Hoosier Posted May 20, 2014 Share Posted May 20, 2014 URGENT - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WATCH NUMBER 161 NWS STORM PREDICTION CENTER NORMAN OK 355 PM CDT TUE MAY 20 2014 THE NWS STORM PREDICTION CENTER HAS ISSUED A * SEVERE THUNDERSTORM WATCH FOR PORTIONS OF CENTRAL AND EASTERN IOWA NORTHERN ILLINOIS NORTHWEST INDIANA SOUTHERN WISCONSIN LAKE MICHIGAN * EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 355 PM UNTIL 1100 PM CDT. * PRIMARY THREATS INCLUDE... WIDESPREAD LARGE HAIL LIKELY WITH ISOLATED VERY LARGE HAIL EVENTS TO 2 INCHES IN DIAMETER POSSIBLE SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 45 STATUTE MILES NORTH AND SOUTH OF A LINE FROM 50 MILES SOUTHEAST OF RACINE WISCONSIN TO 65 MILES WEST OF DES MOINES IOWA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES. OTHER WATCH INFORMATION...CONTINUE...WW 160... DISCUSSION...THUNDERSTORMS ARE EXPECTED TO DEVELOP AND INTENSIFY ALONG A WEAK BOUNDARY EXTENDING FROM CENTRAL IA INTO SOUTHERN WI. THESE STORMS WILL SPREAD EAST-SOUTHEASTWARD ACROSS THE WATCH AREA THIS AFTERNOON AND EVENING. MODERATE INSTABILITY COUPLED WITH STEEP LAPSE RATES AND STRONG WINDS ALOFT WILL PROMOTE ORGANIZED MULTICELL OR ISOLATED SUPERCELL STORMS CAPABLE OF LARGE HAIL. DAMAGING WINDS MAY BECOME AN INCREASING THREAT LATER THIS EVENING. AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 26030. ...HART Link to comment Share on other sites More sharing options...
The_Doctor Posted May 20, 2014 Share Posted May 20, 2014 That's a pretty big watch Link to comment Share on other sites More sharing options...
Geos Posted May 20, 2014 Share Posted May 20, 2014 Cumulus field lining up nicely to the corridor Alek pointed out. Link to comment Share on other sites More sharing options...
tornadotony Posted May 20, 2014 Share Posted May 20, 2014 The question I've been asking myself regarding the hail threat is what changed since this morning... and it seems like nothing really has. The instability is being realized and low level flow has been a concern all along, or at least since I've been paying attention to this setup. The lack of low level flow should be more of a negative factor as far as the tornado threat but of course it can't entirely be ruled out with the boundary and any storm scale interactions that occur. Absolutely nothing has changed. And the now svr-warned cells near Dubuque/Galena are rotating aloft. Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted May 20, 2014 Share Posted May 20, 2014 These things are going to train once they really get rolling. Flash flooding will be a concern as well Link to comment Share on other sites More sharing options...
Baum Posted May 20, 2014 Share Posted May 20, 2014 over under, largest hail size at 1.25" in diameter First call .2-.5 Link to comment Share on other sites More sharing options...
RyanDe680 Posted May 20, 2014 Share Posted May 20, 2014 Bigtime training... Galena is just getting soaked. Link to comment Share on other sites More sharing options...
tornadotony Posted May 20, 2014 Share Posted May 20, 2014 72.5 dBZ ref at a estimated height of 26.5 kft. on that supercell near DBQ from KDVN. Link to comment Share on other sites More sharing options...
Stebo Posted May 20, 2014 Share Posted May 20, 2014 72.5 dBZ ref at a estimated height of 26.5 kft. on that supercell near DBQ from KDVN. Someone is getting rocked with baseballs or greater in that case. Link to comment Share on other sites More sharing options...
A-L-E-K Posted May 20, 2014 Share Posted May 20, 2014 explosive development…nice dbq cell took a jog right Link to comment Share on other sites More sharing options...
A-L-E-K Posted May 20, 2014 Share Posted May 20, 2014 watch the lead cell in se mchenry co Link to comment Share on other sites More sharing options...
McDude Posted May 20, 2014 Share Posted May 20, 2014 Awesome training Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted May 20, 2014 Share Posted May 20, 2014 DBQ cell looking solid. Link to comment Share on other sites More sharing options...
RyanDe680 Posted May 20, 2014 Share Posted May 20, 2014 McHenry into Lake County now... Link to comment Share on other sites More sharing options...
A-L-E-K Posted May 20, 2014 Share Posted May 20, 2014 Awesome training we should do well once the complex matures into the city, don't you think? Link to comment Share on other sites More sharing options...
Hoosier Posted May 20, 2014 Share Posted May 20, 2014 Golfball size hail is the biggest report so far on that DBQ cell. Link to comment Share on other sites More sharing options...
McDude Posted May 20, 2014 Share Posted May 20, 2014 we should do well once the complex matures into the city, don't you think? Don't know. Think that will swing our way or go to the north? Thinking something else might develope as it moves our way. Never know with these things. Link to comment Share on other sites More sharing options...
A-L-E-K Posted May 20, 2014 Share Posted May 20, 2014 Don't know. Think that will swing our way or go to the north? Thinking something else might develope as it moves our way. Never know with these things. definitely not worried about a miss north, that's for sure…should congeal into a nascent MCS over the city Link to comment Share on other sites More sharing options...
kevlon62 Posted May 20, 2014 Share Posted May 20, 2014 Big ol rain drops in Crystal Lake. Just a sloppy shower though. Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted May 20, 2014 Share Posted May 20, 2014 Kind of a cool striated cloud look overhead. Link to comment Share on other sites More sharing options...
The_Doctor Posted May 20, 2014 Share Posted May 20, 2014 MESOSCALE DISCUSSION 0625NWS STORM PREDICTION CENTER NORMAN OK0549 PM CDT TUE MAY 20 2014AREAS AFFECTED...CNTRL IA...NRN IL AND ADJACENT SRN WI...SRN LAKEMI...NWRN IND AND SWRN MICONCERNING...SEVERE THUNDERSTORM WATCH 161...VALID 202249Z - 210015ZTHE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 161CONTINUES.SUMMARY...STRONG TO SEVERE STORM DEVELOPMENT IS EXPECTED TOPERSIST...AND MAY STILL INCREASE SOME THROUGH 00-01Z. ACTIVITY ISALREADY FORMING AS FAR WEST AS AREAS NEAR/NORTH OF OMAHA NEB...WITHADDITIONAL ISOLATED DEVELOPMENT POSSIBLE INTO PORTIONS OF SOUTHERNLOWER MICHIGAN AND NORTHERN INDIANA BY EARLY EVENING. WHILE IT ISNOT CLEAR THAT THIS WILL REQUIRE ADDITIONAL WATCHES...TRENDS WILLCONTINUE TO BE MONITORED FOR THIS POSSIBILITY.DISCUSSION...VIGOROUS CONVECTIVE DEVELOPMENT IS NOW WELLUNDERWAY...GENERALLY ALIGNED ALONG THE EDGE OF STEEPER MID-LEVELLAPSE RATES ASSOCIATED WITH THE WARMER...MORE STRONGLY CAPPINGELEVATED MIXED-LAYER AIR ADVECTING NORTHEAST OF THE CENTRAL/SOUTHERNPLAINS REGION. THIS ROUGHLY CORRESPONDS TO 700 MB THERMAL GRADIENTARCING ACROSS CENTRAL IOWA...NEAR THE INTERSTATE 80 CORRIDOR...INTONORTHERN ILLINOIS...NEAR/WEST THROUGH SOUTH OF THE CHICAGOMETRO...ALONG WHICH CONVECTION PROBABLY WILL PROPAGATE INTO EARLYEVENING.THOUGH SOMEWHAT MODEST IN MAGNITUDE...HIGHER PRECIPITABLE WATERCONTENT IS ALSO FOCUSED ALONG THIS AXIS...SUPPORTING MODERATELYLARGE CAPE ON THE ORDER OF 1500 TO 2000 J/KG. BENEATH 40-50 KTWESTERLY 500 MB FLOW...THE ENVIRONMENT SHOULD REMAIN CONDUCIVE TOSUPERCELL DEVELOPMENT CAPABLE OF PRODUCING LARGE HAIL AND LOCALLYSTRONG WIND GUSTS. LOW-LEVEL FLOW FIELDS AND SHEAR REMAIN RATHERWEAK...AND ANY ORGANIZED DAMAGING WIND POTENTIAL WILL LARGELY HINGEON UPSCALE CONVECTIVE GROWTH AND CONSOLIDATING/MERGING COLD POOLS.POTENTIAL FOR THIS REMAINS A BIT UNCLEAR...BUT SEEMS LOW AT THEPRESENT TIME...DUE...ADDITIONALLY...TO THE APPARENT LACK OF STRONGERLARGE-SCALE FORCING FOR UPWARD VERTICAL MOTION...KERR.. 05/20/2014 Link to comment Share on other sites More sharing options...
Geos Posted May 20, 2014 Share Posted May 20, 2014 Storms firing away overhead now. These cells contain some huge raindrops. Link to comment Share on other sites More sharing options...
hm8 Posted May 20, 2014 Share Posted May 20, 2014 1.75" hail report from Dubuque Link to comment Share on other sites More sharing options...
A-L-E-K Posted May 20, 2014 Share Posted May 20, 2014 1.75" hail report from Dubuque given that report, 1.25 should be a good over/under number for LOT the weak forcing is definitely keeping this event in check…decent but in check Link to comment Share on other sites More sharing options...
McDude Posted May 20, 2014 Share Posted May 20, 2014 Sun disappeared. Cool now. Better storm Link to comment Share on other sites More sharing options...
tornadotony Posted May 20, 2014 Share Posted May 20, 2014 63 dBZ at over 27kft estimated height from KLOT in Ogle County. Link to comment Share on other sites More sharing options...
tornadotony Posted May 20, 2014 Share Posted May 20, 2014 given that report, 1.25 should be a good over/under number for LOT the weak forcing is definitely keeping this event in check…decent but in check I'm betting the over is about to be hit in Ogle County now. 70 dBZ aloft. Question is whether or not anyone will be under it. Link to comment Share on other sites More sharing options...
tornadotony Posted May 20, 2014 Share Posted May 20, 2014 65.5 dBZ to almost 33kft in Ogle County. Wow. Link to comment Share on other sites More sharing options...
tornadotony Posted May 20, 2014 Share Posted May 20, 2014 And 73 dBZ on the lowest tilt. There may be baseballs+ falling out of this thing. Link to comment Share on other sites More sharing options...
Stebo Posted May 20, 2014 Share Posted May 20, 2014 And 73 dBZ on the lowest tilt. There may be baseballs+ falling out of this thing. Hopefully someone is under it so all of us "overs" can win. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.