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About dallen7908

  • Rank
    Atmospheric Scientist

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  • Four Letter Airport Code For Weather Obs (Such as KDCA)
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  • Location:
    College Park, MD

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  1. dallen7908

    MLK Weekend Event - Making Lemonade Out of Lemons

    Not necessarily ... grab your cell phone ... purchase a sling psychrometer ... have it delivered by a drone ... open the package ... read the directions ... take it outside ... measure the wet bulb temperature ... estimate the RH from the wet bulb temperature using https://www.sailangle.com/articles/details/id/10 ... Go to http://www.sciencebits.com/SnowProbCalc?calc=yes ; plug in the RH and T Estimate your chances
  2. dallen7908

    January Banter 2019

    I'm back after a week at the AMS meeting in Phoenix and a few days vacation in the Tucson area. Did I miss anything? Ironically, I also missed last March's storm due to a trip to spring training, the St. Patrick's Day storm in 2014 due to business trip, Commutageddon in 2011 due to AMS, ... My next out of town trip -- February 14 - 20
  3. dallen7908

    January Medium/Long Range Discussion

    CPC on board for transition to colder than average pattern and wintry precipitation for mid-Atlantic (week 3-4 discussion lead by S. Baxter) http://www.cpc.ncep.noaa.gov/products/predictions/WK34/
  4. dallen7908

    January Medium/Long Range Discussion

    I wouldn't call 1989-1990 a horrible winter. Although my memory may be faulty, I recall snow on Thanksgiving eve and being very cold watching Macy's parade in NYC. I also recall snow in early December; much of which sublimated. I recall ice skating on local ponds I also remember an abrupt end to winter between XMAS and New Years. I suspect he is saying that the 2nd half of the winter is unlikely to be mild and snowless but based on 89/90 alone he could be saying that the transition will not be as abrupt as 89/90
  5. dallen7908

    January Medium/Long Range Discussion

    Thanks for stepping up and taking over as bannerman for a mid-month pattern change ... may the odds be ever in your favor
  6. dallen7908

    January Medium/Long Range Discussion

    How long does it take for a "perfect" pattern at 85000 feet to translate into a snow storm at the surface (for us)? Can I just add 20-30 days to the 16 day forecast?
  7. dallen7908

    January Medium/Long Range Discussion

    Likely, wrong but over the next 10 days the EURO for my backyard has more days with highs in the 60s (4) than below 50 (3) ... and two of those below 50 highs are 49.
  8. dallen7908

    January Medium/Long Range Discussion

    Looks like the next rain event on the Euro ends just as the New Year begins --- a good sign?? Is that wraparound snow the Euro is showing early morning to the NW of DC on the 5th; the Low appears to be well past us. Is the January 8/9th storm still forming or is it that clipper moving across New England?
  9. dallen7908

    January Medium/Long Range Discussion

    That's a good question. I wonder if the upgrade will be delayed due to the partial government shutdown.
  10. dallen7908

    January Medium/Long Range Discussion

    Yes does look encouraging; however, note the increasing low-bias in the model forecast with time. This bias is one reason why on average models' 7-14 day climatologies are colder and stormier than reality.
  11. dallen7908

    December/January Medium/Long Range Discussion

    The 12UT Dec 23 and 00 UT Dec 24 EPS give College Park a 30% chance of >1" of snow during the day 8-11 time period. However, the chance for >3" of snow during this period has decreased from 18% for the 12UT run to 8% for the most recent run. Interestingly, the chance of >1" increases by ~2% (1 ensemble member) per 12-hour period between days 10 and 15 reaching 46% by day 15. As expected as this range, the models have no clue which shortwave to focus on.
  12. dallen7908

    December/January Medium/Long Range Discussion

    Week 3-4 Forecast Discussion Valid Sat Jan 05 2019-Fri Jan 18 2019 http://www.cpc.ncep.noaa.gov/products/predictions/WK34/ "While we do not issue explicit forecasts of winter weather potential at this lead, it would seem prudent to note that the forecast circulation pattern would favor an enhanced chance of winter storm events east of the Appalachians, including the major population centers of the Mid-Atlantic and Northeast, especially later in the period."
  13. dallen7908

    December/January Medium/Long Range Discussion

    EPS gives DCA a 34% chance of >3" of snow between days 10 and 15. 40-50% chance in northern Maryland