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Everything posted by Newman

  1. Probability of Watch Issuance...80 percent SUMMARY...The severe threat is increasing across portions of central PA into MD. Damaging gusts and perhaps a few tornadoes may accompany the strongest, longer lived storms. A WW issuance will be needed within the next couple of hours. DISCUSSION...A remnant mid-level MCV (evident via water vapor imagery and 700-500 mb objective analysis fields) is currently located just west of the OH/PA border and continues to track eastward towards central PA, and is expected to support more robust convective initiation in the next few hours. Immediately ahead of the MCV center lies a highly sheared low-level environment, with recent PBZ VAD data showing relatively long, curved low-level hodographs and over 300 m2/s2 of associated 0-1km SRH. At the moment, buoyancy remains scant across portions of western into central PA. However, modest breaks in the clouds are contributing to modest surface heating, with mid 60s F surface temperatures already noted across central PA, with low 70s F along the PA/MD border. With surface dewpoints around 60F across several locales, RAP forecast soundings suggest temperatures need to warm into the lower 70s for appreciable buoyancy to develop given the presence of relatively poor (5.5-6.5 C/km) low and mid-level lapse rates. While buoyancy is expected to initially be marginal (i.e. at or below 1000 J/kg MLCAPE), localized deep-layer ascent and strong low-level shear associated with the approaching MCV should support at least a few strong to severe storms developing early this afternoon. Damaging gusts and perhaps a few tornadoes will be the primary concerns, though a brief instance or two of marginally severe hail cannot be completely ruled out with the longer-lived, persistent rotating updrafts. A WW issuance will be needed within the next couple of hours to address the severe threat.
  2. SPC just bumped tornado probs to 5% and expanded the slight risk. We have a warm front draped just north of the region, with an approaching potent MCV... boy it *could* be quite the severe weather day. Possible supercells and a bow-echo will be the main storm modes
  3. Could see some legit storms move through central PA today. Anytime you have a remnant MCV approaching with sufficient sunshine and instability... oh boy watch out. We'll see if the capping near the surface helps to downplay the event, but as of now 5% risk of tornadoes from the SPC and a slight risk overall.
  4. 45% damaging wind probs today. I could possibly see an upgrade to moderate if conditions appear even more favorable for a squall line
  5. Western posters could see 70s and possibly an 80 for the Pittsburgh folk, us in the LSV will be socked in the 50s and low 60s with the easterly fetch and clouds sticking around
  6. Models are definitely too warm. HRRR and NAM says much of the LSV should be 41-43.... but no one (or nearly no one) is above 40 right now. 39 at Millersville. Could definitely see sleet (or stray snow flakes) mix in with the heavier stuff this evening here in Lancaster
  7. HRRR and NAM have very impressive long hodographs for the LSV this evening. What will likely limit the severe chances is the lack of instability with lots of morning cloud debris. IF we can see sun pop out this afternoon and increase CAPE values, there is LOTS of bulk shear and SRH for the storms to tap into. Tornadoes are a real threat, although damaging winds will be the primary.
  8. Snow has lightened here in Millersville. Probably 1-2" of accums on grass and colder surfaces. Roads are slushy
  9. Snow in Lancaster now, grass and cars caving immediately. 34°
  10. Just started snowing here in Lancaster, temp is dropping quick. 34° and sticking tk grass already
  11. Sun angle and rates will be a factor, yes... but with the crashing temps in the wake of the front I still don't think it'll be that much of an issue. I've seen 6" of snow in April a few years ago. With the heavier rates and plummeting temps forecasted, I think roads will be covered and colder/grassier surfaces will still see a decent accumulation. Those of us in Berks and the Lehigh Valley should expect 4-6" of snow, with probably 3-4" on roads and pavement if the rates do come in heavy. Also, don't forget about the winds behind and during this system. Should see some decent gusts and sporadic tree damage/power outages.
  12. 12z CMC is impressive for Berks and the Lehigh Valley with 6+"
  13. NAM and Euro seem on board for a decent advisory, maybe warning level, event for those especially NW of the fall line and into the Lehigh Valley. EE Rule?
  14. https://www.thriftbooks.com/w/meteorology-today-introductory-weather-climate--environment-an-introduction-to-weather-climate-and-the-environment_c-donald-ahrens/20323561/item/43492526/?gclid=CjwKCAiApfeQBhAUEiwA7K_UHxNMEWTNmfi3gcnDaax_tgAH84e7KbH62lNyEDLiqHjIj3gVXJHCjBoCJxMQAvD_BwE#idiq=43492526&edition=21646488 ^^This was an optional text for my intro to meteorology course
  15. Precip came in pretty heavy here in Millersville. Little ice accretion due to the heavy rates
  16. Mount Holly ice forecast and 18z RGEM below. Definitely not going to see 1" of ice like the RGEM, but parts of the Lehigh Valley could definitely see up to, or perhaps over, 0.5" of ice. I still think sleet will keep accretion down
  17. It'll be interesting to see how much accretion actually occurs considering it could reach 70 in spots Wednesday
  18. The CMC has a ton of freezing rain and sleet for Friday
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