The Humidity Is Back
One of the dramatic things about the drought that’s been severely dented in the region is that it was marked by unusually low humidity values, that are strange by KC standards for the summer season. This is a result of the parched land unable to give back moisture into the lowest part of the atmosphere via evaporation. Essentially there was nothing to evaporate anymore. The trees/crops also send moisture into the air through transpiration (the loss of water vapor through leaves) but the crops are mostly lost, especially the corn, and many of the trees lost their green foliage weeks ago in the withering heat and due to a lack of significant rainfall. This dry air contributed to unusually low temperatures, which in a way prevented this summer’s heat to be in the top 10 of hottest summers. See yesterday’s blog for more information on that.
So now that we’ve seen anywhere from 2-7+” of rainfall in the region from the remnants of Isaac, there is finally moisture to again evaporate into the atmosphere. As the sunshine starts the heat the terrain that moisture will take the form of higher humidity values (dewpoints) that will be more typical of the summer season around these parts. Look at all the rain we’ve seen in the region, courtesy of the NWS in Pleasant Hill.
Looking at the models this AM, while I’m expecting some hot and humid weather for the next few days, you can see the atmosphere is starting to change. While summer weather will still be around there are going to be some seasonably strong cold fronts moving into the region over the next 10+ days and with those fronts will come some rain opportunities. Again, just to be clear, we can see 95°+ days again, but if the soils stay charged with some moisture those days will really dwindle over the next 10 days as we approach mid September (of course the advancing calendar helps as well in that). Clearly however the weather is in the process of becoming more active…it’s as if Isaac flipped on the weather switch again in the atmosphere.
Right now the better chances of rain look to be on Tuesday and Friday. Widespread rain may be tough to come by on Tuesday but I think there might be the better chance on Friday as a seasonably strong cold front moves in and drops our temperatures heading towards next weekend.
Strange weather fact…Las Vegas, NV just finished the month of August with a record 13 days with thunder heard at the airport there. The average is a little more than 3. Their rainfall for the month was also well above the average of .33″. They received 2.28″ of rain.
Weather fact #2) Sioux Falls, SD had 2.73″ of rainfall from June-August marking their driest meteorological summer in history.
Onto the tropics, where activity continues as we’re nearing the peak time for tropical storms/hurricanes. There are two named storms out there, Leslie and Kirk. Neither storm will affect the USA to great degree although the recurving Leslie may bring some nice surf to the NE part of the country.
Sadly the folks in LA are still fighting the effects of Isaac in the form of flooding and power outages. some 250K customers are still without power there.
That’s about it for today. I’ll be filling in the the AM shows all week long so I’ll see you tomorrow and should have the blog updates done by about 11AM every day this week. I’ll send out twitter/FB notifications when they’re done.
Joe
