Wednesday, August 10, 2016

Fallacy of the Forecast

One of the definitions of fallacy is “misinterpretation”.  Kind of like what Author John Gray (Mars/Venus) said about men & women…”he said this, she heard that.”   Yesterday NWS came out with a Flood Watch 24 hours in advance.  Although all of the weather programs I watched clearly indicated most of the rain would not come until later today (correctly I might add), many people were fixed on that 80% chance of rain.    I was on the golf course this morning at 9 AM and very few golfers were out.  I asked the pro shop what happened and they said…”people cancelled because they thought it would rain”.   Misinterpretation of the forecast.   I have often stated that rain chances have nothing to do with time.    Thursday has near 100% chance for rain, but that does not mean it will rain all the time.  In fact, there could be many dry hours between storms.   So I feel for my colleagues trying to explain the weather to folks who may not pay attention to every word.  


So what is going on?   Everybody was singing from the same songbook tonight.   NWS has the flood watch in effect, computer models are showing increasing moisture & rain amounts, but the models may be overstating the flood threat.  Why do I say that?   1)  the surface low on the daylight pictures slowly drifted westward and (best as I could tell) was just NE of Mobile at sunset.  As NHC said yesterday, the center would stay inland and it did.   2) the upper high has drifted northward into Mississippi near the Alabama border north of Meridian.  3) the upper low along Florida’s east coast is gone with the spreading of winds (divergence) over the eastern Gulf gone.  4) Cloud tops have warmed to our east and radar returns have diminished telling me the boundary along the northern Gulf is dissipating.  So what’s a forecaster to do.  My guess is most will follow the computer guidance out of caution until NWS cancels the Flood Watch.   Could something explode overnight and drench us in the morning?   Absolutely.  I am not suggesting the flood threat is over.  I am suggesting there is high uncertainty in the forecast, unless you put your full faith in computer models.   I’ll let you know as I have a morning tee time of 8:52 AM.  Stay tuned!


Pompo/Webmaster said...

Enjoy your game tomorrow Bob and by the way... Even if you are retired you are still on top of the game!!

Bob Breck Fan said...

Bob, you are "the only weather authority" I trust. Thank you for taking time to update your blog.
Lori in Grand Isle

Brandon said...


Watching closely radar returns you can see multiple small swirls all around southeast Louisiana... Even some storms moving in a 90 degree angle crossing paths! Weird! What is this?