General Weather Discussion - April 2014

[venture]

The chat will be up and going for today...I'll be back and forth until we start seeing storms getting ready to go.

Weather Spotlight - Live Chat Room for Weather Event Coverage

[venture]

New Day 1 Outlook...

...OK/WESTERN AR...
12Z MODEL SOLUTIONS ARE CONVERGING ON A SCENARIO WHERE ISOLATED
STORMS DEVELOP IN THE 19-21Z TIME FRAME ALONG THE COLD FRONT/DRYLINE
OVER CENTRAL OK. THESE STORMS WILL LIKELY BECOME RAPIDLY SEVERE AND
TRACK EASTWARD ACROSS EASTERN OK INTO WESTERN AR DURING THE LATE
AFTERNOON/EVENING. THERMODYNAMIC PARAMETERS APPEAR FAVORABLE FOR
SEVERE/SIGNIFICANT HAIL IN THE STORMS THAT FORM. ACTIVITY THAT
DEVELOPS ALONG THE DRYLINE HAS A BETTER CHANCE OF STAYING DISCRETE
OVER SOUTHEAST OK...POSING A GREATER RISK OF A FEW TORNADOES. MOST
MODEL GUIDANCE SUGGESTS THE STORMS MAY ORGANIZE INTO A SQUALL LINE
THIS EVENING WITH AN ENHANCED THREAT OF DAMAGING WINDS AS THEY MOVE
INTO AR.

[venture]

MESOSCALE DISCUSSION 0333
NWS STORM PREDICTION CENTER NORMAN OK
1110 AM CDT SUN APR 13 2014

AREAS AFFECTED...ERN KS AND ADJACENT AREAS OF WRN MO/NRN OK

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 131610Z - 131845Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE RISK FOR SEVERE THUNDERSTORMS...INCLUDING
SUPERCELLS...APPEARS LIKELY TO INCREASE BY MID AFTERNOON...PROBABLY
REQUIRING A WATCH BY AROUND 17-18Z.

DISCUSSION...ONE SIGNIFICANT SURFACE FRONTAL WAVE...NOW NORTHEAST OF
MEDICINE LODGE...APPEARS LIKELY TO CONTINUE TRACKING TOWARD THE
FALLS CITY NEB/ST. JOSEPH MO AREA THROUGH 18-20Z. THIS IS EXPECTED
TO OCCUR AS AN INITIAL SHORT WAVE TROUGH...PROGRESSING EAST OF THE
ROCKIES... GRADUALLY SHIFTS EAST NORTHEAST OF THE CENTRAL/SOUTHERN
HIGH PLAINS.

THE LATEST RAPID REFRESH AND HIGH RESOLUTION RAPID REFRESH...AMONG A
CONSENSUS OF OTHER MODEL DATA...ARE SUGGESTIVE THAT ASSOCIATED
FORCING FOR UPWARD VERTICAL MOTION WILL CONTRIBUTE TO THE INITIATION
OF THUNDERSTORM DEVELOPMENT ACROSS EASTERN KANSAS AROUND 18-19Z.
THIS PROBABLY WILL OCCUR BOTH ALONG THE WARM FRONT TO THE NORTHEAST
OF THE LOW...NEAR/NORTHEAST OF SALINA THROUGH THE MANHATTAN/TOPEKA
AREA...AS WELL AS ALONG THE DRYLINE TO THE SOUTH OF THE LOW....TO
THE NORTH AND EAST OF WICHITA INTO THE EMPORIA/CHANUTE AREAS.

GIVEN THE PRESENCE OF STEEP MID-LEVEL LAPSE RATES...WHICH ARE
SUPPORTING SIZABLE WARM SECTOR CAPE...DEEP LAYER SHEAR PROBABLY WILL
BE SUFFICIENT FOR SUPERCELLS WITH AT LEAST A RISK FOR SEVERE
HAIL...EVEN WITH ACTIVITY FORMING TO THE IMMEDIATE COOL SIDE OF THE
WARM FRONT. WITH THE STRONGER 500 MB JET REMAINING WELL TO THE
SOUTH OF THE REGION...THE RELATIVE WEAKNESS OF THE MID-LEVEL FLOW
PROVIDES SOME UNCERTAINTY CONCERNING THE EXTENT OF THE TORNADO
POTENTIAL. HOWEVER...LOW-LEVEL HODOGRAPHS AHEAD OF THE
DRYLINE...ACROSS SOUTHEASTERN KANSAS...SHOULD REMAIN FAIRLY LARGE
AND CLOCKWISE CURVED...PROVIDING THE BEST CHANCE FOR AT LEAST A
COUPLE OF SHORT-LIVED TORNADOES.

..KERR/HART.. 04/13/2014

[venture]

For those not in the chat room, storms starting to go up in NW OK from Medford down to Lahoma.

[venture]

MESOSCALE DISCUSSION 0334
NWS STORM PREDICTION CENTER NORMAN OK
1226 PM CDT SUN APR 13 2014

AREAS AFFECTED...MUCH OF CENTRAL INTO EASTERN OKLAHOMA...INTO PARTS
OF NW TEXAS

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

VALID 131726Z - 131900Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE RISK FOR SEVERE STORMS COULD INCREASE BY 19-20Z ACROSS
PARTS OF CENTRAL OKLAHOMA...BEFORE SPREADING EASTWARD LATER THIS
AFTERNOON.

DISCUSSION...A NARROW PRE-FRONTAL CORRIDOR OF STRONGER SURFACE
HEATING AND DEEPER BOUNDARY LAYER MIXING IS ONGOING ACROSS PARTS OF
NORTHWEST TEXAS/SOUTHWEST OKLAHOMA...INTO NORTH CENTRAL/CENTRAL
OKLAHOMA. AND AN INCREASINGLY WELL DEFINED DRYLINE IS EXPECTED TO
ADVANCE EASTWARD ACROSS THE INTERSTATE 35 CORRIDOR OF OKLAHOMA
DURING THE NEXT FEW HOURS. AS IT DOES...COINCIDING WITH STRONGER
MID-LEVEL HEIGHT FALLS SPREADING EAST OF THE HIGH PLAINS...IT
APPEARS PROBABLE THAT FORCING FOR UPWARD VERTICAL MOTION WILL WEAKEN
INHIBITION SUFFICIENTLY FOR THE INITIATION OF BOUNDARY LAYER BASED
STORMS BY AROUND 19-20Z...IF NOT BEFORE. ONCE THIS OCCURS...IN THE
PRESENCE OF AN ENVIRONMENT CHARACTERIZED BY STEEP MID-LEVEL LAPSE
RATES...SUPPORTIVE OF LARGE CAPE...AND MODERATELY STRONG DEEP LAYER
MEAN FLOW AND SHEAR /500 MB WIND ON THE ORDER OF 40-50
KT/...DISCRETE SUPERCELL DEVELOPMENT APPEARS LIKELY...AT LEAST
INITIALLY.

LARGE HAIL MAY BE THE PRIMARY THREAT INITIALLY...BUT ACTIVITY
PROPAGATING OFF...AND OUT AHEAD OF...THE DRYLINE MAY BE ACCOMPANIED
BY INCREASING TORNADIC POTENTIAL...IN THE PRESENCE OF LARGER
CLOCKWISE CURVED LOW-LEVEL HODOGRAPHS WHICH SHOULD PERSIST ACROSS
EASTERN OKLAHOMA LATE THIS AFTERNOON. OTHERWISE...AS THE SOUTHWARD
SURGING COLD FRONT OVERTAKES THE DRYLINE...AN UPSCALE GROWING SQUALL
LINE APPEARS POSSIBLE...ACCOMPANIED MAINLY BY THE RISK FOR SEVERE
WIND AND HAIL.

..KERR/HART.. 04/13/2014

[bchris02]

What time do you expect storms to fire in the metro area?

[venture]

What time do you expect storms to fire in the metro area?

Next couple of hours.

[Anonymous.]

Dryline is cutting through Kingfisher and Blaine county right now, very sharp gradient.

The mixing along and ahead of the dryline will be favorable for explosive development. But I think largest hail threat will be early with cells that take on supercell characteristics, I think storms will quickly try to form a line and decrease large hail and off tornado chances. However, this will create potential widespread severe winds across E and S OK.

[venture]

New development from Medford to Pond Creek to Enid and Waukomis. More CU development around the Metro and SW. Stay alert.

[venture]

New hints of a cell going up west of us near Weatherford.

[venture]

Dryline is about to go now. Cell near Lamont/Deer Creek showing hail now. Also storms forming down into Northern TX as well.

[venture]

New Tornado Watch

[venture]

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 74
NWS STORM PREDICTION CENTER NORMAN OK
200 PM CDT SUN APR 13 2014

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF
CENTRAL AND EASTERN OKLAHOMA
NORTH TEXAS

* EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 200 PM UNTIL
800 PM CDT.

* PRIMARY THREATS INCLUDE...
A COUPLE TORNADOES POSSIBLE
SCATTERED LARGE HAIL LIKELY WITH ISOLATED VERY LARGE HAIL EVENTS
TO 2.5 INCHES IN DIAMETER POSSIBLE
SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 75 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES NORTHWEST OF
BARTLESVILLE OKLAHOMA TO 60 MILES WEST SOUTHWEST OF SHERMAN
TEXAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 73...

DISCUSSION...THUNDERSTORMS ARE BEGINNING TO FORM ALONG THE COLD
FRONT IN NORTH CENTRAL OK...AND WILL SOON FORM ALONG THE DRYLINE
SOUTHWARD INTO NORTH TX. STRONG INSTABILITY WILL PROMOTE SUPERCELL
STRUCTURES WITH DRYLINE STORMS...CAPABLE OF VERY LARGE HAIL AND
DAMAGING WINDS. THE TORNADO THREAT APPEARS GREATEST LATE THIS
AFTERNOON AND EVENING OVER SOUTHEAST OK...WHERE STRONGEST LOW LEVEL
SHEAR AND BOUNDARY LAYER MOISTURE WILL BE PRESENT.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 26030.

Tornadoes

Probability of 2 or more tornadoes	Mod (40%)
Probability of 1 or more strong (F2-F5) tornadoes	Low (20%)

Wind

Probability of 10 or more severe wind events	Mod (50%)
Probability of 1 or more wind events > 65 knots	Low (10%)

Hail

Probability of 10 or more severe hail events	Mod (60%)
Probability of 1 or more hailstones > 2 inches	Mod (30%)

Combined Severe Hail/Wind

Probability of 6 or more combined severe hail/wind events

High (80%)

[Anonymous.]

Kiowa, Wash!ta, and Caddo counties. Explosive cumulus along cool front here.

Cool front looks to be taking over dryline very quickly. Not saying it will, but the timing of this occurrence appears to put the triple point into Canadian county within an hour.

[venture]

New cell developing near Tuttle/Mustang.

On the new chat page (click on link in signature) I do have the radar stream going now.

[Mel]

Getting a few drops of rain out in Mustang now.

[OKCDrummer77]

Raining and still sunny near NW 23rd & Portland.

[PennyQuilts]

The Mustang storm flying towards OKC.

[Bunty]

It's looking plenty stormy toward the north and northwest in Stillwater where there is a severe storm warning out. It looks less stormy to the southwest. Rain cooled wind coming in.

[venture]

MESOSCALE DISCUSSION 0339
NWS STORM PREDICTION CENTER NORMAN OK
0309 PM CDT SUN APR 13 2014

AREAS AFFECTED...CNTRL/ERN OKLAHOMA

CONCERNING...TORNADO WATCH 74...

VALID 132009Z - 132145Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 74 CONTINUES.

SUMMARY...RISK FOR DAMAGING WIND GUSTS WITH AN EVOLVING SQUALL LINE
MAY INCREASE THROUGH 23-00Z...WHILE THE RISK FOR SEVERE HAIL
CONTINUES.

DISCUSSION...WHILE DRYLINE CONVECTION CONTINUES TO STRUGGLE...LIFT
ALONG THE SURFACE FRONT AS IT OVERTAKES THE DRYLINE HAS BEEN
SUFFICIENT TO FORCE VIGOROUS STORM DEVELOPMENT. THE UPSCALE GROWTH
OF A SQUALL LINE IS NOW WELL UNDERWAY ACROSS EASTERN KANSAS INTO
NORTH CENTRAL OKLAHOMA...AND SOUTHWARD DEVELOPMENT IS EXPECTED TO
CONTINUE TOWARD THE RED RIVER THROUGH 23-00Z...THOUGH THIS MAY
MOSTLY OCCUR NORTH THROUGH EAST OF THE OKLAHOMA CITY METRO. SEVERE
HAIL WILL REMAIN A THREAT WITH SQUALL LINE CONVECTION...AND HEAVY
PRECIPITATION LOADING/DOWNWARD TRANSPORT OF MOMENTUM BENEATH 30-50
KT SOUTHERLY 850 MB FLOW ARE EXPECTED TO GRADUALLY CONTRIBUTE TO AN
INCREASING RISK FOR SEVERE WIND GUSTS. OTHERWISE...DISCRETE
SUPERCELL DEVELOPMENT STILL MAY NOT BE OUT OF THE QUESTION...
PARTICULARLY ACROSS PARTS OF SOUTH CENTRAL INTO SOUTHEASTERN
OKLAHOMA TOWARD EARLY EVENING.

..KERR.. 04/13/2014

[venture]

Whole line is severe warned now north of Edmond. Additional development starting south through Mustang.

[BlackmoreRulz]

Pretty good hail storm for a few seconds here just now

[venture]

The national weather service in norman has issued a

* severe thunderstorm warning for...
Oklahoma county in central oklahoma...
Northwestern cleveland county in central oklahoma...

* until 415 pm cdt

* at 341 pm cdt...severe thunderstorms were located along a line
extending from near edmond to near oklahoma city...moving east at
25 mph.

Hazard...ping pong ball size hail and 60 mph wind gusts.

Source...radar indicated.

Impact...people and animals outdoors will be injured. Expect hail
damage to roofs...siding...windows and vehicles. Expect
wind damage to roofs...siding and trees.

* locations impacted include...
Oklahoma city...western norman...edmond...moore...midwest city...
Del city...choctaw...the village...spencer...nichols hills...
Jones...nicoma park...luther...valley brook...arcadia...stanley
draper lake...tinker air force base...forest park...lake aluma and
smith village.

[OKCMallen]

Clouds just now covered half the sun in north-central Norman. Radar doesn't show we'll be getting any rain at this point. PLEASE bring some rain.

[Tydude]

Severe weather statement
national weather service norman ok
402 pm cdt sun apr 13 2014

okc081-083-119-132115-
/o.con.koun.sv.w.0005.000000t0000z-140413t2115z/
lincoln ok-payne ok-logan ok-
402 pm cdt sun apr 13 2014

...a severe thunderstorm warning remains in effect until 415 pm cdt
for northwestern lincoln...eastern payne and southeastern logan
counties...

At 401 pm cdt...severe thunderstorms were located along a line
extending from near maramec to 3 miles west of fallis...moving east
at 25 mph.

Hazard...ping pong ball size hail and 60 mph wind gusts.

Source...radar indicated.

Impact...people and animals outdoors will be injured. Expect hail
damage to roofs...siding...windows and vehicles. Expect
wind damage to roofs...siding and trees.

Locations impacted include...
Cushing...perkins...yale...carney...tryon...ripley ...agra...fallis
and ingalls.

Precautionary/preparedness actions...

For your protection move to an interior room on the lowest floor of a
building.

&&

a tornado watch remains in effect until 800 pm cdt sunday evening for
oklahoma and northern texas.