Originally posted by Mike Mezeul II
I was just curious what everyones opinion was about how many moderate risks we have seen issued so far this season. I mean, its only April 1, and we have had about 5 or 6 days with mod risks issued, is this a heads up for what to come? Or is it just jumping the gun? Also, it seems as if with almost every moderate risk issued there has been a 15% tornado \"probability\", but very few confirmed tornadoes. I just want to see what everyones thoughts were about this, is SPC over doing it? or are we in for a great season?
Best Wishes
I really don't want to judge or critic the forecasts by SPC, since I'm not in a position to do so accurately. I'd prefer to do such a critique using a systematic methodology, which I don't really have, and thus I don't feel qualified to make such a critique. However, I think we're 0-4 for 15% tornado probability verification thus far this year, not including the 15% tornado prob included in the 3-31 6z outlook. This holds for PDS tornado watches, as well, which have had a difficult time verifying, though I don't know the exact statistics on these... The 6z outlook for tomorrow (well, today -- April 1st) has another 15% hatched tornado prob in the Carolina's, though I fear that the overall situation looks pretty similar to last week's storm that affected the southern U.S., though the surface low this time is progged to move a little farther northward than last week. This time, it appears that Gulf moisture should really be able to make it northward into the southeastern US, though I wonder about the effeects of widespread precipitation across the area on instability. At any rate, don't want this to turn into a forecast, so I'll stop discussion today's forecast...
SPC forecasters have a pretty tough job, seeing how they are trying to forecast stormscale processes (tornadoes, microbursts, etc) for a synoptic-scale domain (CONUS). This time of the year seems to be especially difficult, since there seems to be favorable kinematics with many of these types of systems, with the limiting factor oftentimes being moisture (and resultant instability). I would blame part of the high false alarm ratio (for tornadoes at least) on very poor NWP model performance lately. You can't dog the SPC too much if all available model guidance is suggesting that there'll be sufficient instability when it doesn't verify. Weds busted for tornadoes largely because of insufficient moisture, which resulted in insufficient instability and LCLs that were just too hight for the situation. What will happen later today? Who knows with the way things have been lately.
If anything, this teaches folks the importance of making ones own forecast! People who chase solely based on SPC forecasts (or NWSFO forecasts, or TWC forecasts, etc) are more likely to be 'burned', I believe, given that no forecast is perfect. This isn't a comment on newbie's, since I think we all started off that way (very heavy reliance on SPC forecasts), myself included. But the best way to learn about chase forecasting is looking at the data yourself, examing why things happened the way they did, regardless of it the particular event was a bust or an outbreak.