high risk Posted April 1 Share Posted April 1 1 hour ago, Kmlwx said: NAM and NAM nest seem better with parameters for Thursday now - but sim reflectivity doesn't really have any initiation at least on the panels I've seen (through 0z Fri). Right. Parameters, especially the shear, are very favorable Thursday. But will there be a trigger? As you noted, the NAM says no, but the HiResW FV3 opens the door to at least a few cells in the Mid-Atlantic. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted April 1 Share Posted April 1 18 hours ago, Kmlwx said: TBWI shows outflow moving out ahead of the storms. Classic issue when we have bad mid level lapse rates and dry air at the surface. Storms just can't get above 10,000 feet and the updrafts kick the storms apart. Link to comment Share on other sites More sharing options...
Kmlwx Posted April 1 Author Share Posted April 1 7 minutes ago, Eskimo Joe said: Classic issue when we have bad mid level lapse rates and dry air at the surface. Storms just can't get above 10,000 feet and the updrafts kick the storms apart. And my excuse of "it's still early in the season" gets less relevant each passing day. By April, we often have much better thermodynamic profiles - though May/June would be even better. Though that admittedly won't solve mid-level lapse rates! I will say - yesterday ahead of the storms did feel juicier than the prior few events this year so far. So we are "getting there" in terms of better dew points and temps. One thing I do like is that we haven't had a shortage of "chances" this year so far. While there has sometimes been a week+ between risks, there's been a pretty steady stream of at least potential systems showing up. Thursday has my interest at least for now. 3 Link to comment Share on other sites More sharing options...
Kmlwx Posted April 1 Author Share Posted April 1 12z CSU MLP maps 2 Link to comment Share on other sites More sharing options...
Kmlwx Posted April 1 Author Share Posted April 1 18z NAM and NAM nest continue with the theme of no initiation/storms for Thur. Parameters look a bit worse than prior runs as well. Still worth watching. Link to comment Share on other sites More sharing options...
high risk Posted April 2 Share Posted April 2 Early take on Thursday: some CAMs have storms in the area by late afternoon or early evening, and some don't. If, however, storms do form, the environment actually features some decent low-level shear and a resultant conditional tornado threat. 2 Link to comment Share on other sites More sharing options...
yoda Posted April 2 Share Posted April 2 SLGT risk up for Thursday 2/5/15 .OH Valley into the Mid Atlantic... Complications abound from overnight convection likely persisting into the daylight hours across the OH Valley. The front is forecast to continue to sag south and stall eventually across the OH Valley and Mid Atlantic by midday Thursday. South of the boundary low 60s F surface dewpoints and some filtered diurnal heating should support around 1000 J/kg of MLCAPE. Several embedded mid-level perturbations may provide enough ascent for additional convective development through the day. Vertical shear will remain strong as increasingly zonal winds aloft overspread the frontal zone. Several clusters of strong to severe storms are possible along the front with a risk primarily for damaging winds and tornado or two, given the relatively poor mid-level lapse rates and veered low-level flow. Link to comment Share on other sites More sharing options...
WxUSAF Posted April 2 Share Posted April 2 Wide range of options on 12z mesos. I vote FV3. Link to comment Share on other sites More sharing options...
yoda Posted April 2 Share Posted April 2 2 hours ago, WxUSAF said: Wide range of options on 12z mesos. I vote FV3. 12z HRRR wasn't too bad either... 12z WRF-ARW looked decent in MD Link to comment Share on other sites More sharing options...
high risk Posted April 2 Share Posted April 2 2 hours ago, WxUSAF said: Wide range of options on 12z mesos. I vote FV3. Yeah, lots of uncertainty, but most of the CAMs (NAM Nest is notably bearish) have at least a couple of cells - a widespread severe event does not appear likely, but localized severe appears to be on the table. I maintain that there is a slightly higher tornado risk; SPC notes the veered surface winds but that may be offset by a greater westerly component in the flow just above. More widespread storm coverage may be possible later Thursday night, but these would have very limited severe potential. 2 Link to comment Share on other sites More sharing options...
yoda Posted April 2 Share Posted April 2 Still 2/5/15 on 1730z SPC OTLK... but 15% hail was moved NE into W VA and WV Link to comment Share on other sites More sharing options...
yoda Posted April 2 Share Posted April 2 Day 2 1730z SPC OTLK disco for our region ...Kentucky to the Mid-Atlantic... Day 1 convection and cloud cover will significantly inhibit severe weather potential on Day 2 along the frontal zone from Kentucky to the Mid-Atlantic. Trimmed probabilities farther south near the Ohio River based on latest forecast front location. Otherwise, a moist airmass will remain in place along and south of the front/remnant outflow. Therefore, only minimal heating will be needed for some storms to develop which could be supercellular given 45 to 55 knots of effective shear along the frontal zone. Overall height rises should keep stronger storm coverage isolated to potentially scattered. Some damaging wind/large hail, and perhaps a tornado threat may exist within this corridor on Thursday, but the exact locations of this threat remains uncertain at this time. Link to comment Share on other sites More sharing options...
yoda Posted April 3 Share Posted April 3 @high risk why would looping hodos suppress updraft development? Too much wind shear? NEAR TERM /THROUGH TONIGHT/... A warm front lifting north of the area today combined with southerly flow from high pressure offshore, will lead to plenty of warm and moist air in the forecast area. Additionally, a cold front approaching from the west will create an environment conducive to rain showers and possible severe thunderstorms. Moderate CAPE, strong shear, and the frontal boundary approaching during peak heating lead to possible strong to severe thunderstorms. That being said, model soundings show looping hodographs, due to wind shear,which may suppress updraft development.Showers and a few thunderstorms continue this evening and into the overnight as the cold front moves through the forecast area. Link to comment Share on other sites More sharing options...
yoda Posted April 3 Share Posted April 3 I'll take the 06z and 07z HRRR btw. Wonder if that severe squall line out west will be laying down boundaries for this afternoon 06z NAM NEST still not enthusiastic for really anything, 06z NAM now shows storms coming in around 21z 00z FV3 also not enthusiastic... 06z RAP seems its very enthusiastic lol Link to comment Share on other sites More sharing options...
yoda Posted April 3 Share Posted April 3 @Kmlwx you'd like the 08z HRRR helicity swath lol Sim radar looks pretty nice on that run as well Link to comment Share on other sites More sharing options...
Kmlwx Posted April 3 Author Share Posted April 3 20 minutes ago, yoda said: @Kmlwx you'd like the 08z HRRR helicity swath lol Sim radar looks pretty nice on that run as well Goes north of me but that HRRR run looks pretty good for storms. Link to comment Share on other sites More sharing options...
Kmlwx Posted April 3 Author Share Posted April 3 CSU MLP for today 4 Link to comment Share on other sites More sharing options...
Kmlwx Posted April 3 Author Share Posted April 3 It was pretty darn misty and damp out there this morning on the way to work. I'm closer to meh-ing than I am to "woo storms-ing" lol 1 Link to comment Share on other sites More sharing options...
yoda Posted April 3 Share Posted April 3 2 minutes ago, Kmlwx said: It was pretty darn misty and damp out there this morning on the way to work. I'm closer to meh-ing than I am to "woo storms-ing" lol I think we are waiting for the WF to come through later Link to comment Share on other sites More sharing options...
high risk Posted April 3 Share Posted April 3 4 hours ago, yoda said: @high risk why would looping hodos suppress updraft development? Too much wind shear? NEAR TERM /THROUGH TONIGHT/... A warm front lifting north of the area today combined with southerly flow from high pressure offshore, will lead to plenty of warm and moist air in the forecast area. Additionally, a cold front approaching from the west will create an environment conducive to rain showers and possible severe thunderstorms. Moderate CAPE, strong shear, and the frontal boundary approaching during peak heating lead to possible strong to severe thunderstorms. That being said, model soundings show looping hodographs, due to wind shear,which may suppress updraft development.Showers and a few thunderstorms continue this evening and into the overnight as the cold front moves through the forecast area. I’m not totally sure, but I think they’re referring to the profiles having stronger winds in the mid levels and then weaker winds above, creating looping hodographs. Those can sometimes prevent proper tilting of the updraft/downdraft structure needed to maintain persistent strong updrafts. We’ll see if the upper level winds are really weaker. 1 3 Link to comment Share on other sites More sharing options...
Kmlwx Posted April 3 Author Share Posted April 3 Just now, high risk said: I’m not totally sure, but I think they’re referring to the profiles having stronger winds in the mid levels and then weaker winds above, creating looping hodographs. Those can sometimes prevent proper tilting of the updraft/downdraft structure needed to maintain persistent strong updrafts. We’ll see if the upper level winds are really weaker. I'm pretty close to calling you out as a meteorology AI robot. You always have superb explanations and insight. We're watching you though....robot. 2 2 Link to comment Share on other sites More sharing options...
high risk Posted April 3 Share Posted April 3 2 hours ago, Kmlwx said: CSU MLP for today I’ve been saying that today has some sneaky tornado potential, confirmed by the CSU prog above. I think that storm rotation is somewhat likely today but 1) I’m still unsure about storm coverage 2) sfc winds might be a bit weak too weak let’s see how much we warm this afternoon. Nam nest has the coolest temps and therefore the least storm coverage. 3 Link to comment Share on other sites More sharing options...
Kmlwx Posted April 3 Author Share Posted April 3 2 minutes ago, high risk said: I’ve been saying that today has some sneaky tornado potential, confirmed by the CSU prog above. I think that storm rotation is somewhat likely today but 1) I’m still unsure about storm coverage 2) sfc winds might be a bit weak too weak let’s see how much we warm this afternoon. Nam nest has the coolest temps and therefore the least storm coverage. It's seems like one of those weird conditional severe days where coverage is low, and who knows if we'll even see any storms pop during peak time - but if one goes up it could really dominate even if isolated. 3 Link to comment Share on other sites More sharing options...
The Dude Posted April 3 Share Posted April 3 4 minutes ago, Kmlwx said: I'm pretty close to calling you out as a meteorology AI robot. You always have superb explanations and insight. We're watching you though....robot. He's better than an AI robot; he's always right! 2 1 Link to comment Share on other sites More sharing options...
SnowenOutThere Posted April 3 Share Posted April 3 2 hours ago, Kmlwx said: It's seems like one of those weird conditional severe days where coverage is low, and who knows if we'll even see any storms pop during peak time - but if one goes up it could really dominate even if isolated. Sounds in some ways similar (though far less potential) to last years mini tornado outbreak Link to comment Share on other sites More sharing options...
yoda Posted April 3 Share Posted April 3 12z NAM and the NAM NEST aren't really enthused for anything... HRRR is though and has been for many runs Link to comment Share on other sites More sharing options...
yoda Posted April 3 Share Posted April 3 Which is interesting because if you take a peak at the 12z NAM Nest soundings, you'd think something would go. But looking deeper, I see ConvT is 84 degrees - so I'm assuming that since we aren't forecasted to reach that temperature, the NAM Nest sim radar isn't showing convection. Am I reading that correctly or am I offbase? Link to comment Share on other sites More sharing options...
Kmlwx Posted April 3 Author Share Posted April 3 CAPE inching upward in a little "tongue" where the front may have cleared. Nearly touching Southern Maryland. Link to comment Share on other sites More sharing options...
Kmlwx Posted April 3 Author Share Posted April 3 PWS is reporting 66.4 on the temp and 65.8 on the dew point. Pretty saturated surface airmass! And soupy for this time of year! Other than storm fuel - really not looking forward to 70+ dew point season. Link to comment Share on other sites More sharing options...
Kmlwx Posted April 3 Author Share Posted April 3 15z HRRR sends a nice cluster through after 0z. Funny because HRRR tends to undergo storms (at least previously when it would have dews too low) 2 Link to comment Share on other sites More sharing options...
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