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Rainshadow

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Everything posted by Rainshadow

  1. Hello, with this weekend system Tom & I will start the new cold season qpf verification. Like last season, we will wait until there is a clear end within 84 hours (to include the nam & sref) before starting any evaluations. Last season it was all about the EPS: out of 48 events, it came in first place 20 times. While the GEFS gave it a run for its money, the NAM came in last place in 16 events. If all models had equal skill, they would have come in first/last place 8 times each. This is the average error & bias (in inches) for all events: This was the accumulative stats for predicted/observed snow events at PHL:
  2. Rainshadow

    Temps/Obs/Boring Weather Discussion

    We hit the 50 page threshold, so with the start of the new season, we will start a new thread. The 69F at Midnight cost PHL the chance to tie 1978 for the most number of days with mins of 70F or higher for August.
  3. Last time PHL had a September with an average temperature less than 70F was 2013.....
  4. Sounds like we are starting another spread sheet.
  5. It looks like the sref just won this completed event. EC & GFS family were both too low.
  6. It does tend to run too cold. This is really all about the evap cooling between 850mb and 700mb and then the waa at the same levels. Farther inland, yes surface temps may be an issue.
  7. It is within the Philly will measure range now.
  8. Combination going on here. There is the modeling error (all would be), Cowan algorithms that have snowfall accumulating where ptype is rain (not even sleet) and also treating sleet as a 10:1 ratio. Here is a verification map that covers the approximate forecast time we are looking at. Little Rock snow weenies are angry this morning.
  9. Looks like the 546 rule of thumb is going to be put to test with this one.
  10. I wouldn't ignore the front end. Granted not all snow, but sure looks like a prolonged period of sleet and farther north freezing rain.
  11. Just a PSA, there remains issues (beyond the usual and typical issues) with TTidbits snowfall accumulation maps for the FV3 GFS. Pivotal's algorithms right now are better. Yes it is the same model run, thru the same valid time, same 10:1 slr algorithm ratio.
  12. Yup, could see some freezing rain out of this where cold air gets trapped in the higher terrain, maybe even threatening it along the Paul-Tom-Chris axis in the northwest burbs.
  13. Models do struggle to predict warm air aloft between 850mb and 700mb. As Tom posted above, it has to be pretty much thumping to get snow above a 546 thickness around the local Philly area.
  14. 00z NOV 10th GEFS Topsy-turvy with 500mb departures this upcoming week. We start below, get above oh the 12th, below on the 13th, above on the 15th and below on the 17th. The above on the 15th as a forecast was missed on the previous post. Stretching the limits but above normal heights on the 18th-22nd look to be warmest part of this run with greatest departures near us. After that a trof / ridge /trof conus combo brings below normal heights on the 23rd. Run ends with a deeper west coast trof and near normal heights here on the 25th. -NAO east is there, but so is Aleutian Ridge, GEPS looks better in the pacific at end of run. EPS looks above normal Thanksgiving week, so more in GEFS camp. 00z NOV 12th GEFS Above normal 500mb heights arrive on the 15th before the Thursday-Fri event. I smell sleet. Below normal 500mb heights then return on the 17th and continue into Thanksgiving Day. This is a total flip from two days ago (highlight above). Ninoish pattern with near normal heights over us and below southern conus thru Thanksgiving weekend. Then below normal heights return for the start of the following week 27th-28th (as far as run goes). GEPS not as cold, As Tom noted EPS not exactly the same.
  15. Rainshadow

    20s club, the destruction of the figs

    27F with frost. They survived yesterday, today not so much.
  16. CFS2 Monday Weeklies for 11/12 December Still Looking Good (La La Land Caveat) Week 1......Ridge / Trof / East Coast Ridge combo Week 2......Eastern Pacific Trof/ Zonal Conus Flow / -NAO East Week 3.....Western NOAM Trof / Eastern NOAM Ridge Weeks 4 thru 6, other than being weeks 4-6, the set up is ideal for cold, Aleutian Trof, West Coast/NOAM Ridge, Great Lakes or Eastern NOAM Trof. Week 5 did advance to week 4. Week 1 Verification............0F (0F)......over. Actual -2F. Temps Previous Monday Outlook for same week in parentheses. Week 1............-7F (-4F)........under....Tom's Halloween candy is sweet. Week 2............-5F (-2F).......over but still below Week 3............+1F (+2F)......over Week 4............+1F (-1F)......under Week 5............0F (0F) (TTidbits)...under Week 6............-1F (TTidbits)...under Pcpn Week 1..........wet Week 2..........dry Week 3.........dry Week 4.........dry Week 5..........dry (TTidbits) Week 6..........wet (TTidbits)
  17. Well this November is not doing anything to take away from a typical weak to moderate el nino winter. The temp recovery keeps on getting pushed back and November's first week is getting erased locally. The Alaskan warm pool has not been going anywhere.
  18. Given the ground is warm, I think (dangerous I know) this would be more of a bridge/overpass issue and ice clinging to trees, etc if it came to be.
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