General Weather Discussion - June 2014

[venture]

I am surprised they didn't PDS it based on the likelihood of damaging straightline winds as (potentially multiple) MCS(s) develop into evening.

I think they stayed away from PDS wording based on the tornado probabilities. If it evolves to a definite derecho threat then a PDS Severe might happen.

[venture]

Day 4-8 Graphic finally updated for me... keep in mind these are 30% risk areas, slight risk starts at 15%.

[venture]

I'll be in the chat room for the afternoon if anyone is bored.

[venture]

That monster storm is aiming directly for Omaha now. Radar indicated 3"+ hail and some pretty destructive winds.

[venture]

SPC just went High Risk for NE/IA. Expect a new PDS watch to be issued for them soon.

[Anonymous.]

That is a crazy setup.

Your going to have supercells developing up ahead of the main MCS, then a monster derecho blow through as it eats up the supercells.

Very rare event.

[venture]

Yup, this is heading right into OMA.

[venture]

Ummm...this is going to hurt. Estimate hail size is on the right.

[Anonymous.]

They're likely going to have flooding also. All of these clusters will be traveling over the same areas into the night. Talk about 'all modes of severe weather'.

[venture]

Slight Risk Today - Far NW OK & the PH

...THE WRN DAKOTAS SWD TO THE TX PANHANDLE...
ELY LOW-LEVEL UPSLOPE FLOW IS FORECAST TO EVOLVE ACROSS THE WRN HALF
OF THE CENTRAL PLAINS AND VICINITY...IN A POST-FRONTAL FLOW REGIME N
OF A W-E FRONT EXPECTED TO LIE FROM THE TX/OK PANHANDLE VICINITY
ENEWD INTO THE MIDWEST BY LATE AFTERNOON.

WITH THE UPSLOPE FLOW OCCURRING WITHIN A DIURNALLY DESTABILIZING
ENVIRONMENT...EXPECT ISOLATED STORMS TO DEVELOP ACROSS THE CENTRAL
AND NRN HIGH PLAINS AREA. IN ADDITION TO AMPLE CAPE...MODERATE WLY
FLOW ALOFT ATOP THE LOW-LEVEL ELYS WILL RESULT IN SHEAR SUFFICIENT
FOR ORGANIZED/ROTATING STORMS. THUS...LARGE HAIL AND DAMAGING WINDS
WILL BE POSSIBLE WITH THE STRONGEST STORMS ACROSS THIS REGION.
DURING THE EVENING/OVERNIGHT...STORM COVERAGE MAY INCREASE OVER SRN
PORTIONS OF THE RISK AREA -- I.E. THE WRN KS/NWRN OK VICINITY -- AS
A NOCTURNAL LOW-LEVEL JET INTENSIFIES. ALONG WITH THE RISK FOR
ISOLATED HAIL/WIND SPREADING INTO THIS AREA...AN ISOLATED TORNADO
WILL ALSO BE POSSIBLE AS LOW-LEVEL SHEAR INCREASES.

Slight Risk Thursday - Far NE OK


...KS...NRN OK AND THE LOWER MS VALLEY AND TN VALLEY REGIONS...

PRIMARY UNCERTAINTY THIS FORECAST WILL BE LOCATION OF FRONT AND
ONGOING MCS OUTFLOW BOUNDARIES. STRONG INSTABILITY WILL RESIDE IN
VICINITY OF MEANDERING FRONT SUPPORTED BY RICH LOW-LEVEL MOISTURE
AND STEEP LAPSE RATES. HOWEVER...A CAPPING INVERSION WILL ALSO
LIKELY EXIST WHERE THE EML WILL HAVE OVERSPREAD THIS REGION. THIS
WILL LIKELY LIMIT SFC BASED THUNDERSTORM INITIATION IN WARM SECTOR.
HOWEVER...A FAVORED CORRIDOR FOR STORMS WILL REMAIN NORTH OF THE
FRONT ACROSS NRN OK INTO KS SUPPORTED BY ISENTROPIC
ASCENT...ESPECIALLY DURING THE EARLY MORNING AND OVERNIGHT HOURS
WHEN THE LLJ WILL BE MAXIMIZED.

MODELS TIME THE SHORTWAVE TROUGH NOW OVER CA INTO THE CNTRL PLAIN
EARLY THURSDAY WHERE AN MCS WILL LIKELY BE IN PROGRESS OVER KS.
STORMS ARE EXPECTED TO DEVELOP SEWD...GENERALLY NORTH OF FRONT
THROUGH ERN AND SRN KS...NERN OK INTO SRN MO...NRN ARKANSAS AND
EVENTUALLY WRN PARTS OF THE TN VALLEY AREA. INFLUX OF HIGH THETA-E
AIR FROM THE MODERATELY UNSTABLE WARM SECTOR AND STRONG VERTICAL
SHEAR WILL SUPPORT ORGANIZED STORMS INCLUDING SUPERCELLS AND BOWING
SEGMENTS WITH HIGH POTENTIAL FOR MCS EPISODES. LARGE HAIL AND
DAMAGING WIND WILL BE THE MAIN THREATS...BUT A COUPLE OF TORNADOES
CANNOT BE RULED OUT.

Slight Risk Friday - Northern 2/3rds of OK


...THERE IS A SLGT RISK OF SVR TSTMS FROM A PORTION OF THE CNTRL AND
SRN PLAINS INTO THE LOWER MS VALLEY AND TN VALLEY REGIONS...

...SUMMARY...
SEVERE STORMS WILL BE POSSIBLE FROM A PORTION OF THE CENTRAL HIGH
PLAINS EASTWARD THROUGH KANSAS AND OKLAHOMA INTO THE LOWER
MISSISSIPPI VALLEY AND TENNESSEE VALLEY REGIONS FRIDAY AND FRIDAY
NIGHT.

...SYNOPSIS...

LITTLE CHANGE IN THE OVERALL SYNOPTIC REGIME WILL OCCUR ON FRIDAY
WITH UPPER PATTERN REMAINING QUASI-ZONAL PROGRESSIVE. SEVERAL LOW
AMPLITUDE SHORTWAVE TROUGHS WILL ADVANCE THROUGH THIS FLOW REGIME
INCLUDING THE CNTRL PLAINS INTO THE TN VALLEY WHERE A MEANDERING
BOUNDARY /AT TIMES REINFORCED BY CONVECTIVE OUTFLOWS/ WILL LINGER.

...KS...OK THROUGH LOWER MS AND TN VALLEY...

HIGHER SEVERE PROBABILITIES WILL PROBABLY BE WARRANTED AT SOME TIME
OVER PORTIONS OF THIS REGION. HOWEVER...UNCERTAINTY REGARDING WHERE
MCS BOUNDARIES WILL BE AND TIMING OF INDIVIDUAL SHORTWAVE TROUGHS
PRECLUDE MORE THAN 15% SEVERE PROBABILITIES AT THIS TIME.

MODERATE TO STRONG INSTABILITY WILL RESIDE IN WARM SECTOR AND IN
VICINITY OF THE MEANDERING FRONT OR OUTFLOW BOUNDARIES SUPPORTED BY
RICH LOW-LEVEL MOISTURE WITH NEAR 70F DEWPOINTS. MUCH OF THE WARM
SECTOR WILL LIKELY REMAIN CAPPED AS MODERATE WLY FLOW MAINTAINS WARM
AIR ALOFT AT BASE OF EML PLUME. HOWEVER...THE COMBINATION OF
ISENTROPIC ASCENT NORTH OF EFFECTIVE BOUNDARIES...AUGMENTED BY
MIGRATORY IMPULSES ALOFT WILL LIKELY MAINTAIN AN ACTIVE CORRIDOR OF
THUNDERSTORM DEVELOPMENT FROM KS INTO NRN OK EWD THROUGH THE LOWER
MS VALLEY AND TN VALLEY REGIONS. STORMS MAY BE ONGOING AT THE START
OF THE PERIOD NORTH OF THE FRONT AND THIS ACTIVITY WILL HAVE THE
POTENTIAL TO INTENSIFY AS HIGHER THETA-E AIR FROM THE DESTABILIZING
WARM SECTOR IS ADVECTED INTO THE FRONTAL ZONE. OTHER STORMS MAY ALSO
DEVELOP ALONG/NORTH OF THE FRONT DURING THE DAY AS WELL AS OVERNIGHT
AS THE LLJ STRENGTHENS. MODERATE WLY FLOW ALOFT IN PROXIMITY TO THE
FRONT WILL MAINTAIN SUFFICIENT VERTICAL SHEAR /40-50 KT/ FOR STORM
ORGANIZATION WITH SUPERCELLS POSSIBLE AS WELL AS LEWP/BOW ECHOES
ASSOCIATED WITH MCS ACTIVITY. LARGE HAIL AND DAMAGING WIND GUSTS ARE
EXPECTED TO BE THE MAIN THREATS.

...CNTRL THROUGH SRN HIGH PLAINS...

OTHER STORMS MAY DEVELOP OVER THE HIGHER TERRAIN AND SPREAD EWD INTO
THE HIGH PLAINS WHERE DIABATIC WARMING...STEEP LAPSE RATES AND LOW
LEVEL DEWPOINTS IN THE 40S TO 50S WILL SUPPORT MODERATE INSTABILITY.
THIS REGION WILL ALSO REMAIN WITHIN BELT OF FLOW AND VERTICAL SHEAR
FOR SOME SUPERCELL STRUCTURES. SOME OF THIS ACTIVITY MIGHT
EVENTUALLY CONGEAL INTO AN MCS OR TWO DURING THE EVENING.

[Anonymous.]

The frontal boundaries responsible for the onslaught of MCSs in the northern plains the last few days will keep sagging south. Eventually parking over OK/KS. With this, pieces of energy will spark off complexes of showers and storms over the next week+.

Here is the projected rain amounts over the next 7 days:




Yes that is over 10 inches in SW MO and 5+ inches over much of OK.

This is pretty rare event this far south at this time, relatively speaking. With the slow crawler system 2 weeks ago, and now this stalled front swinging down - this has been a very strange Spring-Summer transition.

[HangryHippo]

The frontal boundaries responsible for the onslaught of MCSs in the northern plains the last few days will keep sagging south. Eventually parking over OK/KS. With this, pieces of energy will spark off complexes of showers and storms over the next week+.

Here is the projected rain amounts over the next 7 days:




Yes that is over 10 inches in SW MO and 5+ inches over much of OK.

This is pretty rare event this far south at this time, relatively speaking. With the slow crawler system 2 weeks ago, and now this stalled front swinging down - this has been a very strange Spring-Summer transition.

Will the rain be here by this weekend?

[haildamage]

Need to go from Dallas to Okc either Saturday or Sunday. Which day looks to be the best for travel.

[venture]

Need to go from Dallas to Okc either Saturday or Sunday. Which day looks to be the best for travel.

Neither really look great...though Saturday precip may be a bit later in the day but Sunday might be all day.

[venture]

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 224
NWS STORM PREDICTION CENTER NORMAN OK
925 PM CDT WED JUN 4 2014

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
SOUTHEAST KANSAS
SOUTHERN MISSOURI
FAR NORTHEAST OKLAHOMA

* EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 925 PM
UNTIL 500 AM CDT.

* PRIMARY THREATS INCLUDE...
ISOLATED VERY LARGE HAIL EVENTS TO 2.5 INCHES IN DIAMETER
POSSIBLE
ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 45
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES WEST OF
CHANUTE KANSAS TO 40 MILES EAST NORTHEAST OF WEST PLAINS
MISSOURI. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 221...WW 222...WW 223...

DISCUSSION...ISOLD TO WDLY SCTD SUSTAINED STORMS/POSSIBLE SUPERCELLS
WITH LARGE HAIL MAY OCCUR THROUGH EARLY THU IN MOIST...WEAKLY
CONFLUENT SWLY LOW-LVL FLOW BENEATH DEEP/STRONG EML. LARGELY
UNIDIRECTIONAL ...WLY CLOUD-LAYER SHEAR SUGGESTS POTENTIAL FOR A
SPLITTING STORM OR TWO IF SUSTAINED UPDRAFTS TO INDEED DEVELOP.

AVIATION...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 550. MEAN STORM
MOTION VECTOR 28020.


...CORFIDI

[haildamage]

Thanks Venture. We will plan on Saturday afternoon and hope for the best.

[venture]

Sounding for next Wednesday... the temp and dewpoint spread is pretty high, but the rest of the parameters look interesting if this even materializes. I think our storm season is finally showing up.

[venture]

Upgrade to Moderate Risk has taken place for extreme NE OK today through AR and S MO. On going severe MCS is moving through NE OK this morning.

Slight Risk today is north of a line from Hobart - Chickasha - Purcell - McAlester - Talihina. Includes the OKC metro.

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0753 AM CDT THU JUN 05 2014

VALID 051300Z - 061200Z

...THERE IS A MDT RISK OF SVR TSTMS TODAY INTO THIS EVENING ACROSS
FAR SERN KS...FAR NERN OK...SRN MO...NRN AR AND WRN TN...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL HIGH PLAINS TO
MID SOUTH...

...SUMMARY...
WIDESPREAD DAMAGING WINDS...LARGE HAIL...AND A FEW TORNADOES ARE
POSSIBLE TODAY FROM SOUTHEAST KANSAS AND NORTHEAST OKLAHOMA THROUGH
SOUTHERN PARTS OF MISSOURI AND NORTHERN ARKANSAS INTO WESTERN
TENNESSEE. ELSEWHERE...ISOLATED TO WIDELY SCATTERED THUNDERSTORMS
ARE POSSIBLE OVER THE CENTRAL HIGH PLAINS.

...SYNOPSIS...

A QUASI-ZONAL MIDLEVEL FLOW REGIME WILL PERSIST ACROSS THE NRN/CNTRL
CONUS TO THE N OF AN ELONGATED ANTICYCLONE CENTERED OVER NWRN MEXICO
INTO TX. WITHIN THIS BROADER-SCALE PATTERN...A MULTI-STREAM
SHORT-WAVE TROUGH WILL TRACK FROM THE NRN/CNTRL PLAINS INTO THE
UPPER GREAT LAKES...OH VALLEY...AND MID SOUTH. FARTHER W...A NUMBER
OF LOW-AMPLITUDE PERTURBATIONS WILL PROGRESS THROUGH THE WRN STATES
TOWARD THE GREAT PLAINS.

AT THE SURFACE...A MIGRATORY LOW JUST OFF THE NJ COAST WILL DEVELOP
NEWD WHILE A TRAILING COLD FRONT SETTLES SWD THROUGH THE MID
ATLANTIC STATES AND CAROLINAS. THE WRN EXTENSION OF THIS FRONT WILL
REMAIN QUASI-STATIONARY FROM THE TN VALLEY TO LOW PRESSURE OVER NRN
OK...THOUGH SOME FLUCTUATION OF ITS POSITION WILL OCCUR DUE TO
CONVECTIVE OUTFLOW ASSOCIATED WITH ONGOING TSTMS. ELSEWHERE...A
TROUGH WILL ADVANCE THROUGH THE ERN DAKOTAS INTO WRN MN BEFORE
STALLING. UPSTREAM...A COLD FRONT WILL PUSH SEWD FROM THE CANADIAN
PRAIRIE PROVINCES INTO THE NRN PLAINS.

...OZARK PLATEAU TO MID SOUTH TODAY INTO THIS EVENING...

AN INTENSE MCS COMPRISED OF SUPERCELLS AND BOWING STRUCTURES IS IN
PROGRESS AS OF 12Z OVER ERN KS WITH AN OBSERVED SYSTEM MOTION OF
290/45 KT. REGIONAL SOUNDINGS INDICATE THAT THIS MCS IS SITUATED ON
THE NERN FRINGE OF A STRONG CAP SITUATED AT THE BASE OF THE EML
WHICH WILL LIMIT A SWWD EXPANSION OF STORMS TODAY. LATEST
CONVECTION-ALLOWING MODEL GUIDANCE REMAINS IN GOOD AGREEMENT IN
SUGGESTING THAT THIS BOW ECHO WILL CONTINUE SEWD ACROSS SRN MO/NRN
AR INTO WRN TN/NRN MS ALONG THE STATIONARY SURFACE FRONT. GIVEN THE
WELL-ESTABLISHED COLD POOL...40-50+ KT OF EFFECTIVE BULK SHEAR...AND
THE CONTINUED INFLUX OF A VERY MOIST AND MODERATE-STRONGLY UNSTABLE
AIR MASS...EXPECT WIDESPREAD DAMAGING WIND POTENTIAL TO CONTINUE
ALONG THE MCS TRACK. LARGE HAIL AND A FEW TORNADOES ARE ALSO
POSSIBLE.

FOR ADDITIONAL NEAR-TERM GUIDANCE...SEE MCD 833.

...CNTRL/SRN HIGH PLAINS INTO THE LOWER ELEVATIONS OF KS/OK THIS
AFTERNOON INTO TONIGHT...

THE MAINTENANCE OF AN ELY LOW-LEVEL UPSLOPE FLOW REGIME AND THE
POSSIBLE INFLUENCE OF RIDGE-CRESTING VORTICITY MAXIMA ARE EXPECTED
TO FOSTER ISOLATED TO WIDELY SCATTERED TSTM DEVELOPMENT OFF THE CO
FRONT RANGE...PERHAPS AS FAR S AS THE RATON MESA. SIMILAR TO
WEDNESDAY AFTERNOON/EVENING...STORMS WILL PROGRESS EWD/SEWD INTO A
PROGRESSIVELY MORE MOIST/UNSTABLE ENVIRONMENT WHERE MLCAPE WILL
APPROACH 1000-1500 J/KG. GIVEN THE PRESENCE OF ELY LOW-LEVEL WINDS
VEERING TO WLY AT 40-50 KT IN THE MID-TROPOSPHERE...THE SETUP WILL
FAVOR SUPERCELL MORPHOLOGIES WITH A RISK FOR LARGE HAIL AND DAMAGING
WINDS.

AMALGAMATING STORM-SCALE OUTFLOWS MAY PROMOTE UPSCALE GROWTH OF
STORMS INTO AN EWD/SEWD-MOVING MCS TONIGHT WITH A CONTINUED RISK FOR
DAMAGING WINDS AND HAIL.

ADDITIONAL TSTMS WILL BE POSSIBLE THIS AFTERNOON ACROSS PORTIONS OF
KS/OK ALONG THE COMPOSITE OUTFLOW-SYNOPTIC BOUNDARY IN THE WAKE OF
THIS MORNINGS MCS. THE PRIMARY FORCING MECHANISMS APPEAR TO BE WEAK
WAA...CONVERGENCE INVOF THE SURFACE LOW AND ASSOCIATED FRONT...AND
STRONG BOUNDARY-LAYER HEATING OVER WRN OK. SHOULD STORMS DEVELOP AND
BECOME SUSTAINED...THE OVERLAP OF A MODERATE-STRONGLY UNSTABLE AIR
MASS /MLCAPE OF 2000-3000 J PER KG/ AND 50-60+ KT OF EFFECTIVE BULK
SHEAR WILL BE QUITE SUPPORTIVE FOR INTENSE SUPERCELLS CAPABLE OF
VERY LARGE HAIL AND A FEW TORNADOES. UNCERTAINTY IN THIS SCENARIO
REMAINS HIGH...THEREFORE BASELINE-SLIGHT-RISK PROBABILITIES WILL BE
MAINTAINED.

[Anonymous.]

First of many MCSs to blast through here is up in NE OK right now, trying to back build SW towards C OK, but looks like it is moving too fast for anything significant.

Bring on the rain!

[venture]

MESOSCALE DISCUSSION 0833
NWS STORM PREDICTION CENTER NORMAN OK
0740 AM CDT THU JUN 05 2014

AREAS AFFECTED...EASTERN KS/NORTHEAST OK TO MUCH OF WESTERN/SOUTHERN
MO AND NORTHERN AR

CONCERNING...SEVERE THUNDERSTORM WATCH 227...228...

VALID 051240Z - 051445Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
227...228...CONTINUES.

SUMMARY...POTENTIALLY WIDESPREAD WIND DAMAGE...IN ADDITION TO SOME
SEVERE HAIL...WILL REMAIN A CONCERN THROUGH THE MORNING WITH A
MESOSCALE CONVECTIVE SYSTEM MOVING ACROSS EASTERN KS/NORTHEAST OK
INTO MUCH OF WESTERN/SOUTHERN MO AND NORTHERN AR. SEVERE
THUNDERSTORM WATCHES 227/228 CONTINUE UNTIL 15Z/18Z RESPECTIVELY.
CURRENT THINKING IS THAT AN ADDITIONAL WATCH IS LIKELY TO BE NEEDED
ACROSS ADDITIONAL PARTS OF SOUTHERN /AND POSSIBLY WESTERN/ MO AND
NORTHERN AR.

A CATEGORICAL UPGRADE TO MODERATE RISK WILL OCCUR WITH THE 13Z
UPDATE.

DISCUSSION...A VERY WELL-ORGANIZED SEVERE MCS/BOW ECHO WILL CONTINUE
TO SPREAD SOUTHEASTWARD ACROSS SOUTHEAST KS/MUCH OF NORTHEAST OK
INTO SOUTHERN MO/NORTHERN AR THIS MORNING. THIS MCS IS ASSOCIATED
WITH A NOTABLE SURFACE PRESSURE FALL/RISE COUPLET WHILE THRIVING IN
A MOIST/UNSTABLE ENVIRONMENT NEAR/NORTH OF A SURFACE BOUNDARY ACROSS
THE REGION. THE MCS IS ALSO LIKELY BE AIDED BY AN MCV/REAR INFLOW
JET WITH 50+ KT WINDS AS LOW AS 4KM AGL AS PER THE WICHITA WSR-88D
VWP. WARM SECTOR MLCAPE IS AS HIGH AS 2000 J/KG ACROSS NORTHEAST
OK/SOUTHWEST MO INTO AR...WHICH WILL BE INCREASINGLY REALIZED AS THE
BOUNDARY LAYER WARMS. WITH A RELATIVELY MOISTURE-RICH ENVIRONMENT
ALREADY IN PLACE /SURFACE DEWPOINTS NEAR 70 F/...EARLY DAY VISIBLE
SATELLITE IMAGERY SHOW THAT THE MCS-PRECEDING AIR MASS WILL INDEED
STEADILY HEAT THROUGH THE MORNING FROM FAR EASTERN OK INTO
AR/SOUTHERN MO.

FARTHER NORTH...AS THE MCS CONTINUES TO UNDERGO AN ASYMMETRIC SQUALL
LINE-TYPE EVOLUTION...THE POTENTIAL FOR NORTH-SIDE COMMA HEAD
VORTICES CAPABLE OF WIND DAMAGE MAY INCREASE POTENTIALLY AS FAR
NORTH AS ROUGHLY THE I-70 CORRIDOR. A 53 KT GUST WAS RECENTLY
MEASURED AT SALINA KS AS OF AROUND 1210Z. ADDITIONALLY...WAKE LOW
RELATED WINDS TO SEVERE-CALIBER LEVELS MAY BE POSSIBLE IN ACCORDANCE
WITH PRONOUNCED PRESSURE FALLS /8-9MB PER 2HR FALLS/ ACROSS CENTRAL
KS WITH MCS-TRAILING EASTERLY WINDS.

..GUYER.. 06/05/2014

[venture]

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 228
NWS STORM PREDICTION CENTER NORMAN OK
630 AM CDT THU JUN 5 2014

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
NORTHWEST ARKANSAS
FAR SOUTHEAST KANSAS
SOUTHWEST MISSOURI
NORTHEAST OKLAHOMA

* EFFECTIVE THIS THURSDAY MORNING AND AFTERNOON FROM 630 AM UNTIL
100 PM CDT.

* PRIMARY THREATS INCLUDE...
WIDESPREAD DAMAGING WIND GUSTS TO 70 MPH LIKELY
SCATTERED LARGE HAIL AND ISOLATED VERY LARGE HAIL EVENTS TO 2
INCHES IN DIAMETER POSSIBLE

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 105
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 50 MILES NORTH OF
PONCA CITY OKLAHOMA TO 35 MILES SOUTHEAST OF MONETT MISSOURI.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU8).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 226...WW 227...

DISCUSSION...A FAST-MOVING MESOSCALE CONVECTIVE SYSTEM WILL CONTINUE
TO POSE A POTENTIALLY WIDESPREAD WIND DAMAGE RISK THIS MORNING AS IT
CONTINUES TO SPREAD GENERALLY SOUTHEASTWARD. A STRONG SOUTHWESTERLY
LOW-LEVEL JET WILL CONTINUE TO FUEL THIS MCS VIA WARM/MOIST
ADVECTIONS FOCUSED TO THE IMMEDIATE NORTH OF A FRONTAL BOUNDARY THAT
ANGLES ROUGHLY WEST-NORTHWEST TO EAST-SOUTHEAST ACROSS THE REGION.

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 600. MEAN STORM
MOTION VECTOR 30045.

[venture]

Day 2 Slight Risk covers much of the same area as today...all but mostly Southern OK. It includes the Metro - mostly.

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT THU JUN 05 2014

VALID 061200Z - 071200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM A PORTION OF THE CNTRL AND
SRN PLAINS THROUGH THE LOWER MS VALLEY AND WRN TN VALLEY...

...SUMMARY...
SEVERE STORMS WILL BE POSSIBLE FROM A PORTION OF THE CENTRAL AND
SOUTHERN HIGH PLAINS EASTWARD THROUGH KANSAS AND OKLAHOMA INTO THE
LOWER MISSISSIPPI VALLEY AND TENNESSEE VALLEY REGIONS FRIDAY AND
FRIDAY NIGHT.

...SYNOPSIS...

LITTLE CHANGE IN THE OVERALL SYNOPTIC REGIME WILL OCCUR ON FRIDAY
WITH UPPER PATTERN REMAINING QUASI-ZONAL PROGRESSIVE. SEVERAL LOW
AMPLITUDE SHORTWAVE TROUGHS WILL ADVANCE THROUGH THIS FLOW REGIME
INCLUDING THE CNTRL PLAINS INTO THE TN VALLEY WHERE A MEANDERING
BOUNDARY /AT TIMES REINFORCED BY CONVECTIVE OUTFLOWS/ WILL LINGER.

...KS...OK THROUGH LOWER MS AND TN VALLEY...

UNCERTAINTIES LINGER REGARDING WHERE MCS BOUNDARIES WILL BE AND
TIMING OF INDIVIDUAL SHORTWAVE TROUGHS. NEVERTHELESS...MODERATE TO
STRONG INSTABILITY WILL RESIDE IN WARM SECTOR AND IN VICINITY OF THE
MEANDERING FRONT OR OUTFLOW BOUNDARIES SUPPORTED BY RICH LOW-LEVEL
MOISTURE WITH NEAR 70F DEWPOINTS BENEATH PLUME OF STEEPER MID-LEVEL
LAPSE RATES. MUCH OF THE WARM SECTOR WILL LIKELY REMAIN CAPPED AS
MODERATE WLY FLOW MAINTAINS WARM AIR ALOFT AT BASE OF EML PLUME.
HOWEVER...COMBINATION OF ISENTROPIC ASCENT NORTH OF EFFECTIVE
BOUNDARIES...AUGMENTED BY MIGRATORY IMPULSES ALOFT WILL LIKELY
MAINTAIN AN ACTIVE CORRIDOR OF THUNDERSTORM DEVELOPMENT FROM KS INTO
OK EWD THROUGH THE LOWER MS VALLEY AND TN VALLEY REGIONS. STORMS MAY
BE ONGOING AT THE START OF THE PERIOD NORTH OF THE EFFECTIVE
FRONT...AND THIS ACTIVITY WILL HAVE THE POTENTIAL TO INTENSIFY AS
HIGHER THETA-E AIR FROM THE DESTABILIZING WARM SECTOR IS ADVECTED
INTO THE FRONTAL ZONE. OTHER STORMS MAY ALSO DEVELOP ALONG/NORTH OF
THE FRONT DURING THE DAY AS WELL AS OVERNIGHT AS THE LLJ
STRENGTHENS. MODERATE WLY FLOW ALOFT IN PROXIMITY TO AND NORTH OF
THE FRONT WILL MAINTAIN SUFFICIENT VERTICAL SHEAR /40-50 KT/ FOR
STORM ORGANIZATION WITH SUPERCELLS POSSIBLE AS WELL AS LEWP/BOW
ECHOES ASSOCIATED WITH MCS ACTIVITY. LARGE HAIL AND DAMAGING WIND
GUSTS ARE EXPECTED TO BE THE MAIN THREATS...THOUGH A FEW TORNADOES
CANNOT BE RULED OUT.

Day 3 Slight Risk for nearly all of Oklahoma except a small part of NW/NC OK.


DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0239 AM CDT THU JUN 05 2014

VALID 071200Z - 081200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM A PORTION OF THE SRN
PLAINS INTO THE LOWER-MIDDLE MS VALLEY AND WRN TN VALLEY REGIONS...

...SUMMARY...
STRONG TO SEVERE STORMS WILL BE POSSIBLE FROM THE SOUTHERN PLAINS
INTO THE LOWER TO MIDDLE MISSISSIPPI VALLEY ON SATURDAY. DAMAGING
WIND AND LARGE HAIL WILL BE THE MAIN THREATS.

...SYNOPSIS...

QUASI-ZONAL FLOW REGIME WITH PROGRESSIVE...LOW AMPLITUDE SHORTWAVE
TROUGHS WILL CHARACTERIZE THE SYNOPTIC PATTERN OVER MUCH OF U.S. ON
SATURDAY. A QUASI-STATIONARY FRONT WILL PERSIST FROM THE SRN PLAINS
EWD INTO THE MS LOWER-MID MS VALLEY AND SERN STATES. HOWEVER...A
SHORTWAVE TROUGH THAT IS FORECAST TO MOVE THROUGH THE CNTRL PLAINS
AND MIDDLE MS VALLEY DURING THE DAY WILL INDUCE A SFC LOW ON THE
FRONT WITH A REINFORCING COLD FRONT ADVANCING SWD INTO THE SRN
PLAINS THE WAKE OF THIS FEATURE. MEANWHILE...A WARM FRONT WILL SHIFT
ENEWD THROUGH THE MS AND WRN TN VALLEY IN ASSOCIATION WITH THIS
WAVE.

...SOUTHERN PLAINS AREAS...

A REINFORCING COLD FRONT WILL RESULT IN THE STATIONARY BOUNDARY
SHIFTING FARTHER SWD INTO THE SRN PLAINS IN WAKE OF THE SHORTWAVE
TROUGH. RICH GULF MOISTURE WILL REMAIN IN VICINITY OF AND SOUTH OF
THE FRONT...SUPPORTING MODERATE INSTABILITY IN WARM SECTOR AS WELL
AS IN POST FRONTAL UPSLOPE REGIME OVER THE SRN HIGH PLAINS. IN WAKE
OF MORNING STORMS ACROSS KS...ADDITIONAL STORMS WILL LIKELY DEVELOP
OVER THE HIGHER TERRAIN AND SPREAD EWD WITHIN EVOLVING ELY UPSLOPE
REGIME FROM NM INTO SERN CO DURING THE AFTERNOON AND EVENING WITH
THE APPROACH OF ANOTHER IMPULSE. THIS ACTIVITY WILL SPREAD EWD...AND
ADDITIONAL STORMS WILL DEVELOP NORTH OF THE FRONT OVER THE SRN
PLAINS SUPPORTED BY AN INTENSIFYING LLJ. EFFECTIVE SHEAR WILL BE
SUFFICIENT FOR SUPERCELLS WITH ACTIVITY MOVING OFF THE HIGHER
TERRAIN...BUT STORMS MAY EVENTUALLY EVOLVE INTO AN MCS OVER THE SRN
PLAINS. THESE STORMS COULD POSE A THREAT FOR LARGE HAIL AND STRONG
TO DAMAGING WIND GUSTS.

[Anonymous.]

SPC seems to be jumping the trigger on the risk upgrades. Couple days ago upgraded to HIGH over the incorrect area, and today upgraded to MODERATE in advance of a squall line that has lost its umph.

[Achilleslastand]

So the main chance for rain is Sunday? Is this going to be just rain or do we need to be on the watch for hail/etc?

[venture]

So the main chance for rain is Sunday? Is this going to be just rain or do we need to be on the watch for hail/etc?

Severe weather risk each day.