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June 28-July 1 Severe Threat


Thundersnow12

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Since WI is in this region, this is the highest STP I've seen out of the NAM so far:

post-595-0-09784100-1403922959_thumb.gif

 

Regardless of it storms manage to stay discrete or organize into an MCS, I would imagine that there's going to be a pretty significant tornado threat in part of MN/WI/IA into the evening and overnight hours. 

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Since WI is in this region, this is the highest STP I've seen out of the NAM so far:

namCGP_con_stp_051.gif

Regardless of it storms manage to stay discrete or organize into an MCS, I would imagine that there's going to be a pretty significant tornado threat in part of MN/WI/IA into the evening and overnight hours.

Might want to look at 18z Monday

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A little OT but anyone been following that system that the models are trying to develop off the southeast coast?  Fortunately it doesn't really look like it's going to play a role in what happens in our area (in terms of cloud cover/precip) so I guess we can be thankful to have one potential complication off the table lol

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Monday definitely has tremendous conditional potential.  Don't see wind fields as impressive as what's forecast very often in late June.  If Sunday/Sunday night's sloppy seconds don't muddle things too badly Monday will be a high end event to be sure.  With such an impressive synoptic setup I'm guessing even if Sunday's leftovers muddle things some there will still likely be widespread severe taking off later in the day on Monday.  If the previous day's convection/debris gets out of the way early enough then the ceiling for Monday is sky high.  Gonna be interesting to watch how this evolves later this weekend.

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Monday definitely has tremendous conditional potential.  Don't see wind fields as impressive as what's forecast very often in late June.  If Sunday/Sunday night's sloppy seconds don't muddle things too badly Monday will be a high end event to be sure.  With such an impressive synoptic setup I'm guessing even if Sunday's leftovers muddle things some there will still likely be widespread severe taking off later in the day on Monday.  If the previous day's convection/debris gets out of the way early enough then the ceiling for Monday is sky high.  Gonna be interesting to watch how this evolves later this weekend.

 

 

That's kinda what the 00z NAM was hinting at.

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Allow me to analog drop for a sec... June 30, 1977.  It's not a great match synoptically (and Monday's threat looks like it will be farther north) but the shear appears similar and there was a 70+ kt 500 mb jet.  Bonus points for falling on June 30.  ;)

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Just south of MSN you have SBCAPE of 4100 j/kg, helicity values of 950 and an EHI of 20....

At 21z Monday

Noticed that as well, not surprised that these off the wall parameters showed up now that we lost the VV explosions at 500/700mb overnight Sunday Night. I would expect a talked up outlook for Monday and Sunday back west as well.

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Noticed that as well, not surprised that these off the wall parameters showed up now that we lost the VV explosions at 500/700mb overnight Sunday Night. I would expect a talked up outlook for Monday and Sunday back west as well.

 

 

Lack of a risk area on this morning's day 4 outlook makes me wonder about that.  I'm expecting a 30% area on the new day 3 outlook when it comes out but I don't think I'd be shocked if it's only 15%.

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Lack of a risk area on this morning's day 4 outlook makes me wonder about that.  I'm expecting a 30% area on the new day 3 outlook when it comes out but I don't think I'd be shocked if it's only 15%.

 

I would be shocked if it is a 15%, all models are at the very least showing a strong squall line for Monday in  E IA/IL/WI

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Day 2 text

 

 

 

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1223 AM CDT SAT JUN 28 2014

VALID 291200Z - 301200Z

...THERE IS A SLGT RISK OF SVR TSTMS SUNDAY INTO SUNDAY NIGHT ACROSS
PARTS OF THE NORTH CENTRAL PLAINS/MID MISSOURI VALLEY REGION INTO
PARTS OF THE UPPER MISSISSIPPI VALLEY...

...SUMMARY...
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING LARGE HAIL...A FEW
TORNADOES...AND SWATHS OF DAMAGING WIND GUSTS APPEAR POSSIBLE SUNDAY
INTO SUNDAY NIGHT ACROSS PORTIONS OF THE MIDDLE MISSOURI VALLEY
NORTHEASTWARD INTO THE UPPER MISSISSIPPI VALLEY.

...SYNOPSIS...
MODELS STILL INDICATE THAT A STRONG ZONAL MID/UPPER JET STREAK
EMERGING FROM THE PACIFIC WILL CONTINUE TO PROGRESS INLAND ACROSS
THE NORTHERN TIER OF THE U.S. DURING THIS PERIOD. AS THIS
OCCURS...SUBTROPICAL RIDGING LIKELY WILL BECOME MORE PROMINENT
ACROSS THE SOUTHERN TIER STATES. THIS RIDGING IS FORECAST TO REMAIN
RATHER FLAT...HOWEVER...AS FLOW EAST OF THE NORTHERN ROCKIES THROUGH
THE GREAT LAKES REGION REMAINS BROADLY CYCLONIC...TO THE SOUTH OF A
DEEPENING LOWER/MID TROPOSPHERIC CYCLONE NEAR THE NORTHWEST
ONTARIO/MANITOBA BORDER. WITHIN THE STRONG BELT OF FLOW NOSING TO
THE SOUTH OF THIS FEATURE...THE FIRST COUPLE IN A SERIES OF SHORT
WAVE PERTURBATIONS ARE EXPECTED TO PROGRESS ACROSS THE NORTHERN
PLAINS THROUGH THE UPPER MISSISSIPPI VALLEY AND UPPER MIDWEST.

WHILE MOISTENING AHEAD OF THE REMNANTS OF THE MID/UPPER TROUGHING
NOW ADVANCING THROUGH THE PLAINS IS EXPECTED TO CONTRIBUTE TO
CONSIDERABLE THUNDERSTORM ACTIVITY SUNDAY EAST OF THE MISSISSIPPI
VALLEY THROUGH THE APPALACHIANS...THE LOWER GREAT LAKES AND
SOUTHEAST...STRONGEST STORM DEVELOPMENT LIKELY WILL BECOME FOCUSED
ACROSS PARTS OF THE MID MISSOURI INTO UPPER MISSISSIPPI VALLEY.
MOISTURE RETURN ON STRENGTHENING SOUTHERLY LOW INTO THIS REGION IS
EXPECTED...AHEAD OF A SOUTHWARD ADVANCING COLD FRONT. THIS IS
FORECAST TO COINCIDE WITH THE NORTHEASTWARD ADVECTION OF VERY WARM
ELEVATED MIXED-LAYER AIR ACROSS THE NORTH CENTRAL PLAINS...TOWARD
THE MID/UPPER MISSISSIPPI VALLEY...CONTRIBUTING TO LARGE CAPE ON THE
SOUTHERN FRINGE OF THE STRONGER WESTERLIES.

...N CNTRL PLAINS/MID MO VALLEY INTO UPPER MS VALLEY...
UNCERTAINTIES PERSIST CONCERNING THE DETAILS OF THE CONVECTIVE
EVOLUTION ON SUNDAY...AND PERHAPS THE TIMING OF STORM INITIATION.
HOWEVER...GUIDANCE HAS GENERALLY BEEN SUGGESTIVE THAT A DEVELOPING
AREA OF LOW-LEVEL WARM ADVECTION ON THE SOUTHERN FRINGE OF THE
WESTERLIES COULD PROVIDE THE FORCING AND FOCUS FOR STORM INITIATION
SOMETIME SUNDAY AFTERNOON NEAR OR JUST WEST OF THE SIOUX FALLS
SD/SIOUX CITY IA AREA. THIS DEVELOPMENT PROBABLY WILL INITIALLY BE
DISCRETE...AND COULD INTENSIFY RAPIDLY IN AN ENVIRONMENT
CHARACTERIZED BY STEEP MID-LEVEL LAPSE RATES...CAPE OF 2000-4000
J/KG AND STRONG SHEAR SUPPORTIVE OF TORNADIC SUPERCELLS. JUST HOW
LONG ACTIVITY LIKELY WILL BE ABLE TO REMAIN DISCRETE IS NOT
CLEAR...BUT SUPERCELLS COULD PERSIST AND PERHAPS INCREASE IN NUMBER
WHILE SPREADING EASTWARD THROUGH PARTS OF SOUTHERN MINNESOTA AND
NORTHERN IOWA.

EARLY SUNDAY EVENING...IF NOT EARLIER...INITIAL ACTIVITY STILL SEEMS
LIKELY TO CONGEAL INTO AN INCREASINGLY ORGANIZED CONVECTIVE CLUSTER
CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WIND GUSTS NEAR/EAST OF
THE MISSISSIPPI VALLEY. AT SOME POINT...ANOTHER AREA OF
STRENGTHENING LOWER/MID TROPOSPHERIC WARM ADVECTION...ON THE NOSE OF
WARMER AND MORE STRONGLY CAPPING ELEVATED MIXED-LAYER AIR...SEEMS
LIKELY TO FOCUS ADDITIONAL INTENSE CONVECTIVE DEVELOPMENT ACROSS
PARTS OF CENTRAL AND EASTERN NEBRASKA. VERY LARGE HAIL MAY BE THE
PRIMARY THREAT WITH THIS ACTIVITY INITIALLY. HOWEVER...INCREASING
ORGANIZATION AND UPSCALE CONVECTIVE GROWTH APPEARS POSSIBLE ON THE
NOSE OF A STRENGTHENING /30-50 KT/ SOUTHERLY 850 MB JET
OVERNIGHT...ACCOMPANIED BY THE RISK FOR POTENTIALLY DAMAGING WIND
GUSTS.

..KERR.. 06/28/2014
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The Euro is pretty incredible for Monday as well and it continues potential after dark maintaining good instability as the LLJ cranks up across lower Michigan, not to mention at 06z there is a 991mb low near Marquette, the wind fields with this system are going to be damn impressive for this time of year.

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New day 3

 

 

 

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0230 AM CDT SAT JUN 28 2014

VALID 301200Z - 011200Z

...THERE IS A SLGT RISK OF SVR TSTMS MONDAY INTO MONDAY NIGHT ACROSS
PORTIONS OF THE CENTRAL PLAINS...MID MISSOURI VALLEY...SOUTHWESTERN
GREAT LAKES REGION AND LOWER OHIO VALLEY...

...SUMMARY...
SEVERE THUNDERSTORMS...ACCOMPANIED BY MAINLY THE RISK FOR LARGE HAIL
AND POTENTIALLY DAMAGING WIND GUSTS...WILL BE POSSIBLE MONDAY INTO
MONDAY NIGHT...FROM THE MIDDLE MISSISSIPPI VALLEY EASTWARD INTO
SOUTHWESTERN PORTIONS OF THE GREAT LAKES...AND WEST SOUTHWESTWARD
THROUGH THE CENTRAL PLAINS.

...SYNOPSIS...
MODELS SUGGEST THAT THE WESTERLIES WILL UNDERGO AMPLIFICATION ACROSS
THE NORTHERN TIER OF THE U.S. DURING THIS FORECAST PERIOD. THIS
LIKELY WILL INCLUDE INCREASINGLY CYCLONIC MID/UPPER FLOW DEVELOPING
SOUTHWARD THROUGH MUCH OF THE NORTH CENTRAL STATES...WITH THE BASE
OF THE POSITIVELY TILTED TROUGH AXIS AS FAR SOUTH AS THE CENTRAL
PLAINS/MIDDLE MISSISSIPPI VALLEY BY 12Z TUESDAY. THIS STILL APPEARS
LIKELY TO BE PRECEDED BY THE EASTWARD ADVECTION OF A PLUME OF VERY
WARM ELEVATED MIXED LAYER ACROSS THE CENTRAL PLAINS AND MIDDLE
MISSISSIPPI VALLEY...THE LEADING EDGE OF WHICH MAY CONTINUE THROUGH
MUCH OF THE OHIO VALLEY DURING THE DAY MONDAY. BENEATH THE STEEP
MID-LEVEL LAPSE RATES...AND AHEAD OF A SOUTHWARD ADVANCING COLD
FRONT ASSOCIATED WITH THE UPPER TROUGH...SEASONABLY HIGH MOISTURE
CONTENT MAY CONTRIBUTE TO THE DEVELOPMENT OF STRONG BOUNDARY LAYER
BASED CAPE BY MONDAY AFTERNOON OVER A SIZABLE AREA FROM THE CENTRAL
PLAINS THROUGH MIDDLE MISSISSIPPI AND LOWER OHIO VALLEY.

...CNTRL PLAINS/MID MS VALLEY/SWRN GREAT LAKES/LWR OH VALLEY...
UNCERTAINTIES REGARDING THE DETAILS OF THE CONVECTIVE EVOLUTION ON
SUNDAY LEAD TO INCREASING UNCERTAINTY FOR THIS FORECAST PERIOD.
HOWEVER...ASSUMING CONVECTIVE DEVELOPMENT AND ASSOCIATED OUTFLOW
SUNDAY THROUGH SUNDAY NIGHT DOES NOT BECOME MORE EXTENSIVE THAN
CURRENTLY ANTICIPATED... IT APPEARS PROBABLE THAT CONSIDERABLE
THUNDERSTORM ACTIVITY MAY BE ONGOING NEAR/EAST OF THE MIDDLE
MISSOURI VALLEY AT 12Z MONDAY. THEREAFTER...IT APPEARS POSSIBLE
THAT SOME COMBINATION OF A REMNANT CONVECTIVELY GENERATED CYCLONIC
VORTEX...OR ASSOCIATED LARGER-SCALE FORCING FOR UPWARD VERTICAL
MOTION...WILL BECOME THE FOCUS FOR RENEWED INTENSE STORM DEVELOPMENT
ACROSS PARTS OF SOUTHERN/EASTERN IOWA AND NORTHERN MISSOURI DURING
THE DAY. THIS ACTIVITY SHOULD TEND TO PROPAGATE EAST SOUTHEASTWARD
THROUGH NORTHERN AND CENTRAL ILLINOIS AND INDIANA...PERHAPS PORTIONS
OF LOWER MICHIGAN. AT THE SAME TIME...ADDITIONAL INTENSE STORM
DEVELOPMENT APPEARS LIKELY TO DEVELOP WEST SOUTHWARD ALONG THE
PRE-COLD FRONTAL THERMAL RIDGE AXIS...ACROSS MISSOURI AND PARTS OF
EASTERN/SOUTHERN KANSAS...INTO THE CENTRAL HIGH PLAINS BY EARLY
MONDAY EVENING.

VARIABILITY DOES EXIST AMONG THE MODELS/ENSEMBLE DATA CONCERNING THE
STRENGTH OF THE PRE-FRONTAL LOW-LEVEL FLOW...AND THE STRENGTH OF
WESTERLY MID-LEVEL FLOW TO THE SOUTH OF THE FRONT REMAINS UNCERTAIN.
HOWEVER...GIVEN THE MAGNITUDE OF THE EXPECTED POTENTIAL INSTABILITY
/2000-3000+ J PER KG/...VERTICAL SHEAR SHOULD BE SUFFICIENT TO
SUPPORT THE RISK FOR ORGANIZED CONVECTIVE DEVELOPMENT CAPABLE OF
PRODUCING CONSIDERABLE HAIL AND POTENTIALLY DAMAGING WIND GUSTS.

..KERR.. 06/28/2014

 

post-4544-0-27501800-1403940896_thumb.gi

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With only 15% and no mention of the T word, you could call that a conservative outlook.  Should start to see the probabilities/wording ramp up as uncertainties become resolved. 

Ultra conservative to say the least, not to mention the MI fear mixed in as well.

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