Originally Posted by grampi
You do realize these private businesses get their information from the National Weather Service, don't you? So why not cut out the middle man and just get your weather from the NWS? I never understood why people are willing to get 2nd hand info...
I get almost all of my weather information from the NWS....
But with a twist...
I learned how to read those computer models 16 years ago... I looked at thousands and thousands of computer model runs... Read forecast discussions... And finally understood how those models are to be read and utilized. By 2004 I had a good understanding of the models and how to read them... I have enjoyed doing it ever since.
I made my first difficult forecast in December 2005... Local snow storm that was going to be very hard to figure out... I put it all together and forecast the mix of rain and snow would be in my area... And just 10 miles north of me would see mostly snow... And daggone... Got up the next am... Snow and some rain at my place. Drove north in rte 17 to school... Which was 14 miles north of me... Snowing good... Snow on the ground, roads, everything... Temp was 31. They saw 3 inches up there... My house/area saw no accumulation. I hit that right on.
In April 2007... Very, very late snow storm for my area possible... Local NWS had been forecasting snow for 2 days straight... With good reason..the GFS and NAM models showed temps at 850mb aka roughly a mile up... At -9°C... With plenty of precipitation happening eatly that Saturday morning... Well... With 850 temp of aboit 16°F it is easy to extrapolate the ground temps being 30°F... Plus the mid level thickness values were well cold enough to show the entire air column below freezing... Aka it's going to snow if that is the case.. but for some inexplicable reason... The local NWS changed their forecast that Friday evening... They changed it to rain/snow mix with little to no snow accumulation... I said horse number2. I told everyone we would get 1-3 inches.... We actually got 3.5 inches... It was awesome. Though this happened on the local Daffodil Festival... They cancelled it at 530 that Saturday morning... Snowing to be the band at that time
Another notable storm in my area.... Day after Christmas storm 2010.... Now leading into this say day 7-8 days out a large East coast snowstorm was being forecast... But then on December 22-23 the models shifted too far east with the storm track... This by the afternoon forecast in the 23rd... Not much if a chance of snow predicted... Made sense to me too at that time... But.... I was watching each computer model run... And when the midnight run came Dec 24th 12am in for the GFS and NAM... They both had slightly shifted the storm track back to the left just a bit... I figured this needed to be watched very closely at the 0600 and 1200 and 1800 upcoming computer model runs... Sure enough... The 0600 and 1200 computer model runs shifted the track a bit further west each run... And the 1800 model run did so yet again... I made a bet with a good friend of mine that our area would see 4-7 inches of snow and that I was being conservative in that... Next am... On December 24th... Winter Storm watches up from South Carolina to New England... Including my area... They only had forecasted 3-5 of snow... Well I have done the calculations and knew that was way way too low... I told everyone at the hospital that day at work we would see 8-12 inches with 14 inches possible... One of my co workers Charlyn could believe it... I told her yeah it is legit... This was at 330 pm on December 25th by the way.. She said that the local TV weather people hadn't said that.. I told her... They arent too bright... Well guess what... At 6 pm the local stations and the NWS both updated their forecast amounts to exactly what I had said earlier that afternoon.... Later that evening it started snowing at the hospital in Newport News though no real accumulation when I left there at 1215 am.. Drove home northward and we had 2 inches already by the time I got home.. The next day I had to work... We had 6 inches where I was at home... Driving to work took an hour and it was actually snowing harder near the hospital in Newport News than it had been at home... Visibility was only 1/4 by the time I got to the hospital.. By the end of the next evening on the 26th Norfolk had 14.3 inches of snow... Newport News had 13 inches... And my area at home saw 10 inches.... Not bad on my part...
The tornado outbreak in 2011... I remember looking at the radar and seeing a line of strong storms split into individual supercell thunderstorms... I told everyone that people were going to die that afternoon... I had looked up the instability forecast and it was scary... And because that line of storms broke off into individualized storms... They would be much more prone to rotate... Which they did... 15 people died that afternoon and evening. 2 people died in my hometown... And that very strong tornado missed my x girlfriends house by 50 yards... One beautiful two story home in the woods was obliterated... Only the stairwell was left standing... The rest of the 2400 sq foot house was completely destroyed... No outside walls left standing. Another house off rte 614 was completely destroyed... I wasn't surprised people died in that... The middle school took a major hit from that tornado has well. And the C hall section was completely flattened... I told my lady that meant this tornado was at least a EF-3... I was right about that. That intermediate School was closed and a new built.
I could tell a good number of other instances where I figured out the forecast better than the others. In fact everyone knew at the hospital to ask me what was going to happen weather wise.... I had that kind of reputation because I had been very accurate with my own analysis.
Computer model runs are only part of the matrix in making a forecast... Knowing past climatology matters a lot has well... Using past forecast analogs is extremely helpful has well. The University of St. Louis has a great analog program... I have used that has well to help come up with a forecast.. I can remember every major storm in my region since I was 5 years old. That does help quite a bit.
Though sometimes like this past winter a storm happens that is extremely unusual... The early 2018 East coast snowstorm is an example of this... I have never seen a coastal storm form so far south in the Bahamas... Except one...In fact the only one I remember is the one in December 1989 which affected the South Carolina and NC coast... In that system Wilmington NC saw 15 inches of snow!!! Has did Cape Hatteras.... But this year's January 2018 system actually headed nortward up the Atlantic coastline... First time I have seen that... In all other cases the surface low forms off the coast of SC or more typically near Cape Hatteras... Then they move north or northeast from there... This year's snowstorm actually formed in the Bahamas and moved due north... I called the local NWS and the nice guy I talked said yeah this is extremely unusual...My area got 7.5 inches of snow. Bit Chesapeake and Norfolk got 10-11 inches of snow... It was quite a system... And 2 days before it hit I told my mom we'd see 6-8 in my area and her area... Pretty decent.
I like be able to decipher the information for myself... It has been a lot of fun... And a lot of learning too. I also understand when a forecast blows up why it happened... Like the non snowstorm for NJ and New York from several years ago.... Winter storm warnings up for Philadelphia, all of NJ and New York City and areas northward from there.... Storm didn't happen at all... The GFS model showed a whoomping snowstorm for that whole region... NAM showed very, very little to no storm... Euro model showed a pretty good storm... So the guys at the Mt Holly NWS office did make the best forecast they could based upon the preponderance of information available to them... And has fate would have it... NOTHING happened in Philadelphia and most of NJ.... Weather Channel looked dumb as well by the way.... But again... they both made the best forecast based upon the best evidence they had at that moment... The fact was the upper level system did not get wrapped into the developing surface low quick enough to cause the storm to deepen fast enough to have snow in places like Philadelphia and NJ at that time... In other words they got handed to them what happens farther south quite a bit... But I understood why it did not happen. And why they all were not dumb... They weren't.
Just like this last week's snowstorm in NYC... No model and no one forecasted what did ultimately happen.. What got everyone into trouble was that the overrunning precipitation reached the NYC area faster than first forecast... And it was heavier precipitation has well... Which sided in pulling down colder air from aloft as well... And by those two factors alone it led to a much heavier event... And it did not help that the heavy snow developed at 1 to 230 pm... Thus running into rushour traffic timing... a lot of apologizing in this case...but really not necessary in my opinion. Truth is weather happens and changes very fast...
