JoeD Posted December 23, 2010 Share Posted December 23, 2010 Folks - In case you didn't know about this site, here's something to check in between model runs... CIPS Winter Weather Analog Guidance calculates the best analogs off the 00z and 12z GFS runs using NARR reanalysis data. CIPS stands for Cooperative Institute for Precipitation Systems, which is run by Chad Gravelle at St Louis University. NWS Caribou has been working with them for a couple of years and we recently have started looking at this guidance at NWS Taunton. Keep in mind it only compares the latest GFS run and is intended for potential systems in the 36-120 hour time frame. So if the GFS is not preferred, be especially careful! Also, this will not "give you the answer" as to what will happen or is most likely to happen - use it as a guidance source (much like ensembles) to gauge the range of possible outcomes! On the main page, find the time of interest by looking at when a potential system is in the red box. Click on the red button next to the model run time On the next page, you will see a list of the top 15 analogs. You can look at each event by clicking on the date, but it is easier to use the "Winter Weather Guidance" or "Thumbnail Guidance" menus to view the data. I've attached a couple of images that I find useful...these are both from the best analog match off the 00z GFS. The first is a map of CoOp snowfall totals and the other is the probability of getting more than 12 inches of snow (based upon CoOP totals). There certainly is a lot of data to look at and I'm still learning my way around this site...but if you have any questions let me know and I'll answer then as best I can! Have fun! Link to comment Share on other sites More sharing options...
Ginx snewx Posted December 23, 2010 Share Posted December 23, 2010 Joe you forgot the link http://www.eas.slu.edu/CIPS/ANALOG/analog.php Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted December 23, 2010 Share Posted December 23, 2010 I tried using this the other day... someone (Bob?) had put up the link... Still not sure how to read/use it... Link to comment Share on other sites More sharing options...
Baroclinic Zone Posted December 23, 2010 Share Posted December 23, 2010 I tried using this the other day... someone (Bob?) had put up the link... Still not sure how to read/use it... The analogs are based off of the GFS model guidance. As you scrolldown the list you can see the forecast hours of the GFS models starting at 36h and going all the way out to 120h. There are 2 groupings, one is system relative (ie. a storm) and the other is fixed geographical area. The red dots represent the current run and the previous runs of the GFS. So, for example, scroll down to System Relative: GFS212 F096 and clich the current run of the GFS on the far right panel. It will pull up historical analogs to the current modeled pattern. It rates the analogs on all the listed data and spits out the top analog on the right with an overall score. You can click on each analog and it will give you the historical maps for those analogs. You can also see the snowfalls porduced out of those analogs under the thumbnails. There is a wealth of information and it takes a little time to navigate around but it's an awesome site. Link to comment Share on other sites More sharing options...
wxologist Posted December 24, 2010 Share Posted December 24, 2010 Folks - In case you didn't know about this site, here's something to check in between model runs... CIPS Winter Weather Analog Guidance calculates the best analogs off the 00z and 12z GFS runs using NARR reanalysis data. CIPS stands for Cooperative Institute for Precipitation Systems, which is run by Chad Gravelle at St Louis University. NWS Caribou has been working with them for a couple of years and we recently have started looking at this guidance at NWS Taunton. Keep in mind it only compares the latest GFS run and is intended for potential systems in the 36-120 hour time frame. So if the GFS is not preferred, be especially careful! Also, this will not "give you the answer" as to what will happen or is most likely to happen - use it as a guidance source (much like ensembles) to gauge the range of possible outcomes! On the main page, find the time of interest by looking at when a potential system is in the red box. Click on the red button next to the model run time On the next page, you will see a list of the top 15 analogs. You can look at each event by clicking on the date, but it is easier to use the "Winter Weather Guidance" or "Thumbnail Guidance" menus to view the data. I've attached a couple of images that I find useful...these are both from the best analog match off the 00z GFS. The first is a map of CoOp snowfall totals and the other is the probability of getting more than 12 inches of snow (based upon CoOP totals). There certainly is a lot of data to look at and I'm still learning my way around this site...but if you have any questions let me know and I'll answer then as best I can! Have fun! Thanks for the post about the analog guidance Joe...you and Eleanor (I believe) have explained things well. I can also help answer any questions about the analog guidance. Chad Link to comment Share on other sites More sharing options...
SnowGoose69 Posted December 24, 2010 Share Posted December 24, 2010 The #1 analog currently at 72 hours in the NE sector is 12/27/04....similar to the storm just 2-3 days ago. Link to comment Share on other sites More sharing options...
JoeD Posted December 24, 2010 Author Share Posted December 24, 2010 Thanks for the post about the analog guidance Joe...you and Eleanor (I believe) have explained things well. I can also help answer any questions about the analog guidance. Chad Hey Chad - Great to see you here! By the way, for the 12/20 storm that brought a foot of snow to Cape Cod, the 2nd best analog (96h) was from 12/81 which dumped a foot of snow in southeast Mass! Granted, it was only one of 3 analogs that showed heavy snow somewhere in southern New England, but that was a clue that there was a "low probability" of seeing that amount of snow! Link to comment Share on other sites More sharing options...
wxologist Posted December 24, 2010 Share Posted December 24, 2010 Hey Chad - Great to see you here! By the way, for the 12/20 storm that brought a foot of snow to Cape Cod, the 2nd best analog (96h) was from 12/81 which dumped a foot of snow in southeast Mass! Granted, it was only one of 3 analogs that showed heavy snow somewhere in southern New England, but that was a clue that there was a "low probability" of seeing that amount of snow! Hey Joe...that's one of the great uses of the guidance and in particular looking at the individual analogs. Sometimes the analogs will remind and/or suggest to the forecaster that the forecast may need a bit of extra attention or investigation. It could be fine as is...but its a double check if you will. This storm coming up is really interesting IMO...I've been emailing with Todd up in CAR the last few days...there are a couple analogs that I have really liked...20041227...the Cape and down-east Maine get hit...and 19960217 is growing on me...but its a bit west. Now that the gfs is trending even further west this morning it seems this analog could potentially be better and suggests the impacts could be felt further inland. The 12/F048 will be out any minute...these and 12/F060 should be interesting. Link to comment Share on other sites More sharing options...
wxologist Posted December 24, 2010 Share Posted December 24, 2010 Hey Joe...that's one of the great uses of the guidance and in particular looking at the individual analogs. Sometimes the analogs will remind and/or suggest to the forecaster that the forecast may need a bit of extra attention or investigation. It could be fine as is...but its a double check if you will. This storm coming up is really interesting IMO...I've been emailing with Todd up in CAR the last few days...there are a couple analogs that I have really liked...20041227...the Cape and down-east Maine get hit...and 19960217 is growing on me...but its a bit west. Now that the gfs is trending even further west this morning it seems this analog could potentially be better and suggests the impacts could be felt further inland. The 12/F048 will be out any minute...these and 12/F060 should be interesting. Guess the gfs had a double dose of error flakes this morning. Ah well...so much for this set of analogs...they are amusing to look at though. Link to comment Share on other sites More sharing options...
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