July 12-15, 2014 Severe Weather Threat

[Chicago WX]

Why not, I'll try my luck.

 

Day 2 outlook

 

 

DAY 2 CONVECTIVE OUTLOOK CORR 1
NWS STORM PREDICTION CENTER NORMAN OK
0110 AM CDT FRI JUL 11 2014

VALID 121200Z - 131200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CENTRAL
PLAINS TO UPPER MIDWEST...

CORRECTED TO INCLUDE NO THUNDER AREA WEST OF THE APPALACHIANS.

...SUMMARY...
STRONG TO SEVERE THUNDERSTORMS ARE FORECAST TO DEVELOP FROM PORTIONS
OF CENTRAL PLAINS AND UPPER MIDWEST INTO PARTS OF THE WESTERN GREAT
LAKES ON SATURDAY. MORE SCATTERED STRONG TO SEVERE STORMS MAY ALSO
DEVELOP FROM THE NORTHERN ROCKIES TO THE CENTRAL HIGH PLAINS.

...SYNOPSIS...
MID-LEVEL HEIGHT FALLS WILL BEGIN TO SPREAD SOUTHEAST FROM SOUTHERN
CANADA TOWARD THE NORTHERN PLAINS AND UPPER GREAT LAKES THIS PERIOD.
MOST SUBSTANTIAL AMPLIFICATION OVER THESE AREAS IS FORECAST TO OCCUR
THROUGH EARLY SUN...A BIT LATER/SLOWER THAN PREVIOUS FORECASTS.
AHEAD OF THE AMPLIFYING TROUGH...A LEADING WEAK TROUGH/FRONTAL ZONE
WILL EXTEND FROM LOWER MI SOUTHWEST TO KS/NEB BORDER AREA AND THEN
CURVE WEST-NORTHWEST INTO THE CENTRAL HIGH PLAINS EARLY SAT. A VERY
WARM AIRMASS WILL RESIDE SOUTH OF THIS BOUNDARY...COINCIDENT WITH A
BROAD MID/UPPER-LEVEL RIDGE AND WEAKER FLOW ALOFT. LOW-AMPLITUDE
DISTURBANCES ORBITING THE UPPER RIDGE AND EMANATING FROM DIURNAL
CONVECTION ACROSS THE ROCKIES AND SOUTHWEST...IN CONCERT WITH THE
GREAT PLAINS LOW-LEVEL JET...WILL LIKELY RESULT IN ONE OR MORE
CLUSTERS OF ONGOING/ELEVATED STORMS ALONG/NORTH OF THE SURFACE
BOUNDARY...FROM THE CENTRAL PLAINS TO UPPER MIDWEST. A MORE
SUBSTANTIAL COLD FRONT ASSOCIATED WITH THE MID/UPPER TROUGH
AMPLIFICATION SHOULD DEVELOP SOUTHEAST ACROSS NORTHEAST ND AND
NORTHERN MN DURING SAT EVENING. WHILE ISOLATED STRONG STORMS ARE
POSSIBLE NEAR THIS FRONT...GREATER SEVERE WEATHER POTENTIAL DURING
THE DAY WILL LIKELY EVOLVE WELL AHEAD OF THE COLD FRONT...ALONG THE
LEADING BOUNDARY FROM EASTERN NEB TO LOWER MI AND NORTHERN IND.

...CENTRAL PLAINS TO UPPER MIDWEST...
A CORRIDOR OF STRONG TO LOCALLY EXTREME INSTABILITY /SBCAPE
2000-4000 J PER KG/ IS FORECAST TO DEVELOP ACROSS THESE AREAS WITH
HEATING OF THE DAY. CONTINUATION OF AFOREMENTIONED NOCTURNALLY
SUSTAINED CONVECTIVE SYSTEMS SHOULD CONTRIBUTE TO LOCALLY ENHANCED
LOW LEVEL CONVERGENCE AND DIFFERENTIAL HEATING BOUNDARIES AMIDST
INCREASING...BUT GENERALLY CAPPED INSTABILITY...FROM NEB ACROSS IA
INTO SOUTHERN WI. WEAK HEIGHT FALLS AND MODEST STRENGTHENING OF THE
WESTERLY MID-LEVEL FLOW SHOULD SUPPORT AN INCREASE IN BOTH
CONVECTIVE COVERAGE AND ORGANIZATION THROUGH THE DAY WITH SEVERE
HAIL/WIND POTENTIAL DEVELOPING EAST FROM THE MO RIVER VALLEY TO THE
MS RIVER THROUGH THE EVENING. SOME OF THESE STORMS MAY PERSIST EAST
INTO LOWER MI AND PARTS OF NORTHWEST OH LATE INTO SAT NIGHT GIVEN
THE INCREASE IN FORCING AND ASCENT AS THE UPPER TROUGH UNDERGOES
STRONGER AMPLIFICATION. HOWEVER...DIMINISHING INSTABILITY WITH
EASTWARD EXTENT...AND TIME OF DAY SHOULD LIMIT SEVERE POTENTIAL WITH
TIME.

[Chicago WX]

Day 3 outlook

 

 

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0237 AM CDT FRI JUL 11 2014

VALID 131200Z - 141200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MIDWEST AND OH VALLEY
TO WESTERN PA/NY...

...SUMMARY...
SEVERE STORMS WILL BE POSSIBLE OVER PARTS OF THE OHIO VALLEY AND
NORTHEAST ON SUNDAY. MORE ISOLATED STRONG TO SEVERE STORMS WILL ALSO
BE POSSIBLE ACROSS THE CENTRAL PLAINS...THE SOUTHWEST...AS WELL AS
OREGON.

...SYNOPSIS...
A POSITIVE-TILT MID/UPPER TROUGH AND ASSOCIATED DEEP-LAYER CYCLONE
WILL CONTINUE TO UNDERGO AMPLIFICATION/DEEPENING ACROSS THE NORTHERN
PLAINS AND GREAT LAKES THROUGH SUNDAY. AS A LEADING SHORTWAVE TROUGH
ON THE EASTERN FLANK OF THE UPPER LOW TRACKS FROM NEAR LAKE HURON TO
SOUTHERN QUEBEC...NORTH OF THE ST. LAWRENCE VALLEY...A STRONGER
IMPULSE IS FORECAST TO PIVOT AROUND THE WESTERN FLANK OF THE UPPER
LOW AND DIG SOUTH ACROSS THE NORTHERN PLAINS AND UPPER MS VALLEY.
BETWEEN THESE TWO SHORTWAVE TROUGHS...A BELT OF FASTER MID-LEVEL
CYCLONIC FLOW WILL EXTEND FROM THE DAKOTAS ACROSS THE GREAT LAKES TO
NORTHERN NEW ENGLAND...COINCIDENT WITH A SURFACE COLD FRONT. A
WEAKER/LEADING TROUGH AND ASSOCIATED WARM/MOIST CONVEYOR BELT WILL
EXTEND FROM THE MIDWEST/OH VALLEY NORTHEAST TO NY/NEW ENGLAND.

ELSEWHERE...MID-LEVEL ANTICYCLONE WILL REMAIN CENTERED ACROSS THE
GREAT BASIN WHILE A PACIFIC SHORTWAVE TROUGH PRODUCES WEAK HEIGHT
FALLS OVER THE NORTHWEST.

...MIDWEST/OH VALLEY...
THIS SHOULD BE THE MOST LIKELY REGION TO EXPERIENCE SCATTERED SEVERE
STORMS DURING THE DAY ON SUNDAY. WHILE REGION WILL LIE AMIDST A
RELATIVE MIN IN TERMS OF STRONGER HEIGHT FALLS ASSOCIATED WITH THE
DEVELOPING UPPER TROUGH...ONGOING CONVECTION AND/OR CONVECTIVE
DEBRIS SHOULD AID IN THE DEVELOPMENT OF STRONGER LOW LEVEL
BOUNDARIES TO RE-FOCUS STORMS DURING THE DIURNAL HEATING CYCLE.
AREAS OF STRONG INSTABILITY ARE LIKELY GIVEN 1) PROXIMITY TO STEEPER
MID-LEVEL LAPSE RATES EMANATING FROM THE CENTRAL PLAINS...AND 2)
CORRIDOR RICH LOW LEVEL MOISTURE WITH ORIGINS ACROSS THE SOUTH/LOWER
MS VALLEY. STRENGTHENING AND DIFFLUENT MID-LEVEL FLOW WILL FURTHER
AID STORM DEVELOPMENT/ORGANIZATION WITH THE POSSIBILITY OF CLUSTERS
AND/OR LINES OF STORMS CAPABLE OF PRODUCING WIND DAMAGE.

[Chicago WX]

Day 4 outlook

 

 

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0359 AM CDT FRI JUL 11 2014

VALID 141200Z - 191200Z

...DISCUSSION...
THERE APPEARS TO BE RELATIVELY GOOD AGREEMENT AMONGST THE
EURO...GFS...UKMET...AND THE GLOBAL ENSEMBLE MEANS WITH RESPECT TO
THE OVERALL EVOLUTION TO THE STRONG POSITIVE-TILT MID/UPPER TROUGH
ACROSS EASTERN NORTH AMERICA THROUGH THE BEGINNING OF NEXT WEEK.
DISPARITY BEGINS TO APPEAR NOT LONG THEREAFTER IN BOTH STRENGTH AND
ORIENTATION OF THE LARGE-SCALE TROUGH BUT THE MEDIUM RANGE WILL
LIKELY FEATURE WEAK FLOW AND RIDGING ACROSS MUCH OF THE WEST WITH
LOWER HEIGHTS AND CYCLONIC FLOW PERSISTING IN THE EAST. IN
BETWEEN...NORTHWEST FLOW ALOFT WILL RESIDE FROM EAST OF THE
CONTINENTAL DIVIDE TO THE CENTRAL AND SOUTHERN PLAINS.

...D4/OHIO VALLEY TO MID-ATLANTIC...
AFTER SEVERAL DAYS OF RELATIVELY WIDESPREAD CONVECTION...PRIMARILY
ASSOCIATED WITH A WARM/MOIST CONVEYOR BELT PRECEDING COLD FRONTAL
SURGES WITH GREAT LAKES TROUGH AMPLIFICATION...A COMPOSITE RESULTANT
BOUNDARY WILL LIKELY LIE FROM NEAR THE OHIO RIVER VALLEY
EAST-NORTHEAST INTO NEW ENGLAND. SIMILAR TO PREVIOUS DAYS...AIRMASS
ALONG AND SOUTH OF THIS BOUNDARY WILL BE CHARACTERIZED BY ABUNDANT
MOISTURE AND MODEST LAPSE RATES THAT SHOULD CONTRIBUTE TO A CORRIDOR
OF POTENTIALLY STRONGER DESTABILIZATION. THIS WILL OCCUR COINCIDENT
WITH MODEST HEIGHT FALLS AND STRENGTHENING MID-LEVEL FLOW AOA 30KT.
THUS...EXPECT THE INGREDIENTS TO BE IN PLACE FOR ORGANIZED
STORMS/SUPERCELLS WITH HAIL AND DAMAGING-WIND POTENTIAL.

THE D4 AREA DEPICTED IS APPROXIMATELY BASED ON THE GFS-ENSEMBLE
JOINT PROBABILITY OF 30-70 PERCENT FOR MUCAPE AOA 1000
J/KG...EFFECTIVE SHEAR AOA 30KT...AND 0.01 INCH CONVECTIVE
PRECIPITATION NEAR THE PEAK OF THE DIURNAL HEATING CYCLE.

[A-L-E-K]

i'm not too high on severe chances IMBY but love the prospects for more heavy rain and frequent convection.

 

gotta admit, this does look like another one of those setups where LAF is missed NW and then SE...feel like I was caught in that rut last year.

[Chicago WX]

gotta admit, this does look like another one of those setups where LAF is missed NW and then SE...feel like I was caught in that rut last year.

 

Yeah, looking at the models this morning seem to indicate that. I guess we'll see, but our luck with severe (or even fun run-of-the-mill thunderstorms) hasn't been the greatest this year. 

[Brewers]

With the large upper level low sinking south, shear is more than favorable. Not sure if the instability can make it past the IL/WI border though.

[A-L-E-K]

timing of the complex saturday morning definitely doesn't lend much confidence to a good recovery further north

[Hoosier]

No changes to the risk area for tomorrow

 

.....

DAY 2 CONVECTIVE OUTLOOK    NWS STORM PREDICTION CENTER NORMAN OK  1226 PM CDT FRI JUL 11 2014    VALID 121200Z - 131200Z    ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN NEB TO SRN WI AND A  PORTION OF THE SRN GREAT LAKES...     ..SUMMARY    STRONG TO SEVERE THUNDERSTORMS ARE FORECAST TO DEVELOP FROM PORTIONS  OF THE CENTRAL PLAINS TO SOUTHERN WISCONSIN AND A PORTION OF THE  SOUTHERN GREAT LAKES ON SATURDAY. MORE SCATTERED STRONG TO SEVERE  STORMS MAY ALSO DEVELOP FROM THE NORTHERN ROCKIES TO THE CENTRAL  HIGH PLAINS.     ..SYNOPSIS    STRONG UPPER RIDGE CENTERED OVER THE SRN HIGH PLAINS TODAY WILL  SHIFT WWD INTO THE SWRN STATES AND GREAT BASIN ON SATURDAY.  THIS  WILL OCCUR AS A SHORTWAVE TROUGH...CURRENTLY APPROACHING NRN  ALBERTA/SASKATCHEWAN FROM THE NORTHWEST TERRITORIES...DIGS SEWD  THROUGH THE WRN TO SRN PERIPHERIES OF A CLOSED LOW CENTERED OVER NRN  MANITOBA.  ALTHOUGH THERE WILL BE WEAK HEIGHT FALLS WITH THE  CANADIAN SYSTEM DURING THE FIRST-HALF OF DAY 2...A SHORTWAVE TROUGH  /CURRENTLY LOCATED OVER UT/...IS EXPECTED TO TRACK EWD FROM SD  ACROSS THE SLIGHT RISK AREA SATURDAY AFTERNOON AIDING IN TSTM  DEVELOPMENT.     ..ERN NEB/IA/FAR NRN MO TO SRN WI AND SRN GREAT LAKES REGION    A WEAK FRONTAL ZONE STRETCHING FROM SRN NEB THROUGH IA TO SRN WI IS  EXPECTED TO BE MODULATED SOME BY ONGOING TSTMS AT THE START OF DAY 2  WITH THE SRN PERIPHERY OF THIS ACTIVITY BEING A DIFFERENTIAL HEATING  BOUNDARY INTO SATURDAY AFTERNOON.  MEANWHILE...A COLD FRONT  STRETCHING FROM NRN WI THROUGH CENTRAL MN TO SRN SD AT 12Z SATURDAY  IS EXPECTED TO ADVANCE S/SEWD AND MERGE/OVERTAKE THE WEAKER FRONTAL  ZONE.  THE COLD FRONT SHOULD EXTEND FROM SWRN ONTARIO THROUGH NRN  IND/IL/MO TO SRN KS AND THE TX PANHANDLE BY 12Z SUNDAY.  THESE  BOUNDARIES WILL BE THE FOCUS FOR TSTM DEVELOPMENT ON DAY 2.    VERY RICH MOISTURE WILL RESIDE INVOF THESE BOUNDARIES WITH PW VALUES  OF 1.75-2 INCHES.  SURFACE HEATING...EXPECTED TO BE STRONGEST SOUTH  OF THE WEAK FRONT/DIFFERENTIAL HEATING BOUNDARY...COMBINED WITH THE  MOIST AIR MASS WILL RESULT IN MODERATE-STRONG INSTABILITY /2500-3500  J PER KG/.  FORCING FOR ASCENT ATTENDANT TO THE UT SHORTWAVE TROUGH  AND WAA WITHIN THE NOSE OF A CENTRAL PLAINS LLJ EXTENDING INTO THE  SLIGHT RISK AREA WILL SUPPORT TSTM DEVELOPMENT INTO SATURDAY  AFTERNOON/EVENING.  EFFECTIVE BULK SHEAR OF 35-55 KT...GIVEN  STRENGTHENING WLY MIDLEVEL WINDS ATTENDANT TO THE UT TROUGH AND  AMPLIFYING CANADIAN TROUGH...WILL SUPPORT BOTH BOWING LINE SEGMENTS  AND SUPERCELLS.  ALL SEVERE HAZARDS ARE POSSIBLE...WITH DAMAGING  WINDS BECOMING A GREATER THREAT SATURDAY NIGHT WITH ANY UPSCALE  GROWTH INTO AN MCS.  SOME OF THESE STORMS MAY PERSIST EAST INTO  LOWER MI AND PARTS OF NORTHWEST OH LATE INTO SATURDAY NIGHT...GIVEN  THE INCREASE IN FORCING AND ASCENT AS THE CANADIAN UPPER TROUGH  UNDERGOES STRONGER AMPLIFICATION. 

[Geos]

18 0z NAM showing where the focus of the storms will be. At least from the NAM's perspective.

 

[snowlover2]

18z NAM showing where the focus of the storms will be. At least from the NAM's perspective.

 

Did you mean 0z?

[Geos]

Did you mean 0z?

 

Oops! Yes, the 0z. Lol, been a long day!

 

Local forecast has heavy rain wording starting after 4am tonight.

[snowlover2]

New day 1

 

 

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1257 AM CDT SAT JUL 12 2014

VALID 121200Z - 131200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID-MO VALLEY TO THE
SRN LK MI REGION...

...SUMMARY...
ISOLATED TO SCATTERED SEVERE STORMS ARE ANTICIPATED FROM PARTS OF
THE MID-MISSOURI VALLEY TO THE SOUTHERN LAKE MICHIGAN REGION DURING
THE LATE AFTERNOON INTO TONIGHT. DAMAGING WINDS SHOULD BE THE
PRIMARY HAZARD...BUT SEVERE HAIL AND A TORNADO OR TWO WILL BE
POSSIBLE.

...SYNOPSIS...
AN UPPER-LEVEL TROUGH WILL AMPLIFY OVER S-CNTRL CANADA AS A VIGOROUS
SHORTWAVE IMPULSE DIGS SE TOWARDS THE INTERNATIONAL BORDER ALONG N
MN/LK SUPERIOR. UPSTREAM...A MID-LEVEL RIDGE WILL BUILD N FROM A
STRENGTHENING ANTICYCLONE OVER THE GREAT BASIN. A WEAK CONVECTIVELY
INDUCED MID-LEVEL IMPULSE OVER THE CNTRL HIGH PLAINS SHOULD TRACK
TOWARDS THE CNTRL GREAT LAKES. THIS FEATURE IN CONJUNCTION WITH
CONVECTIVE OUTFLOW SHOULD AID IN THE CONSOLIDATION OF TWO FRONTAL
BOUNDARIES OVER THE CNTRL PLAINS BY EVENING. FARTHER N...A COLD
FRONT WILL SWEEP INTO ND/N MN THIS EVENING.

...MID-MO VALLEY TO THE LK MI REGION...
DECAYING CONVECTION SHOULD BE ONGOING FROM PARTS OF THE DAKOTAS TO
IL AT 12Z THIS MORNING IN ASSOCIATION WITH LOW-LEVEL WAA AND ASCENT
AIDED BY THE WEAK MID-LEVEL IMPULSE TRACKING E ACROSS THE UPPER
MIDWEST. IN THE WAKE OF THIS ACTIVITY...INTENSE INSOLATION SHOULD
OCCUR FROM KS TO THE MID-MO VALLEY ALONG/S OF THE SRN FRONT.
DIFFERENTIAL HEATING SHOULD BE PRONOUNCED AND AMIDST A RESERVOIR OF
1.5-2.0 INCH PW VALUES...AID IN THE DEVELOPMENT OF SCATTERED LATE
AFTERNOON TO EVENING STORMS ACROSS PARTS OF NEB/IA.

MID-LEVEL LAPSE RATES WILL BE MARGINAL AND MAY HINDER DEVELOPMENT OF
STRONG BUOYANCY. NEVERTHELESS...GUIDANCE IS CONSISTENT IN DEPICTING
A BELT OF ENHANCED MID-LEVEL WLYS /AROUND 35-45 KT TO 700 MB/
DOWNSTREAM OF THE AMPLIFYING S-CNTRL CANADIAN TROUGH. THIS
ENHANCEMENT SHOULD HELP FOSTER UPSCALE GROWTH INTO AN MCS ON SAT
EVENING WITH SCATTERED SWATHS OF WIND DAMAGE AND A COUPLE TORNADOES
POSSIBLE.

 

 

[snowlover2]

New day 2

 

 

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0100 AM CDT SAT JUL 12 2014  
 
VALID 131200Z - 141200Z  
 
...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE OHIO VALLEY  
AND NORTHEAST...  
   
..SUMMARY  
 
SEVERE THUNDERSTORMS WILL BE POSSIBLE OVER PARTS OF THE OHIO VALLEY  
AND NORTHEAST ON SUNDAY. MORE ISOLATED STRONG TO SEVERE STORMS WILL  
ALSO BE POSSIBLE ACROSS FRONT RANGE AND CENTRAL PLAINS...THE  
SOUTHWEST...AS WELL AS OREGON.  
   
..SYNOPSIS  
 
A STRONG POSITIVE-TILT MID/UPPER TROUGH AND ASSOCIATED DEEP-LAYER  
CYCLONE WILL UNDERGO AMPLIFICATION/DEEPENING FROM JAMES BAY  
SOUTHWEST TO THE NORTHERN PLAINS/UPPER MS VALLEY REGIONS THROUGH  
SUNDAY. A LEADING SHORTWAVE TROUGH ON THE EASTERN FLANK OF THE  
AMPLIFYING UPPER LOW WILL TRACK FROM THE GREAT LAKES ACROSS THE  
NORTHEAST AND SOUTHERN QUEBEC AS A STRONGER SHORTWAVE IMPULSE PIVOTS  
AROUND THE WESTERN FLANK OF THE UPPER LOW AND DIGS SOUTH ACROSS THE  
NORTHERN PLAINS AND UPPER MS VALLEY THROUGH MONDAY MORNING. BETWEEN  
THESE TWO SHORTWAVES...A BELT OF MODEST CYCLONIC AND DIFLUENT FLOW  
ALOFT WILL EXTEND FROM THE DAKOTAS ACROSS THE GREAT LAKES TO  
NORTHERN NEW ENGLAND...COINCIDENT WITH A LEADING SURFACE COLD  
FRONTAL SURGE. A WARM/MOIST CONVEYOR BELT WILL EXIST AHEAD OF THIS  
LEADING FRONT...FROM THE MIDWEST/OH VALLEY NORTHEAST TO NY/NEW  
ENGLAND.  
 
A SECONDARY COLD FRONT ASSOCIATED WITH AFOREMENTIONED STRONGER  
SHORTWAVE TROUGH AND DEEPENING UPPER LOW WILL SPREAD SOUTH AND EAST  
FROM THE UPPER MS VALLEY AND IA TO THE UPPER MIDWEST THROUGH EARLY  
MONDAY. ELSEWHERE...A MID-LEVEL ANTICYCLONE WILL REMAIN CENTERED  
ACROSS THE GREAT BASIN WHILE A COMPACT SHORTWAVE TROUGH ACTS TO  
BREAK DOWN THE UPPER RIDGE ACROSS THE PACIFIC NORTHWEST.  
   

   
..OH VALLEY  
 
AN AXIS OF STRONGER INSTABILITY /MLCAPE 1500-2500 J PER KG/ BUT  
WEAKER FLOW/SHEAR WILL EXIST FARTHER SOUTHWEST AHEAD OF THE FRONTAL  
SURGE...FROM WESTERN PA WESTWARD ACROSS THE MIDWEST AND OH VALLEY.  
NONETHELESS...HEIGHT FALLS WILL CONTRIBUTE TO ASCENT ACROSS THESE  
AREAS AS MID-LEVEL FLOW STRENGTHENS COINCIDENT WITH DIURNAL  
DESTABILIZATION AND STORM INITIATION. EXPECT ONE OR MORE WEST-EAST  
BANDS OF CONVECTION TO EVOLVE THROUGH THE LATE AFTERNOON WITH  
DAMAGING WINDS LIKELY BECOMING THE PRIMARY HAZARD.  

 

[Stebo]

Ahh the old Michigan 2-step...

[IWXwx]

Ahh the old Michigan 2-step...

 

LAF and FWA are in the same boat.  The SPC givith and the SPC taketh away.

 

That'll teach Tim to think he can be successful in starting a thread about summer weather.

 

Meanwhile, it looks like once again, Iowa and Northern IL could be the big winners which seems to be the severe story of 2014.

[andyhb]

06z NAM is pretty nasty looking across IA this afternoon/evening (00z Euro looked decent as well)...meanwhile the roadrunner speed 06z GFS brings the stronger parameters to Chicago already by 00z.

 

2014 models FTW.

 

Have to think the I-80 corridor from Des Moines to Iowa City/Cedar Rapids to DVN might get something noteworthy assuming the slower projections are on the right track.

[A-L-E-K]

I think somewhere in the middle is the way to go. EIther way, looks like a nice event from the I80 corridor from IA to the southern suburbs of Chicago

 

Should do well on the garden variety/heavy rain threat up this way

[A-L-E-K]

lots of towers and popcorn convection pushing in with another complex from IA right on its heels…but we should still clear out by mid afternoon

[LizardMafia]

LAF and FWA are in the same boat.  The SPC givith and the SPC taketh away.

 

That'll teach Tim to think he can be successful in starting a thread about summer weather.

 

Meanwhile, it looks like once again, Iowa and Northern IL could be the big winners which seems to be the severe story of 2014.

[Chicago WX]

Ha, we suck at thunderstorms, let alone severe weather this year in the LAF. Knew we were screwed all along.

 

Anyways, for those that are in the threat area...Iowa, southern WI, northern IL, northwest IN, and southwest lower MI peeps...newest day one outlook.

 

 

 

 

 

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0758 AM CDT SAT JUL 12 2014  
 
VALID 121300Z - 131200Z  
 
...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL PLAINS TO SRN  
LM AND ADJACENT LAND AREAS...  
   
..SUMMARY  
 
ISOLATED TO SCATTERED SEVERE STORMS ARE ANTICIPATED FROM PARTS OF  
THE MID-MISSOURI VALLEY TO THE SOUTHERN LAKE MICHIGAN REGION DURING  
THE LATE AFTERNOON INTO TONIGHT. DAMAGING WINDS SHOULD BE THE  
PRIMARY HAZARD...BUT SEVERE HAIL AND A TORNADO OR TWO WILL BE  
POSSIBLE.  
 
--- TECHNICAL DISCUSSION ---  
   
..SYNOPSIS  
 
IN MID-UPPER LEVELS...SYNOPTIC-SCALE RIDGE IS FCST TO AMPLIFY ACROSS  
ERN NORTH AMERICA...WITH 500-MB ANTICYCLONE BUILDING OVER GREAT  
BASIN. DOWNSTREAM CYCLONE IS FCST TO MEANDER ACROSS NRN/NERN  
AB...AS STG/ATTACHED SHORTWAVE TROUGH MOVES SEWD FROM CURRENT  
POSITION OVER NRN SK. LATTER TROUGH SHOULD REACH SERN MB AND NERN  
ND BY 00Z...THEN PIVOT CYCLONICALLY TO NWRN ONT AND LS BY END OF  
PERIOD. SMALL SHORTWAVE TROUGH -- INITIALLY LOCATED OVER SRN SD/NRN  
NEB -- SHOULD MOVE EWD ACROSS UPPER MS VALLEY TO WI/LM BY 00Z. THIS  
FEATURE THEN WILL ACCELERATE NEWD AND WEAKEN CONSIDERABLY...AS  
HEIGHTS FALL IN ADVANCE OF MUCH MORE INTENSE CANADIAN PERTURBATION.  
 
AT SFC...COLD FRONTOGENESIS IS EXPECTED OVER CANADIAN PRAIRIE  
PROVINCES...WITH RESULTING BOUNDARY MOVING QUICKLY SEWD OVER  
PORTIONS ND/ERN MT BY 00Z. MEANWHILE...WAVY...MOSTLY  
QUASISTATIONARY FRONT WAS EVIDENT IN 12Z ANALYSIS FROM LS SWWD  
ACROSS SRN MN...N-CENTRAL NEB...THROUGH WEAK FRONTAL-WAVE LOW OVER  
SWRN NEB...TO ANOTHER WEAK LOW IN SERN CO. ERN LOW SHOULD MOVE EWD  
TO ERN NEB/SWRN IA BY 00Z...THEN TO NEAR SRN LM AT 12Z. BY THAT  
TIME...FRONTS MAY MERGE OVER LOWER MI...WITH SRN BOUNDARY EXTENDING  
SWWD ACROSS NRN MO...ERN KS AND OK PANHANDLE...AND STRONGER/NRN  
FRONT ACROSS WI...SRN MN/NRN IA...SD AND CENTRAL/ERN MT.  
   
..CENTRAL PLAINS TO SRN LM AND ADJACENT LAND AREAS  
 
DECAYING CONVECTION IS ONGOING FROM PARTS OF DAKOTAS TO  
IL...EXTENDING WNWWD FROM MERIDIONAL BAND OF ELEVATED TSTMS OVER ERN  
IL ATTM. STG INSOLATION IS EXPECTED S OF ASSOCIATED CLOUD COVER  
TODAY...WHICH SHOULD THIN AND BREAK UP THROUGHOUT AFTN PERMITTING  
AIR MASS RECOVERY N OF CURRENT OUTFLOW/BAROCLINIC BOUNDARY OVER SRN  
IA. SCATTERED TSTMS ARE EXPECTED TO DEVELOP THIS AFTN OVER PORTIONS  
NEB/IA...MOVING EWD TO ESEWD WITH EARLY WIND/HAIL THREAT BEFORE  
CONGEALING INTO ONE OR TWO PRIMARY COMPLEXES. LATTER CONVECTION  
THEN WILL OFFER DAMAGING GUSTS AND ISOLATED LARGE HAIL.  
 
SFC ANALYSIS SHOWS AXIS OF UPPER 60S TO 70S F SFC DEW POINTS...FROM  
WRN GULF NNEWD ACROSS MO TO WRN IL THEN NWWD ACROSS IA TO SUX/FSD  
REGION. ACCOMPANYING BOUNDARY-LAYER MOIST PLUME CONTRIBUTES TO  
1.75-2 INCH PW...WITH ISOLATED VALUES EXCEEDING 2 INCHES. THIS WILL  
SUPPORT PRECONVECTIVE MLCAPE IN 1500-3000 J/KG RANGE BY LATE  
AFTN...WITH STRONGEST LOW-LEVEL SHEAR...LARGEST HODOGRAPHS AND  
GREATEST STORM-RELATIVE INFLOW VECTORS LOCATED ALONG AND N OF  
RESIDUAL BOUNDARY. 45-55 KT EFFECTIVE-SHEAR MAGNITUDES AND 0-3 KM  
SRH 200-300 J/KG MAY DEVELOP...THOUGH WEAK SFC WINDS SHOULD LIMIT  
0-1-KM HODOGRAPH SIZE. STILL...SOME SUPERCELLS ARE POSSIBLE BEFORE  
CONVECTION AGGREGATES INTO MCS MODE.  
 
CLOUD COVER/PRECIP RELATED TO MORNING CONVECTION WILL CAUSE ERN  
PORTIONS CATEGORICAL OUTLOOK AREA TO TAKE LONGER TO DESTABILIZE.  
NONETHELESS...PRIND SUFFICIENT THETAE ADVECTION AND RELATED  
MOISTURE/BUOYANCY RECOVERY WILL OCCUR BY LATE/EVENING/OVERNIGHT  
HOURS...SUPPORTING POTENTIAL EWD MOVEMENT OF MCS ACROSS SRN LM  
REGION.

[Gilbertfly]

solid PWAT's available region wide to assist later and satellite loop is encouraging in eastern Iowa at the moment

[Powerball]

Ahh the old Michigan 2-step...

 

 

We gotta get these systems to come through at a more ideal time, versus the early morning hours.

 

Though, as the derecho from a week or so ago showed, the relatively stron dynamics can very well make up for the marginal instability. 

[A-L-E-K]

Going to end up with over an inch from this morning, so anything that falls later will be trouble.

 

the signs for w-e back building along a slow moving front are concerning

[A-L-E-K]

Actually getting some decent gusts with this batch of heavy rain…minor street flooding occurring already

[McDude]

It's raining

[Gilbertfly]

Actually getting some decent gusts with this batch of heavy rain…minor street flooding occurring already

 

As that line went overhead it provided just heavy rain with 2 or 3 lightning strikes as it was moving out....but since I have been hearing near constant rumbling to my east....it sure did pick up a little "gusto" as it progressed east...In-laws in NW IL (Jo Davies County) just texted me that they have a few spots of clearing here and there already starting to mix in

[A-L-E-K]

As that line went overhead it provided just heavy rain with 2 or 3 lightning strikes as it was moving out....but since I have been hearing near constant rumbling to my east....it sure did pick up a little "gusto" as it progressed east...In-laws in NW IL (Jo Davies County) just texted me that they have a few spots of clearing here and there already starting to mix in

 

 

HRRR has a good handle with ongoing action….gets us quite unstable later with a nice MCS organizing over the IA/WI/IL border region

[Thundersnow12]

HRRR has a good handle with ongoing action….gets us quite unstable later with a nice MCS organizing over the IA/WI/IL border region

With plenty of sfc based instability still hanging around and sky high sig tor parameters at least on the HRRR. Tail end Charlie or any discrete storm might be interesting further west

[tornadotony]

With plenty of sfc based instability still hanging around and sky high sig tor parameters at least on the HRRR. Tail end Charlie or any discrete storm might be interesting further west

I'm concerned about the 4km NAM showing what may be quasi-discrete convection in the metro later.  This seems like a situation where there might be an unwelcomed lake-driven baroclinicity-induced surprise in the metro or NWI this evening.

[A-L-E-K]

whoa, i hadn't even seen the 4km NAM, big time run