Indystorm Posted March 21, 2011 Share Posted March 21, 2011 LAF 65 and Goshen 45 at present. Since I'm ne of the retreating warm front I do think I might see some good hail cores in a few hours with lift from the LLJ pointed in my direction. Gil Sebenste of NIU Weather always says warm fronts can turn active at night with prolific lightning displays. Link to comment Share on other sites More sharing options...
Indystorm Posted March 21, 2011 Share Posted March 21, 2011 BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 754 PM CDT SUN MAR 20 2011 THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHERN COOK COUNTY IN NORTHEAST ILLINOIS... SOUTHERN DUPAGE COUNTY IN NORTHEAST ILLINOIS... NORTHWESTERN WILL COUNTY IN NORTHEAST ILLINOIS... * UNTIL 815 PM CDT * AT 746 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE... OR 1 INCH DIAMETER...HAIL. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM YORK CENTER TO PLAINFIELD...AND MOVING EAST AT 60 MPH. * LOCATIONS IMPACTED INCLUDE... MAYWOOD...LEMONT...RIVER FOREST...BURR RIDGE...LA GRANGE...FOREST PARK...BROOKFIELD...OAK PARK...RIVERSIDE...HOMER GLEN...WILLOW SPRINGS...LYONS...BERWYN...SUMMIT...CICERO...JUSTICE...STICKNEY... ORLAND PARK...MIDWAY AIRPORT AND LINCOLN PARK. Link to comment Share on other sites More sharing options...
Fred Gossage Posted March 21, 2011 Share Posted March 21, 2011 I guess that SmartModel isn't smart enough to disguise itself from looking like a PowerPoint image. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 21, 2011 Share Posted March 21, 2011 first good lightning show of the year with those storms,no hail though. will put a video up later. Link to comment Share on other sites More sharing options...
cyclone77 Posted March 21, 2011 Share Posted March 21, 2011 Looks like we finally have initiation along the cold front near Ottumwa. Instability is on the decline though. Link to comment Share on other sites More sharing options...
OceanStWx Posted March 21, 2011 Share Posted March 21, 2011 Looks like we finally have initiation along the cold front near Ottumwa. Instability is on the decline though. Definitely has the look of something struggling against the cap. Link to comment Share on other sites More sharing options...
cyclone77 Posted March 21, 2011 Share Posted March 21, 2011 Definitely has the look of something struggling against the cap. Too bad it waited so long to initiate. Per SPC mesoscale analysis the surface cape has already dropped over 600j/kg in that area over the last few hours. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 21, 2011 Share Posted March 21, 2011 A few of them made it look like it was daytime, very nice treat. Link to comment Share on other sites More sharing options...
ksstormhunter Posted March 21, 2011 Share Posted March 21, 2011 I guess that SmartModel isn't smart enough to disguise itself from looking like a PowerPoint image. Nope, that would be the creator with lack of graphics knowledge to make it more professional looking... Link to comment Share on other sites More sharing options...
Fred Gossage Posted March 21, 2011 Share Posted March 21, 2011 Nope, that would be the creator with lack of graphics knowledge to make it more professional looking... We all gotta start somewhere. WSI didn't start with 3D fly-throughs..... Link to comment Share on other sites More sharing options...
Chicago Storm Posted March 21, 2011 Share Posted March 21, 2011 Cells in SE. Iowa further developing a bit. Tops are around 40KFT with small hail reported. Not that it matters much at this point... Link to comment Share on other sites More sharing options...
Indystorm Posted March 21, 2011 Share Posted March 21, 2011 Spectacular light show here now with rolling thunder that is impressive as well. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 21, 2011 Share Posted March 21, 2011 Cells in SE. Iowa further developing a bit. Tops are around 40KFT with small hail reported. also getting develop along the front now west of Oregon, IL with some higher echoes aloft. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 21, 2011 Share Posted March 21, 2011 tomorrow is looking pretty nice...this is for UEX tomorrow evening at 0z, look at those SR-winds. Link to comment Share on other sites More sharing options...
SmokeEater Posted March 21, 2011 Share Posted March 21, 2011 0z NAM says hello Nebraska. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 21, 2011 Share Posted March 21, 2011 taken from about a 1/4 mile south of my house looking WSW Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 21, 2011 Share Posted March 21, 2011 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1245 AM CDT MON MAR 21 2011 VALID 221200Z - 231200Z ...THERE IS A SLGT RISK OF SVR TSTMS TUE/TUE NIGHT FROM PARTS OF THE CNTRL PLAINS THROUGH THE MID MS VALLEY...SOUTHWARD INTO THE SRN PLAINS... ..SYNOPSIS MODELS REMAIN CONSISTENT CONCERNING THE LARGE-SCALE PATTERN EVOLUTION THROUGH THIS FORECAST PERIOD. A BLOCKING UPPER RIDGE IS PROGGED TO EVOLVE TO THE EAST OF THE CANADIAN ROCKIES...WITH A LARGE HIGH CENTER STRENGTHENING OVER THE CENTRAL CANADIAN PROVINCES DURING THE DAY TUESDAY. AS THIS PROCEEDS...A LARGE UPPER TROUGH...LIFTING THROUGH THE INTERMOUNTAIN WEST AND ROCKIES BY 12Z TUESDAY...SHOULD GRADUALLY BE FORCED EASTWARD INTO AN INCREASINGLY CONFLUENT REGIME ACROSS THE UPPER MIDWEST...WHILE ANOTHER AMPLIFYING SHORT WAVE TROUGH DIGS TOWARD THE CALIFORNIA COAST. WITHIN THE LEAD WAVE...A SIGNIFICANT EMBEDDED IMPULSE EMERGING FROM THE SOUTHERN ROCKIES IS STILL FORECAST TO PIVOT INTO AND NORTHEAST OF THE MID/LOWER MISSOURI VALLEY IN INCREASINGLY NEGATIVELY TILTED FASHION BY TUESDAY EVENING. THIS SHOULD RESULT IN STRONG MID-LEVEL HEIGHT FALLS OVERSPREADING THE WARM SECTOR OF A SUB 1000 MB SURFACE LOW MIGRATING ACROSS THE MID MISSOURI VALLEY AND UPPER PORTIONS OF THE MIDDLE MISSISSIPPI VALLEY. FORCING WILL BE FOCUSED ALONG AND NORTH OF A STRONG MID/UPPER JET STREAK...AROUND 90 KT AT 500 MB...WHICH WILL GRADUALLY VEER FROM A SOUTHWESTERLY TO WESTERLY COMPONENT AS IT PROPAGATES ACROSS THE SOUTH CENTRAL PLAINS/OZARK PLATEAU AND MIDDLE MISSISSIPPI VALLEY. GIVEN THE STRENGTH OF THE LARGE-SCALE FORCING FOR UPWARD VERTICAL MOTION...AND THE SIZE OF THE AREA THAT IT COULD IMPACT...A CONSIDERABLE INCREASE IN CONVECTIVE POTENTIAL IS ANTICIPATED ACROSS MUCH OF THE PLAINS...THE MID/UPPER MISSISSIPPI AND OHIO VALLEYS AND UPPER GREAT LAKES REGION. COUPLED WITH THE LIKELIHOOD THAT THIS WILL BE PRECEDED BY THE EASTWARD ADVECTION OF WARM ELEVATED MIXED LAYER AIR THROUGH MUCH OF CENTRAL U.S...THE RISK FOR SEVERE THUNDERSTORMS COULD BE SUBSTANTIAL...AS VERTICAL SHEAR BECOMES STRONG. HOWEVER...IT STILL APPEARS THAT THIS POTENTIAL MAY NOT BE FULLY REALIZED. OBSERVATIONAL AND MODEL DATA CONTINUE TO INDICATE THAT A SUBSTANTIVE INLAND INCREASE IN BOUNDARY LAYER MOISTURE OFF THE GULF OF MEXICO TO THE WARM SECTOR OF THE LOW IS UNLIKELY...THROUGH AT LEAST THIS PERIOD...AS LOW-LEVEL RIDGING IS SLOW TO LOSE INFLUENCE OVER THE CENTRAL AND EASTERN GULF. STILL...LOW-LEVEL MOISTURE CHARACTERIZED BY MID 50S TO LOWER 60S SURFACE DEW POINTS SHOULD BE SUFFICIENT TO SUPPORT SEVERE THUNDERSTORMS...WHICH COULD BECOME FAIRLY NUMEROUS OR WIDESPREAD ACROSS UPPER PORTIONS OF THE MIDDLE MISSISSIPPI VALLEY LATE TUESDAY AFTERNOON AND EVENING. ..PLAINS/MISSISSIPPI VALLEY CONFIDENCE IS GREATER THAT SURFACE DEW POINTS NEAR OR JUST ABOVE 60F MAY BECOME COMMON IN A CORRIDOR FROM NEAR THE SURFACE CYCLONE EAST SOUTHEASTWARD ALONG A STALLED FRONTAL ZONE EXTENDING INTO THE OHIO VALLEY. BENEATH THE NOSE OF A PLUME OF ELEVATED MIXED LAYER AIR...THIS IS EXPECTED TO BE SUFFICIENT TO CONTRIBUTE TO MIXED LAYER CAPE IN EXCESS OF 1000 J/KG...NEAR THE MISSOURI RIVER EASTWARD ACROSS PARTS OF SOUTHERN IOWA AND NORTHERN MISSOURI BY PEAK HEATING. STORMS ARE EXPECTED TO DEVELOP AS STRONGER FORCING FOR ASCENT OVERSPREADS THE REGION DURING THE LATE AFTERNOON. THIS SHOULD INCLUDE A FEW SUPERCELLS BEFORE GROWING UPSCALE INTO A MESOSCALE CONVECTIVE SYSTEM...WHICH SHOULD TRACK EAST SOUTHEASTWARD ALONG AND JUST SOUTH OF THE FRONT. WITH THE BOUNDARY LAYER JUST TO THE NORTH OF THE FRONT EXPECTED TO BE RATHER COOL AND STABLE...TORNADIC POTENTIAL WITH STORMS CROSSING THE BOUNDARY MAY BE LIMITED. DAMAGING WINDS AND LARGE HAIL STILL APPEAR TO BE THE PRIMARY CONCERNS WITH THE CONVECTION...WHICH COULD CONTINUE AND SPREAD INTO PARTS OF THE LOWER OHIO VALLEY TUESDAY NIGHT. ADDITIONAL...MORE WIDELY SCATTERED...STORM DEVELOPMENT IS EXPECTED ALONG THE DRY LINE TO THE SOUTH OF THE LOW...ACROSS EASTERN PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS DURING THE LATE AFTERNOON AND EVENING. SUPERCELLS ARE POSSIBLE...PRIMARILY WITH THE RISK FOR LARGE HAIL AND LOCALLY DAMAGING WIND GUSTS. ..KERR.. 03/21/2011 Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 21, 2011 Share Posted March 21, 2011 It looks like SPC is using a compromise of the NAM/GFS for the placement of the warm front tuesday evening as it correlates well with the area of highest probs on the day 2outlook but if the GFS ends up verifying those probs will need to be shifted northward, other way around if it ends up a bit further south like the NAM. Link to comment Share on other sites More sharing options...
thewxmann Posted March 21, 2011 Share Posted March 21, 2011 I dont get it... if they're so uncertain about the threat why did they outline a 45% risk? IMO there isn't much of a substantial threat here... at least to warrant a 45% on Day 2. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 21, 2011 Share Posted March 21, 2011 I dont get it... if they're so uncertain about the threat why did they outline a 45% risk? IMO there isn't much of a substantial threat here... at least to warrant a 45% on Day 2. agreed, a 30% is wha I thought we would see. Link to comment Share on other sites More sharing options...
thewxmann Posted March 21, 2011 Share Posted March 21, 2011 agreed, a 30% is wha I thought we would see. Yeah I agree, 30% would've made sense. While we're on the topic, the new day 1 is kinda weird too... the decent-looking TP (which will probably remain capped, but still...) has a 2% torn risk associated juxtaposed with a 0% hail risk... kinda weird when H5 temps are -15C and any storm that busts the cap will prob be isolated and discrete. EDIT: well they do have a 5% wind risk there, I guess they think storms will gust out fast. EDIT2: They have a 15% hail across a non-SLGT area. Lol probably a problem with my cache... Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 21, 2011 Share Posted March 21, 2011 Yeah I agree, 30% would've made sense. While we're on the topic, the new day 1 is kinda weird too... the decent-looking TP (which will probably remain capped, but still...) has a 2% torn risk associated juxtaposed with a 0% hail risk... kinda weird when H5 temps are -15C and any storm that busts the cap will prob be isolated and discrete. EDIT: well they do have a 5% wind risk there, I guess they think storms will gust out fast. They do have 15% probs for hail, must of not updated on yours when you looked at it. Link to comment Share on other sites More sharing options...
Chicago Storm Posted March 21, 2011 Share Posted March 21, 2011 FWIW, the 0z SPC does not have any surface based development in NE/KS/IA/MO...everything is elevated well north of the warm front. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 21, 2011 Share Posted March 21, 2011 DVN regarding potential tomorrow, LOT also favoring the further north solution of the placement of the warm front tomorrow evening TUESDAY...LATEST 00Z MODEL RUNS AND THEIR SYNOPTIC/MASS FIELD PLACEMENT STILL POINT TO A POTENTIALLY VOLATILE SEVERE WEATHER EPISODE TUE AFTERNOON AND INTO THE EVENING. SPC/S SVR WX PARAMETERS LEAD TO INCREASING PERCENTILES THAT WOULD SUPPORT AN EVENTUAL MODERATE RISK FOR AT LEAST THE SOUTH HALF OF THE DVN CWA. THROWING OUT THE FURTHER SOUTH PLACED/OUTLYING NAM...THE REST OF THE MODELS SUGGEST IDEAL STRONGLY SPRAWLING/DIFFLUENT MID AND UPPER LEVEL SOUTHWEST FLOW ACRS IA AHEAD OF AN INCREASINGLY NEGATIVELY TILTED CENTRAL-NORTHERN PLAINS CYCLONE BY LATE TUE AFTERNOON. ORGANIZING WNW-ESE ORIENTED LLVL WARM FRONT WILL LOOK TO SLOWLY RETREAT ACRS THE NORTH HALF OF THE DVN CWA AFTER MOST OF THE ELEVATED MORNING CONVECTION LIFTS NORTH OF THE CWA. THIS WILL MAKE FOR THE POTENTIAL OF TEMPS ZOOMING INTO THE 70S WITH HIGH 50S DPTS SOUTH OF THE WARM FRONT AND THE SOUTHERN HALF OF THE DVN CWA FOR CAPES OF 1K+ J/KG. WITH THE EARLY INDICATORS OF THE EXTENT OF BULK SHEAR UNDER THE DEEP CYCLONICALLY CURVED FLOW AND LIFT WITH THIS KIND OF INSTABILITY...AGREE WITH THE PREVIOUS SHIFT THAT SUPERCELLS/SVR WX OUTBREAK MAY BE AT HAND FOR MUCH OF THE SOUTHEAST HALF OF IA THIS PERIOD. A TORNADIC POTENTIAL ALONG THE DEVELOPING TRIPLE POINT...AND SOME LARGE HAIL INDICATORS SUPPORTING GOLF BALL SIZE STONES IF THE CURRENTLY PROGGED THERMODYNAMICS AND KINEMATICS PAN OUT CORRECTLY. DAMAGING WIND THREAT ALSO THERE. MANY CONCEPTUAL SVR WX INDICATORS ARE THEIR WITH THIS MORNINGS PROGS AND WILL EAGERLY AWAIT ADDITIONAL RUNS OVER THE NEXT 12-24 HRS. WILL KEEP MODERATE TO HIGH POPS WALKING IN FROM THE WEST FROM TUE AFTERNOON AND INTO THE EVENING. AS THE MAIN SFC LOW OCCLUDES ACRS NORTH CENTRAL IA AND INTO THE IA/MN/WI TRI-STATE REGION...BULK OF CONVECTION TO BE NORTH AND EAST OF THE DVN CWA BY 06Z WED WITH DRYING LLVL COLD CONVEYOR WRAPPING ACRS IA FROM THE WEST- NORTHWEST. Link to comment Share on other sites More sharing options...
Hoosier Posted March 21, 2011 Share Posted March 21, 2011 I dont get it... if they're so uncertain about the threat why did they outline a 45% risk? IMO there isn't much of a substantial threat here... at least to warrant a 45% on Day 2. Yeah I'd hate (or love) to see what they would've gone with if they thought the full potential would be realized. Link to comment Share on other sites More sharing options...
Hoosier Posted March 21, 2011 Share Posted March 21, 2011 DVN regarding potential tomorrow, LOT also favoring the further north solution of the placement of the warm front tomorrow evening I'm not saying the NAM is gonna pan out exactly but I've been thinking about how the still-cold lake could influence the boundary placement. I wouldn't be surprised to see it struggle to get as far north as the GFS is showing. Link to comment Share on other sites More sharing options...
Hoosier Posted March 21, 2011 Share Posted March 21, 2011 I'm not saying the NAM is gonna pan out exactly but I've been thinking about how the still-cold lake could influence the boundary placement. I wouldn't be surprised to see it struggle to get as far north as the GFS is showing. And it looks like the 12z GFS nudges south. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted March 21, 2011 Share Posted March 21, 2011 And it looks like the 12z GFS nudges south. Yep. And here is the WRF too Link to comment Share on other sites More sharing options...
OceanStWx Posted March 21, 2011 Share Posted March 21, 2011 Here's a good example of what the SPC is talking about when they talk about full potential not being realized. In this sig. tornado ingredients product you have five factors (the probabilities of MLCAPE > 1000, MLLCL< 1km, 0-1km helicity > 100, 0-6km shear >40 kts, and convective precip being measurable). Even just yesterday we saw this sig. tornado ingredients parameter approaching I believe 20%, and what is being regarded as a larger potential outbreak here is only 5%. What we know is with a 90 kt westerly jet streak at 500 mb we will have the shear. Warm front in the vicinity will surely produce high helicity values. Morning convection will keep LCLs low. And finally we are expecting convective precipitation. What that leaves us with is an instability limited scenario. The probability of CAPEs reaching 1000 j/kg on this SREF run were around 10%, and multiplying that by the other probabilities is really going to cut the sig. tornado ingredient parameter down. If the dewpoints increase faster than progged, or if we can get rid of morning convective debris (isn't that what we're always waiting for?) then more potential instability can be realized and a larger outbreak is possible. We also know that these low CAPE high shear events can surprise. And I think DVN is wise, with the warm front progged to be draped through the CWA, to be concerned. Link to comment Share on other sites More sharing options...
OceanStWx Posted March 21, 2011 Share Posted March 21, 2011 15z SREF run now brings 30% probs for MLCAPE>1000 into east central Iowa. Subsequently, the sig. tornado ingredients have jumped to a 10% contour. Link to comment Share on other sites More sharing options...
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