Can it be too hot for rain?
POSTED: Monday, July 21, 2014 - 6:39pm
UPDATED: Thursday, July 24, 2014 - 11:12am
The Borderland has had a few days of record triple digit heat along with area late day storms
Monday, July 21st, 2014 — Yesterday, Sunday July 20th, El Paso hit a record setting 104º (tying the old record of 104º set way back in 1891.) and there were also area rain showers and thunderstorms into the nighttime hours!
I was with my 4 year old god son, Lex, outside his grandparents house watering, when the skies opened up for a 20 minute light, but steady rain shower. He thought if he sprayed the sky he could make it rain more, very cute! The rain stopped and then a stronger thunderstorm rolled in with heavier rain and then blowing dust. This all was happening while my thermometer read 102º!
That is when I asked my self, “Can it be too hot to rain?” that is the topic of today’s “Weather Talk”.
First I thought I would investigate what was the hottest ever recorded rain fall. On Monday, August 13th, 2012 , A strong upper level ridge of high pressure had produced a sizzling “heat wave” and sent temperatures soaring to record levels in the town of Needles, California tying its record high for the date of 118°F (47.8°C)! A thunderstorm rolled in and at 3:56 P.M.. PDT, rain began falling at a temperature of 115°F (46.1°C)! That set a new world record for the "hottest rainfall." We knew then that 115º is not a temperature that is “too hot for rain”.
Two records were set there that day, with that rainfall at 115º. The rain fell within a very dry air mass at just 11% humidity, setting another world record for the lowest humidity level that rain has ever occurred!
As a result of the dry air, only a small amount of the super-heated rain small drops actually made it to the surface. Rain gauges in the area only recorded a trace of precipitation.
What is also amazing is that previous "old world record" for this weather event was set just a few months earlier in Morocco!
According to weather records researcher Maximiliano Herrera, that's the hottest rain ever recorded, Dr. Jeff Masters, co-founder of the website Weather Underground, reported.
“The previous record for hottest rain was a rain shower at 109 degrees earlier this year in Mecca, Saudi Arabia on June 5 and in Marrakech, Morocco on July 10, 2010, according to the National Weather Service (NWS).”
Now we do know that it is very rare to get rain when the temperature rises above 100°F, since those kinds of temperatures usually require a strong high pressure system with sinking air that discourages rainfall. The rain in the Borderland Sunday night and the hottest record rain in Needles were due to a flow of moisture coming from the south caused by the Southwest U.S.. monsoon. Last night the Borderland saw a push of extra moisture and storms from northern Mexico that pushed our way. We had plenty of humid air already in place as well.
Well know we know that a few drops can make it to the ground at 115º with just 11% humidity. At the time of writing this “Weather Talk” El Paso International Airport has a reading of 94º, a dew point of 49º and relative humidity is 21%. We are going to top out close to the record high of 102º set on this date in 1981. After researching I think I will keep my slight, 10% chance of a heat caused storm or shower in the forecast for tonight and maybe for a couple more days just to be on the safe side.