Welcome to American Weather


  • Content count

  • Joined

  • Last visited


  • Rank
  • Birthday 05/27/1984

Profile Information

  • Gender
  • Location:
    Naperville, IL
  1. We'll see what the 00z Euro run shows tonight but the 12z run slightly trended toward the GFS and Canadian which have been consistently showing the more active ring of fire type setup being farther south into IA, IL and IN. It's all about the strength and position of the ridge, which looking at Thursday's 12z Euro vs Friday's, Friday's run showed a bit weaker and farther southwest mid level ridge position.
  2. Maybe worth creating a dedicated thread for this upcoming stretch? Large scale pattern is quite favorable for multiple rounds and likely across the subforum, starting with later Sunday-Sunday night through Monday-Monday night. With a persistent huge CAPE reservoir and likelihood of enhanced northwest mid-level flow associated with any stronger shortwaves, this appears to be one of the better extended stretches of potential for a larger area in recent years. Sent from my SM-G935V using Tapatalk
  3. Can't rule out rapid upscale growth with this setup but to me this seems similar to what we've since several times since 2010 with strong west to west northwest flow aloft. It seems that the default tendency is for SPC to favor MCS development but with the very favorable directional and speed shear and orientation to boundary, discrete/semi-discrete supercells appear probable for a while followed by possible eventual congealing/upscale growth. Am favoring the GFS and ECMWF for now given that the NAM12 appears convectively contaminated but what the globals show especially with GFS and ECMWF now in pretty good agreement, what they paint is a pretty ominous scenario for eastern IA, northern IL and southern WI late day Saturday through the evening. If the 12z 12km NAM scenario somehow becomes favored, then all bets are off.
  4. That's exactly what I was thinking upon seeing the outlook. Pattern recognition alone and pretty decent consistency on the guidance in the track, strength and timing of the synoptic system should enable one to outline a broad area where severe is possible and then fine tune it with subsequent outlooks once trends become more clear. To the less informed user, it appears severe storms are unlikely, whereas at the WFO level we've been mentioning the conditional severe potential for the past few days in AFDs.
  5. Yeah, looks like you'll end up with hefty totals there. Thankfully though it's been wet overall, it had been relatively quiet over the past week or so.
  6. 1) I think the mosaicked basin average qpf had widespread 4-6" basin average amounts. There might be a way to check that on NCRFC page but not sure. 2) Most often, 24 hour qpf is used, with 48 hour some of the time and in rare cases 72 hour because qpf is so fickle/tough to forecast accurately. That's also a good reason why 48 hour may have been a better choice for this event.
  7. Wanted to offer comment on the very high river forecasts that went out. This is not meant to throw the North Central River Forecast Center under the bus. However, all forecasts for this area are issued by NCRFC in collaboration with NCRFC. They decided to go with 72 hour qpf for this event to catch the storm total but the qpf used in their forecast hydrographs yesterday was extremely high. They went with that bullish forecast and we didn't have too much advanced notice of it, but what we did do is go with flood watches instead of warnings because the forecasts are entirely qpf driven. In hindsight, we could have done a better job of working with NCRFC to play things more conservatively to start out and then adjust upward as trends became more clear. For example, perhaps we could've requested to just use 48 hour qpf, or to adjust the qpf for the models down 25% or thereabouts. Given the potential impacts of the stages being forecast, I definitely understand the angst and criticism, especially if it doesn't work out due to convection south robbing the moisture transport. Sent from my SM-G935V using Tapatalk
  8. 100% valid concern, if cape is even less than what's being progged then any updraft attempt near WF/TP could get sheared apart. Also wondering if kinematics of mature and strengthening synoptic system help overcome the potential negating issues.
  9. Yep agree, was focusing on IL but the threat could extend farther east as well. The mid and upper winds are also a bit more veered with eastward extent as well. Hard to say if NAM is handling synoptic side well yet but it does typically do a better job depicting low level instability than GFS. Had pulled a sounding with >100 j/kg 3km CAPE from NAM in central IL and if storm mode can remain discrete that would get it done given magnitude of LL shear. Sent from my SM-G935V using Tapatalk
  10. Definitely agree on potential severe threat on Sunday. Very high shear, especially low level, low cape and very moist/low LCL setup, with NAM being on more bullish side with instability. If the low level cape is sufficient, an appreciable tornado threat could get into or near LOT CWA. Could see warm front being reinforced south by convection a bit and thus late to get into CWA. For that reason, my guess is SPC brings a slight risk up to ILX CWA and marginal into southern LOT CWA on day 3 outlook. Interested to see what they do.
  11. Did you happen to catch the comparison graphic my office put up for the 18z 12km and 3km NAM runs? The 3km NAM gets more rain into the metro area but still nowhere near close to the NAM and the globals. Obviously can't take the 3km NAM solution verbatim but it's been showing a reasonable depiction of how convection could rob moisture transport well north of the warm front. WPC seemed to be accounting for that in their placement of the day 3 excessive rain outlook.
  12. With a lead supercell right across the Chicago metro during the early evening.
  13. 00z 12km NAM does have a discrete signal from Kankakee into north central IN tomorrow 21-00z. It'll definitely be a day to monitor the GOES-16 data closely. Presumably we'll be in a mesoscale sector tomorrow, so we'll be able to watch for bubbling cu along the warm front. Sent from my SM-G935V using Tapatalk
  14. Quite the interesting looking warm front setup from IA into western and central IL on Wednesday afternoon and evening. Pretty good agreement overall on the 12z operational guidance. Excellent directional shear with backed surface flow, southwest at 850 and west or even west-northwest at 500, along with dew points pooled into the 60s along the front. Sent from my SM-G935V using Tapatalk
  15. I'm not sure of additional surveying because I'm out of the office, but additional information is still being gathered. There is video that should help with additional determinations, as well as possibly more surveying.