Hoosier Posted November 13, 2011 Share Posted November 13, 2011 SPC has beefed up the wording a bit compared to last night and there is now a slight risk for portions of the Ohio Valley. ..MIDWEST/OH VALLEY AHEAD OF THE AFOREMENTIONED COLD FRONT...CONTINUED NORTHEASTWARD ADVECTION OF A MODESTLY MOIST BOUNDARY LAYER /CHARACTERIZED BY 50S TO SOME LOWER 60S F SURFACE DEWPOINTS/ WILL OCCUR INTO THE REGION ON MONDAY WITH AID OF A STRONG /50+ KT/ AND SUSTAINED SOUTHWESTERLY LOW LEVEL JET. ON THE SOUTHERN PERIPHERY OF EARLY DAY SHOWERS/SOME EMBEDDED TSTMS...THE BOUNDARY LAYER SHOULD GRADUALLY DESTABILIZE/BECOME NEGLIGIBLY CAPPED INTO THE AFTERNOON WITHIN A PRE-COLD FRONTAL CORRIDOR FROM NEAR/JUST NORTH OF THE OH/MS RIVER CONFLUENCE /ACROSS SOUTHERN IL/...NORTHEASTWARD INTO MUCH OF INDIANA AND PORTIONS OF KY/OH. WHILE AN APPRECIABLE DEEPENING PHASE OF THE CYCLONE/CONSEQUENTIAL SURFACE CYCLOGENESIS IS NOT NECESSARILY EXPECTED...SUFFICIENT MOISTURE AND INSTABILITY /TO AROUND 500 J PER KG MLCAPE/ SHOULD BE IN PLACE IN THE PRESENCE OF AN EXTREMELY STRONG DEEP LAYER WIND FIELD SUCH THAT AT LEAST A SEMI-ORGANIZED/ISOLATED SEVERE RISK MAY DEVELOP MONDAY AFTERNOON/EARLY EVENING. WHILE THE EXACT DEGREE/SPATIAL LOCATION OF PEAK DESTABILIZATION IS A BIT UNCERTAIN...FAST-MOVING LOW-TOPPED TSTMS SHOULD GRADUALLY INCREASE/LINEARLY ORGANIZE MONDAY AFTERNOON ALONG /OR PERHAPS MORE SO/ JUST AHEAD OF THE EASTWARD ADVANCING COLD FRONT...WITH PROBABLE QLCS-TYPE EVOLUTIONS INCLUDING BOWING SEGMENTS AND EMBEDDED SUPERCELLS/MESOVORTICES CAPABLE OF AN ENHANCED WIND DAMAGE/POSSIBLE TORNADO THREAT. ASIDE FROM SOME HAIL POTENTIAL...THE PRIMARY HAZARDS ARE LIKELY TO BE DAMAGING WINDS ALONG WITH THE POSSIBILITY OF A FEW TORNADOES /MAINLY ASSOCIATED WITH QLCS-TYPE STRUCTURES/. Link to comment Share on other sites More sharing options...
Hoosier Posted November 13, 2011 Author Share Posted November 13, 2011 Hodos would appear to be pretty supportive of splitting cells but I'm not sure how long it will take for things to get messy. I don't expect a big tornado day by any means but would not be entirely shocked to see a strong tornado tomorrow given 0-1 km shear of 35-40+ kts, favorable LCL/LFC, decent 0-3 km CAPE and modest turning in the lowest km. The profiles are pretty unidirectional though. Link to comment Share on other sites More sharing options...
Hoosier Posted November 13, 2011 Author Share Posted November 13, 2011 Link to comment Share on other sites More sharing options...
tornadotony Posted November 13, 2011 Share Posted November 13, 2011 Hodos would appear to be pretty supportive of splitting cells but I'm not sure how long it will take for things to get messy. I don't expect a big tornado day by any means but would not be entirely shocked to see a strong tornado tomorrow given 0-1 km shear of 35-40+ kts, favorable LCL/LFC, decent 0-3 km CAPE and modest turning in the lowest km. The profiles are pretty unidirectional though. I could see a rather interesting QLCS tornado threat tomorrow across IN/OH. NAM had the threat farther NW yesterday up to I-80 but has since shifted back S. We will have to watch to see if that shifts back N some again. Link to comment Share on other sites More sharing options...
Hoosier Posted November 13, 2011 Author Share Posted November 13, 2011 I could see a rather interesting QLCS tornado threat tomorrow across IN/OH. NAM had the threat farther NW yesterday up to I-80 but has since shifted back S. We will have to watch to see if that shifts back N some again. This setup seems to be atypical compared to most other November setups that I can remember. The main surface low is way up in Canada and there's only a weak low that moves across N/C IL/IN. Can you recall something like this? Link to comment Share on other sites More sharing options...
tornadotony Posted November 13, 2011 Share Posted November 13, 2011 This setup seems to be atypical compared to most other November setups that I can remember. The main surface low is way up in Canada and there's only a weak low that moves across N/C IL/IN. Can you recall something like this? No, it's more typical of a SE US setup, with almost a mesolow sort of deal. 12z EMC WRF has what looks like supercells across N IN and N OH tomorrow afternoon. Link to comment Share on other sites More sharing options...
theweatherman12 Posted November 13, 2011 Share Posted November 13, 2011 I think tomorrow's severe threat is a rather interesting situation, its starting to look like that things might get fairly active , depending on 00z and 06 model runs coming up tonight , i wouldn't be shocked if we get some rather high probs. from the SPC tomorrow, i personally think the best tornado threat will be along I-70 from Dayton Ohio to Pittsburgh PA. I won't be shocked if we get a strong tornado or two in that region tomorrow with an impressive low level jet. Tomorrow is indeed an interesting and highly unusual situation for sure Link to comment Share on other sites More sharing options...
Hoosier Posted November 13, 2011 Author Share Posted November 13, 2011 No, it's more typical of a SE US setup, with almost a mesolow sort of deal. 12z EMC WRF has what looks like supercells across N IN and N OH tomorrow afternoon. Looks like the 18z NAM went back north somewhat. Link to comment Share on other sites More sharing options...
tornadotony Posted November 13, 2011 Share Posted November 13, 2011 Looks like the 18z NAM went back north somewhat. If we get a little impulse along that front tomorrow to back the low-level winds, then things could get rather spicy along and SE of the front. Link to comment Share on other sites More sharing options...
Jim Martin Posted November 13, 2011 Share Posted November 13, 2011 Plenty of 1km Shear as well. Nearly 50 knots in SE Indiana/SW Ohio/Northern KY. Link to comment Share on other sites More sharing options...
Hoosier Posted November 13, 2011 Author Share Posted November 13, 2011 I think tomorrow's severe threat is a rather interesting situation, its starting to look like that things might get fairly active , depending on 00z and 06 model runs coming up tonight , i wouldn't be shocked if we get some rather high probs. from the SPC tomorrow, i personally think the best tornado threat will be along I-70 from Dayton Ohio to Pittsburgh PA. I won't be shocked if we get a strong tornado or two in that region tomorrow with an impressive low level jet. Tomorrow is indeed an interesting and highly unusual situation for sure If instability trends any higher then I could see them going with some pretty decent probs. Right now this event is seemingly on the borderline between low end and something more robust. Link to comment Share on other sites More sharing options...
theweatherman12 Posted November 13, 2011 Share Posted November 13, 2011 Plenty of 1km Shear as well. Nearly 50 knots in SE Indiana/SW Ohio/Northern KY. Here's the 1km shear for 00z Tuesday, the belt of 40-50 Kt shear moves from SE Indiana/SW Ohio/Northern KY to Western PA/NY by sundown, it's starting to look like there might be a decent swath of severe weather from Indiana/Ohio to the Appalachians, if we get some decent backing of the winds, oh there is going to be some big trouble Link to comment Share on other sites More sharing options...
theweatherman12 Posted November 13, 2011 Share Posted November 13, 2011 The Significant Tornado Parameters are increasing according to the 18z NAM Run, looks like Central Ohio to Western PA could be a hot spot tomorrow, waiting for the 00z Runs this evening Link to comment Share on other sites More sharing options...
Hoosier Posted November 13, 2011 Author Share Posted November 13, 2011 I've been watching the SREF sigtor probs for the last couple runs but still not seeing anything showing up. The parameters that it's based on all seem to be favorable with the exception of MLCAPE so I have to think that is what is holding it back. Link to comment Share on other sites More sharing options...
tornadotony Posted November 13, 2011 Share Posted November 13, 2011 I've been watching the SREF sigtor probs for the last couple runs but still not seeing anything showing up. The parameters that it's based on all seem to be favorable with the exception of MLCAPE so I have to think that is what is holding it back. That's likely...but it ain't gonna matter if you get 0-3km CAPE over 200J/kg... Link to comment Share on other sites More sharing options...
theweatherman12 Posted November 13, 2011 Share Posted November 13, 2011 That's likely...but it ain't gonna matter if you get 0-3km CAPE over 200J/kg... yeah i agree tornado tony, i doesn't take much if it cape is next to non-existent, there will be some nasty storms, i think on December 1st 2006, around here we had an F1 Tornado, and i think the CAPE was only 50 0-3km J/kg, but the low level shear was 40-50 kts Link to comment Share on other sites More sharing options...
andyhb Posted November 13, 2011 Share Posted November 13, 2011 Impressive 0-1 km SRH in the region by 18z tomorrow afternoon. Link to comment Share on other sites More sharing options...
snowlover2 Posted November 14, 2011 Share Posted November 14, 2011 Looks like a small line of storms developing in western IN/eastern IL at this moment. Link to comment Share on other sites More sharing options...
Hoosier Posted November 14, 2011 Author Share Posted November 14, 2011 00z NAM looks to be a couple mb deeper with the surface low. Link to comment Share on other sites More sharing options...
Jim Martin Posted November 14, 2011 Share Posted November 14, 2011 00z NAM Sounding for Findlay at 4pm tomorrow. 3km CAPE looking good. So is helicity. Just wonder if Findlay will be too far north of the severe weather risk tomorrow in Ohio. Link to comment Share on other sites More sharing options...
Hoosier Posted November 14, 2011 Author Share Posted November 14, 2011 00z NAM looks to be a couple mb deeper with the surface low. Also a little more instability. There are pockets of 700-800 J/kg MLCAPE showing up in IN/OH. Link to comment Share on other sites More sharing options...
Hoosier Posted November 14, 2011 Author Share Posted November 14, 2011 Very impressive bulk shear Link to comment Share on other sites More sharing options...
theweatherman12 Posted November 14, 2011 Share Posted November 14, 2011 Well i am going to a analysis on the severe weather threat for the Ohio Valley on Monday November 14th 2011 Well my thoughts on this is coming off the 00z NAM Model, i think tomorrow will be a rather interesting day severe weather wise for the fall season, I've been watching this situation for the last several days, it seemed like severe weather was possible, but i doubt that it would have been a tornado threat, i thought damaging wind gust or two were going to be likely earlier on, and i saw that some the models were starting to show a decent warm sector and some good shear for this time of the year. The SREF Models from the Storm Prediction Center was starting to show a severe threat, on the Day 2 this morning i thought there would've been a Slight Risk out for the Upper Ohio Valley, but there was a sliver of a 5% severe risk for liner wind gusts from low topped storms. Then the afternoon SPC Day 2 update came, and the adjusts seemed more right, the text was more beefy sounding, but seemed conservative just a bit. Now the 00z NAM Model run has just came off the wire, and i was impressed MLCAPE across the warm sector from Eastern Indiana to Western Pennsylvania is 250 j/kg to 800 j/kg which is a decent amount for severe weather during fall and winter months. When the EHI Values start to increase tomorrow across the threat area, it will look best from Western Ohio to Western PA. Lift Index will range from -1 to possibly -4 across the warm sector tomorrow. There are some impressive 0-1KM SRH in the Ohio Valley with values of 200 with an area of 300 in an area from Zanesville Ohio to Pittsburgh Pennsylvania. 500MB Winds 70 to 80 Kts over the Warm Sector, and SFC Bulk Shear of 35-45 Kts over the Warm Sector, which will favor storm rotation. The new run of the NAM also does show a 1000MB low over NW Ohio/SE Michigan during afternoon. This situation looks pretty good. It's starting to look like we might see a handful or two of tornadoes (and perhaps a strong one or two from Central Ohio to Western PA), and also damaging winds is likely, with some small hail likely. It will be interesting to see what the SPC puts out on the new day 1 outlook later. I think the will have the probs. raised to a high end slight risk Link to comment Share on other sites More sharing options...
Thundersnow12 Posted November 14, 2011 Share Posted November 14, 2011 00z NAM looks to be a couple mb deeper with the surface low. quite a bit actually, 999mb near IKK at 18z tomorrow with a better response to the sfc winds due to stronger p-falls. Link to comment Share on other sites More sharing options...
TheWeatherPimp Posted November 14, 2011 Share Posted November 14, 2011 DAY peaks at just over 1100 J/kg MLCAPE Link to comment Share on other sites More sharing options...
Hoosier Posted November 14, 2011 Author Share Posted November 14, 2011 quite a bit actually, 999mb near IKK at 18z tomorrow with a better response to the sfc winds due to stronger p-falls. There's some decent backing near the sfc low/front but question about how much instability can make it up there. Otherwise the winds are veered farther south in the warm sector and I think that will be tough to avoid unless we see better deepening. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted November 14, 2011 Share Posted November 14, 2011 There's some decent backing near the sfc low/front but question about how much instability can make it up there. Otherwise the winds are veered farther south in the warm sector and I think that will be tough to avoid unless we see better deepening. Exactly, the sfc winds are S-SSE right on the front but hardly any instability to work with that far north. 60 dews get up to you on this run of the NAM. Link to comment Share on other sites More sharing options...
Hoosier Posted November 14, 2011 Author Share Posted November 14, 2011 I'm usually wrong but my guess for the 6z outlook is 30% wind, 15% hail, 5% tor. I think the risk area will be adjusted/expanded northwest. Link to comment Share on other sites More sharing options...
tornadotony Posted November 14, 2011 Share Posted November 14, 2011 I'm usually wrong but my guess for the 6z outlook is 30% wind, 15% hail, 5% tor. I think the risk area will be adjusted/expanded northwest. The NAM trends are a bit disturbing. Still not sure exactly how this is going to evolve, but it could certainly get interesting. Link to comment Share on other sites More sharing options...
Hoosier Posted November 14, 2011 Author Share Posted November 14, 2011 The NAM trends are a bit disturbing. Still not sure exactly how this is going to evolve, but it could certainly get interesting. I don't think we'll have problems realizing the NAM CAPE values. Tomorrow is ripe to overachieve with the strong SSW flow. If we somehow end up with less veered sfc flow then look out. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.