Oklahoma Weather Discussion - August/September 2012

[venture]

Hey, Venture, what are the models suggesting for late-week, Fri evening in particular? Hearing conflicting notions...low chance of precip, to remnants of hurricane dumping heavy rain

Low-Mid 70s with isolated showers and storms the way it looks now.

Oh great weather god Venture please tell me what your crystal ball says about Saturday aftermoon-evening? My son is having a birthday party and has a moon bounce planned. Do we need to change plans to a Noahs Ark themed party

Mid 30s...heavy snow...or not. Looks like about the same as Friday but rain chances look a bit better.

[Easy180]

Payne says 1-3 inches if the tropical storm stays on track...2 inches for most of the state would be nice

[Bunty]

Payne says 1-3 inches if the tropical storm stays on track...2 inches for most of the state would be nice

Hopefully, it won't bypass most of Oklahoma, like Isaac did.

[venture]

Slight Risk today roughly along and North of I-44

...WRN OK INTO THE OZARKS THIS AFTERNOON INTO TONIGHT...

THE WRN EXTENSION OF AN EML MENTIONED IN THE PREVIOUS SECTION IS
CLEARLY OBSERVED BY 12Z REGIONAL SOUNDINGS WHERE 700-500-MB LAPSE
RATES RANGED FROM 7.5-9.0 C/KM. AND WHILE BOUNDARY LAYER MOISTURE
CONTENT WILL BE LESS THAN THAT OVER THE LOWER/MID MS
VALLEY...STRONGER DIABATIC HEATING WILL YIELD WARMER SURFACE
TEMPERATURES...A DEEPLY MIXED BOUNDARY LAYER...AND MLCAPE OF
1500-2500 J/KG.

FORCING ASSOCIATED WITH THE VORTICITY MAXIMUM MOVING EWD FROM SERN
CO/NERN NM ALONG WITH A WEAKER CYCLONIC CIRCULATION OBSERVED OVER
CNTRL KS AS OF LATE MORNING WILL AUGMENT LOW-LEVEL UPLIFT ALONG THE
SYNOPTIC FRONT AND DEVELOPING DRYLINE TO SUPPORT AN INCREASE IN
TSTMS THIS AFTERNOON AND EVENING FROM CNTRL MO INTO WRN OK. WHILE
VERTICAL SHEAR WILL BE RELATIVELY WEAK /I.E. LESS THAN 25-30 KT
THROUGH THE LOWEST 6 KM/...THE PRESENCE OF THE STEEP LAPSE RATES AND
MODERATE INSTABILITY WILL SUPPORT MULTICELL CLUSTERS CAPABLE OF
DAMAGING WINDS AND HAIL. THIS THREAT MAY PERSIST INTO TONIGHT AS
STORMS GROW UPSCALE INTO AN MCS AT THE TERMINUS OF A DEVELOPING
NOCTURNAL LOW-LEVEL WIND MAXIMUM

[soonerguru]

Slight Risk today roughly along and North of I-44

...WRN OK INTO THE OZARKS THIS AFTERNOON INTO TONIGHT...

THE WRN EXTENSION OF AN EML MENTIONED IN THE PREVIOUS SECTION IS
CLEARLY OBSERVED BY 12Z REGIONAL SOUNDINGS WHERE 700-500-MB LAPSE
RATES RANGED FROM 7.5-9.0 C/KM. AND WHILE BOUNDARY LAYER MOISTURE
CONTENT WILL BE LESS THAN THAT OVER THE LOWER/MID MS
VALLEY...STRONGER DIABATIC HEATING WILL YIELD WARMER SURFACE
TEMPERATURES...A DEEPLY MIXED BOUNDARY LAYER...AND MLCAPE OF
1500-2500 J/KG.

FORCING ASSOCIATED WITH THE VORTICITY MAXIMUM MOVING EWD FROM SERN
CO/NERN NM ALONG WITH A WEAKER CYCLONIC CIRCULATION OBSERVED OVER
CNTRL KS AS OF LATE MORNING WILL AUGMENT LOW-LEVEL UPLIFT ALONG THE
SYNOPTIC FRONT AND DEVELOPING DRYLINE TO SUPPORT AN INCREASE IN
TSTMS THIS AFTERNOON AND EVENING FROM CNTRL MO INTO WRN OK. WHILE
VERTICAL SHEAR WILL BE RELATIVELY WEAK /I.E. LESS THAN 25-30 KT
THROUGH THE LOWEST 6 KM/...THE PRESENCE OF THE STEEP LAPSE RATES AND
MODERATE INSTABILITY WILL SUPPORT MULTICELL CLUSTERS CAPABLE OF
DAMAGING WINDS AND HAIL. THIS THREAT MAY PERSIST INTO TONIGHT AS
STORMS GROW UPSCALE INTO AN MCS AT THE TERMINUS OF A DEVELOPING
NOCTURNAL LOW-LEVEL WIND MAXIMUM

So, translated into English, is it going to rain in OKC?

[SoonerDave]

So, translated into English, is it going to rain in OKC?

Possibility. What it really says is that the weather setup involves a dryline where storms could form somewhat quickly later this afternoon/evening generally along the I-44 corridor from Missouri to SW Oklahoma. The probability of tornadoes is low due to the absence of the winds that create the necessary rotation, but there could be enough strength for some pretty blustery/windy storms with some hail.

What makes it tough to say whether it will actually rain in OKC is that the I-44 alignment more or less splits the OKC area right down the middle. A few miles either way could make the difference between a rainstorm and nothing.

[venture]

Latest HRRR is increasing chances for storms a good deal later. Looks like we might have a bow segment come through Central/Southern OK later tonight.

One isolated severe storm now out in the panhandle.

Loop

[venture]

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 650
NWS STORM PREDICTION CENTER NORMAN OK
730 PM CDT TUE SEP 25 2012

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

WESTERN OKLAHOMA
NORTHWEST TEXAS

EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 730 PM
UNTIL 100 AM CDT.

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 EAST AND WEST OF A LINE FROM 35 MILES EAST
NORTHEAST OF ALVA OKLAHOMA TO 55 MILES SOUTHWEST OF WICHITA FALLS
TEXAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

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.

OTHER WATCH INFORMATION...CONTINUE...WW 648...WW 649...

DISCUSSION...SCATTERED MULTI-CELL TSTMS AND PERHAPS A FEW WEAK
SUPERCELLS WILL SPREAD ACROSS WRN OK AND NWRN TX AHEAD OF A WEAK MID
LEVEL SHORT-WAVE TROUGH. PRIMARY SEVERE THREAT WITH THIS ACTIVITY
IS EXPECTED TO BE HAIL GIVEN THE STEEP LAPSE RATE ENVIRONMENT
CHARACTERIZED BY MODEST INSTABILITY.

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 500. MEAN STORM
MOTION VECTOR 27020.

[venture]

Watch extended just for Oklahoma County.

WATCH COUNTY NOTIFICATION FOR WATCH 650...UPDATED
NATIONAL WEATHER SERVICE NORMAN OK
834 PM CDT TUE SEP 25 2012


OKC109-260600-
/O.EXA.KOUN.SV.A.0650.000000T0000Z-120926T0600Z/


THE NATIONAL WEATHER SERVICE HAS EXTENDED SEVERE THUNDERSTORM
WATCH 650 TO INCLUDE THE FOLLOWING AREAS UNTIL 1 AM CDT WEDNESDAY


IN OKLAHOMA THIS WATCH INCLUDES 1 COUNTY


IN CENTRAL OKLAHOMA


OKLAHOMA


THIS INCLUDES THE CITIES OF...OKLAHOMA CITY.

[pw405]

Norman is cursed. Little to no rain here so far.

[Bunty]

Well, at least Norman isn't getting the high winds from storms that bypassed it: It became real windy in the counties just to the northeast of OKC from dissipating storms. One of the statements highlighted below.

SPECIAL WEATHER STATEMENT - PAYNE (OKLAHOMA):

Message summary: ...significant weather advisory for northern lincoln...payne and southeastern noble counties until 115 am cdt...
At 1247 am cdt...dissipating storms have generated an area of strong to near severe winds to the north of the storms from near perkins south to stillwater to chandler. These strong wind gusts may persist through 130 am. Hazards include...
Potentially severe winds gusting over 55 mph...
Locations impacted include...

Stillwater...cushing...perry...perkins...yale...ca rney...morrison...
Glencoe...tryon...ripley...agra...avery...lake carl blackwell...
Lake mcmurtry...ingalls and parkland.

[venture]

Well, at least Norman isn't getting the high winds from storms that bypassed it: It became real windy in the counties just to the northeast of OKC from dissipating storms. One of the statements highlighted below.

Huh? Norman mesonet had 54 mph recorded. Here in East Norman we probably pushed 60 mph a few times.

Anyway, slight risk again today for most of Oklahoma along and north of I-44.

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1242 AM CDT WED SEP 26 2012

VALID 261200Z - 271200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE ERN TX/OK PANHANDLES
EWD ACROSS NRN OK...SRN KS...AND SWRN MO...

...SYNOPSIS...
A GENERALLY ZONAL FLOW REGIME WILL EXIST ACROSS MUCH OF THE CNTRL
AND SRN CONUS WITH A BELT OF STRONG FLOW FROM THE CNTRL PLAINS EWD
INTO THE OH VALLEY LINKING WITH THE BASE OF A NERN TROUGH. AT THE
SURFACE...A COLD FRONT WILL BE OVER WRN NY AT 00Z...THEN BECOMING
QUASI-STATIONARY SWWD ACROSS THE MIDWEST AND INTO THE SRN PLAINS
NEAR THE KS/OK BORDER. SHOWERS AND STORMS SHOULD BE ONGOING ALONG
THE LENGTH OF THE BOUNDARY EARLY WED...WITH AIR MASS RECOVERY TO THE
S DURING THE DAY. THE GREATEST INSTABILITY WILL DEVELOP FROM THE SRN
PLAINS INTO THE OH VALLEY...WITH WEAK INSTABILITY AND LAPSE RATES
TOWARD THE E COAST WHERE FLOW WILL BE STRONGEST.

...MUCH OF NRN OK...SRN KS...ERN TX/OK PANHANDLES...SWRN MO...
THUNDERSTORMS SHOULD BE ONGOING FROM ERN KS/NERN OK INTO MO AND INTO
THE OH VALLEY AS A SWLY LOW LEVEL JET MAINTAINS LIFT NEAR THE
SYNOPTIC BOUNDARY. MOST OF THE EARLY ACTIVITY SHOULD BE
NON-SEVERE...BUT MARGINAL HAIL OR WIND COULD OCCUR. HEATING WILL
OCCUR S OF THE FRONT FROM OK TO KY WHICH WILL RESULT IN A LARGE AREA
OF UNCAPPED INSTABILITY. NEW STORMS ARE EXPECTED ALONG THE DRYLINE
IN W TX AS WELL AS ALONG THE FRONT IN NRN OK/SRN KS...AND POSSIBLY
REDEVELOPING ACROSS MO INTO KY. SHEAR PROFILES WILL AGAIN BE
MARGINAL FOR ANY WIDESPREAD SEVERE...BUT LAPSE RATES AND INSTABILITY
WILL COMPENSATE ESPECIALLY OVER TX/OK/KS AND A FEW LONG LIVED
CLUSTERS OF STORMS MAY FORM.

[Roadhawg]

I got some lightening and thunder but very little rain.

[venture]

MESOSCALE DISCUSSION 1992
NWS STORM PREDICTION CENTER NORMAN OK
0204 PM CDT WED SEP 26 2012

AREAS AFFECTED...CENTRAL/EASTERN OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 261904Z - 262030Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...AT LEAST AN ISOLATED SEVERE THREAT WILL EXIST THIS
AFTERNOON ACROSS PORTIONS OF EASTERN/CENTRAL OK. SEVERE
HAIL/DAMAGING WINDS WILL BE POSSIBLE...AND A BRIEF TORNADO CANNOT BE
RULED OUT.

DISCUSSION...A RECENT INCREASE IN STRONG TSTMS HAS OCCURRED ACROSS
EAST-CENTRAL OK NEAR I-40...NEAR THE HENRYETTA VICINITY AS OF 1845Z.
THIS DEVELOPMENT IS OCCURRING NEAR AN OUTFLOW BOUNDARY THAT ROUGHLY
EXTENDS WEST-EAST ACROSS OK...WITH OTHER TOWERING CU NOTED IN
VICINITY OF THIS BOUNDARY ACROSS CENTRAL OK IN LATEST VISIBLE
SATELLITE IMAGERY. THE PURCELL OK PROFILER REFLECTS AROUND 35 KT OF
0-6 KM...WHICH IS MORE THAN ADEQUATE FOR A SUPERCELLULAR/SUSTAINED
STORM MODE ESPECIALLY NEAR THE OUTFLOW BOUNDARY WHERE LOW-LEVEL
WINDS HAVE AN EASTERLY COMPONENT ON ITS IMMEDIATE COOL SIDE. WHERE
STORMS DO DEVELOP THIS AFTERNOON...SEVERE HAIL/DAMAGING WINDS WILL
BE POSSIBLE...AND A BRIEF TORNADO CANNOT BE RULED OUT NEAR THE
OUTFLOW BOUNDARY GIVEN AN ENHANCED LOW-LEVEL SRH/VORTICITY-RICH
ENVIRONMENT.

..GUYER/MEAD.. 09/26/2012

[Bunty]

Huh? Norman mesonet had 54 mph recorded. Here in East Norman we probably pushed 60 mph a few times.

I was in reference to collapsing storms NOT affecting Norman. Apparently, contrary to a previous complainer about Norman not getting rain, so far, a storm did eventually arrive to Norman with rain before collapsing.

[venture]

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 651
NWS STORM PREDICTION CENTER NORMAN OK
220 PM CDT WED SEP 26 2012

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

WEST-CENTRAL ARKANSAS
CENTRAL AND EASTERN OKLAHOMA

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 220 PM UNTIL
1000 PM CDT.

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

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 40
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES SOUTHWEST
OF CHANDLER OKLAHOMA TO 20 MILES EAST NORTHEAST OF FORT SMITH
ARKANSAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).

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...AN OUTFLOW BOUNDARY EXTENDING FROM NEAR THE OKC METRO
AREA ESEWD ALONG OR JUST SOUTH OF I-40 HAS FOCUSED ISOLATED STORM
DEVELOPMENT THIS AFTERNOON. INFLOW AIR MASS HAS WARMED INTO THE
MID-UPPER 80S AND WHEN COUPLED WITH STEEP MIDLEVEL LAPSE RATES AND
DEWPOINTS IN THE MID 60S IS RESULTING IN MLCAPE OF 1500-2500 J/KG.
MOREOVER...LOCALLY BACKED NEAR-GROUND FLOW NEAR THE OUTFLOW BOUNDARY
IS COLLOCATED WITH 30 KT WLY WINDS IN THE MIDLEVELS...YIELDING A
VERTICALLY VEERING WIND PROFILE WITH AROUND 40 KT OF DEEP-LAYER
SHEAR. AS SUCH...SETUP WILL SUPPORT SUPERCELL EVOLUTION WITH A RISK
FOR LARGE HAIL...DAMAGING WINDS...AND PERHAPS A BRIEF TORNADO.

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 500. MEAN STORM
MOTION VECTOR 27020.

[Bunty]

A, so far, slender line of storms are trying to form just to the north and northwest of OKC.

[venture]

Looks like main show is going to come from the TX Panhandle and then have another complex moving through OK later this evening/overnight.