHILLIPS PROWERS
SEDGWICK WASHINGTON YUMA


KSC023-071-075-093-109-153-171-181-193-199-203-130200-
/O.NEW.KWNS.TO.A.0157.120412T1850Z-120413T0200Z/

KS
. KANSAS COUNTIES INCLUDED ARE

CHEYENNE GREELEY HAMILTON
KEARNY LOGAN RAWLINS
SCOTT SHERMAN THOMAS
WALLACE WICHITA


NEC029-057-085-087-135-130200-
/O.NEW.KWNS.TO.A.0157.120412T1850Z-120413T0200Z/

NE
. NEBRASKA COUNTIES INCLUDED ARE

CHASE DUNDY HAYES
HITCHCOCK PERKINS

[jdrenken]

[Illinois blizzar...]

High tornado probs

Tornadoes
Probability of 2 or more tornadoes


High (70%)
Probability of 1 or more strong (F2-F5) tornadoes


Low (20%)
Wind
Probability of 10 or more severe wind events


Mod (40%)
Probability of 1 or more wind events > 65 knots


Mod (30%)
Hail
Probability of 10 or more severe hail events


High (80%)
Probability of 1 or more hailstones > 2 inches


Mod (60%)
Combined Severe Hail/Wind
Probability of 6 or more combined severe hail/wind events


High (>95%)

[heatburst]

S/w moving through CO will start to interact with the fairly narrow area of MLCAPE values between 1000-1500J/Kg. The strong forcing with this feature will lead to the development of supercells that will become a threat for large hails and tornadoes. Further south, although recent sat trends are promising we are in a race against time. Right now looks promising but keep in mind these areas to the south do not have the strong forcing that KS into CO has, so we are relying more on the thermodynamics and convergence along the dryline. Lets see how this plays out...

[jdrenken]

Should be seeing something along the Red River Valley...

MESOSCALE DISCUSSION 0500
NWS STORM PREDICTION CENTER NORMAN OK
0334 PM CDT THU APR 12 2012

AREAS AFFECTED...NWRN TX THROUGH WRN OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 122034Z - 122200Z

SEVERE STORMS COULD DEVELOP FROM NWRN TX THROUGH WRN OK DURING NEXT
FEW HOURS. SUPERCELLS CAPABLE OF VERY LARGE HAIL AND ISOLATED
TORNADOES WILL BE THE MAIN THREATS.

THE ATMOSPHERE HAS DESTABILIZED IN MOIST AXIS EAST OF THE DRYLINE
FROM WRN TX NWD THROUGH WRN OK WITH MLCAPE TO 2000 J/KG AND 7.5 C/KM
MID LEVEL LAPSE RATES. A WEAK BOUNDARY WAS ALSO INDICATED FROM
N-CNTRL NWWD THROUGH NWRN TX ALONG THE OK/TX BORDER. NORTH OF THIS
FEATURE WINDS ARE BACKED ESELY RESULTING IN 200-250 M2/S2 EFFECTIVE
STORM RELATIVE HELICITY. LOW CLOUDS CONTINUE TO DIMINISH FROM THE
WEST WITHIN ZONE OF DEEPER MIXING ACROSS NWRN TX WHERE A FIELD OF
CUMULUS AND A FEW SHOWERS HAVE DEVELOPED. ISOLATED STORMS MAY
EVENTUALLY FORM WHERE THIS ZONE INTERSECTS THE BOUNDARY FROM NWRN TX
INTO SWRN OK. EFFECTIVE BULK SHEAR FROM 40-45 KT FAVORS
SUPERCELLS...AND 0-1 KM HODOGRAPH SIZE WILL INCREASE FURTHER AS THE
LOW LEVEL JET STRENGTHENS DURING THE EVENING.

..DIAL.. 04/12/2012

[jdrenken]

Along with the Panhandles of OK/TX...

MESOSCALE DISCUSSION 0499
NWS STORM PREDICTION CENTER NORMAN OK
0228 PM CDT THU APR 12 2012

AREAS AFFECTED...SWRN KS THROUGH THE ERN OK AND TX PANHANDLES

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 121928Z - 122130Z

SWRN KS THROUGH THE ERN TX AND OK PANHANDLES ARE BEING MONITORED FOR
THUNDERSTORM INITIATION. OVERALL THREAT IS CONDITIONAL GIVEN
UNCERTAINTY REGARDING INITIATION. SHOULD STORMS DEVELOP COVERAGE
SHOULD REMAIN SPARSE...BUT DISCRETE SUPERCELLS CAPABLE OF VERY LARGE
HAIL AND A WINDOW FOR ISOLATED TORNADOES WILL BE THE MAIN THREATS
INTO THE EARLY EVENING.

THE BOUNDARY LAYER IS MIXING OUT WITH A DECREASE IN STRATOCUMULUS
FROM THE WEST ACROSS SWRN KS THROUGH THE OK AND TX PANHANDLES TO THE
EAST OF A DRYLINE THAT EXTENDS FROM ERN CO SWD THROUGH WRN TX.
HOWEVER...THE BOUNDARY LAYER REMAINS CAPPED BY AN EML THAT HAS
ADVECTED THROUGH THE WARM SECTOR BENEATH AXIS OF UPPER 50S
DEWPOINTS...CONTRIBUTING TO 1500-2000 J/KG MLCAPE. THE DEEPER
FORCING ATTENDING SHORTWAVE TROUGH CURRENTLY EJECTING NEWD THROUGH
CO WILL REMAIN NORTH OF THIS REGION. HOWEVER...CONTINUED DIABATIC
WARMING AND DRYLINE CONVERGENCE MIGHT BE SUFFICIENT TO INITIATE AT
LEAST AN ISOLATED STORM OR TWO LATER THIS AFTERNOON OR EARLY
EVENING. SHOULD STORMS DEVELOP...EFFECTIVE BULK SHEAR OF 40-50 KT
WILL SUPPORT SUPERCELLS. THE 0-1 KM HODOGRAPH SIZE WILL ALSO
INCREASE AS THE LLJ STRENGTHENS TOWARD EVENING SUPPORTING A WINDOW
FOR ISOLATED TORNADOES BEFORE THE BOUNDARY LAYER DECOUPLES.

..DIAL.. 04/12/2012

[The Snowman]

THE NATIONAL WEATHER SERVICE IN NORTH PLATTE HAS ISSUED A

* TORNADO WARNING FOR...
EASTERN PERKINS COUNTY IN SOUTHWEST NEBRASKA...

* UNTIL 630 PM MDT

* AT 550 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
STORM WAS LOCATED 8 MILES SOUTHEAST OF GRANT...AND MOVING NORTHEAST
AT 30 MPH.

* THIS DANGEROUS STORM WILL BE NEAR...
MADRID AROUND 605 PM MDT.
ELSIE AROUND 615 PM MDT.

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.

[The Snowman]

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHERN HITCHCOCK COUNTY
UNTIL 715 PM CDT...

AT 654 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A FUNNEL CLOUD.
THIS TORNADIC STORM WAS LOCATED 6 MILES NORTH OF TRENTON...AND WAS
MOVING NORTHEAST AT 25 MPH.

IN ADDITION TO THE DEVELOPING TORNADO...THIS STORM IS CAPABLE OF
PRODUCING LARGE DESTRUCTIVE HAIL UP TO TENNIS BALL SIZE.

LOCATIONS IMPACTED INCLUDE...
PALISADE.

THIS INCLUDES HIGHWAY 34 BETWEEN MILE MARKERS 56 AND 72.

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.

[heatburst]

Today was a bad forecast day for the Southern Plains. Luckily nothing happened as early morning cloud cover prevented a much bigger outbreak than we will see. Still an active night in store. But moving on to tomorrow's forecast. My map is below and I know I am setting myself up for disaster again with this forecast (timing is everything) but I think tomorrow we will see another favorable day for tornadic potential. Keyword being potential as we saw today a lot of things can go wrong, but during the evening into the overnight it appears a few areas will get hit pretty hard. During the daylight hours I really don't see much developing but it is one of those things that you cannot overlook since if something does develop it could be big. I highlight a low-mid level s/w for Eastern OK combining with day time heating. Hopefully I can get one forecast right here...I was on a hot streak until I started posting...haha.

SEVERE WX MAP FRIDAY

[snowlover2]

Looks like we had a touchdown.

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE GOODLAND KS
751 PM CDT THU APR 12 2012

THE NATIONAL WEATHER SERVICE IN GOODLAND HAS ISSUED A

* TORNADO WARNING FOR...
NORTHEASTERN HITCHCOCK COUNTY IN SOUTHWEST NEBRASKA...

* UNTIL 815 PM CDT

* AT 745 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A BRIEF TORNADO
3 MILES NORTHWEST OF TRENTON. DOPPLER RADAR SHOWED THIS TORNADO
MOVING NORTHEAST AT 25 MPH.

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING
DESTRUCTIVE HAIL UP TO HEN EGG SIZE.

* LOCATIONS IMPACTED INCLUDE...
MAINLY RURAL AREAS OF NORTHERN HITCHCOCK COUNTY.

THIS INCLUDES HIGHWAY 34 BETWEEN MILE MARKERS 61 AND 74.

[jdrenken]

Frank Strait's thoughts. I had a 12 hour day at work, so wasn't able to look at anything before you ask.

[snowlover2]

Guessing the new day 1 goes here.


Tornado


Hail

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1233 AM CDT FRI APR 13 2012

VALID 131200Z - 141200Z

...THERE IS A SLGT RISK OF SVR TSTMS LATE FRIDAY AFTERNOON THROUGH
FRIDAY NIGHT ACROSS THE SOUTH CENTRAL PLAINS INTO THE LOWER MISSOURI
VALLEY...

...SYNOPSIS...
MODELS CONTINUE TO INDICATE THAT THE PRIMARY UPPER IMPULSE...
ASSOCIATED WITH A BROADLY CYCLONIC MID/UPPER JET STREAK NOSING
INLAND OFF THE PACIFIC...WILL FINALLY DIG ACROSS THE SOUTHERN
CALIFORNIA COAST TODAY. BY THE END OF THE PERIOD...A DEEP CLOSED
LOW APPEARS LIKELY TO FORM ACROSS THE LOWER COLORADO VALLEY/
SOUTHERN PLATEAU REGION. AS UPPER RIDGING BUILDS DOWNSTREAM...
ACROSS THE GULF OF MEXICO AND MUCH OF THE EASTERN U.S...A
SIGNIFICANT UPPER IMPULSE ALREADY EMERGING FROM THE INTERMOUNTAIN
WEST IS EXPECTED TO LIFT FROM THE NORTH CENTRAL PLAINS INTO THE
UPPER MISSISSIPPI VALLEY/GREAT LAKES REGION.

FORCING ASSOCIATED WITH THIS LEAD FEATURE IS EXPECTED TO TEND TO
OUTRUN BETTER LOW-LEVEL MOISTURE RETURN FROM THE GULF OF MEXICO...AS
MOISTURE LEVELS CONTINUE TO GRADUALLY INCREASE OFF THE WESTERN GULF
INTO THE SOUTHERN AND CENTRAL PLAINS. AFTER INITIALLY SHIFTING
EASTWARD...IN RESPONSE TO THE UPPER IMPULSE...THE DRY LINE IS
EXPECTED TO RETREAT BACK TO THE WEST AND NORTH ACROSS THE PLAINS BY
THIS EVENING...AS NEW SURFACE CYCLOGENESIS COMMENCES ACROSS THE
SOUTH CENTRAL HIGH PLAINS.

COOL/STABLE AIR ASSOCIATED WITH A RETREATING SURFACE HIGH PROBABLY
WILL MAINTAIN LOW CONVECTIVE POTENTIAL TODAY ACROSS MUCH OF THE
EAST...WITH THE EXCEPTION OF SOUTHEAST FLORIDA COASTAL AREAS...WHERE
A FEW STORMS MAY FORM ON THE SEA BREEZE THIS AFTERNOON.
MEANWHILE...CONSIDERABLE THUNDERSTORM ACTIVITY APPEARS PROBABLE WITH
THE MOISTURE AND ASSOCIATED INSTABILITY ACROSS PARTS OF THE PLAINS
AND MISSISSIPPI VALLEY...WHILE SCATTERED STORMS AGAIN DEVELOP
BENEATH THE COLD UPPER TROUGH ACROSS PARTS OF THE WEST AND
INTERMOUNTAIN WEST.

...SOUTH CENTRAL PLAINS INTO PARTS OF THE LWR MO VALLEY...
AS SURFACE DEW POINTS CONTINUE TO GRADUALLY CLIMB INTO THE LOWER AND
MID 60S...BENEATH AT LEAST MODESTLY STEEP MID-LEVEL LAPSE
RATES...POTENTIAL INSTABILITY IS EXPECTED TO CONTINUE TO INCREASE
ACROSS MUCH OF THE SOUTHERN PLAINS TODAY. BY LATE AFTERNOON...
MIXED LAYER CAPE MAY REACH 2000+ J/KG ACROSS A SIZABLE PORTION OF
TEXAS/OKLAHOMA AND ADJACENT PORTIONS OF THE CENTRAL PLAINS/OZARK
PLATEAU. FORCING FOR STORM DEVELOPMENT PRIOR TO 14/00Z IS
UNCLEAR...WITH GENERALLY WEAK MID/UPPER SUPPORT...AND IT IS NOT
CERTAIN THAT SURFACE BOUNDARIES...INCLUDING THE RETREATING DRY
LINE...WILL BE A SIGNIFICANT FACTOR.

HOWEVER...BY THIS EVENING...GUIDANCE IS SUGGESTIVE THAT A FOCUSED
AREA OF STRENGTHENING LOWER/MID TROPOSPHERIC WARM ADVECTION...
BENEATH INCREASINGLY DIFLUENT AND DIVERGENT HIGH LEVEL FLOW...WILL
DEVELOP ACROSS PARTS OF WESTERN INTO NORTH CENTRAL OKLAHOMA...BEFORE
GRADUALLY SHIFTING NORTHEASTWARD OVERNIGHT. AS THIS OCCURS IN THE
PRESENCE OF MODERATELY LARGE BOUNDARY LAYER CAPE...AND STRONG
VERTICAL SHEAR...STRONG/SEVERE STORMS APPEAR LIKELY...INCLUDING
DISCRETE SUPERCELLS. COINCIDING WITH STRENGTHENING SOUTHERLY 850
WIND FIELDS /30-50+ KT/...WHICH WILL RESULT IN ENLARGING CLOCKWISE
CURVED LOW-LEVEL HODOGRAPHS...A FEW TORNADOES WILL BE POSSIBLE. ONE
OR TWO COULD BE STRONG...ALONG WITH THE RISK FOR VERY LARGE
HAIL...BEFORE CONVECTION GRADUALLY WEAKENS AS BOUNDARY LAYER
INSTABILITY WANES LATE THIS EVENING INTO THE OVERNIGHT HOURS.