kab2791 Posted June 4, 2011 Share Posted June 4, 2011 Conditions becoming rather unstable across lower MI with SB LIs of -6 to -10, steep LL/ML lapse rates, and SB/ML CAPE of 3500+ j/kg over south/central lower MI. Supercell/derecho composites continue to increase. Link to comment Share on other sites More sharing options...
cyclone77 Posted June 4, 2011 Share Posted June 4, 2011 Sig hail is up to 2 over parts of northern Illinois now. Boundary layer continues to get more unstable by the hour. Most of northern Illinois is under 4000j/kg of surface cape now. SPC meso also shows a small area of non-supercell tornado parameter bubble near Chicago. Link to comment Share on other sites More sharing options...
smoof Posted June 4, 2011 Share Posted June 4, 2011 Not the 0z run. Touche, but I was in bed waiting for my tstorm to arrive an hour or 2 after that run without seeing it Link to comment Share on other sites More sharing options...
Thundersnow12 Posted June 4, 2011 Share Posted June 4, 2011 Izzi had a nice mid day write up. AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 1144 AM CDT SAT JUN 4 2011 MESOSCALE DISCUSSION 1145 AM CDT ATMOSPHERE CONTINUES TO COOK OVER THE CWA THIS MORNING WITH FULL SUNSHINE ALLOWING TEMPS TO CLIMB INTO THE MID-UPPER 80S WITH DEWPOINTS IN THE LOWER 70S. MODIFYING MORNING SOUNDINGS FOR CURRENT CONDITIONS AND SPC MESOANALYSIS BOTH SUGGEST ATMOSPHERE IS GROWING STRONGLY UNSTABLE WITH CONVECTIVE INHIBITION QUICKLY DECREASING. ONE ROGUE LONG-LIVED THUNDERSTORM CONTINUES TO TRACK ALONG THE IL/WI BORDER WITH HIGH RESOLUTION VISIBLE SATELLITE IMAGERY SHOWING AN OUTFLOW BOUNDARY ARCING SOUTH THEN SOUTHWEST FROM THIS CELL. THIS OUTFLOW BOUNDARY WOULD CERTAINLY SEEM TO BE A PRIME CANDIDATE TO FOCUS CONVECTIVE INITIATION THIS AFTERNOON AS REMAINING CONVECTIVE INHIBITION IS REMOVED. STRONGLY VEERED LOW LEVEL FLOW IS REDUCING DEEP LATER SHEAR VALUES WITH THE STRONGEST SHEAR IN THE POST FRONTAL/OUTFLOW ENVIRONMENT. EVEN STILL...30-40KT OF FLOW IN THE 6KM LAYER SHOULD BE SUFFICIENT TO RESULT IN 20-30KT OF DEEP LAYER SHEAR AND EVOLUTION INTO ORGANIZED MULTI-CELLULAR CLUSTER. DESPITE THE SOMEWHAT MARGINAL DEEP LAYER SHEAR VALUES...MLCAPE VALUES OVER 3500 J/KG AND STEEP MID-LEVEL LAPSE RATES STILL SUPPORT A THREAT FOR LARGE HAIL...PARTICULARLY BEFORE CONVECTION MORPHS INTO LINE/CLUSTER. STRONG INSTABILITY/STEEP LAPSE RATES ALSO SUPPORT A THREAT OF WET-MICROBURSTS AND LOCALIZED WIND DAMAGE. THREAT FOR WIND DAMAGE COULD TEND TO INCREASE OVER OUR SE CWA AS CONVECTION WILL HAVE MORE TIME/OPPORTUNITY TO HAVE DEVELOPED A COLD POOL AND MESOSCALE ORGANIZATION BY THAT POINT. PROBABLY ONE OF THE BIGGER THREATS THIS AFTERNOON COULD EVOLVE INTO HEAVY RAINFALL/FLASH FLOODING...ESPECIALLY SOUTH OF INTERSTATE 80. THE VERY MOIST ENVIRONMENT AND HIGH PRECIPITATION EFFICIENCY COULD RESULT IN SOME EXTREME RAINFALL RATES...POSSIBLY OVER TWO INCHES PER HOUR. OUTFLOW BOUNDARY/FRONT IS BECOMING ORIENTED MORE EAST- WEST OVER SOUTHEAST IOWA INTO NW IL WHICH IS MORE ALIGNED WITH THE MEAN FLOW AND ANTICIPATED STORM MOTION. THIS COULD RESULT IN AT LEAST SOME TEMPORARY TRAINING CELLS...WHICH GIVEN POTENTIAL FOR SUCH HIGH PRECIP RATES COULD RESULT IN FLASH FLOODING. DID CONSIDER A SHORT FUSED FLASH FLOOD WATCH BUT DECIDED TO JUST HIT THE POTENTIAL HARD IN HWO SINCE IT IS NOT CURRENTLY EXPECTED TO TURN INTO ANYTHING VERY WIDESPREAD OF MAJOR. IZZI Link to comment Share on other sites More sharing options...
Thundersnow12 Posted June 4, 2011 Share Posted June 4, 2011 lake breeze boundary is now onshore in extreme southeast WI marked by the small area of cumulus around RAC which now has a northeast wind. Link to comment Share on other sites More sharing options...
A-L-E-K Posted June 4, 2011 Share Posted June 4, 2011 lake breeze boundary is now onshore in extreme southeast WI marked by the small area of cumulus around RAC which now has a northeast wind. yeah, i posted about that in the June thread, should be pushing into my area within the next couple hours and into western cook county right around the time when the storms should be coming through. Link to comment Share on other sites More sharing options...
Powerball Posted June 4, 2011 Share Posted June 4, 2011 12z WRF-NMM develops three areas of t'storms this afternoon. One around Detroit back into SW Ontario, another one in North Central Ohio/Indiana and a third area from SE Iowa/West Central Illinois through Northern Missouri and NE Kansas. 12z WRF-ARW isn't much different either. None of them are handling the current MCS in Western PA very well however. Link to comment Share on other sites More sharing options...
SEMIweather Posted June 4, 2011 Share Posted June 4, 2011 CU Field developing in Lower MI... Link to comment Share on other sites More sharing options...
L.B. LaForce Posted June 4, 2011 Share Posted June 4, 2011 Thar she be! Link to comment Share on other sites More sharing options...
A-L-E-K Posted June 4, 2011 Share Posted June 4, 2011 got some towers trying to go up overhead and just west, lake front is trying to go off. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted June 4, 2011 Share Posted June 4, 2011 got some towers trying to go up overhead and just west, lake front is trying to go off. The RUC was saying it goes in a big way. Also looks like southeast/eastern IA should go pretty soon too. Link to comment Share on other sites More sharing options...
Powerball Posted June 4, 2011 Share Posted June 4, 2011 91*F at City Airport. 89*F at Metro Airport. Link to comment Share on other sites More sharing options...
cyclone77 Posted June 4, 2011 Share Posted June 4, 2011 There are some towers off to the north and west of here. They look very elevated though. Link to comment Share on other sites More sharing options...
Powerball Posted June 4, 2011 Share Posted June 4, 2011 Our first cell is developing near the Quad Cities. A line may be forming back to the WSW. Link to comment Share on other sites More sharing options...
Powerball Posted June 4, 2011 Share Posted June 4, 2011 Meanwhile, GRR's not impressed... 000FXUS63 KGRR 041727 AFDGRR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 127 PM EDT SAT JUN 4 2011 A COLD FRONT CUT ACROSS THE AREA FROM ROUGHLY AMN TO BIV AS OF 17Z. DESPITE THIS...WINDS HAVE ALREADY PIVOTED TO THE WEST OR WEST NORTHWEST SOUTH OF THE FRONT. THIS WILL REDUCE THE AMOUNT OF LOW LEVEL CONVERGENCE AND THE CHANCES OF STORMS WAS DWINDLING FOR THE REST OF THE AFTERNOON. THERE COULD BE AN ISOLATED CB AROUND...BUT IT SHOULD NOT AMOUNT TO MUCH MORE THAN THAT. WINDS WILL DIMINISH THIS EVENING BEHIND THE FRONT WITH VFR CONDITIONS. ONE SMALL CAVEAT TO THAT...THERE WAS AREAS OF DENSE FOG OVER LAKE MICHIGAN THAT WAS MAKING IT ONSHORE WITHIN A MILE OF THE COAST IN SOME AREAS. THIS IS EXPECTED TO IMPROVE BY THIS EVENING AS THE DEW POINTS LOWER BEHIND THE FRONT. Link to comment Share on other sites More sharing options...
Powerball Posted June 4, 2011 Share Posted June 4, 2011 91*F at City Airport. 89*F at Metro Airport. In fact, City Airport's tied with Willow Run for the warmest place in the state right now. And Metro Airport had a intra-hour high of 91*F. Link to comment Share on other sites More sharing options...
hm8 Posted June 4, 2011 Share Posted June 4, 2011 DTX aviation update AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 103 PM EDT SAT JUN 4 2011 AVIATION //DISCUSSION... A SLOW MOVING COLD FRONT NOW ADVANCING ACROSS CENTRAL MICHIGAN WILL INCH ITS WAY ACROSS SE MI LATE THIS AFTERNOON AND EVENING. THIS FRONT WILL PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT TODAY AS IT COLLIDES WITH A VERY UNSTABLE AIRMASS OVER SE MI. THE FRONT SHOULD REACH MBS AROUND 21Z...THEN PUSH SOUTH OF METRO DETROIT SHORTLY AFTER 00Z. THERE REMAINS SOME UNCERTAINTY AS TO HOW EXTENSIVE THE COVERAGE OF STORMS MAY BE. CONFIDENCE REMAINS HIGH ENOUGH TO AT LEAST CARRY A TWO HOUR TEMPO GROUP FOR THUNDERSTORMS IN ADVANCE OF THIS FRONT. MUCH DRIER AIR WILL THEN FILTER INTO THE REGION TONIGHT IN THE WAKE OF THE FRONT...ALLOWING SKIES TO CLEAR. FOR DTW...THE FRONT IS EXPECTED TO PASS THROUGH BETWEEN 23Z AND 02Z. THE MOST PROBABLE TIMING ON THUNDERSTORMS IS THEN BETWEEN 22Z AND 03Z. THERE WILL BE A NOTABLE WIND SHIFT TO THE NORTH-NORTHEAST IN THE WAKE OF THE FRONT. WIND SPEEDS SHOULD REMAIN BELOW 15 KTS. //DTW THRESHOLD THREATS... * MEDIUM CONFIDENCE ON THUNDERSTORMS THIS EVENING. Link to comment Share on other sites More sharing options...
Hoosier Posted June 4, 2011 Share Posted June 4, 2011 In fact, City Airport's tied with Willow Run for the warmest place in the state right now. And Metro Airport had a intra-hour high of 91*F. Perhaps you should post about it in the June thread. Link to comment Share on other sites More sharing options...
Chicago Storm Posted June 4, 2011 Author Share Posted June 4, 2011 In fact, City Airport's tied with Willow Run for the warmest place in the state right now. And Metro Airport had a intra-hour high of 91*F. http://www.americanwx.com/bb/index.php/topic/19133-june-2011-general-discussionobs-thread/ Link to comment Share on other sites More sharing options...
Powerball Posted June 4, 2011 Share Posted June 4, 2011 You can see the lake breeze off Lake Michigan pretty nicely on the satellite. TCU is exploding ahead of it too. Link to comment Share on other sites More sharing options...
Powerball Posted June 4, 2011 Share Posted June 4, 2011 MESOSCALE DISCUSSION 1085 NWS STORM PREDICTION CENTER NORMAN OK 0127 PM CDT SAT JUN 04 2011 AREAS AFFECTED...NRN IL...NRN IND CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 041827Z - 041930Z UPPER RIDGE IS EXPECTED TO GRADUALLY FLATTEN ACROSS THE NRN OH VALLEY PERHAPS IN RESPONSE TO SRN INFLUENCE OF UPPER GREAT LAKES SHORTWAVE TROUGH. THIS FLATTENING PROCESS SHOULD LEAD TO A ZONE OF MORE FAVORABLE LOW LEVEL CONFLUENCE SHIFTING INTO NRN IL/IND WHICH WILL BE ENHANCED BY LAKE MI BREEZE. STRONG SUNSHINE HAS STEEPENED LOW LEVEL LAPSE RATES ACROSS THIS REGION AND A DEEPENING BOUNDARY LAYER IS NOW MORE CONDUCIVE FOR CU DEVELOPMENT ALONG LAKE BREEZE...PER LATEST VIS IMAGERY. ADDITIONALLY...SHOWERS ARE GRADUALLY INCREASING ACROSS SERN IA INTO NWRN IL WITH ISOLATED LIGHTNING NOW OBSERVED WITH STRONGER UPDRAFTS. RECENT HRRR MODEL SUPPORTS ROBUST CONVECTIVE INITIATION ACROSS NRN IL/IND BY 19Z...AND ALTHOUGH THIS MAY BE A BIT EARLY IT WOULD SEEM TO BE SUPPORTED BY LATEST OBSERVATIONAL TRENDS. FOR THIS REASON A SEVERE THUNDERSTORM WATCH MAY BE WARRANTED SOON. ..DARROW.. 06/04/2011 ATTN...WFO...IWX...IND...LOT...ILX...DVN... LAT...LON 42188914 42078792 41538706 41718528 40618509 40518780 41489005 42188914 Link to comment Share on other sites More sharing options...
Hoosier Posted June 4, 2011 Share Posted June 4, 2011 I was literally just about to post that I would expect an MD/watch very soon. Link to comment Share on other sites More sharing options...
cyclone77 Posted June 4, 2011 Share Posted June 4, 2011 More towers to the west, but this time they look much more surface based. Could be the real deal. Gonna have to blow up fast to impact us though lol. Link to comment Share on other sites More sharing options...
Indystorm Posted June 4, 2011 Share Posted June 4, 2011 Derecho composite steadily building. Now up to 8 across ne IL and northern IN. Link to comment Share on other sites More sharing options...
Chicago Storm Posted June 4, 2011 Author Share Posted June 4, 2011 Another Izzi/LOT update... 1252 PM CDT SHALLOW CONVECTION THAT HAD BEEN DEVELOPING ALONG THE OUTFLOW BOUNDARY OVER NORTHWESTERN ILLINOIS HAS CHOKED ON THE CONVECTIVE INHIBITION AS THEY MOVED EAST. A COUPLE OF RECENT ACARS SOUNDINGS FROM ORD SHOW A VERY FORMIDABLE CAP PRESENT...MUCH STRONGER THAN WHAT HAD BEEN FORECAST BY MOST MODELS. IN FACT...PLUGGING IN CURRENT T/TD AT ORD INTO ONE OF THESE SOUNDINGS YIELDS SBCINH AROUND 100 J/KG. THIS SHOULD BE MORE THAN SUFFICIENT TO NOT ONLY PREVENT CONVECTION FROM FIRING ALONG THIS QUICKLY ADVANCING OUTFLOW BOUNDARY...BUT ALSO KEEP A LID ON ANY CONVECTION FIRING ALONG THE LAKE BREEZE FOR THE NEXT HOUR OR TWO AT LEAST. RADAR/SATELLITE TRENDS HAVE SHOWN A RECENT DEEPENING OF CONVECTION OVER SOUTHERN/EASTERN IOWA...WHICH IS LIKELY INDICATIVE OF A WEAKER CAP IN PLACE THERE AS HEIGHT FALLS AND A GLANCING BLOW OF UVV'S FROM SHORTWAVE PASSING BY TO THE NORTH LIKELY HAVE ERODED THE CAP SOMEWHAT. THIS TREND SHOULD CONTINUE EASTWARD INTO NORTHERN ILLINOIS AND NOW THINKING THAT THE CONVECTION OVER EASTERN/SOUTHERN IOWA HAS A BETTER CHANCE OF BECOMING THE MORE ROBUST AND SUSTAINABLE CONVECTION/SEVERE THREAT FOR US THIS AFTERNOON. THE ORIENTATION OF THIS CONVECTION IS EVEN MORE EAST-WEST THAN WITH THE INITIAL OUTFLOW SURGE AND AGAIN COULD POSE A VERY REAL THREAT FOR FLASH FLOODING. Link to comment Share on other sites More sharing options...
SEMIweather Posted June 4, 2011 Share Posted June 4, 2011 Seeing some towers try to go up here... Link to comment Share on other sites More sharing options...
cyclone77 Posted June 4, 2011 Share Posted June 4, 2011 It's been thundering here for the last ten minutes or so. Convection looks very weak though. I was wrong about surface based clouds. These are still very elevated. Link to comment Share on other sites More sharing options...
ksstormhunter Posted June 4, 2011 Share Posted June 4, 2011 Just pushed out 19Z Severe Analysis. Right now showing main target areas in and near Columbus, OH - Dayton, OH- Fort Wayne, IN -Detriot, MI- and Kokomo, IN. Seeing values in these areas of SFC CAPE 2993 J/KG, LI's -8.6, 0-1KM SRH 85.9 m/s. Potential for convective gust up to 74 knots and hail up to 1.2" in diameter. Detailed severe output uploaded at http://smartwxmodel.net Link to comment Share on other sites More sharing options...
hm8 Posted June 4, 2011 Share Posted June 4, 2011 Both the RUC and HRRR look decent for here, with initiation occurring in northern Oakland county and pushing south... Link to comment Share on other sites More sharing options...
SEMIweather Posted June 4, 2011 Share Posted June 4, 2011 Got an STW here. SEVERE THUNDERSTORM WATCH OUTLINE UPDATE FOR WS 426NWS STORM PREDICTION CENTER NORMAN OK 210 PM CDT SAT JUN 4 2011 SEVERE THUNDERSTORM WATCH 426 IS IN EFFECT UNTIL 900 PM CDT FOR THE FOLLOWING LOCATIONS MIC021-023-025-027-049-059-065-075-087-091-093-099-115-125-147- 149-155-161-163-050200- /O.NEW.KWNS.SV.A.0426.110604T1910Z-110605T0200Z/ MI . MICHIGAN COUNTIES INCLUDED ARE BERRIEN BRANCH CALHOUN CASS GENESEE HILLSDALE INGHAM JACKSON LAPEER LENAWEE LIVINGSTON MACOMB MONROE OAKLAND SHIAWASSEE ST. CLAIR ST. JOSEPH WASHTENAW WAYNE $$ Link to comment Share on other sites More sharing options...
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