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    State College, PA

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  1. Pretty cool seeing the back-door front come through here; the temperature dropped from low 70s to mid 50s and the winds picked up and shifted to northeasterly.
  2. The Euro has the pressure "only" down to 987 mb 12z Tuesday when it will be affecting our region; it does drop to 973 mb once it reaches coastal Maine. As you can see in the NARR image the superstorm had SLP values in the 970s over the mid-Atlantic. The pressure gradient was therefore much stronger during that event over central PA than the forecasts for this storm. Because of the early phasing, the storm was quite intense all the way up the east coast, producing heavy snow and blizzard conditions from the southeast to New England.
  3. Yeah, this is not March '93. That storm had a full phasing of the northern and southern streams over the southeast US.
  4. The 00z Euro had significant differences with respect to yesterday's 12z run in how close to the region the easterly 700 mb flow component gets. That difference seems to be a consequence of how much interaction there is between the primary low and the shortwave moving through the southeast. I would want to see how that feature plays out in future guidance to get a better sense of the potential for more intense banding over the northern and western parts of the subforum. Even the region north of I78 had substantially less QPF on the 00z GFS and yesterday's 12z Euro compared with last night's 00z Euro.
  5. It will be interesting to see how wrapped up the system gets as it intensifies off the mid-Atlantic coast. The 12z GFS has more interaction compared to the 12z Euro between the 500 mb low over the Great Lakes and the shortwave over the southeast, leading to a more intense system closer to the coast. As a result, the enhanced easterly 700 mb flow reaches farther inland and leads to stronger banded precip over eastern PA. We would have to watch the dry slot in this scenario given the stronger dry air intrusion that would occur with a more wrapped up system. In contrast, the 12z Euro has less interaction between the two 500 mb features and thus a weaker and farther east track. Most of the heavy precipitation depicted by that model occurs closer to the low pressure center than in the GFS depiction. I will be in the DC area for a conference during this event and thus in the strange position of rooting for the mid-Atlantic to get hit.
  6. I've seen a lot of references to the Kuchera snow ratio, but there's nothing published about so I have no idea if it is an improvement over 10:1 or not. Forecasting snow ratio is difficult because you have to account for snow growth, aggregation, riming, and melting throughout the atmosphere as ice particles fall to the ground. Probably the easiest way to estimate snow-liquid ratio is to start with climo, adjust upward if there is a favorable region for dendritic growth, adjust downward if temperatures are colder than -20 degrees C or warmer than -12 degrees C throughout the profile, and adjust downward if there is any part of the profile close to freezing. Here is a map of snow-liquid ratio climatology for the US: http://www.eas.slu.edu/CIPS/SLR/slrmap.htm
  7. It's associated with deformation at 700 mb increasing the thermal gradient (i.e., frontogenesis) and producing lift. I haven't measured the snow accumulation here, but there is noticeably more snow on the trees now compared to before the band was over us.
  8. Getting some larger aggregates now with the heavier band of precipitation.
  9. Yeah the lapse rates tomorrow afternoon look pretty impressive; the 12z 4K NAM has a most absolutely unstable layer at MDT between 900-800 mb and ~150 J/kg CAPE. Conditions are basically perfect for that with strong cold air advection aloft and surface warming with the increased mid-March sun angle.
  10. Pretty low visibility here with the squall.
  11. Heard some thunder this morning. The convection this morning may not allow for much destabilization later and will probably limit the instability, at least over central PA. However, we may still have a threat for strong winds as an MCS develops later today and mixes the high momentum air to the surface. There could still be some more discrete convection in SE PA as that area probably has a better chance of clearing out before the MCS arrives, and may be initiated by the gust front and/or the residual outflow boundaries from the morning/early-afternoon convection.
  12. The 4K NAM has very impressive soundings for south central PA on Wednesday afternoon. Hodographs are elongated and curve rightward with the large increase in wind speed and veering from the surface to 850 mb. With surface temperatures in the low 70s, dew points in the low 60s, and cold air aloft, CAPE is substantial enough for severe convection. I almost wonder if the shear is strong enough to inhibit convection to some degree given modest, but not exceptional instability. Like MAG said, if we get discrete convection initiating ahead of the surface front, these storms could be in an environment highly favorable for supercells and potential tornadoes. The GFS has less instability with lower surface temperatures and dew points, and thus a less favorable environment. Either way, we may still have a damaging wind threat as any convection could mix the strong winds at 700 mb down to the surface.
  13. Was just about to post this...freakishly warm stretch this week. It will also be the only time we have recorded two 70F+ temperatures in February.
  14. Is it really "paying the price" if you want it to happen? But I agree that snow is still quite common in March, especially in central and northern PA.
  15. It would be amazing if Albany ended up with more snow than Buffalo. My family in Albany still has over a foot of snow on the ground.