July 26-27 Severe Threat

[Stebo]

Could be a good chasing opportunity for Stebo on his way home from the conference. Well, other than a lot of the terrain not being very favorable for chasing.

If I didn't already have plans for Sunday I would consider it, my concern though is exactly what you mention, the terrain and subsequently the cell/data network is sparse at best outside of the freeway system. It would be a very difficult chase especially alone, plus the location I am going to in central PA will more than likely experence some severe weather that evening. Now if you were discussing western Ohio vs eastern Ohio I would cancel my plans. Overall with respect to the potential Sunday, I can't think of any July potentials with this high of a ceiling. You just don't get 70kts at 500mb this time of year.

[Powerball]

Something tells me that this MIGHT (although unlikely) be another derecho event.  Not sure if it'll turn out that way, though.  Could be rough for cities such as Peoria, Illinois and Indianapolis, Indiana.  Which, a matter of fact, Peoria has escaped major severe weather so far this year.  That could end tomorrow, though...

 

EDIT: One really sad fact is that NWS Lincoln does not yet have SAILS installed.

 

^^^This may be a good call.

 

The storms in SD will probably evolve into the main action for later today...

[TimChgo9]

Day 1 has the SLGT risk cutting off the N 1/3 of Cook County, but everything below that is in the risk area, but I am thinking we might get some storms later, but the main action will be way south. I wouldn't be surprised if they drop the N edge of the risk area south of I-80 in later updates.

[Hvward]

Not sure where to put this but the cell near Stickney/Storia, SD is really getting going. Classic supercell look but there is a bit of range folding on velocity radar. Radar to the north showing decent couplet. Strong storm for 9:30am in that area. Could possibly be tor warned. Also showing possible debris ball on CC.

 

next CC scan:

[TimChgo9]

Currently 75 here, 81% humidity and dew point of 68.  Area of decent CAPE moving into the southern sections of the forecast area, but there seems to be a decent cap with this as well.

[andyhb]

Also showing possible debris ball on CC.

 

It's not a TDS.

[Thunder Road]

Not sure where to put this but the cell near Stickney/Storia, SD is really getting going. Classic supercell look but there is a bit of range folding on velocity radar. Radar to the north showing decent couplet. Strong storm for 9:30am in that area. Could possibly be tor warned. Also showing possible debris ball on CC.

 

next CC scan:

 

Other criteria have to be met for a TDS.  Region of low CC needs to be bounded, and coincident with a ZDR near 0 (and of course a couplet in BV).  Typically inflow dust will lower CC values over a broad region, which is what you're seeing.

[Hvward]

It's not a TDS.

 

 

Other criteria have to be met for a TDS.  Region of low CC needs to be bounded, and coincident with a ZDR near 0 (and of course a couplet in BV).  Typically inflow dust will lower CC values over a broad region, which is what you're seeing.

 

Thanks for clarify guys.  Still a pretty intense storm with large hail.  Velocity was almost out of range so thought it would be interesting to discuss.  Interesting to learn about the inflow dust on CC, thanks for the education.  Much appreciated!

[Central Illinois]

Edit:11am update Full sunshine here Temp83/Dew72

[TimChgo9]

Sun is coming out here. 

Temp 77.

DewPoint 68

Humditiy 72%

Wind: Calm. 

[JasonOH]

Sun is fully out in Middletown, OH (30 miles north of Cincy)

[eureka22]

Solid overcast here for the past couple of hours.  ILX updated the zones to add severe wording but notes the clouds may limit heating and instability over the north part of the CWA.

 

Area Forecast Discussion

National Weather Service Lincoln IL

1045 AM CDT Sat Jul 26 2014

 

.DISCUSSION...

ISSUED 1045 AM CDT Sat Jul 26 2014

Update the forecast to include the mention of severe thunderstorms

possible late this afternoon sw counties and across area this evening.

SPC has moderate risk of severe storms late this afternoon and

evening across central IL except slight risk over Stark, Marshall

and northern Knox counties. Has 5% risk of tornadoes, 30% risk of

large hail (10% risk of 2 inch or larger hail) and 45% risk of

damaging wind gusts.

Also trended pops lower through early afternoon and higher late

this afternoon and evening. Most of central IL has been dry so far

this morning. Low clouds have spread into nw counties by late

morning and this may limit heating and instability. Kept highs in

the upper 80s and lower 90s with afternoon heat indices peaking

from 95 to 103F, lowest north of Peoria where more low clouds found.

 

A frontal boundary over NW IL and near the IA/MO border will press

se into central IL later this afternoon and tonight and collide

with an increasingly unstable airmass with CAPES projects to

surpass 3000 j/kg and bulk shear rising to 40-50 kts by 00Z/7 pm.

07

[Central Illinois]

Moderate Risk expanded to the West to include S IA and N MO also they shaved some off the SE side of the moderate

[snowlover2]

New day 1

 

 

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1128 AM CDT SAT JUL 26 2014  
 
VALID 261630Z - 271200Z  
 
...THERE IS A MDT RISK OF SVR TSTMS FROM SOUTHERN IA/NORTHERN  
MO...ACROSS CENTRAL IL...INTO CENTRAL/SOUTHERN IND...  
 
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE MID MS AND  
OH VALLEYS...  
   
..SUMMARY  
 
SEVERE STORMS...SOME ACCOMPANIED BY VERY LARGE HAIL...DAMAGING GUSTS  
AND A COUPLE OF TORNADOES ARE EXPECTED LATER THIS AFTERNOON INTO  
TONIGHT FROM EASTERN NEBRASKA TO PARTS OF THE MIDDLE MISSISSIPPI AND  
LOWER OHIO VALLEYS. THE MOST CONCENTRATED RISK AREA SHOULD BE THIS  
EVENING INTO TONIGHT FROM SOUTHERN IOWA AND NORTHERN  
MISSOURI...ACROSS CENTRAL ILLINOIS...AND INTO CENTRAL/SOUTHERN  
INDIANA...WHERE ONE OR MORE ORGANIZED THUNDERSTORM CLUSTERS COULD  
PRODUCE SWATHS OF DAMAGING WINDS. THE DAMAGING WIND RISK COULD  
REACH AS FAR AS SOUTHERN OHIO AND NORTHERN KENTUCKY OVERNIGHT.  
 
...POTENTIAL FOR MULTIPLE SEVERE THUNDERSTORM COMPLEXES TO AFFECT  
PARTS OF MID/UPPER MS VALLEY INTO OH VALLEY TODAY AND TONIGHT...  
 
MORNING WATER VAPOR LOOPS SHOW THE PRIMARY BAND OF WESTERLIES  
EXTENDING ACROSS THE NORTHERN PLAINS INTO THE GREAT LAKES REGION. A  
STRONG UPPER LOW OVER SASK/MANITOBA WILL DEVELOP  
SOUTHEASTWARD...WHILE SEVERAL SMALLER SHORTWAVE TROUGHS TRAVEL  
ACROSS THE MID/UPPER MS VALLEY INTO THE GREAT LAKES. THE RESULT  
WILL BE SEVERAL POTENTIAL AREAS OF CONCERN FOR SEVERE STORMS  
TODAY...AND HIGHER-THAN-USUAL UNCERTAINTY REGARDING WHICH CLUSTER  
WILL BE OF GREATEST RISK.  
   
..SD/NEB/WESTERN IA THIS AFTERNOON  
 
AN INTENSE THUNDERSTORM CLUSTER HAS FORMED THIS MORNING OVER  
SOUTHEAST SD. THESE STORMS ARE EXPECTED TO TRACK SOUTHEASTWARD  
THROUGH THE LATE MORNING AND AFTERNOON ACROSS EASTERN NEB AND  
WESTERN IA. THE STORMS HAVE NOT SHOWN ANY SIGNS OF WEAKENING...BUT  
IT REMAINS UNCERTAIN IF THIS CLUSTER IS THE START OF A LARGER  
LONG-LIVED BOW ECHO EVENT...OR IF THE OUTFLOW FROM THESE STORMS WILL  
EVENTUALLY LEAD TO UPSCALE GROWTH LATER TODAY. REGARDLESS...VERY  
LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE THROUGH THE  
AFTERNOON.  
   
..MO/IL THIS AFTERNOON  
 
A WEAK REMNANT MCV IS NOTED IN VISIBLE SATELLITE IMAGERY OVER  
NORTHEAST KS. SCATTERED SHOWERS AND THUNDERSTORMS HAVE BEGUN TO  
FORM AHEAD OF THIS FEATURE OVER WESTERN MO. 12Z MODEL SOLUTIONS  
LEND LESSENED CONFIDENCE THAT THIS GROUP OF CONVECTION WILL BECOME  
AN ORGANIZED SEVERE-PRODUCING SYSTEM. HOWEVER...AMPLE MOISTURE/CAPE  
AND INCREASING WINDS ALOFT INDICATE THE RISK OF UPSCALE-GROWTH DOES  
EXIST. IF THESE STORMS MATURED...THEY WOULD LIKELY POSE A RISK OF  
SEVERE WIND AND HAIL ACROSS MO INTO IL.  
   
..NORTHERN IL INTO OH THIS AFTERNOON  
 
A SMALL-SCALE VORTICITY MAX IS SHOWN IN MOST 12Z INITIALIZATIONS  
OVER SOUTHERN MN. THIS FEATURE IS EXPECTED TO TRACK SOUTHEASTWARD  
ACROSS NORTHERN IL THIS AFTERNOON AND EVENTUALLY INTO THE OH VALLEY  
THIS EVENING. STRONG INSTABILITY IS DEVELOPING AHEAD OF THIS  
SYSTEM...AND IT APPEARS LIKELY THAT SCATTERED THUNDERSTORMS WILL  
DEVELOP BY MID AFTERNOON. IF THIS SCENARIO OCCURS...ISOLATED SEVERE  
STORMS INCLUDING DAMAGING WINDS AND HAIL COULD OCCUR IN THIS REGION  
THROUGH THE EVENING.  
   
..MO/IL/IND THIS EVENING  
 
MODELS SOLUTIONS ARE QUITE DIVERSE REGARDING THE LOCATION AND TIMING  
OF STRONG CONVECTION BY THIS EVENING. HOWEVER...GIVEN THE MESOSCALE  
ORGANIZATION OF THE SYSTEM OVER NEB...IT APPEARS PROBABLE THAT THIS  
CLUSTER OR A REMNANT OUTFLOW WILL CONTINUE TO BE A RISK OF SEVERE  
WIND AND HAIL THROUGH THE EVENING. ITS UNCLEAR WHICH OF THE  
AFOREMENTIONED CONVECTIVE CLUSTERS WILL BECOME A DOMINANT RISK  
TODAY...BUT THIS SCENARIO WOULD LIKELY POSE THE GREATEST RISK OF  
WIDESPREAD DAMAGING WINDS THIS EVENING AND TONIGHT ACROSS THE  
MODERATE RISK AREA.  
 
..HART/ROGERS.. 07/26/2014  

 

[Hoosier]

Some hailers this morning, slipping by to my southwest. 1" reported in Covington (Fountain County). Cell still warned as it passes to the west of Indy.

 

Looks like most of the recent model guidance has tonight's action to the south of LAF. I guess I shouldn't be surprised by that.

 

 

I'd rather be farther south tonight.  I'd also like to get rid of these clouds.

[Powerball]

I'd rather be farther south tonight.  I'd also like to get rid of these clouds.

 

I imagine the sharp cutoff in the cloud cover will only help to improve low-level covergence (via a differential heating boundary) this afternoon, when the t'storms do arrive or get going...

 

[Tim from Springfield (IL)]

Solid overcast here for the past couple of hours.  ILX updated the zones to add severe wording but notes the clouds may limit heating and instability over the north part of the CWA.

 

Area Forecast Discussion

National Weather Service Lincoln IL

1045 AM CDT Sat Jul 26 2014

 

.DISCUSSION...

ISSUED 1045 AM CDT Sat Jul 26 2014

Update the forecast to include the mention of severe thunderstorms

possible late this afternoon sw counties and across area this evening.

SPC has moderate risk of severe storms late this afternoon and

evening across central IL except slight risk over Stark, Marshall

and northern Knox counties. Has 5% risk of tornadoes, 30% risk of

large hail (10% risk of 2 inch or larger hail) and 45% risk of

damaging wind gusts.

Also trended pops lower through early afternoon and higher late

this afternoon and evening. Most of central IL has been dry so far

this morning. Low clouds have spread into nw counties by late

morning and this may limit heating and instability. Kept highs in

the upper 80s and lower 90s with afternoon heat indices peaking

from 95 to 103F, lowest north of Peoria where more low clouds found.

 

A frontal boundary over NW IL and near the IA/MO border will press

se into central IL later this afternoon and tonight and collide

with an increasingly unstable airmass with CAPES projects to

surpass 3000 j/kg and bulk shear rising to 40-50 kts by 00Z/7 pm.

07

 

Speaking of ILX-- I meant to quote this earlier but unless they were seeing something we're not or have been totally missing the boat on today's threat until late this morning, I am surprised that their 6AM HWO (quoted below) seemed to pooh-pooh today's severe threat in spite of the 0100 outlook putting almost all of their CWA in a Moderate Risk.  Normally they would always have conference calls any time there was a moderate risk--but their earlier HWO barely mentioned severe:

 

000FLUS43 KILX 261102HWOILXHAZARDOUS WEATHER OUTLOOKNATIONAL WEATHER SERVICE LINCOLN IL602 AM CDT SAT JUL 26 2014ILZ027>031-036>038-040>057-061>063-066>068-071>073-271100-CASS-CHAMPAIGN-CHRISTIAN-CLARK-CLAY-COLES-CRAWFORD-CUMBERLAND-DE WITT-DOUGLAS-EDGAR-EFFINGHAM-FULTON-JASPER-KNOX-LAWRENCE-LOGAN-MACON-MARSHALL-MASON-MCLEAN-MENARD-MORGAN-MOULTRIE-PEORIA-PIATT-RICHLAND-SANGAMON-SCHUYLER-SCOTT-SHELBY-STARK-TAZEWELL-VERMILION-WOODFORD-602 AM CDT SAT JUL 26 2014THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRALILLINOIS...EAST CENTRAL ILLINOIS AND SOUTHEAST ILLINOIS..DAY ONE...TODAY AND TONIGHTSEVERE THUNDERSTORMS ARE LIKELY ACROSS CENTRAL AND SOUTHEASTILLINOIS...MAINLY THIS AFTERNOON AND EVENING. SEVERE WIND GUSTSOF 60 TO 75 MPH ARE THE GREATEST THREAT...WITH SOME POTENTIAL OFGUSTS OVER 75 MPH. IN ADDITION LARGE HAIL AND ISOLATED TORNADOESARE POSSIBLE...MAINLY IN THE AFTERNOON AND EARLY EVENING.HOT AND HUMID CONDITIONS ARE ALSO EXPECTED THIS AFTERNOON.HEAT INDICES AROUND 100 DEGREES WILL APPROACH HAZARDOUS LEVELSFOR PROLONGED EXPOSURE OR PHYSICAL ACTIVITY..DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAYISOLATED THUNDERSTORMS ARE AGAIN POSSIBLE ON SUNDAY..SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING.$$ONTON

[eureka22]

ILX did have a conference call at 11AM.  I didn't know about it either until I saw someone comment on it in NWSChat.

[Chicago WX]

I'd rather be farther south tonight.  I'd also like to get rid of these clouds.

 

Yep. Socked in solid overcast right now.

 

Pretty juicy to the west though (70+ dewpoints galore).

 

[Hoosier]

Moderate risk shifted north for tomorrow.  Also, the slight risk was expanded north to include more of MI.

[snowlover2]

Moderate risk shifted north for tomorrow.  Also, the slight risk was expanded north to include more of MI.

And west a bit.

 

 

DAY 2 CONVECTIVE OUTLOOK  

NWS STORM PREDICTION CENTER NORMAN OK  

1230 PM CDT SAT JUL 26 2014  

 

VALID 271200Z - 281200Z  

   

..THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF OH  

NE KY AND  

WV...  

 

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE OH  

VALLEY...TN VALLEY...MID-ATLANTIC...PA...NY AND SRN NEW ENGLAND...  

   

..SUMMARY  

 

TORNADOES...DAMAGING WINDS AND LARGE HAIL ARE EXPECTED ACROSS MUCH  

OF EASTERN KENTUCKY...SOUTHERN OHIO AND WEST VIRGINIA DURING THE  

AFTERNOON AND EVENING. SEVERE WEATHER IS ALSO EXPECTED ACROSS MUCH  

OF THE MID-ATLANTIC AND NORTHEASTERN STATES WITH MAINLY DAMAGING  

WINDS AND HAIL. ISOLATED HAIL AND WIND IS ALSO POSSIBLE ACROSS  

SOUTHEASTERN ARIZONA.  

   

..OH VALLEY/SRN GREAT LAKES AND CNTRL APPALACHIAN MTNS  

 

A POSITIVELY-TILTED UPPER-LEVEL TROUGH WILL MOVE SEWD ACROSS THE WRN  

GREAT LAKES ON SUNDAY AS A WELL-DEFINED 60 TO 75 KT MID-LEVEL JET  

MOVES OVER THE MID MS VALLEY AND INTO THE OH VALLEY. AT THE SFC...A  

LOW WILL DEEPEN AND MOVE SEWD ACROSS THE GREAT LAKES REGION AS A  

COLD FRONT ADVANCES EWD INTO THE OH AND TN VALLEYS. THUNDERSTORMS  

MAY BE ONGOING ACROSS PARTS OF THE UPPER OH VALLEY AT THE START OF  

THE PERIOD. THIS ACTIVITY SHOULD EXPAND IN COVERAGE AS SFC TEMPS  

WARM AND MODERATE TO STRONG INSTABILITY DEVELOPS ACROSS MUCH OF THE  

OH VALLEY. SEVERAL CONVECTIVE CLUSTERS ARE FORECAST TO ORGANIZE  

DURING THE AFTERNOON WITH MODEL FORECASTS EXPANDING CONVECTIVE  

DEVELOPMENT NWD INTO THE SRN GREAT LAKES REGION AND NEWD ACROSS THE  

CNTRL APPALACHIAN MTNS BY LATE AFTERNOON. THE APPROACHING  

UPPER-LEVEL TROUGH AND ASSOCIATED MID-LEVEL JET ALONG WITH MODERATE  

TO STRONG INSTABILITY MAY SUPPORT THE DEVELOPMENT OF NUMEROUS SEVERE  

THUNDERSTORMS WITH THE POSSIBILITY FOR TORNADOES ACROSS PARTS OF THE  

OH VALLEY AND CNTRL APPALACHIAN MTNS FROM MIDDAY SUNDAY PERSISTING  

INTO THE AFTERNOON AND EVENING.  

 

NAM FORECAST SOUNDINGS ACROSS THE MODERATE RISK AREA FOR HUNTINGTON  

AND CHARLESTON WV AT 21Z/MON SHOW IMPRESSIVE THERMODYNAMIC AND SHEAR  

PROFILES. SFC DEWPOINTS ARE FORECAST TO BE IN THE LOWER 70S F WITH  

MLCAPE VALUES INCREASING INTO THE 2000 TO 3000 J/KG RANGE. IN  

ADDITION...0-6 KM SHEAR IS FORECAST TO BE IN THE 50 TO 60 KT RANGE  

WITH SHEAR GRADUALLY INCREASING DURING THE AFTERNOON. THIS SHOULD  

EASILY SUPPORT SUPERCELL DEVELOPMENT AS THE EXIT REGION OF THE  

MID-LEVEL JET OVERSPREADS THE MODERATE RISK AREA. THE STRONG SHEAR  

PROFILES SHOULD HELP MAINTAIN DISCRETE CELLS AND SUPERCELLS WILL BE  

LIKELY EVEN AS STORM COVERAGE INCREASES AND CELL MERGERS OCCUR  

DURING THE AFTERNOON. FORECAST SOUNDINGS ALSO SHOW 0-3 KM STORM  

RELATIVE HELICITIES IN THE 300 TO 400 M2/S2 SUGGESTING LOW-LEVEL  

SHEAR WILL BE FAVORABLE FOR TORNADOES. THE GREATEST POTENTIAL FOR  

SUPERCELLS WITH TORNADO POTENTIAL IS FORECAST TO BE WHERE THE EXIT  

REGION OF THE MID-LEVEL JET INTERSECTS THE LOW-LEVEL JET IN OH...ERN  

KY AND WV. A STRONG TORNADO OR TWO WILL BE POSSIBLE WITH THE MORE  

DOMINANT SUPERCELL STORMS. ANY STORM THAT CAN ROTATE WILL ALSO BE  

CAPABLE OF PRODUCING LARGE HAIL AND WIND DAMAGE. BOWING LINE  

SEGMENTS WITH WIND DAMAGE POTENTIAL SHOULD ALSO DEVELOP SUNDAY  

AFTERNOON IN THE MODERATE RISK AREA. THE SEVERE THREAT SHOULD ALSO  

IMPACT THE SRN GREAT LAKES AND PARTS OF THE TN VALLEY SUNDAY  

AFTERNOON WITH THE THREAT INCREASING ACROSS MD AND PA DURING THE  

LATE AFTERNOON. 

[Powerball]

Moderate risk shifted north for tomorrow.  Also, the slight risk was expanded north to include more of MI.

 

Yep. 

 

Detroit's in the 30% risk area now.

 

But we still have to get through today though to see what will happen tomorrow. 

[Hoosier]

Easier thresholds aside, it's pretty impressive to see this so far south in late July.

 

 

[Hoosier]

 

 

[Powerball]

BTW, with that impressive vorticity maximum advecting into what will be a very unstable atmosphere, I suspect the storms tomorrow could be fairly prolific lightning producers.

[geddyweather]

Sun has now broken out... As a result, lots of spotty, strong storms forming over northern Indiana and NW Ohio.

[Powerball]

http://www.spc.noaa.gov/products/md/md1469.html

 

4

 

MESOSCALE DISCUSSION 1469
NWS STORM PREDICTION CENTER NORMAN OK
0141 PM CDT SAT JUL 26 2014

AREAS AFFECTED...NERN IND...WRN/CNTRL OH

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 261841Z - 261945Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...ISOLATED TSTMS ARE DEVELOPING ACROSS NERN IND AND NWRN OH
THIS AFTERNOON. AN ACCOMPANYING THREAT FOR ISOLATED DMGG WIND GUSTS
AND LARGE HAIL IS POSSIBLE...BUT IT IS UNCERTAIN WHETHER COVERAGE
WILL BE SUFFICIENT FOR A WW.

DISCUSSION...ISOLATED TSTMS HAVE DEVELOPED OVER THE PAST 1-2 HRS
ACROSS NERN IND AND NWRN OH...AND APPEARS TO PRIMARILY BE INITIATED
BY LOW-LEVEL WARM ADVECTION AHEAD OF AN UPPER IMPULSE MOVING THROUGH
SRN WI. 18Z SFC ANALYSIS SHOWS LITTLE IN THE WAY OF ANY NOTABLE
LOW-LEVEL MESOSCALE FEATURES OR SOURCES OF CONVERGENCE. CLOUD COVER
HAS INHIBITED HEATING SOMEWHAT THIS MORNING...BUT THE AIR MASS IS
STILL RELATIVELY MOIST /SFC DEW POINTS IN THE UPPER 60S TO LOWER 70S
F/...AND LOW-LEVEL MOISTURE IS FORECAST TO ADVECT EWD WITH TIME INTO
PARTS OF WRN/CNTRL OH. AS A RESULT...ADDITIONAL DESTABILIZATION IS
LIKELY INTO THE MID-AFTERNOON...WITH MLCAPE VALUES FORECAST TO
APPROACH 1500-2000 J/KG. DEEP-LAYER SHEAR WILL BE MORE THAN
SUFFICIENT TO SUPPORT ORGANIZED CONVECTION...PERHAPS IN THE FORM OF
SUPERCELLS OR SMALL BOWING SEGMENTS...IN THE PRESENCE OF 40-50 KT OF
NWLY MIDLEVEL FLOW. AS A RESULT...AT LEAST A LOCALLY ENHANCED THREAT
FOR DMGG WIND GUSTS AND LARGE HAIL MAY ACCOMPANY SUSTAINED TSTMS
THAT DEVELOP...WITH WW ISSUANCE CONTINGENT ON WHETHER TRENDS SUGGEST
CONVECTION WILL BECOME MORE NUMEROUS OVER THE NEXT COUPLE HRS.

..ROGERS/HART.. 07/26/2014


ATTN...WFO...PBZ...RLX...CLE...ILN...IWX...IND...

LAT...LON 39298403 40148517 41188628 41538604 41498505 41608434
41528316 41098198 40398172 39808182 39298230 39018323
39298403 

[RCNYILWX]

Hellacious caps on the 18z ILX and DVN soundings. Over 500 J/kg of CINH above the LFC on the DVN sounding. Almost 200 J/kg of CINH on the ILX sounding.

Sent from my SCH-I535 using Tapatalk

[eureka22]

ILX out early with AFD, thinking they'll be a bit busy later? Storms are firing over NE MO into WC IL.

 

Area Forecast Discussion
National Weather Service Lincoln IL
157 PM CDT Sat Jul 26 2014

.DISCUSSION...
ISSUED 150 PM CDT Sat Jul 26 2014

ILX Local objective analysis as of 18z indicating the cap holding
strong across our northern forecast area where the frontal boundary
has slipped south of early this afternoon. Further south, we have
seen the cap weaken with Mixed Layer Cins down to around 100 along
the I70 corridor with Mixed Layer Capes were up to 3800 j/kg over
far west central IL where temps have climbed into the upper 80s
with dew points in the mid to upper 70s. 18z sounding from ILX and
DVN showing some moisture around 2500-3000 feet with a dry layer
from 850 to 500 mb and the cap holding strong at both locations.

SHORT TERM...Tonight through Tuesday

Storm coverage tonight the main forecast issue as all models weaken
the cap significantly this evening as the main upper level energy
starts to push into the region accompanied by cooling temperatures
aloft. HRRR and WRF-HOP ensembles were indicating the main convection
would be tracking across northern Missouri and into central to southeast
Illinois late this afternoon and evening, along the differential heating
boundary set up by the lower cloud cover. Further south, nothing but
sunshine and temps in the low to mid 90s, so quite a contrast across
central thru southeast Illinois which many times these storms tend to
propagate through. If the cap is breached there is plenty of CAPE and
Shear to interact with this evening with a fast moving QLCS still looking
more likely at least over our southern half of the forecast this evening.
Damaging winds and large hail will be the primary threats but enough
low level shear prevalent, especially near the boundary across our
northern counties, that a tornado could develop with a persistent
rotating updraft. Some of the storms could start to back-build later
this evening as the low level jet starts to back more into a southwest
to west direction increasing the threat for locally heavy rainfall.

Storms should start to edge out of our forecast area Sunday morning
as the front settles to our southeast by afternoon. Will still keep
low chance pops going, especially across the east but some fairly
decent dry air will be advecting in on a gusty west to northwest
wind during the afternoon. Cooler and much less humid air will filter
southeast into our area Monday and Tuesday as an unseasonably deep
trof settles in north of the Great Lakes.

[Chinook]

Hellacious caps on the 18z ILX and DVN soundings. Over 500 J/kg of CINH above the LFC on the DVN sounding. Almost 200 J/kg of CINH on the ILX sounding.

Sent from my SCH-I535

I did not see the DVN sounding on the SPC web page.