hm8 Posted July 22, 2012 Share Posted July 22, 2012 Go. Link to comment Share on other sites More sharing options...
StormDude81 Posted July 22, 2012 Share Posted July 22, 2012 Well i was going through the models, and here's the NAM Significant Tornado Parameters, pretty high values across Western NY/Western PA , Monday Evening, we could be seeing a decent severe weather outbreak on Monday across the Upper Ohio Valley into Lower Lakes SPC has a 5% risk, but i see them putting out a slight risk later on tonight on the new day 2, waiting for the new Nam run to come out Link to comment Share on other sites More sharing options...
Geos Posted July 22, 2012 Share Posted July 22, 2012 LOT discussion on Monday night/Tuesday Morning MCS potential. THE MONDAY NIGHT THROUGH THURSDAY NIGHT PERIOD LOOKS TO BE A MORE ACTIVE PERIOD AND WE COULD SEE AT LEAST A COUPLE OF POTENTIALLY HEALTHY MCS`S TRACK ACROSS THE REGION. IN FACT...COMBINATION OF SEASONABLY HIGH PWATS POOLING ALONG THE BOUNDARY AND BELT OF STRONGER NORTHWESTERLY FLOW ALOFT NEARBY COULD RESULT IN A ROUND OR TWO OF SEVERE WEATHER AND EVEN THE POTENTIAL FOR HEAVY RAINFALL. UNFORTUNATELY THE CLOSE PROXIMITY TO THE BAROCLINIC ZONE WILL MEAN A HIGHER THAN AVERAGE BUST POTENTIAL FOR TEMPS...THOUGH FREQUENTLY IN SITUATIONS LIKE THIS CONVECTION ENDS UP RE-ENFORCING THE FRONT AND KEEPING IT FARTHER SOUTH THAN EXPECTED WHICH WOULD KEEP TEMPS COOLER THAN FORECAST. IZZI Link to comment Share on other sites More sharing options...
Thundersnow12 Posted July 22, 2012 Share Posted July 22, 2012 Monday night looks like our first shot at and nice MCS if the GFS is right, lots of instability near the frontal boundary to work with (-14 LI's/near 80 dews per GFS) will be curious to see if those are underdone. Will come down to any subtle waves in the flow plus how/if cloud debris affects heating. Link to comment Share on other sites More sharing options...
PatrickSumner Posted July 22, 2012 Share Posted July 22, 2012 Monday night looks like our first shot at and nice MCS if the GFS is right, lots of instability near the frontal boundary to work with (-14 LI's/near 80 dews per GFS) will be curious to see if those are underdone. Will come down to any subtle waves in the flow plus how/if cloud debris affects heating. What looks to be the track of this potential MCS? I'm heading to Ann Arbor on Monday. Link to comment Share on other sites More sharing options...
StormDude81 Posted July 22, 2012 Share Posted July 22, 2012 Looking at the 00z NAM, Monday looks interesting during the afternoon across Upper Ohio Valley into Great Lakes (nice low level jet streak across OH/PA/NY/Ontario) could lead to supercell/possibly tornadic activity, then Monday Night into Early Tuesday, watch for overnight MCS activity from Western Lakes/MS Valley into Ohio Valley/Appalachians This looks like it could be a fairly interesting severe event Link to comment Share on other sites More sharing options...
Chicago Storm Posted July 22, 2012 Share Posted July 22, 2012 I'm onboard with MCS/storm potential, but not so much with any decent severe potential. Worst case scenario is a few wimpy MCS's/storms that ruin what would otherwise add to the yearly 90F total. Link to comment Share on other sites More sharing options...
andyhb Posted July 22, 2012 Share Posted July 22, 2012 Southern Quebec/Ottawa Valley/Eastern ON region southward into Central OH could get interesting if the 00z NAM is on the right track, especially judging by the build up of low level shear across parts of the Great Lakes basin and western St. Lawrence Valley indicated by the model. Link to comment Share on other sites More sharing options...
hm8 Posted July 22, 2012 Author Share Posted July 22, 2012 Central and Eastern lower MI and parts of northern OH in a slight risk on the new D2 outlook Link to comment Share on other sites More sharing options...
Jim Martin Posted July 22, 2012 Share Posted July 22, 2012 0z NAM from last night backing way off on the Significant Tornado Parameter for tomorrow, as compared to the 12z NAM from yesterday. Link to comment Share on other sites More sharing options...
StormDude81 Posted July 22, 2012 Share Posted July 22, 2012 0z NAM from last night backing way off on the Significant Tornado Parameter for tomorrow, as compared to the 12z NAM from yesterday. 12z NAM from from today, has bumped up the Significant Tornado Parameter for tomorrow, compared to the last nights 0z NAM run Eastern Canada to Western NY/PA/East OH could get nasty Link to comment Share on other sites More sharing options...
Jim Martin Posted July 22, 2012 Share Posted July 22, 2012 Could the cap be an issue with the possible storm development tomorrow? Link to comment Share on other sites More sharing options...
StormDude81 Posted July 22, 2012 Share Posted July 22, 2012 Could the cap be an issue with the possible storm development tomorrow? That's why the SPC has left a 15% Slight Risk over the region, for numerous uncertainties, if the cap breaks and numerous storms fire up tomorrow we could be looking at some big problems for Ohio,Western PA,West NY, i can look at famous example of a tornado event that had the same issues was the May 31st, 1985 Tornado Outbreak, if i recall they had Cap issues, they had a Slight Risk out early in the morning, then they upgrade to either a Moderate or High Risk type event during late in the day after the storms fired up, not trying to compare but has similar implications and capping issues Link to comment Share on other sites More sharing options...
Thundersnow12 Posted July 22, 2012 Share Posted July 22, 2012 well said by Gino ANYWHERE STRONG HEATING TAKES PLACE MONDAY THE POTENTIAL WOULD EXIST FOR THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON...PARTICULARLY ALONG ANY REMNANT OUTFLOW BOUNDARIES. ANY STORMS THAT DO DEVELOP WOULD POSE AN APPRECIABLE RISK OF BECOMING SEVERE GIVEN THE DEEP LAYER SHEAR VALUES PROGGED TO BE 35KT+ ALONG THE PERIPHERY OF THE UPPER RIDGE. GREATER CONVECTIVE AND SEVERE POTENTIAL APPEARS TO BE TIED TO NOCTURNAL WARM AIR ADVECTION NEAR AND NORTH OF SURFACE BOUNDARY THAT MOVES THROUGH THE AREA TOMORROW NIGHT. MODEL GUIDANCE IN GENERAL AGREEMENT ON SOME SEMBLANCE OF A SHORTWAVE AND ASSOCIATED 50KT+ SPEED MAX CRESTING THE UPPER RIDGE AND MOVING INTO THE REGION TOMORROW NIGHT. SYNOPTICALLY SPEAKING IT LOOKS LIKE A PRETTY CLASSIC SET-UP FOR A NW FLOW SEVERE WEATHER EPISODE MONDAY NIGHT HERE OR NEARBY...WITH PRIMARY THREAT BEING DAMAGING WINDS AND LOCALLY HEAVY (EXCESSIVE?) RAINFALL WITH PWATS OF NEARLY 2 INCHES POOLING ALONG THE FRONT. Link to comment Share on other sites More sharing options...
Gilbertfly Posted July 22, 2012 Share Posted July 22, 2012 decent CAPE...nada for cap in parts of IL Link to comment Share on other sites More sharing options...
Thundersnow12 Posted July 23, 2012 Share Posted July 23, 2012 0z NAM favoring our MCS tomorrow night getting going across northeast IA/southwest WI centered around DBQ by 0z with scattered convection as early as 21z, then pushing it ESE across southern WI/northern IL. Then another round comes through overnight. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted July 23, 2012 Share Posted July 23, 2012 Day 1 Slight ...WRN OH VALLEY THROUGH WRN GREAT LAKES AND UPPER MS VALLEY... EML WILL EXIST ABOVE MOIST AXIS RESIDING IN VICINITY OF STALLED FRONT FROM ERN SD THROUGH WRN PARTS OF THE GREAT LAKES RESULTING IN A CAP. DIABATIC WARMING WILL CONTRIBUTE TO AXIS OF 2000-2500 J/KG MLCAPE. THE FRONT WILL ALSO EXIST ALONG SRN FRINGE OF STRONGER WLYS WITH 30-40 KT 0-6 KM SHEAR. PRIMARY CONCERN IS EXTENT OF STORM COVERAGE DURING THE DAY GIVEN LIKELIHOOD OF A CAP. HOWEVER...ISOLATED TO WIDELY SCATTERED STORMS MAY DEVELOP BY LATE AFTERNOON WHERE STRONG HEATING AND MIXING WILL LIKELY WEAKEN THE CAP NEAR FRONT. STEEP LAPSE RATES...MODERATE INSTABILITY AND 30-40 KT VERTICAL SHEAR WILL SUPPORT A THREAT OF LARGE HAIL AND DAMAGING WIND WITH ANY STORMS THAT DEVELOP IN THIS ENVIRONMENT. STORM COVERAGE WILL LIKELY INCREASE DURING THE EVENING AS THE LLJ STRENGTHENS AND ENHANCES ISENTROPIC LIFT NORTH OF FRONT. STORMS MAY EVENTUALLY EVOLVE INTO CLUSTERS/MCS AND ADVANCE SEWD WITH A CONTINUED THREAT OF DAMAGING WIND. Link to comment Share on other sites More sharing options...
StormDude81 Posted July 23, 2012 Share Posted July 23, 2012 Day 1 Slight ...WRN OH VALLEY THROUGH WRN GREAT LAKES AND UPPER MS VALLEY... EML WILL EXIST ABOVE MOIST AXIS RESIDING IN VICINITY OF STALLED FRONT FROM ERN SD THROUGH WRN PARTS OF THE GREAT LAKES RESULTING IN A CAP. DIABATIC WARMING WILL CONTRIBUTE TO AXIS OF 2000-2500 J/KG MLCAPE. THE FRONT WILL ALSO EXIST ALONG SRN FRINGE OF STRONGER WLYS WITH 30-40 KT 0-6 KM SHEAR. PRIMARY CONCERN IS EXTENT OF STORM COVERAGE DURING THE DAY GIVEN LIKELIHOOD OF A CAP. HOWEVER...ISOLATED TO WIDELY SCATTERED STORMS MAY DEVELOP BY LATE AFTERNOON WHERE STRONG HEATING AND MIXING WILL LIKELY WEAKEN THE CAP NEAR FRONT. STEEP LAPSE RATES...MODERATE INSTABILITY AND 30-40 KT VERTICAL SHEAR WILL SUPPORT A THREAT OF LARGE HAIL AND DAMAGING WIND WITH ANY STORMS THAT DEVELOP IN THIS ENVIRONMENT. STORM COVERAGE WILL LIKELY INCREASE DURING THE EVENING AS THE LLJ STRENGTHENS AND ENHANCES ISENTROPIC LIFT NORTH OF FRONT. STORMS MAY EVENTUALLY EVOLVE INTO CLUSTERS/MCS AND ADVANCE SEWD WITH A CONTINUED THREAT OF DAMAGING WIND. There are complete uncertainties for the Ohio Valley to Great Lakes and even Northeast Area, MCS activity in the evening into overnight looks possible, east towards East MI, OH, W PA, W NY, Ontario where a better chance of supercells and potentially tornado, i think an enhanced tornado threat is possible in E OH/W PA if conditions come together Link to comment Share on other sites More sharing options...
on_wx Posted July 23, 2012 Share Posted July 23, 2012 There are complete uncertainties for the Ohio Valley to Great Lakes and even Northeast Area, MCS activity in the evening into overnight looks possible, east towards East MI, OH, W PA, W NY, Ontario where a better chance of supercells and potentially tornado, i think an enhanced tornado threat is possible in E OH/W PA if conditions come together Good call .. whole outlook shifted east and a large 5% tornado runs through OH/WV/PA Link to comment Share on other sites More sharing options...
KokomoWX Posted July 23, 2012 Share Posted July 23, 2012 MESOSCALE DISCUSSION 1552 NWS STORM PREDICTION CENTER NORMAN OK 1226 PM CDT MON JUL 23 2012 AREAS AFFECTED...SRN IND...SRN OH...NRN KY...WV CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 231726Z - 231930Z PROBABILITY OF WATCH ISSUANCE...60 PERCENT SUMMARY...SEVERE STORMS MAY EVENTUALLY DEVELOP LATER THIS AFTERNOON WITH ISOLATED HAIL AND WIND. DISCUSSION...VISIBLE IMAGERY SHOWS AN AREA OF CLOUDS MOVING SEWD ACROSS IND AND OH...WITH ISOLATED THUNDERSTORMS CURRENTLY ON THE WRN FRINGE OVER E CNTRL IND. THIS DISTURBANCE APPEARS TO BE ASSOCIATED WITH THE SRN END OF A SHORTWAVE TROUGH...AND IS ALSO ALIGNED WITH AN AREA OF INCREASINGLY CONFLUENT 850 MB FLOW. THIS AREA OF ASCENT WILL CONTINUE ESEWD INTO AN AREA WHERE STRONG INSTABILITY EXISTS. WEAKLY VEERING LOW LEVEL FLOW WILL INCREASE TO 30-40 KT IN THE MIDLEVELS...PROVIDING FAVORABLE HODOGRAPHS FOR SSEWD MOVING SUPERCELLS. ANY STORMS THAT DEVELOP WILL BE CAPABLE OF LARGE HAIL...LOCALLY DAMAGING DOWNBURSTS AND PERHAPS AN ISOLATED TORNADO. ..JEWELL/HART.. 07/23/2012 ATTN...WFO...RNK...RLX...JKL...ILN...LMK...IND... Link to comment Share on other sites More sharing options...
A-L-E-K Posted July 23, 2012 Share Posted July 23, 2012 impressive theta-e/moisture pooling over NW Illinois...anything that goes up there this evening should be quality Link to comment Share on other sites More sharing options...
Thundersnow12 Posted July 23, 2012 Share Posted July 23, 2012 impressive theta-e/moisture pooling over NW Illinois...anything that goes up there this evening should be quality yeah really a nice axis of juice from southern MN down to northwest IL with a few mid 70 dew point readings along that line. 4000 MUCAPE sitting here at well. Question is do we see sfc based convection before 0z? Link to comment Share on other sites More sharing options...
Gilbertfly Posted July 23, 2012 Share Posted July 23, 2012 16Z HRRR showing a bowing structure coming out of NW IL around 11:00pm ... crap shoot at this point Link to comment Share on other sites More sharing options...
cyclone77 Posted July 23, 2012 Share Posted July 23, 2012 Looks like anything that develops will be elevated at first. Seeing zero cumulus development anywhere along the boundary. Link to comment Share on other sites More sharing options...
A-L-E-K Posted July 23, 2012 Share Posted July 23, 2012 Looks like anything that develops will be elevated at first. Seeing zero cumulus development anywhere along the boundary. yep...looks like a non starter until after 0z and probably closer to 6z this far east. Link to comment Share on other sites More sharing options...
Indystorm Posted July 23, 2012 Share Posted July 23, 2012 Both the derecho and MCS maintenance progs on the SPC meso page are quite promising for our affected areas if something does develop. Link to comment Share on other sites More sharing options...
Indystorm Posted July 23, 2012 Share Posted July 23, 2012 I keep wondering if the elevated convection west of MSP at 20z will become surface based as it moves southeastward. Link to comment Share on other sites More sharing options...
Gilbertfly Posted July 23, 2012 Share Posted July 23, 2012 DVN. . . AREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE QUAD CITIES IA IL 330 PM CDT MON JUL 23 2012 .SYNOPSIS... LATEST SFC ANALYSIS WAS INDICATING A WEAK AND STALLING BOUNDARY ACRS EASTERN SD...EXTENDING EAST-SOUTHEASTWARD INTO NORTHEASTERN IA AND ACRS SOUTHERN WI...HIGHER LOW TO MID 70 DPT FIELD POOLED ALONG AND SOUTH OF IT. MID LEVEL DECK OF CLOUDS ALSO MARKING HIGHER LLVL MOISTURE FIELDS. MAIN COOL FRONT SEEMS TO BE PUSHING FROM AREAS JUST SOUTH OF MSP MN...UP INTO NORTHEASTERN WI. WARM MIXED LAYER ALOFT/CAP KEEPING LID ON ANY SFC DEVELOPMENT OR EVEN LOWER BASED CU ATTM...BUT AS AMBIENT TEMPS ZOOM INTO THE 100/S...CONVECTIVE TEMPS ARE GETTING CLOSED IN ON. SFC DPTS DRY DOWN MIXED INTO THE 50S TO MID 60S THIS AFTERNOON MAKING FOR LESS WIDESPREAD 105+ HEAT INDICES AND SAVING THE NEED FOR AN EXCESSIVE HEAT HEADLINE...BUT MANY HI READINGS FROM 100-105 AND THUS VERY CLOSE. SPECIAL WX STATEMENT ISSUED FOR AFTERNOON HEAT BEFORE NOON. OF COURSE THE DRY AIR ALLOWING THE AMBIENT TEMPS TO REALLY HEAT UP THAN EARLIER EXPECTED. ALOFT...A RIDGE RIDING VORT NOTED ON W/V IMAGERY ROLLING OUT OF SD AND INTO WEST CENTRAL MN. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted July 23, 2012 Share Posted July 23, 2012 DVN SHORT TERM...TONIGHT AND TUESDAY TONIGHT...CAP HOLDING FOR NOW BUT AGAIN CONVECTIVE TEMPS ARE GETTING CLOSE TO BEING REACHED. THE WATCH WILL HAVE TO BE ON FOR SCTRD THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON AND INTO THE EVENING IN ONGOING LLVL MOISTURE CONVERGENT RIBBON AND SFC PRESSURE FALLS AREA ACRS NORTHERN IA...EAST- SOUTHEASTWARD INTO THE NORTHERN DVN CWA TO MAYBE THE STERLING IL AREA. WILL USE SCTRD WORDING IN THE NORTHERN THIRD THIS EVENING. ANY STORM THAT CAN DEVELOP AND BECOME SFC ROOTED MAY EXPLODE UTILIZING 3-4K SBCAPES...WITH A SVR THREAT FOR BOTH LARGE HAIL AND DAMAGING WIND. STILL NICE RIBBONS OF ELEVATED CONVERGENT WINGS/WAA SWATHS FROM NORTHWEST IA...DOWN INTO THE NORTHERN HALF OF THE DVN CWA THIS EVENING AIDING IN POTENTIAL DEVELOPMENT. IF NO SFC DEVELOPMENT CAN TAKE PLACE THIS EVENING LOCALLY...EVEN ELEVATED STORM DEVELOPMENT MAY HAVE TO BE WATCHED AS SHEAR PROFILES ARE MORE FAVORABLE IN THE MID LEVELS TO SUPPORT AND ELEVATED HAILER. THE SOUTHERN CWA MAY REMAIN DRY TIL WELL AFTER MIDNIGHT...IF THEY GET ANY SCTRD TO ISOLATED STORMS IN THOSE AREAS AT ALL. AFTER MIDNIGHT WILL KEEP THE EARLIER INTRODUCED LIKELY POPS WHERE THEY ARE ACRS MUCH OF THE NORTHEASTERN THIRD OF THE DVN CWA FOR THE POTENTIAL OF A CLUSTER OF STORMS DEVELOPING ACRS SOUTHERN MN ON SOUTHERN FLANK OF THE ABOVE MENTIONED MN VORT MAX AS IT STARTS TO PROPAGATE MORE EAST-SOUTHEASTWARD AND DROPS TOWARD NORTHERN IL. CORFIDI VECTORS WOULD SUGGEST AND SOUTHERN MN STORM CLUSTER OR MCS WOULD WANT TO FEED IT/S WAY DOWN INTO AT LEAST THE NORTHERN THIRD OF THE FCST AREA OR EVEN FURTHER SOUTH Link to comment Share on other sites More sharing options...
Thundersnow12 Posted July 23, 2012 Share Posted July 23, 2012 mid-level speed max seen nicely nosing into western/sw MN via the WDLM profiler with 50kts now just below 500mb, a 25kt increase since 19z. Link to comment Share on other sites More sharing options...
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