Jns2183

Seeing that lightning fire up may be a sign of things developing yet . Pro

Reeser’s Summit rain shadow . Pro

It hasn’t been heavy freezing rain at all. Small droplets....perfect for accretion . Pro

High pressure might be introducing dry air to eastern areas due to its location tomorrow . Pro

I’ll never forget January 2016 when the NAM through up, what we all thought were absurd snow totals, and wouldn’t budge, as the EURO and GFS danced all around and finally caved. I remember the SREFs average really trending towards the NAM which caught my eye that both the NAM & ensemble were in lock step. . Pro

It would be nice to get 3 or so 3"-6"/4"-8" snow events to finish out feb. Haven't had a bunch of those in a month in awhile.

Please don't hold back the technical side. I truly enjoy reading the technical posts.

In the last 20 years we had below normal precipitation at KMDT the following years: 1999,2001,2002,2005,2010 So for 15/20 years we have been above normal

If MDT gets below zero you will know because rural areas in Cumberland/Dauphin counties will be -10/-15. Until I see those starting to show up I know MDT won't be below zero.

Since the Winter of 1942 we have had 6 January's where we finished with between 16"-20". They are listed below. Its such a small sample size it shouldn't be taken that seriously, considering if I have made the cut off 15"-19" the yearly average would have increased over 30" I believe, haha. SN End of Jan SN Rest of Winter Total Season SN 1946 16.70 11.40 28.10 1949 19.00 14.10 33.10 1953 17.20 7.00 24.20 1977 18.70 4.70 23.40 2011 17.40 7.70 25.10 2015 16.20 23.00 39.20 Average 17.53 11.32 28.85

Iphone screen busted yesterday. I need to wait a few days for my replacement. I usually use radarscope. What are some good online radar websites?

Thank you for the great resources!!! I have seen some errors and currently am trying to account for a significant issue I found between reported precipitation totals from KMDT and KCXY in the winter time. From 2001 through January 24th, 2019 I looked at the difference in totals from October through March. I then look at when snow was reported at KMDT that was > a Trace, and that occurred on 22.8% of days with a precipitation difference, but those days accounted for 52.13% of the total difference. Then I looked at days it snowed 3"+ which occurred on just 4.82% of the days with a difference, but accounted for 31.16% of the total difference. These differences were almost entirely one sided in that KMDT reported more precipitation. I ran a correlation between snow and difference for all the days that differences occurred in January from 2001 through present and snow was correlated at 44.5% and squaring that gives r^2 of 19.8%, which means that the fact it snowed period, can explain 19.8% of the variability in the differences of precipitation between both stations. I think KCXY must be automated and having an issue with frozen precipitation and correct totals.

Do they have all their snowfall forecast maps for each storm archived somewhere that can be accessed online?

The data certainly needs cleaned up some more. I saw some obvious errors in there in the winter time. I tried to quickly clean it up by taking out all the dates where KCXY was missing an observation (KMDT did not have any missed precipitation daily observations in the time frame) in order to show the general pattern. Almost all the large (if not all) differences were due to convective events (many tropical in nature), but it is a marked pattern I have observed. Looking at the terrain maps, nothing jumps out at me right away. I wish I knew someone knowledgeable enough regarding reasons for consistent microclimate differences to take a look at the data, local geography, prevailing patterns, etc to better explain it. I have a hunch it just has to do with regional tendencies where coastal fronts like to set-up for whichever reasons, and act like a trigger for convective activity, but who knows.

Capital City Airport started taking temperature and precipitation daily observations again on 7/30/2000. The chart below highlights the yearly and month differences in Precipitation between Capital City Airport and KMDT, a mere 5 miles apart, if that. I excluded dates where any observations where missing. Highlighted are the cells where KCXY has a positive difference. SUM of Difference Month Year 1 2 3 4 5 6 7 8 9 10 11 12 Grand Total 2000 0.09 -1.37 -2.06 0.37 -0.75 -0.93 -4.65 2001 -0.31 -0.22 -0.41 0.33 0.53 0.68 -0.36 -1.18 0.55 -0.13 -0.17 0.05 -0.64 2002 -0.21 0.03 -0.03 -0.62 -0.46 0.40 0.25 -0.70 0.30 -0.03 -0.37 -0.42 -1.86 2003 -0.24 0.13 -0.53 0.04 -0.06 -1.06 -0.82 -0.98 -0.05 -0.25 0.05 -0.16 -3.93 2004 -0.21 0.26 -0.30 0.49 -0.57 -0.23 0.58 -1.09 -0.20 -0.12 0.11 -0.05 -1.33 2005 -0.39 -0.24 -0.13 -0.41 -0.14 0.26 -1.99 -0.37 0.57 -0.88 -0.02 0.45 -3.29 2006 0.73 -0.11 0.01 0.05 0.45 -0.64 -0.45 -0.02 0.12 -0.61 -0.71 -0.06 -1.24 2007 -0.30 -0.70 -1.51 -0.98 -0.21 -1.46 -0.24 -0.42 -2.12 -1.65 -1.13 -1.61 -12.33 2008 -0.59 -2.02 -1.90 -1.17 -2.11 0.00 0.35 0.30 -3.90 0.54 -0.50 0.23 -10.77 2009 -0.21 -0.17 -0.17 0.68 -1.77 -1.44 0.62 0.55 -0.45 -0.48 -0.12 -0.36 -3.32 2010 0.21 -0.47 -0.13 0.25 0.16 0.12 -0.58 2.62 1.30 -0.01 0.37 -0.28 3.56 2011 -0.35 -0.43 0.03 1.09 -0.66 -2.41 0.66 -0.67 -9.63 0.79 -0.25 -0.20 -12.03 2012 -0.22 -0.10 -0.15 0.26 0.91 -0.91 0.18 0.02 -1.17 -0.28 -0.06 -0.19 -1.71 2013 -0.23 -0.01 -0.27 0.07 0.37 0.61 -2.25 -0.26 0.23 0.61 -0.08 -0.53 -1.74 2014 -0.68 -0.40 0.45 -0.53 -0.59 1.63 0.49 -1.01 0.22 -0.21 -0.32 -0.04 -0.99 2015 -1.00 -0.77 -0.94 1.11 -1.02 3.13 -0.04 0.57 -3.79 -0.31 0.13 -0.16 -3.09 2016 -2.83 -1.08 0.04 -0.43 0.01 -0.86 -1.05 -1.22 -1.28 0.12 -0.48 -0.28 -9.34 2017 -0.49 -1.10 -1.69 -0.23 -0.53 -0.94 -4.17 0.57 -0.36 0.09 -0.20 0.01 -9.04 2018 -1.31 -0.59 -0.54 -0.46 -1.63 0.20 -1.19 -0.53 1.59 0.06 -0.08 -0.50 -4.98 2019 -0.26 -0.26 Grand Total -8.89 -7.99 -8.17 -0.46 -7.32 -2.92 -9.92 -5.19 -20.13 -2.38 -4.58 -5.03 -82.98 Average -0.48 -0.44 -0.45 -0.03 -0.41 -0.16 -0.56 -0.21 -1.00 -0.15 -0.21 -0.23 -4.34

I think there was at least a trace of snow at KMDT continuously from 12/11/1960 through 3/1/1961

Here are the 1960's more indepth Grouped Snowfall 0.00 - 3.00 3.00 - 6.00 6.00 - 9.00 9.00 - 12.00 12.00 - 15.00 Grand Total Winter of Count Sum Count Sum Count Sum Count Sum Count Sum Count Sum 1960 24 12.20 5 18.20 1 10.50 30 40.90 1961 22 16.70 4 18.20 5 33.30 1 13.10 32 81.30 1962 20 15.90 4 17.20 1 8.80 1 9.70 26 51.60 1963 22 18.60 6 25.90 1 6.00 29 50.50 1964 17 11.50 3 11.10 1 7.50 3 30.60 1 14.00 25 74.70 1965 14 11.10 3 13.10 1 7.60 18 31.80 1966 8 10.60 3 10.80 3 21.20 14 42.60 1967 26 16.00 3 14.40 1 6.70 1 11.30 31 48.40 1968 12 8.90 2 8.90 2 13.20 16 31.00 1969 19 12.50 3 12.50 22 25.00 Grand Total 184 134.00 36 150.30 15 104.30 6 62.10 2 27.10 243 477.80

I also believe the Low was cut-off and spinning and probably had a deformation band that was stationary basically. Those areas with insane totals probably fell within the heaviest part of the band and it helped with cooling. Probably lots of melting going on in areas with that storm.

That March 18-21, 1958 storm was extremely elevation dependent, although not much elevation. We are talking just a couple to few hundred feet. Adamstown in Northeastern Lancaster county is 568', Morgantown, PA is 600', Lancaster is 368', Harrisburg is 322', Philly is 39'. I think Philly got like 2 inches of snow and inches of inches of rain.

last post of the night. The 1960's were ridiculous. Accumulations for 50% above average in the 3"-6" range, almost 100% above average in the 6"-9" range, 100% above average in the 9"-12", and throw in (2) 12"-15" storms for good measure. They accounted for 316.7" (66% roughly) of there 477.80" in 57 3"-12" storms that averaged roughly 5.5" per storm. So whomever here was a child in this area in the 60's, you lived like a king. SUM of Snowfall Grouped Winter of Grouped Snowfall < 1950 1950 - 1959 1960 - 1969 1970 - 1979 1980 - 1989 1990 - 1999 2000 - 2009 2010 - 2018 10 yr Avg 8 yr Avg 0.00 - 3.00 87.2 122.0 134.0 120.5 127.3 113.5 108.2 102.2 120.38 96.31 3.00 - 6.00 58.6 92.8 150.3 111.2 109.5 98.8 70.8 73.5 100.72 80.58 6.00 - 9.00 40.8 41.4 104.3 77.9 33.7 39.8 49.4 34.2 55.46 44.37 9.00 - 12.00 49.6 18.4 62.1 29.4 30.1 10.8 9.5 32.7 31.92 25.54 12.00 - 15.00 12.2 27.1 13.0 14.3 12.6 27.0 13.97 11.18 18.00 - 21.00 19.7 40.1 7.87 6.29 24.00 - 27.00 24.0 26.4 6.63 5.31 Grand Total 268.1 274.6 477.8 352.0 324.6 317.3 250.5 296.0 337.0 269.6 0.00 - 3.00 -9.1 1.6 13.6 0.1 6.9 -6.9 -12.2 5.9 3.00 - 6.00 -22.0 -7.9 49.6 10.5 8.8 -1.9 -29.9 -7.1 6.00 - 9.00 -3.6 -14.1 48.8 22.4 -21.8 -15.7 -6.1 -10.2 9.00 - 12.00 24.1 -13.5 30.2 -2.5 -1.8 -21.1 -22.4 7.2 12.00 - 15.00 1.0 -14.0 13.1 -1.0 -14.0 0.3 -1.4 15.8 18.00 - 21.00 13.4 -7.9 -7.9 -7.9 -7.9 32.2 -7.9 -6.3 24.00 - 27.00 -5.3 -6.6 -6.6 -6.6 17.4 -6.6 -6.6 21.1 Grand Total -1.5 -62.4 140.8 15.0 -12.4 -19.7 -86.5 26.4 COUNTA of Snowfall Grouped Winter of Grouped Snowfall < 1950 1950 - 1959 1960 - 1969 1970 - 1979 1980 - 1989 1990 - 1999 2000 - 2009 2010 - 2018 0.00 - 3.00 105.0 151.0 184.0 146.0 156.0 160.0 115.0 123.0 3.00 - 6.00 15.0 24.0 36.0 28.0 28.0 24.0 18.0 19.0 6.00 - 9.00 7.0 6.0 15.0 11.0 5.0 5.0 7.0 5.0 9.00 - 12.00 5.0 2.0 6.0 3.0 3.0 1.0 1.0 3.0 12.00 - 15.00 1.0 2.0 1.0 1.0 1.0 2.0 18.00 - 21.00 1.0 2.0 24.00 - 27.00 1.0 1.0 Grand Total 134.0 183.0 243.0 189.0 193.0 193.0 142.0 153.0

Since 2/1//1942 I have 11 storms of >15" Begin Date End Date Amt 1/15/1945 1/16/1945 21.00 1/19/1961 1/20/1961 18.70 1/12/1964 1/13/1964 18.10 2/18/1964 2/19/1964 20.50 2/11/1983 2/12/1983 25.00 3/13/1993 3/14/1993 20.40 1/8/1996 1/9/1996 22.20 2/5/2010 2/6/2010 18.00 2/9/2010 2/10/2010 15.70 1/22/2016 1/23/2016 30.20 3/13/2017 3/14/2017 17.00 Decade Storms >15" 1940 1 1950 0 1960 3 1970 0 1980 1 1990 2 2000 0 2010 4

I went down the rabbit hole and looked at days where is snowed consecutively and where the 2 days total was >12". I also included some April snow and notes: Begin Date End Date Amt Notes 3/7/1941 3/8/1941 13.80 1/27/1943 1/28/1943 12.80 1/26 - 1/28 total 15.40" 1/15/1945 1/16/1945 21.00 2/20/1947 2/21/1947 13.20 11/6/1953 11/7/1953 15.40 3/3/1960 3/4/1960 10.70 3/3 - 3/22 (9 snows) 22.00" 12/11/1960 12/12/1960 11.00 12/11 - 12/21 (5 snows) 19.00" 1/19/1961 1/20/1961 18.70 1/15 - 1/20 26.20" 2/3/1961 2/4/1961 12.40 12/23/1961 12/24/1961 13.90 12/28 2.40" brought xmas wk total to 16.30" 1/12/1964 1/13/1964 18.10 2/18/1964 2/19/1964 20.50 1/29/1966 1/30/1966 12.20 2/6/1967 2/7/1967 11.90 12/25/1969 12/26/1969 12.90 2/19/1972 13.00 12/16/1973 12/17/1973 12.10 1/19/1978 1/20/1978 13.40 1/13 - 1/20 3 storms 30.40" 2/18/1979 2/19/1979 14.20 1/22/1982 1/23/1982 10.20 1/21 - 1/23 12.10" 4/5/1982 4/6/1982 6.70 April Storm 2/11/1983 2/12/1983 25.00 3/13/1993 3/14/1993 20.40 1/17/1994 14.30 3/2/1994 3/3/1994 12.30 1/8/1996 1/9/1996 22.20 1/2 - 1/9 27.80" 1/2 - 1/12 38.60" 2/15/2003 2/16/2003 13.90 2/5/2010 2/6/2010 18.00 2/9/2010 2/10/2010 15.70 2/3 - 2/10 34.10" 2/2 - 2/10 36.80" 1/22/2016 1/23/2016 30.20 3/13/2017 3/14/2017 17.00 3/20/2018 3/21/2018 14.20

Here you go https://docs.google.com/spreadsheets/d/14yvCLQG-MlYw9YA0kPNUjHq3lIlGYZE8NDuDQ2o1Km0/edit?usp=sharing It has the Date, Month, Year, Winter of, Max Temp, Min Temp, Precipitation, Snowfall, Snow depth of every day since 2/1/1941 that it has snowed at least a trace. I believe there are around 3060 events. I pulled the data from http://climod2.nrcc.cornell.edu/, formatted it, and added the (Month, Year, Winter of) formulas in order to make it easier to analyze.

I don’t believe there have been any big storms in memory where the difference between the two stations has been significant. Do you know when the current measuring procedures with the snowboard became standard operating procedure? I could see that making a difference possibly. Say they just measured once a day or something. Although not full proof by any means, I probably could compare precipitation totals to snow totals to get a ratio for larger events in the past, along with back to back events too see if anything stands out. . Pro

The records start in 1941, I think I may go all the way back to start in the next few weeks. Also, as I mentioned before, up until 9/30/91 the observations were taken at Capital City Airport in New Cumberland. They are only about 5 miles apart, but has yearly precipitation totals consistently lower than KMDT at Harrisburg Airport. I think it was the last 18/20 or 19/20 years. Some years it was >10% lower, which I found amazing for such a short distance. I did notice most of the discrepancy occurred in the summer months I believe, but not all. For a couple years after KMDT moved no observations were taken at KCXY. I’m going to try to compare observations for snow events where we have overlapping data. . Pro