Poulsbo Snowman Posted December 17, 2014 Report Share Posted December 17, 2014 Me!!!!!! :wub: Quote Link to comment Share on other sites More sharing options...
Gradient Keeper Posted December 17, 2014 Report Share Posted December 17, 2014 MeSame here getting excited, adrenaline pumping, almost peed a little, just slightly, few drips really, and I usually only do that during thunderstorms! Quote Link to comment Share on other sites More sharing options...
Snow Posted December 17, 2014 Report Share Posted December 17, 2014 Last winter I derived an index I call "Pacific Northwest-Alaska Index" to aid in forecasting arctic blasts in the PNW. It is fairly simple and takes 500 mb height in decameters (dam) as inputs. Both the forecast (or historical) plus climatological 500 mb heights are required. The model then takes the modeled/historical 500 mb heights for Salem and Anchorage, normalizes them and adjusts them based on climatology (both at each station and the mean) with an output of an index value generally between +3.0 and -4.0. This value is a measure of the longwave pattern between Anchorage and Salem, whether it is zonal, meridional or somewhere in between as well as how anomalous it is. High heights at ANC and low heights at SLE (relatively speaking) are indicated by negative PAI values, however these can be either muted or intensified based on how the pattern is relative to climatology. For instance Anchorage can have a lower height than Salem and still return a negative PAI. Historical minimum PAI values for recent "arctic blasts": Dec 2008: -3.6Dec 2009: -3.3Nov 2010: -3.1Dec 2013: -3.3Feb 2014: -1.7 (this wasn't too impressive in WA as we know...interesting event) Here is a visual showing the steps in calculating the PAI: http://oi57.tinypic.com/nbw1ec.jpgThanks for sharing, looks awesome! Quote Link to comment Share on other sites More sharing options...
gsax Posted December 17, 2014 Report Share Posted December 17, 2014 I think this is the first time of the year the NWS is saying colder than normal on their 8-14 day outlook. They've been very warm biased. Quote Link to comment Share on other sites More sharing options...
Gradient Keeper Posted December 17, 2014 Report Share Posted December 17, 2014 Last winter I derived an index I call "Pacific Northwest-Alaska Index" to aid in forecasting arctic blasts in the PNW. It is fairly simple and takes 500 mb height in decameters (dam) as inputs. Both the forecast (or historical) plus climatological 500 mb heights are required. The model then takes the modeled/historical 500 mb heights for Salem and Anchorage, normalizes them and adjusts them based on climatology (both at each station and the mean) with an output of an index value generally between +3.0 and -4.0. This value is a measure of the longwave pattern between Anchorage and Salem, whether it is zonal, meridional or somewhere in between as well as how anomalous it is. High heights at ANC and low heights at SLE (relatively speaking) are indicated by negative PAI values, however these can be either muted or intensified based on how the pattern is relative to climatology. For instance Anchorage can have a lower height than Salem and still return a negative PAI. Historical minimum PAI values for recent "arctic blasts": Dec 2008: -3.6Dec 2009: -3.3Nov 2010: -3.1Dec 2013: -3.3Feb 2014: -1.7 (this wasn't too impressive in WA as we know...interesting event) Here is a visual showing the steps in calculating the PAI: http://oi57.tinypic.com/nbw1ec.jpg One thing about the PAI is that it generally bottoms out a couple days BEFORE the really cold stuff hits us here in Oregon. The neat thing about it is you can sorta see the arctic air moving S through western Canada using the index values as you see heights rise over AK and fall over western Canada and the PNW. The values shown are the legit ones for the early Dec 2013 event (00z sounding analysis for SLE and ANC). Notice in Dec 2013 PAI bottomed out on Dec 7th (00z, so actually on evening of Dec 6th) while coldest temps were felt across OR on Dec 8th.Very nice. This had to take some time putting together. I for one really like your PAI Index. It's easy to understand, to apply, and it's accurate. It helps resolve how strong an arctic blast is and upper level support may be. One of the best indexes/indices ever made. Period Quote Link to comment Share on other sites More sharing options...
SilverFallsAndrew Posted December 17, 2014 Report Share Posted December 17, 2014 Since Chris mentioned the Feb 2014 event, here is an insane temp gradient I found from February 8th. Eugene 32/29 50 miles S at Roseburg 61/45 Eugene's coldest day was an astounding 25/20 on the 6th. Roseburg was 45/39. Bet the kids in R-burg were jelly. 1 Quote Snowfall Precip 2022-23: 95.0" 2022-23: 17.39" 2021-22: 52.6" 2021-22: 91.46" 2020-21: 12.0" 2020-21: 71.59" 2019-20: 23.5" 2019-20: 58.54" 2018-19: 63.5" 2018-19: 66.33" 2017-18: 30.3" 2017-18: 59.83" 2016-17: 49.2" 2016-17: 97.58" 2015-16: 11.75" 2015-16: 68.67" 2014-15: 3.5" 2013-14: 11.75" 2013-14: 62.30 2012-13: 16.75" 2012-13: 78.45 2011-12: 98.5" 2011-12: 92.67" It's always sunny at Winters Hill! Fighting the good fight against weather evil. Link to comment Share on other sites More sharing options...
SilverFallsAndrew Posted December 17, 2014 Report Share Posted December 17, 2014 I think this is the first time of the year the NWS is saying colder than normal on their 8-14 day outlook. They've been very warm biased. Well since early February we've been above normal about 90% of the time. Quote Snowfall Precip 2022-23: 95.0" 2022-23: 17.39" 2021-22: 52.6" 2021-22: 91.46" 2020-21: 12.0" 2020-21: 71.59" 2019-20: 23.5" 2019-20: 58.54" 2018-19: 63.5" 2018-19: 66.33" 2017-18: 30.3" 2017-18: 59.83" 2016-17: 49.2" 2016-17: 97.58" 2015-16: 11.75" 2015-16: 68.67" 2014-15: 3.5" 2013-14: 11.75" 2013-14: 62.30 2012-13: 16.75" 2012-13: 78.45 2011-12: 98.5" 2011-12: 92.67" It's always sunny at Winters Hill! Fighting the good fight against weather evil. Link to comment Share on other sites More sharing options...
Gradient Keeper Posted December 17, 2014 Report Share Posted December 17, 2014 49 user(s) are reading this topic 21 members, 28 guests, 0 anonymous users All waiting for a jaw-dropping EURO run Quote Link to comment Share on other sites More sharing options...
Gradient Keeper Posted December 17, 2014 Report Share Posted December 17, 2014 Here we go !http://www.tropicaltidbits.com/analysis/models/ecmwf/2014121700/ Quote Link to comment Share on other sites More sharing options...
BLI snowman Posted December 17, 2014 Report Share Posted December 17, 2014 11 years ago right now the models didn't look very impressive. I remember that due to some impending travel we had coming up. That late December through New Year's sequence surpassed most expectations. Both the snow amounts and the actual temps were impressive, given the forecasts. Quote Link to comment Share on other sites More sharing options...
Jesse Posted December 17, 2014 Report Share Posted December 17, 2014 Yup, already affecting the BDC.So...we're screwed? Quote Link to comment Share on other sites More sharing options...
TT-SEA Posted December 17, 2014 Report Share Posted December 17, 2014 Seems like the last 2 events looked like this at a week out and then became sharply colder in the home stretch. Quote **REPORTED CONDITIONS AND ANOMALIES ARE NOT MEANT TO IMPLY ANYTHING ON A REGIONAL LEVEL UNLESS SPECIFICALLY STATED** Link to comment Share on other sites More sharing options...
Deweydog Posted December 17, 2014 Report Share Posted December 17, 2014 That late December through New Year's sequence surpassed most expectations. Both the snow amounts and the actual temps were impressive, given the forecasts.A lot of needles got threaded over that 10 days or so. 12-30 was most impressive to me, born of such a ridiculously innocuous set up. Quote My preferences can beat up your preferences’ dad. Link to comment Share on other sites More sharing options...
stuffradio Posted December 17, 2014 Author Report Share Posted December 17, 2014 The 00z Euro still going with highs below 32F for Abbotsford on Boxing day. It has maybe only traces of snow too. Quote Link to comment Share on other sites More sharing options...
SilverFallsAndrew Posted December 17, 2014 Report Share Posted December 17, 2014 A lot of needles got threaded over that 10 days or so. 12-30 was most impressive to me, born of such a ridiculously innocuous set up. One of my all-time favorite stretches of winter in the mid-valley. The 12/29 and 1/1 snow events were so under forecasted. The 2nd snow event was a solid 3-6" from Eug to PDX though if I remember it was heavier E of I-5 because it was a wrap around band. The first snow event was really a mid-valley show. We got about 4" in Silverton. SLE had about 6" and places west of Salem toward Dallas had almost 10". Quote Snowfall Precip 2022-23: 95.0" 2022-23: 17.39" 2021-22: 52.6" 2021-22: 91.46" 2020-21: 12.0" 2020-21: 71.59" 2019-20: 23.5" 2019-20: 58.54" 2018-19: 63.5" 2018-19: 66.33" 2017-18: 30.3" 2017-18: 59.83" 2016-17: 49.2" 2016-17: 97.58" 2015-16: 11.75" 2015-16: 68.67" 2014-15: 3.5" 2013-14: 11.75" 2013-14: 62.30 2012-13: 16.75" 2012-13: 78.45 2011-12: 98.5" 2011-12: 92.67" It's always sunny at Winters Hill! Fighting the good fight against weather evil. Link to comment Share on other sites More sharing options...
BLI snowman Posted December 17, 2014 Report Share Posted December 17, 2014 A lot of needles got threaded over that 10 days or so. 12-30 was most impressive to me, born of such a ridiculously innocuous set up. I had a high of 32 that day with 3+" of snow that night. That felt like January 1950 after the five year stretch we had had! Quote Link to comment Share on other sites More sharing options...
Gradient Keeper Posted December 17, 2014 Report Share Posted December 17, 2014 HR 72http://www.tropicaltidbits.com/analysis/models/ecmwf/2014121700/ecmwf_z500_mslp_namer_4.png Quote Link to comment Share on other sites More sharing options...
IbrChris Posted December 17, 2014 Report Share Posted December 17, 2014 If anyone is utilizing the PAI they will need 500 mb height climatology for SLE and ANC...while the values don't change a lot (about 10 dam from early Nov-late Feb at SLE) they will have an effect on the output if not used properly. You could probably get away with a mean value for each month but when I built this I grabbed values for each calendar day.500 mb height Climatology (dam)Date SLE ANC1-Nov 563 5302-Nov 563 5303-Nov 562 5304-Nov 562 5295-Nov 562 5296-Nov 562 5297-Nov 561 5298-Nov 561 5289-Nov 561 52810-Nov 561 52811-Nov 560 52812-Nov 560 52813-Nov 560 52814-Nov 560 52715-Nov 560 52716-Nov 560 52717-Nov 559 52718-Nov 559 52719-Nov 559 52620-Nov 559 52621-Nov 559 52622-Nov 559 52623-Nov 559 52624-Nov 559 52625-Nov 559 52626-Nov 558 52627-Nov 558 52528-Nov 558 52529-Nov 558 52530-Nov 558 5251-Dec 558 5252-Dec 558 5253-Dec 558 5254-Dec 558 5255-Dec 558 5256-Dec 558 5257-Dec 558 5258-Dec 558 5259-Dec 558 52510-Dec 558 52511-Dec 558 52512-Dec 558 52513-Dec 558 52514-Dec 558 52515-Dec 558 52516-Dec 558 52517-Dec 558 52518-Dec 558 52519-Dec 557 52520-Dec 557 52521-Dec 557 52522-Dec 557 52523-Dec 557 52524-Dec 557 52525-Dec 557 52526-Dec 557 52527-Dec 557 52528-Dec 556 52529-Dec 556 52530-Dec 556 52531-Dec 556 5251-Jan 556 5252-Jan 556 5253-Jan 556 5254-Jan 556 5255-Jan 556 5256-Jan 556 5257-Jan 556 5258-Jan 556 5259-Jan 556 52510-Jan 556 52511-Jan 555 52512-Jan 555 52513-Jan 555 52514-Jan 555 52515-Jan 555 52516-Jan 555 52517-Jan 555 52618-Jan 555 52619-Jan 555 52620-Jan 555 52621-Jan 555 52622-Jan 555 52623-Jan 555 52624-Jan 555 52625-Jan 554 52626-Jan 554 52627-Jan 554 52628-Jan 554 52629-Jan 554 52630-Jan 554 52631-Jan 554 5261-Feb 554 5262-Feb 554 5263-Feb 554 5264-Feb 554 5265-Feb 554 5266-Feb 554 5267-Feb 554 5268-Feb 554 5269-Feb 554 52610-Feb 554 52611-Feb 554 52612-Feb 554 52613-Feb 553 52614-Feb 553 52615-Feb 553 52616-Feb 553 52617-Feb 553 52618-Feb 553 52619-Feb 553 52620-Feb 553 52621-Feb 553 52622-Feb 553 52623-Feb 553 52724-Feb 553 52725-Feb 553 52726-Feb 553 52727-Feb 553 52728-Feb 553 52729-Feb 553 527 Quote The Pacific Northwest: Where storms go to die. Link to comment Share on other sites More sharing options...
TT-SEA Posted December 17, 2014 Report Share Posted December 17, 2014 The 00z Euro still going with highs below 32F for Abbotsford on Boxing day. It has maybe only traces of snow too. Boxing Day is such a rarely used term down here. Strange how an imaginary line divides speech and terminology so perfectly. Aboot. Eh? Quote **REPORTED CONDITIONS AND ANOMALIES ARE NOT MEANT TO IMPLY ANYTHING ON A REGIONAL LEVEL UNLESS SPECIFICALLY STATED** Link to comment Share on other sites More sharing options...
stuffradio Posted December 17, 2014 Author Report Share Posted December 17, 2014 Boxing Day is such a rarely used term down here. So strange how an imaginary line has such differences in speech. Aboot. Eh?Only a few people say Eh here. I'll climb on my ruff to look for the Arctic air. Quote Link to comment Share on other sites More sharing options...
Deweydog Posted December 17, 2014 Report Share Posted December 17, 2014 HR 72http://www.tropicaltidbits.com/analysis/models/ecmwf/2014121700/ecmwf_z500_mslp_namer_4.pngToo warm for snow at my house. Quote My preferences can beat up your preferences’ dad. Link to comment Share on other sites More sharing options...
gsax Posted December 17, 2014 Report Share Posted December 17, 2014 HR 72ohttp://www.tropicaltidbits.com/analysis/models/ecmwf/2014121700/ecmwf_z500_mslp_namer_4.pngCorrect me if I'm wrong, but that's a lot of the good stuff that looks to slide down. Quote Link to comment Share on other sites More sharing options...
Bryant Posted December 17, 2014 Report Share Posted December 17, 2014 The 00z Euro still going with highs below 32F for Abbotsford on Boxing day. It has maybe only traces of snow too. You posted that at 10:05... Euro isn't out Quote Link to comment Share on other sites More sharing options...
Gradient Keeper Posted December 17, 2014 Report Share Posted December 17, 2014 HR 120 http://www.tropicaltidbits.com/analysis/models/ecmwf/2014121700/ecmwf_z500_mslp_namer_6.png Quote Link to comment Share on other sites More sharing options...
FroYoBro Posted December 17, 2014 Report Share Posted December 17, 2014 I'm calling it here right now. There will not be an arctic outbreak before New Years.Seems like a pretty easy call at this point. Quote Link to comment Share on other sites More sharing options...
stuffradio Posted December 17, 2014 Author Report Share Posted December 17, 2014 You posted that at 10:05... Euro isn't out It is on Weatherbell. Quote Link to comment Share on other sites More sharing options...
SilverFallsAndrew Posted December 17, 2014 Report Share Posted December 17, 2014 Seems like a pretty easy call at this point. Not everyone agrees with us. Quote Snowfall Precip 2022-23: 95.0" 2022-23: 17.39" 2021-22: 52.6" 2021-22: 91.46" 2020-21: 12.0" 2020-21: 71.59" 2019-20: 23.5" 2019-20: 58.54" 2018-19: 63.5" 2018-19: 66.33" 2017-18: 30.3" 2017-18: 59.83" 2016-17: 49.2" 2016-17: 97.58" 2015-16: 11.75" 2015-16: 68.67" 2014-15: 3.5" 2013-14: 11.75" 2013-14: 62.30 2012-13: 16.75" 2012-13: 78.45 2011-12: 98.5" 2011-12: 92.67" It's always sunny at Winters Hill! Fighting the good fight against weather evil. Link to comment Share on other sites More sharing options...
Bryant Posted December 17, 2014 Report Share Posted December 17, 2014 It is on Weatherbell. My apologies... been working long hours Quote Link to comment Share on other sites More sharing options...
whitechristmas Posted December 17, 2014 Report Share Posted December 17, 2014 Oh, sorry I should have mentioned that. Buehner is from the Seattle NWS. Thanks! Buehner's name didn't ring a bell. 1 Quote Link to comment Share on other sites More sharing options...
Gradient Keeper Posted December 17, 2014 Report Share Posted December 17, 2014 00z ECMWF is FANTASTIC !!!!!!!!! WOW Ideal 500mb pattern! 1 Quote Link to comment Share on other sites More sharing options...
luvssnow_spokane Posted December 17, 2014 Report Share Posted December 17, 2014 00z... Quote My Weather Station https://tempestwx.com/station/61434 Link to comment Share on other sites More sharing options...
Snow Posted December 17, 2014 Report Share Posted December 17, 2014 Quote Link to comment Share on other sites More sharing options...
Gradient Keeper Posted December 17, 2014 Report Share Posted December 17, 2014 Nice amplification and a pretty SW digging trough on the Euro. Looks nice. And this is just hour 192. And still digging southwestward after.... then a southeast US ridge develops before day 10.... beautiful Quote Link to comment Share on other sites More sharing options...
snow_wizard Posted December 17, 2014 Report Share Posted December 17, 2014 Seems like a pretty easy call at this point. Really? Quote Death To Warm Anomalies! Winter 2023-24 stats Total Snowfall = 1.0" Day with 1" or more snow depth = 1 Total Hail = 0.0 Total Ice = 0.2 Coldest Low = 13 Lows 32 or below = 50 Highs 32 or below = 3 Lows 20 or below = 3 Highs 40 or below = 9 Link to comment Share on other sites More sharing options...
snow_wizard Posted December 17, 2014 Report Share Posted December 17, 2014 Nice amplification and a pretty SW digging trough on the Euro. Looks nice. And this is just hour 192. Looks Arctic to me. Quote Death To Warm Anomalies! Winter 2023-24 stats Total Snowfall = 1.0" Day with 1" or more snow depth = 1 Total Hail = 0.0 Total Ice = 0.2 Coldest Low = 13 Lows 32 or below = 50 Highs 32 or below = 3 Lows 20 or below = 3 Highs 40 or below = 9 Link to comment Share on other sites More sharing options...
Gradient Keeper Posted December 17, 2014 Report Share Posted December 17, 2014 Progression from 226 to 240 almost looks odd, looks like an error in data. Pattern change now begins upstream/offshore by day 6 guys(and gals) .... Quote Link to comment Share on other sites More sharing options...
Guest Winterdog Posted December 17, 2014 Report Share Posted December 17, 2014 Looks Arctic to me.Not so much at hour 240 though. Quote Link to comment Share on other sites More sharing options...
Gradient Keeper Posted December 17, 2014 Report Share Posted December 17, 2014 Looks Arctic to me.Kind of chilly yes. Quote Link to comment Share on other sites More sharing options...
Gradient Keeper Posted December 17, 2014 Report Share Posted December 17, 2014 Not so much at hour 240 though.I'm not buying the pattern breaking down that quickly from HR 216 - 240. No way Quote Link to comment Share on other sites More sharing options...
Phil Posted December 17, 2014 Report Share Posted December 17, 2014 So...we're screwed?Wouldn't say that at all..just something to keep in mind. The Midwest/East should be slammed regardless of what happens, in my opinion. Quote Live Weather Cam: https://www.youtube.com/live/KxlIo8-KVpc?si=xKLCFYWbZieAfyh6 PWS Wunderground https://www.wunderground.com/dashboard/pws/KMDBETHE62 PWS CWOP/NOAA: https://www.weather.gov/wrh/timeseries?site=F3819&hours=72 Link to comment Share on other sites More sharing options...
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