June 4-7: Severe wx (Omaha tornado update)

[CrazyC83]

Models seem to be hinting at such next week. Could June be every bit as insane as May?

[CrazyC83]

Looking at models and early trends, here is my thinking:

June 4 - Initial activity in the northern and central High Plains.

June 5 - Major tornado outbreak stretching from Kansas to North Dakota eastward into Iowa and Wisconsin. Possibly stretching into Oklahoma as well.

June 6 - Major tornado outbreak covering a fairly large area - from Illinois northward to Upper Michigan and eastward into Pennsylvania, Ohio and parts of Ontario. Maybe some activity into Kentucky as well.

June 7 - If instability remains, New England and perhaps the mid-Atlantic go under the gun.

[Cyclenall]

I want Ontario to get a real blast of severe weather again.

[CrazyC83]

I want Ontario to get a real blast of severe weather again.

It might be your biggest outbreak in many years.

[CrazyC83]

ZCZC SPCSWOD48 ALL
ACUS48 KWNS 010857
SPC AC 010857

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0357 AM CDT SUN JUN 01 2008

VALID 041200Z - 091200Z

...DISCUSSION...

...D4 /WED JUN 4TH/...

LATEST MEDIUM-RANGE GUIDANCE IS CONSISTENT IN INDICATING THAT STRONG
UPPER JET STREAK DIGGING SEWD FROM THE ERN PACIFIC INTO THE LOWER CO
VALLEY WILL SUPPORT INTENSIFICATION TO LONG WAVE TROUGH OVER THE
INTERMOUNTAIN WEST. AS THIS OCCURS...CYCLOGENESIS WILL COMMENCE
OVER THE SRN HIGH PLAINS WITH A SHARPENING DRYLINE EXTENDING SWD
THROUGH WRN TX. A STATIONARY OR WARM FRONT IS FORECAST TO EXTEND
ENEWD FROM THIS DEEPENING LOW INTO THE MID OR LOWER MO VALLEY.

WARM SECTOR AIR MASS OVER THE SRN AND CNTRL PLAINS IS EXPECTED TO
BECOME MODERATE TO STRONGLY UNSTABLE /NAMELY ALONG WARM FRONT/.
HOWEVER...THE STRONG CAP MAY TEND TO LIMIT THE NUMBER OF STORMS THAT
DEVELOP. THE MOST LIKELY AREA FOR STORM INITIATION APPEARS TO BE
FROM N/NW OF SURFACE LOW IN UPSLOPE FLOW REGIME...EWD ALONG
WARM/STATIONARY FRONT AS THE LEADING EDGE OF STRONGER HEIGHT FALLS
SPREAD E OF THE CNTRL ROCKIES. SHOULD STORMS DEVELOP... ENVIRONMENT
OVER THE CNTRL PLAINS WILL BE QUITE SUPPORTIVE OF SIGNIFICANT SEVERE
WEATHER.

...D5 /THU JUN 5TH/...

A SIGNIFICANT SEVERE WEATHER OUTBREAK IS EXPECTED FROM PORTIONS OF
THE UPPER MIDWEST SWWD INTO THE SRN PLAINS. A DYNAMIC UPPER TROUGH
WILL DEVELOP EWD INTO THE CNTRL U.S. WITH AN ASSOCIATED SURFACE LOW
MOVING NEWD FROM THE CNTRL PLAINS INTO UPPER MS VALLEY. RAPID AIR
MASS DESTABILIZATION WILL OCCUR FROM ALONG SURFACE LOW AND WARM
FRONT SWD AHEAD OF COLD FRONT AND DRYLINE. THIS INSTABILITY
COMBINED WITH STRONG VERTICAL SHEAR WILL SET THE STAGE FOR
WIDESPREAD SEVERE STORM DEVELOPMENT.

...D6 /FRI JUN 6TH/...

LARGE-SCALE SYSTEM WILL UNDERGO OCCLUSION AS NEGATIVELY-TILTED
MIDLEVEL TROUGH LIFTS NEWD THROUGH THE GREAT LAKES. A MOIST AND
UNSTABLE AIR MASS WILL EXIST AHEAD OF SYSTEM COLD FRONT AND GIVEN
THE STRENGTH OF THE WIND FIELDS AND DYNAMIC FORCING FOR ASCENT...THE
THREAT FOR SEVERE WEATHER WILL CONTINUE EWD ACROSS THE GREAT LAKES
INTO OH VALLEY.

...D7 /SAT JUN 7TH/ THROUGH D8 /SUN JUN 8TH/...

DIFFERENCES IN DETERMINISTIC AND ENSEMBLE DATA SETS BEGIN TO
INCREASE BY D7...NAMELY OVER THE WRN STATES WITH REGARD TO LONG WAVE
EVOLUTION. GIVEN THE INCREASING UNCERTAINTY...NO ADDITIONAL SEVERE
WEATHER AREAS WILL BE DELINEATED.

..MEAD.. 06/01/2008

CLICK TO GET WUUS48 PTSD48 PRODUCT

[RL3AO]

Incredible.

[Bunkertor]

Not again, please.

btw: I haven´t seen not even one lightnign this year.

[Cyclenall]

I want Ontario to get a real blast of severe weather again.

It might be your biggest outbreak in many years.

That would be amazing, I wonder if there would be another chance of a supercell somewhere.

I don't have a list of southern Ontario tornado outbreaks, so I don't have much to benchmark on. Other then the May 31, 1985 one, which were the largest ones?

[CrazyC83]

Insanity from NWS Twin Cities:

http://www.crh.noaa.gov/wxstory.php?site=mpx

There appears to be an exceptionally strong potential for severe thunderstorms setting up for Thursday for part of Southern and Central Minnesota as well as a portion of West Central Wisconsin. The combination of strong jet stream winds and instability that is conducive for severe thunderstorm development increases the chances that significant tornadoes may be a part of this severe weather outbreak. Keep informed on weather developments as the week goes on and make a plan NOW for where your family would seek shelter should this severe weather potential actually be realized.

[RL3AO]

Oh boy.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
320 PM CDT SUN JUN 1 2008

SIGNIFICANT SEVERE WEATHER EVENT POSSIBLE DEVELOPING LATER
WEDNESDAY NIGHT/HAIL STG WND AND HEAVY RAIN POTNL/ LASTING
THROUGH THURSDAY NIGHT OVER THE CWA. THURSDAY COULD HAVE MORE OF
A TORNADO THREAT IF SOME HEATING TAKES PLACE DURING THE
DAY...AHEAD OF SFC LOW/AND ALONG FNTL BOUNDARIES. THE 12Z ECMWF
CONTINUE TO INDICATE STRONG UPPER TROUGH AND SFC LOW LIFTING NEWD
FROM THE CNTRL PLAINS TO THE WESTERN GREAT LAKES REGION. RAPID AIR
MASS DESTABILIZATION EXPECTED AS WARM FRONT SURGES NORTH AHEAD OF
COLD FRONT. STRONG INSTABILITY COMBINED WITH STRONG VERTICAL SHEAR
SHOULD SET THE STAGE FOR THE RATHER SIGNIFICANT EVENT THURSDAY.
THIS WILL LINGER INTO FRIDAY AS WELL...BEFORE DRY SURGE/TROUGH
EXITS TO THE EAST OF CWA.

[CrazyC83]

Oh boy.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
320 PM CDT SUN JUN 1 2008

SIGNIFICANT SEVERE WEATHER EVENT POSSIBLE DEVELOPING LATER
WEDNESDAY NIGHT/HAIL STG WND AND HEAVY RAIN POTNL/ LASTING
THROUGH THURSDAY NIGHT OVER THE CWA. THURSDAY COULD HAVE MORE OF
A TORNADO THREAT IF SOME HEATING TAKES PLACE DURING THE
DAY...AHEAD OF SFC LOW/AND ALONG FNTL BOUNDARIES. THE 12Z ECMWF
CONTINUE TO INDICATE STRONG UPPER TROUGH AND SFC LOW LIFTING NEWD
FROM THE CNTRL PLAINS TO THE WESTERN GREAT LAKES REGION. RAPID AIR
MASS DESTABILIZATION EXPECTED AS WARM FRONT SURGES NORTH AHEAD OF
COLD FRONT. STRONG INSTABILITY COMBINED WITH STRONG VERTICAL SHEAR
SHOULD SET THE STAGE FOR THE RATHER SIGNIFICANT EVENT THURSDAY.
THIS WILL LINGER INTO FRIDAY AS WELL...BEFORE DRY SURGE/TROUGH
EXITS TO THE EAST OF CWA.

I have NEVER seen such strong wording at Day 5!

[Bunkertor]

I thought, it was cold in Minnesota ?

Profanity edited out by CM

[RL3AO]

I thought, it was cold in Minnesota ?

-20F in the winter, 100F in the summer.

Profanity in quote edited out by CM

[Bunkertor]

I thought, it was cold in Minnesota ?

-20F in the winter, 100F in the summer.

Wat... something like Kazakhstan ... will you chase the storms ?

Profanity in quote edited out by CM

[CrazyC83]

Current estimate for Friday based on latest models here:

Forecast high temperature - around 82 (near 90 just to the south)

Dewpoint - around 68

CAPE - around 3000

LI - between -5 and -8

Helicity - uncertain

[Thundercloud]

there is even a chance of a major outbreak in the northeast if we can get a few degrees warmer

[CrazyC83]

there is even a chance of a major outbreak in the northeast if we can get a few degrees warmer

Yep, the CAPE in SW PA on Friday according to the GFS will be almost 6000...shades of 05/31/85...

[HarlequinBoy]

Oh boy.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
320 PM CDT SUN JUN 1 2008

SIGNIFICANT SEVERE WEATHER EVENT POSSIBLE DEVELOPING LATER
WEDNESDAY NIGHT/HAIL STG WND AND HEAVY RAIN POTNL/ LASTING
THROUGH THURSDAY NIGHT OVER THE CWA. THURSDAY COULD HAVE MORE OF
A TORNADO THREAT IF SOME HEATING TAKES PLACE DURING THE
DAY...AHEAD OF SFC LOW/AND ALONG FNTL BOUNDARIES. THE 12Z ECMWF
CONTINUE TO INDICATE STRONG UPPER TROUGH AND SFC LOW LIFTING NEWD
FROM THE CNTRL PLAINS TO THE WESTERN GREAT LAKES REGION. RAPID AIR
MASS DESTABILIZATION EXPECTED AS WARM FRONT SURGES NORTH AHEAD OF
COLD FRONT. STRONG INSTABILITY COMBINED WITH STRONG VERTICAL SHEAR
SHOULD SET THE STAGE FOR THE RATHER SIGNIFICANT EVENT THURSDAY.
THIS WILL LINGER INTO FRIDAY AS WELL...BEFORE DRY SURGE/TROUGH
EXITS TO THE EAST OF CWA.

I have NEVER seen such strong wording at Day 5!

I have. Memphis had wording that strong before 4/7/06 (probably shouldn't have) and before 2/5/08. Jackson's had very strong wording a few times and they kind of busted, lol.

[HarlequinBoy]

there is even a chance of a major outbreak in the northeast if we can get a few degrees warmer

Yep, the CAPE in SW PA on Friday according to the GFS will be almost 6000...shades of 05/31/85...

People keep throwing that date around for any potential severe in PA.. and it definitely didn't verify last week. I don't think we should use it so loosely.

[Bunkertor]

Can anyone tell where 6000 CAPE is mentioned ?

I only found maps with the dewpoints. 20°C are forcast in the relevant area...

As to the temp-differences, severe weather likely in west TX up to KS as well for Thu. ...a low pressure system at around 985 hPa should be imminent over KS.