June 12-18 Severe/Heavy Rain Threats/Possibilities

[Tim from Springfield (IL)]

Not sure how thread-worthy this upcoming week will be but SPC's Day 2 outlook for Sunday includes a slight risk west of the Twin Cities, with the rest of MN and NW WI included in the Marginal. The Day 4 for Tuesday already has a 15% that includes parts of SW IA and N/NW MO (so on the slight western fringe of this subforum), but is hinting that this region may be in play for possible strong/severe storm risks the rest of next week (but not warranting a threat area at this time). Looks like the summertime pattern is here along with the first major heat wave of the year.

Sunday, June 12 (includes W MN)

http://www.spc.noaa.gov/products/outlook/day2otlk.html

...UPPER MS VALLEY...
   A 40-50 KT LLJ POSITIONED ACROSS THE CNTRL/ERN DAKOTAS WILL BE IN
   PLACE SUN MORNING AND MAY BE SUPPORTING ELEVATED CONVECTION NEAR THE
   INTERNATIONAL BORDER AT THE BEGINNING OF THE D2 PERIOD. THE GENERAL
   EWD PROGRESSION OF A SRN CANADA UPPER DISTURBANCE AND ASSOCIATED
   LOW-LEVEL COLD FRONT WILL OCCUR DURING THE LATE MORNING AND
   AFTERNOON. STRONG PRE-FRONTAL HEATING...WITH TEMPERATURES EXPECTED
   TO REACH THE 90S F ACROSS THE ERN DAKOTAS INTO WRN MN...SHOULD YIELD
   MLCAPE VALUES NEAR 2000 J/KG WITHIN A NARROW CORRIDOR...BOUNDED TO
   THE E BY A SLOWLY ADVANCING WARM FRONT ACROSS CNTRL/NRN MN. 

   SCATTERED TO WIDESPREAD TSTM DEVELOPMENT IS FORECAST TO OCCUR
   EARLY-MID AFTERNOON AND BE PRIMARILY FOCUSED ALONG THE COLD FRONT OR
   ANY PRE-FRONTAL WIND SHIFT. A COUPLE DOMINANT CLUSTERS COULD EVOLVE
   AND SPREAD INTO WRN MN BY LATE AFTERNOON. GIVEN THE PRESENCE OF A
   WELL-MIXED BOUNDARY LAYER AND WARM TEMPERATURES ALOFT...DMGG WIND
   GUSTS ARE EXPECTED TO BE THE PRIMARY THREAT...WITH ISOLATED
   INSTANCES OF MARGINALLY SVR HAIL ALSO POSSIBLE. TSTMS ARE EXPECTED
   TO WEAKEN BY LATE EVENING WITH EWD PROGRESSION INTO CNTRL/ERN MN DUE
   TO THE LOSS OF DIURNAL HEATING...AS THE STRONGEST FORCING FOR ASCENT
   BECOMES FOCUSED N/E OF THE AREA.

June 14-18 (D4 threat already for parts of SW IA and NW MO)

http://www.spc.noaa.gov/products/exper/day4-8/

DAY 4-8 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0352 AM CDT SAT JUN 11 2016

   VALID 141200Z - 191200Z

   ...DISCUSSION...
   THE MEDIUM RANGE GUIDANCE INDICATES CONSIDERABLE AMPLIFICATION
   WITHIN THE MAIN BELT OF MID-LATITUDE WESTERLIES ACROSS THE EASTERN
   PACIFIC INTO NORTH AMERICA DURING THE MIDDLE TO LATTER PORTION OF
   THE COMING WORK WEEK.  LARGE-SCALE RIDGING APPEARS LIKELY TO REMAIN
   PROMINENT ACROSS MUCH OF THE CENTRAL U.S...BUT...EMBEDDED IN THIS
   REGIME...TROUGHING WITHIN A REMNANT WEAKER SOUTHERN BRANCH OF THE
   SPLIT WESTERLIES EMERGING FROM THE SOUTHERN GREAT BASIN APPEARS
   LIKELY TO REACH THE CENTRAL PLAINS BY TUESDAY.  ENHANCED FORCING FOR
   ASCENT AND SHEAR NEAR THIS FEATURE MAY PROVIDE SUPPORT FOR SEVERE
   STORM DEVELOPMENT...MOSTLY IN THE FORM OF UPSCALE GROWING CONVECTIVE
   SYSTEMS.  ON TUESDAY...THIS MAY BECOME FOCUSED ON THE NOSE OF A
   PLUME OF WARM ELEVATED MIXED LAYER AIR...ACROSS PARTS OF THE CENTRAL
   PLAINS INTO LOWER MISSOURI VALLEY.  

   FROM THE MIDDLE OF NEXT WEEK INTO NEXT WEEKEND...IT APPEARS THAT THE
   UPPER IMPULSE MAY SHIFT NORTHWARD TOWARD THE UPPER MIDWEST...BEFORE
   TURNING SLOWLY EASTWARD...THEN SOUTHWARD...AROUND THE EASTERN
   PERIPHERY OF STRONG MID/UPPER RIDGING BUILDING FROM THE SOUTHERN
   ROCKIES TOWARD THE UPPER MIDWEST.  THE MOST SIGNIFICANT CONVECTIVE
   POTENTIAL PROBABLY WILL REMAIN FOCUSED ON THE SOUTHERN AND
   SOUTHWESTERN PERIPHERY OF THE IMPULSE...ACROSS PARTS OF THE MIDDLE
   MISSISSIPPI VALLEY/OZARK PLATEAU INTO THE  LOWER OHIO/TENNESSEE
   VALLEYS...PERHAPS SPREADING INTO THE GULF STATES AHEAD OF A COLD
   FRONT BY THE END OF THE WEEK.  ADDITIONAL STRONG TO SEVERE STORM
   DEVELOPMENT MAY BECOME FOCUSED ON THE NORTHWESTERN PERIPHERY OF THE
   UPPER RIDGE...ACROSS PARTS OF THE NORTHERN INTERMOUNTAIN REGION AND
   NORTHERN ROCKIES.  HOWEVER...DUE TO LARGE UNCERTAINTIES CONCERNING
   THESE DEVELOPMENTS...SEVERE PROBABILITIES REMAIN BELOW 15 PERCENT.

   ..KERR.. 06/11/2016

[Chicago Storm]

Probably could have just extended the other thread to cover it.

[HillsdaleMIWeather]

The closer we've been getting to Wed. the more interesting it's been on the models. 

[hlcater]

I think tuesday looks decent around here. We may be a tad far east for the best threat, but windfields are pretty good directionally, and speed shear, while not fantastic, would suffice.  Dry layer above 500mb must be some sort of error. There is a very slight veer-back but its slight enough that I wouldn't think it would effect much.

[snowlover2]

Enhanced area for parts of IA/MO on new day 2.

 

DAY 2 CONVECTIVE OUTLOOK 
   NWS STORM PREDICTION CENTER NORMAN OK
   1235 AM CDT MON JUN 13 2016

   VALID 141200Z - 151200Z

   ...THERE IS AN ENH RISK OF SVR TSTMS TUESDAY AFTERNOON AND EVENING
   ACROSS PARTS OF THE MID AND LOWER MISSOURI VALLEY...

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SURROUNDING AREAS OF THE
   LOWER CENTRAL PLAINS INTO MIDDLE MISSISSIPPI VALLEY...

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS SURROUNDING AREAS OF THE
   CENTRAL PLAINS AND MISSISSIPPI VALLEY...

   ...THERE IS A MRGL RISK OF SVR TSTMS TUESDAY AFTERNOON AND EVENING
   ACROSS PARTS OF CENTRAL THROUGH NORTHEAST MONTANA...

   ...SUMMARY...
   SEVERE STORMS ARE EXPECTED ACROSS THE LOWER CENTRAL PLAINS INTO THE
   LOWER MISSOURI AND MIDDLE MISSISSIPPI VALLEYS TUESDAY INTO TUESDAY
   NIGHT.

   ...SYNOPSIS...
   MODELS CONTINUE TO INDICATE THAT AMPLIFICATION WITHIN THE PRIMARY
   BELT OF MID-LATITUDE WESTERLIES WILL COMMENCE ACROSS THE EASTERN
   PACIFIC INTO NORTH AMERICA DURING...IF NOT PRIOR...TO THIS PERIOD.
   ONE SIGNIFICANT SHORT WAVE IMPULSE...LIKELY ALREADY INLAND OF THE
   PACIFIC NORTHWEST COAST BY 12Z TUESDAY...STILL APPEARS LIKELY TO
   PROGRESS ACROSS PARTS OF THE CANADIAN/NORTHERN U.S. ROCKIES INTO THE
   WESTERN CANADIAN PRAIRIES...AS LARGER-SCALE UPPER TROUGHING
   CONTINUES TO DIG ALONG AND WEST OF THE PACIFIC COAST.
   DOWNSTREAM...LARGE-SCALE RIDING MAY CONTINUE TO BUILD NORTH OF THE
   CENTRAL CANADIAN/U.S. BORDER THROUGH HUDSON BAY.

   SUBSTANTIVE AMPLIFICATION OF SUBTROPICAL RIDGING OVER THE INTERIOR
   U.S. STILL APPEARS UNLIKELY DURING THIS PERIOD.  HOWEVER...THE
   EXTENT TO WHICH IT GRADUALLY BUILDS NORTH OF THE GULF COAST STATES
   REMAINS A POINT OF MODEL VARIABILITY...AS THE REMNANTS OF A WEAKER
   SOUTHERN BRANCH CLOSED LOW PROGRESS OUT OF THE SOUTHWESTERN
   U.S...AROUND ITS NORTHERN PERIPHERY.  BY 12Z TUESDAY...THIS MAY BE
   IN THE FORM OF AT LEAST A COUPLE OF SMALLER SCALE IMPULSES WITHIN
   SOMEWHAT BROADER-SCALE TROUGHING SHIFTING NORTHEASTWARD THROUGH THE
   CENTRAL ROCKIES AND ADJACENT HIGH PLAINS.  THE BROADER-SCALE
   TROUGHING MAY GRADUALLY SHARPEN AND TAKE ON MORE OF AN EASTWARD
   TRACK ACROSS THE MIDDLE MISSOURI INTO UPPER MISSISSIPPI
   VALLEY...DOWNSTREAM OF RIDGING BUILDING ACROSS THE CENTRAL AND
   NORTHERN HIGH PLAINS.

   AT THE SAME TIME...THE CENTER OF A BROAD DOWNSTREAM CLOSED LOW MAY
   ONLY GRADUALLY REDEVELOP EAST OF THE NORTHERN NEW ENGLAND...THROUGH
   THE CANADIAN MARITIMES.  IN ITS WAKE...A SIGNIFICANT FRONTAL ZONE
   WILL EITHER REMAIN QUASI-STATIONARY OR EDGE SLOWLY EASTWARD ACROSS
   PARTS OF THE NORTHERN PLAINS AND UPPER MIDWEST...THE MID OHIO VALLEY
   AND CENTRAL APPALACHIANS... AND MID ATLANTIC STATES.  IN RESPONSE TO
   THE UPPER TROUGHING EMERGING FROM THE SOUTHWEST...A SURFACE LOW MAY
   DEVELOP ALONG THE FRONT...ACROSS THE DAKOTAS INTO MINNESOTA TUESDAY
   AND TUESDAY NIGHT.

   ...CENTRAL PLAINS INTO THE MID/UPPER MISSISSIPPI VALLEY...
   THE SURFACE FRONTAL ZONE ACROSS THE UPPER MIDWEST INTO THE NORTHERN
   PLAINS SHOULD PROVIDE THE NORTHERN LIMIT TO ANY APPRECIABLE SEVERE
   WEATHER POTENTIAL FOR THIS PERIOD.  SURFACE TROUGHING...PERHAPS A
   SHARPENING DRYLINE/ZONE OF DIFFERENTIAL HEATING...TRAILING TO THE
   SOUTH OF THE LOW IS EXPECTED TO GRADUALLY PROVIDE THE WESTERN LIMIT.
    BOUNDARY LAYER BASED STORMS MAY INITIATE NEAR/EAST OF THIS LATTER
   FEATURE BY MID TO LATE AFTERNOON ACROSS MUCH OF THE CENTRAL PLAINS.
   HOWEVER...STRONGEST AND MOST WIDESPREAD STORM DEVELOPMENT IS STILL
   EXPECTED NEAR THE NOSE OF A PLUME OF WARM ELEVATED MIXED LAYER AIR
   EMANATING FROM THE SOUTHERN ROCKIES. 

   WHERE THIS POTENTIAL FOCUS ENDS UP REMAINS A BIT UNCLEAR DUE TO THE
   SPREAD AMONG THE MODELS CONCERNING THE TRACK/EVOLUTION OF THE UPPER
   IMPULSE...BUT IT STILL SEEMS MOST PROBABLE THAT THIS WILL BE ACROSS
   PARTS OF THE MID/LOWER MISSOURI VALLEY.  BENEATH AT LEAST MODESTLY
   STEEP MID-LEVEL LAPSE RATES...SURFACE DEW POINTS AROUND OR IN EXCESS
   OF 70F ARE EXPECTED TO CONTRIBUTE TO CAPE OF 2000-3000+ J/KG BY PEAK
   HEATING.  THIS ENVIRONMENT SHOULD BE MORE THAN CONDUCIVE TO
   STRONG/SEVERE STORM DEVELOPMENT CAPABLE OF PRODUCING SEVERE HAIL AND
   POTENTIALLY DAMAGING SURFACE GUSTS.  ALTHOUGH LOWER/MID TROPOSPHERIC
   WIND FIELDS MAY BE SOMEWHAT MODEST /30-40 KT/ ACROSS MOST
   AREAS...VERTICAL SHEAR PROBABLY WILL BECOME AT LEAST MARGINALLY
   SUFFICIENT FOR SUPERCELLS DURING INITIAL STORM DEVELOPMENT.  THIS
   MAY INCLUDE AT LEAST SOME RISK FOR AN ISOLATED TORNADO OR TWO.

   THE UPSCALE GROWTH OF ONE OR TWO ORGANIZING CONVECTIVE CLUSTERS THEN
   APPEARS POSSIBLE ACROSS THE MID/LOWER MISSOURI VALLEY DURING THE
   LATE AFTERNOON AND EVENING.  ACTIVITY IS EXPECTED TO PROPAGATE
   TOWARD THE MIDDLE MISSISSIPPI VALLEY WITH POTENTIALLY DAMAGING WIND
   GUSTS BECOMING THE MOST PROMINENT SEVERE THREAT BEFORE CONVECTION
   WEAKENS TUESDAY NIGHT.

 

[IllinoisWedges]

Day 3 SLGT out for our subforum. 

 

 

 

...CNTRL PLAINS INTO THE MID/UPPER MISSISSIPPI VALLEY...
THE NOSE OF A PLUME OF WARM ELEVATED MIXED LAYER AIR...EMERGING FROM
THE SOUTHERN ROCKIES REGION WITH THE SOUTHERN BRANCH IMPULSE...IS
EXPECTED TO PROVIDE THE GENERAL FOCUS FOR PERHAPS THE MOST
SIGNIFICANT CONVECTIVE DEVELOPMENT DURING THIS PERIOD. THIS STILL
APPEARS MOST LIKELY ACROSS PARTS OF THE LOWER CENTRAL PLAINS INTO
THE LOWER MISSOURI VALLEY REGION BY LATE TUESDAY AFTERNOON...WHERE
RELATIVELY STEEP MID-LEVEL LAPSE RATES AND A BOUNDARY LAYER
CHARACTERIZED BY SURFACE DEW POINTS NEAR 70F MAY CONTRIBUTE TO CAPE
IN EXCESS OF 3000 J/KG. THIS INSTABILITY...COUPLED WITH VERTICAL
SHEAR ASSOCIATED WITH REMNANT LOWER/MID TROPOSPHERIC SPEED
MAXIMA...IS EXPECTED TO CONTRIBUTE TO AN ENVIRONMENT CONDUCIVE TO
THE EVOLUTION OF ONE OR MORE ORGANIZED CONVECTIVE SYSTEMS CAPABLE OF
PRODUCING POTENTIALLY DAMAGING WIND GUSTS AND SEVERE HAIL. ISOLATED
SUPERCELLS MAY BE POSSIBLE AS BOUNDARY LAYER BASED STORMS INITIATE
TUESDAY AFTERNOON.

 

[HillsdaleMIWeather]

IWX for the first time in awhile sounds enthused

The better dynamics arrive Tuesday night into Wednesday, with

potential for a severe weather threat. A broad area of 850-500mb

Qvector convergence overspreads the region from west to east

Wednesday as the upper level low drifts into the western UP of

Michigan. With overnight moisture pumping into the warm sector,

PWATs are nearly 175 percent of normal. Model guidance suggests

dewpoints may reach into the low 70s by late morning, with CAPE

values in the 2-3K J/KG range. Mid level lapse rates approach 7

C/Km during the afternoon associated with a dry, mixed layer

advecting in aloft. Shear is on the weaker side, but sufficient

for storms to become severe-especially considering the

instability. Given all of these factors, I kept the going

forecast of likely showers/thunderstorms in the forecast. SPC has

us in a slight risk for severe weather as of 8z today, with

damaging winds/large hail being the primary threat.

[Chambana]

Best threat for my area appears to be Tuesday night into Wednesday, with a slight risk introduced for Wednesday. Besides that we are dry and hot all week long, a good soaker will be needed after 6+ days in the 90s.

[Chitown Storm]

About an inch overnight with another 1.25"-2.5" in the point for tomorrow. Severe wx looks like it might stay south of here but the heavy rains look like a lock.

[HillsdaleMIWeather]

Today's end of the 12Z 4KNAM looked good with supercells popping in Southern MI Wednesday evening.

[IllinoisWedges]

Day 2 ENH out. 

 

 

 

 
WITHIN THE WARM SECTOR OF THE SURFACE LOW...SEASONABLY HIGH SURFACE  
DEW POINTS IN THE MID/UPPER 60S AND 70S F ARE EXPECTED TO CONTRIBUTE  
TO CAPE ON THE ORDER OF 2000-3000+ J/KG BY PEAK HEATING WEDNESDAY.  
THIS IS EXPECTED WITH INSOLATION...BENEATH INITIALLY MODESTLY STEEP  
MID-LEVEL LAPSE RATES ASSOCIATED WITH THE REMNANTS OF A PLUME OF  
ELEVATED MIXED LAYER AIR.  
 
ALTHOUGH MUCH OF THE MIDDLE MISSISSIPPI INTO OHIO VALLEYS MAY COME  
UNDER THE INFLUENCE OF WEAK LOWER/MID-LEVEL SUBSIDENCE DURING THE  
DAY...INHIBITION MAY BECOME WEAK ENOUGH BENEATH AT LEAST BROADLY  
CYCLONIC MID/UPPER FLOW TO ALLOW FOR SCATTERED AREAS OF STORM  
DEVELOPMENT. PERHAPS AIDED BY SHEAR ASSOCIATED WITH 20-30 KT MEAN  
WEST/NORTHWESTERLY MID-LEVEL FLOW...ACTIVITY COULD GROW UPSCALE INTO  
ORGANIZING STORM CLUSTERS...ACCOMPANIED BY POTENTIALLY DAMAGING WIND  
GUSTS AND PERHAPS SOME SEVERE HAIL.  
 
MORE SUBSTANTIVE POTENTIAL FOR ORGANIZED SEVERE STORM DEVELOPMENT  
MAY EVOLVE IN CLOSER PROXIMITY TO THE SURFACE LOW...FROM PARTS OF  
SOUTHEASTERN WISCONSIN INTO NORTHERN ILLINOIS BY LATE AFTERNOON.  
THIS PROBABLY WILL BE SUPPORTED BY FORCING FOR ASCENT ASSOCIATED  
WITH LOW-LEVEL WARM ADVECTION...JUST AHEAD OF THE MID-LEVEL IMPULSE  
WHICH MAY BE ACCOMPANIED BY A 40-50 KT 500 MB SPEED MAXIMUM. A  
COUPLE OF SUPERCELLS MAY NOT BE OUT OF THE QUESTION  
INITIALLY...BEFORE UPSCALE GROWTH INTO A FORWARD/SOUTHEASTWARD  
PROPAGATING CONVECTIVE SYSTEM OCCURS. DAMAGING SURFACE GUSTS MAY  
BECOME THE MOST PROMINENT SEVERE THREAT AS ACTIVITY PROPAGATES  
ACROSS NORTHEASTERN ILLINOIS/NORTHERN INDIANA AND SOUTHERN MICHIGAN  
WEDNESDAY EVENING.  

[HillsdaleMIWeather]

Well, what a great early morning surprise!

 

If we had more shear this would be one for the books. Still a half descent threat.

[cyclone77]

Classic DVN skip over setup.  With the exception of 2015, this is what we usually expect here in the DVN cwa.

[A-L-E-K]

meh, not expecting much this far north.

 

looking decent further south

[Chitown Storm]

Latest HRRR really hitting the area hard. Might be looking at flooding concerns later today if this verifies. The ground can't hold much more after all of the rain the last week or so. Greater instability working much farther north than previously thought too.

[A-L-E-K]

rather surprising amount of sun, would be nice to see the wf light up this afternoon and then get another round later this evening but the way things have been going, i won't hold my breath

[Indystorm]

Storms popping in central IN this a.m. as the WF advances northward.  At least today and Wed. look interesting for the Midwest.

[A-L-E-K]

holding onto some hope for garden variety stuff this evening but timing still looks like a near miss for chicagoland tomorrow

[Chitown Storm]

Day 1 outlook has the slight risk expanded north to the TC metro. Enhanced risk now into SW MN

[Tim from Springfield (IL)]

Classic DVN skip over setup.  With the exception of 2015, this is what we usually expect here in the DVN cwa.

 

Not quite--all of Putnam and most of Bureau County (roughly along and east of IL-40, including Princeton) are in the western fringe of the ENH for tomorrow.

[A-L-E-K]

first time we've gotten into the 70% thunder probs in a long time

 

[Hoosier]

holding onto some hope for garden variety stuff this evening but timing still looks like a near miss for chicagoland tomorrow

Haven't really had a chance to look at tomorrow but a glance at the 12z 4km NAM doesn't look good for us.

[A-L-E-K]

Haven't really had a chance to look at tomorrow but a glance at the 12z 4km NAM doesn't look good for us.

 

 

none of the 12z guidance looks good for tomorrow so far

 

on the plus side, MCS chances looking up for this evening

[Hoosier]

none of the 12z guidance looks good for tomorrow so far

on the plus side, MCS chances looking up for this evening

Late morning update from LOT sounded skeptical about tomorrow. Wouldn't be surprised to see significant changes on the new outlook.

[weathergy]

For what it's worth, June 5th 2010 is one of the analogs on CIPS.

 

[Indystorm]

Heavy rain at times here in Indy metro area.

[A-L-E-K]

i'd hit it

 

[nwohweather]

Wow Day 2 Enhanced! Thank the lord

[Indystorm]

Enhanced risk scaled back for Wednesday.

[Jim Martin]

 

SPC has scaled back to slight risk for now...