Tuesday, July 28, 2015

Model flip-flopping

Computer models have a difficult time dealing with the lower latitudes in summer.  The subtle changes are often missed even on the higher resolution models.  The past 24 hours is a classic example.  Yesterday evening the models seem to have latched on to the idea of low pressure developing well south of the Louisiana coast later this week.  As it moved farther to the west, we would get on the “wet side” giving us higher rain chances later this week.   Tonight’s runs are totally different.  No closed low forms and moves to the west.  The deep Gulf moisture stays well to our south along an old frontal boundary and we stay very hot & mostly dry.  Go figure.   I often only use the 24 hour model run as anything beyond that has a high degree of uncertainty.  Yet I see on every channel weathercasters showing the models out to 48 hours & beyond.   That’s OK as long as one mentions the degree of uncertainty in the summer.


So let’s take a stab at Wednesday.  From what I’m seeing on satellite & radar loops, the upper high that has kept us mostly dry is shrinking back to the west.  Disturbances are rotating around the high and one such might arrive here late in the afternoon (5-8 PM).  It could bring heavy downpours, gusty winds to 40+ & briefly cooler temperatures.   Let’s hope our daily storms return so we don’t have to deal with the “extreme heat”!  Stay tuned!

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