Multi-day tornado outbreak likely (April 9-11)

[Ntxw]

Looks like the local afd's and SPC have come into agreement with the Euro. Strong cap will inhibit most initation on the dryline until the cold front merges and provides lift for linear line of storms. Hail and wind will be the greatest threat for a wide area. There may be some singular storms that breaks out Tuesday afternoon and drop some tornadoes but it will quickly be undercut by the cold front. Very much trending for a typical severe weather episode, gulf is just not all that open for a moderate/high end (tornado) risk it seems from the latest guidance.

[WeatherGuesser]

Always tough to make any kind of trustworthy call several days ahead, but I'll go with the SPC over boardie hype and so far, they don't seem to be too concerned.

'Typical spring storms' seems about right. People definitely still need rain, so hopefully they'll get it without suffering damage.

[CrazyC83]

Don't underestimate QLCS systems though...

[WeatherGuesser]

Mid-day Monday and nothing so far; not even a watch. Maybe later.

Our local TV met says something about Tuesday night for us, so we'll see.

[TeamPlayersBlue]

I'm in Yuma AZ for the next few weeks visiting family. Wind has picked up here, temps have dropped and they are expecting alot of blowing dust. Yippee! #Duststormsareterrible

[WeatherGuesser]

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 85
NWS STORM PREDICTION CENTER NORMAN OK
220 PM MDT MON APR 8 2013

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

EASTERN COLORADO

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 220 PM UNTIL 900
PM MDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 35
STATUTE MILES EAST AND WEST OF A LINE FROM 60 MILES NORTH
NORTHEAST OF AKRON COLORADO TO 30 MILES SOUTH OF LAMAR COLORADO.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU5).

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...HIGH-BASED THUNDERSTORM DEVELOPMENT IS EXPECTED IN THE
NEXT COUPLE OF HOURS AS SURFACE HEATING/MIXING CONTINUES ACROSS ERN
CO IN A STEEP LAPSE RATE ENVIRONMENT. VERTICAL SHEAR PROFILES WILL
BE FAVORABLE FOR SUPERCELLS...WITH LARGE HAIL THE PRIMARY THREAT
GIVEN THE LIMITED LOW-LEVEL MOISTURE AS OF EARLY AFTERNOON. AREAS
FARTHER E INTO W/NW KS WILL BE MONITORED FOR MORE OF A MOISTURE
INCREASE THIS AFTERNOON/EVENING...AND SOME THREAT FOR A COUPLE OF
TORNADOES AS THE ERN CO STORMS MATURE AND MOVE INTO KS CLOSER TO 23Z
OR SO.

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 450. MEAN STORM
MOTION VECTOR 23025.


...THOMPSON

[TeamPlayersBlue]

I just took a video of the blowing dust and winds here. Its terrible. Open your mouth a wee bit an you end up chewing on sand.

[EF-5bigj]

Well the system is creating tornadoes in Colorado so it will be interesting to see what it does on Tuesday.

[Texas Snowman]

SPC just issued moderate risk today for portions of Oklahoma and North Texas:

" SPC AC 090600

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT TUE APR 09 2013

VALID 091200Z - 101200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF CNTRL OK...SRN
OK AND NORTH TX...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN
PLAINS...CNTRL PLAINS...NW AR...MO...SRN IA AND WRN IL...

...SRN AND CNTRL PLAINS...
AN UPPER-LEVEL LOW OVER THE FOUR CORNERS REGION WILL MOVE NEWD INTO
THE CNTRL ROCKIES ON TUESDAY. AT THE SFC...A COLD FRONT WILL ADVANCE
QUICKLY SEWD ACROSS THE SRN HIGH PLAINS AND CNTRL PLAINS. AHEAD OF
THE FRONT...SFC DEWPOINTS SHOULD REACH THE LOWER 60S F ACROSS ERN KS
WITH MID TO UPPER 60S F ACROSS CNTRL OK AND NORTH TX. MODERATE TO
STRONG INSTABILITY IS FORECAST TO DEVELOP ALONG THIS CORRIDOR WITH
CONVECTIVE INITIATION BEGINNING FIRST IN NRN KS DURING THE
MID-AFTERNOON. THUNDERSTORM DEVELOPMENT SHOULD TAKE PLACE ALONG THE
COLD FRONT...QUICKLY EXPANDING SSWWD ACROSS SRN KS AND CNTRL OK
DURING THE LATE AFTERNOON INTO NCNTRL TX BY EARLY EVENING. THE
STRONG INSTABILITY ALONG WITH COUPLED LOW AND MID-LEVEL JETS WILL BE
FAVORABLE FOR A SIGNIFICANT SEVERE WEATHER EVENT FROM LATE TUESDAY
AFTERNOON INTO TUESDAY EVENING.

FORECAST SOUNDINGS AT OKLAHOMA CITY AND WICHITA FALLS AT 00Z/WED
SHOW MLCAPE VALUES OF 2500 TO 3000 J/KG WITH AN IMPRESSIVE SHEAR
ENVIRONMENT. 0-6 KM SHEAR IS FORECAST TO INCREASE DURING THE LATE
AFTERNOON INTO THE 50 TO 60 KT RANGE AS A MID-LEVEL JET MOVES INTO
THE SRN PLAINS. THE SHEAR ALONG WITH MID-LEVEL LAPSE RATES AROUND
8.0 C/KM SHOULD BE FAVORABLE FOR SUPERCELL DEVELOPMENT WITH LARGE
HAIL. THE MORE DOMINANT SUPERCELLS SHOULD BE CAPABLE OF PRODUCING
HAIL GREATER THAN 2 INCHES IN DIAMETER. 0-1 KM SHEAR IS FORECAST TO
INCREASE INTO THE 25 TO 30 KT RANGE DURING THE EARLY EVENING AS THE
LOW-LEVEL JET STRENGTHENS MAKING CONDITIONS FAVORABLE FOR TORNADOES.
A FEW STRONG TORNADOES COULD OCCUR FROM THE OKLAHOMA CITY AREA SSWWD
TO AROUND WICHITA FALLS WHERE THE COMBINATION OF PARAMETERS APPEARS
TO BE MOST IDEAL. ALTHOUGH SOME CONCERN EXISTS ABOUT THE TIMING OF
INITIATION IN SRN OK AND NORTH TX...THE CURRENT THINKING IS THE
THREAT FOR SUPERCELL DEVELOPMENT WILL PERSIST WELL INTO THE EVENING
DUE TO THE STRONG INSTABILITY THAT IS FORECAST.

FURTHER TO THE NORTH FROM ECNTRL KS SWD INTO NERN OK...THE MODELS
APPEAR TO QUICKLY ORGANIZE A LINE OF THUNDERSTORMS ALONG THE FRONT.
THIS SUGGESTS THAT THE POTENTIAL FOR SIGNIFICANT SEVERE MAY BE
SOMEWHAT LESS THERE. HOWEVER...THE LINE SHOULD BE INTENSE WITH
ROTATING CELL ELEMENTS. SEVERE THREAT COVERAGE COULD BE EXTENSIVE
WITH A POTENTIAL FOR LARGE HAIL...WIND DAMAGE AND TORNADOES AS WELL."

[Ntxw]

they downgraded it, even for hail and wind. The polar front is hauling, models did not handle it well at all. Areas that were supposed to be at risk for tornado warnings may be looking at winter weather advisories.



Dryline has been shoved way south where dynamics just aren't as good. Still think a line of storms will race through central Oklahoma/North Texas but the window is closing until everything is post-frontal. Areas further east in the Miss River valley and southeast has a better chance at severe weather (and maybe tornadoes) as the cold air mass will slow down that way. If I were to put a moderate risk, this would be the legit region to do it tomorrow but they aren't unfamiliar with tornadic events of late...

[apocalypt-flyer]

Yeah, wouldn't go as far as bust yet either cause the plains will get severe weather in some capacity but the models really didn't get a good grip on this at all, it doesn't look like today will be anywhere near the scenario both GFS or ECMWF e.g. were hammering late last week (which is good thing obviously).

[vbhoutex]

Yeah, wouldn't go as far as bust yet either cause the plains will get severe weather in some capacity but the models really didn't get a good grip on this at all, it doesn't look like today will be anywhere near the scenario both GFS or ECMWF e.g. were hammering late last week (which is good thing obviously).

Sure is going to piss off a lot of chasers. They have been deploying and waiting for this for weeks. If it doesn't come to fruition a lot of them will have taken off work for no reason and spent money they probably don't have to spend. Live by the models, die by the models.

[Ntxw]

Well to be fair models weren't that gung-ho on a major outbreak as early as last Friday. Mentioned that the source regions (gulf) was just not that supportive. Too many relied on hodographs which is a very good resource but doesn't mean much if you get no rain to tap into that good profile for thunderstorms. The positive tilted trough sent warm air up from the SW over cooler air below in the plains, the nuclear cap (warm over cool). Too much of daytime heating was spent on warming up that air below, if a warmer gulf air mass was already in place we probably could've broken the cap.

[EF-5bigj]

Well even where I live in Dixie Alley it's no longer looking as bad on Wednesday and Thursday.

[CYCLONE MIKE]

On our news at 4 the OCM just showed a high risk for severe weather outbreak for tomorrow and Thursday in MS ans AL, was like Looked on SPC website and only shows slight risk. This guy is always over hyping weather. Guess he does it for the ratings.

[WeatherGuesser]

Sure is going to piss off a lot of chasers. They have been deploying and waiting for this for weeks.

No tears from me. These are NOT tourist events.

[MGC]

There are plenty of people who enjoy chasing....I've chased hurricanes and tornados over the years. There are some companies that take tourist of chasing events. Got to see an F-3 on my first chase in Oklahoma years ago.....MGC

[EF-5bigj]

Well now we will see what happen's in the Arkansas area..

[Ntxw]

Pretty respectable probabilities for tornadoes in Arkansas (80% of 2 or more and 50% of one or more EF2+). Other areas of the southeast should take some notice.


*****
CENTRAL AND EASTERN ARKANSAS
THE SOUTHERN MISSOURI BOOTHEEL

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 120 PM UNTIL
900 PM CDT.

TORNADOES...HAIL TO 2.5 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 80 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH NORTHWEST OF
WALNUT RIDGE ARKANSAS TO 15 MILES SOUTH OF EL DORADO ARKANSAS.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU9).

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 88...

DISCUSSION...SURFACE HEATING/DESTABILIZATION CONTINUES ACROSS AR
EARLY THIS AFTERNOON...AND THE CAP IS WEAKENING PER 18Z LZK/SHV
SOUNDINGS. CONVECTION IS BEGINNING TO DEVELOP ALONG THE SLOW-MOVING
COLD FRONT IN SW AR...AND ADDITIONAL STORMS WILL LIKELY FORM NWD
ALONG THE FRONT...AND POTENTIALLY IN THE OPEN WARM SECTOR. MLCAPE
IS ALREADY AOA 2000 J/KG WITH A MOIST BOUNDARY LAYER...AND BOTH
DEEP-LAYER AND LOW-LEVEL SHEAR ARE EXPECTED TO INCREASE LATER THIS
AFTERNOON/EVENING. THE INITIAL CONVECTION WILL POSE A RISK FOR
LARGE HAIL/DAMAGING WINDS...WHILE THE TORNADO RISK WILL INCREASE
LATER THIS AFTERNOON IN RESPONSE TO THE STRENGTHENING VERTICAL SHEAR
AND MORE FAVORABLE HODOGRAPH STRUCTURES. ASSUMING A COUPLE OF
SEMI-DISCRETE STORMS CAN PERSIST...ESPECIALLY OFF THE COLD
FRONT...AN ISOLATED STRONG TORNADO WILL BE POSSIBLE.

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
550. MEAN STORM MOTION VECTOR 23040.

[EF-5bigj]

Wow 50% for EF-2 plus yesh.