Tuesday 7/20 10 am
Yesterday, the short-term models struggled with the positioning of the high pressure. Rather than southeast flow, we saw northeast to easterly flow. This led to very isolated storms rather than scattered storms. Which reminds me, I have gotten a couple of emails asking me the difference between the two. Isolated refers to the least amount of storm coverage, then scattered, followed by widespread which refers to the greatest amount of storm coverage throughout the forecast area.
Today’s forecast is once again going to be complicated. We have the ingredients for scattered thunderstorms developing with high CAPE and PWAT values. Of course, we had that yesterday but the flow turned out to be less favorable for most of the forecast area.
This morning’s surface map shows us sandwiched between high pressure to our northeast and a shortwave trough of low pressure in western Utah. In theory, that should be a great delivery system to channel additional moisture into our already moist atmosphere. If that happens and storms develop, the weak steering flow overhead could lead to some heavy rains and training thunderstorms. Training storms are simply storms that continually form over the same area, often leading to flash flooding.
With that being said, after yesterday’s model miss, I don’t have nearly the confidence in today’s forecast as I have for Wednesday and especially Thursday. Today and early Wednesday are a transition period to getting the more direct tap to the monsoonal type of flow.
Here are today’s daily CAPE values.
Here are the “for what it’s worth” forecasted precipitation totals from the major global models ending Monday morning at 6 am.
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