Hottest rain on record? Rain falls at 109°F in Saudi Arabia
Pilgrims to the holy city of Mekkah (Mecca), Saudi Arabia must have been astonished on Tuesday afternoon, June 5, when the weather transformed from widespread dust with a temperature of 113°F (45°C) to a thunderstorm with rain. Remarkably, the air temperature during the thunderstorm was a sizzling 109°F (43°C), and the relative humidity a scant 18%. It is exceedingly rare to get rain when the temperature rises above 100°F, since those kind of temperatures usually require a high pressure system with sinking air that discourages rainfall. However, on June 4, a sea breeze formed along the shores of the Red Sea, and pushed inland 45 miles (71 km) to Mekkah by mid-afternoon. Moist air flowing eastwards from the Red Sea hit the boundary of the sea breeze and was forced upwards, creating rain-bearing thunderstorms. According to weather records researcher Maximiliano Herrera, this is the highest known temperature that rain has fallen at, anywhere in the world. He knows of one other case where rain occurred at 109°F (43°C): in Marrakech, Morocco on July 10, 2010. A thunderstorm that began at 5 pm local time brought rain at a remarkably low humidity of 14%, cooling the temperature down to 91°F within an hour.
Figure 1. Thunderstorms at 109°F? This true-color satellite image of Saudi Arabia taken at 2:10 pm local time (11:10 UTC) on June 5, 2012, shows a line of thunderstorms that developed along the edge of the sea breeze from the Red Sea. Three hours after this image was taken, Mekkah (Mecca) recorded a thunderstorm with rain and a temperature of 109°F (43°C.) Image credit: NASA.
More like a hot shower than a cooling rain?
Thunderstorms often produce big drops of cold rain, since these raindrops form several thousand meters high in the atmosphere, where temperatures are much cooler than near the surface. Some drops even get their start as snow or ice particles, which melt on the way to the surface. Additional cooling of the drops occurs due to evaporation on the way down. However, in the case of the June 4, 2012 Mekkah storm, I think the rain was probably more like a hot shower. Large raindrops, like the kind thunderstorms produce, fall at a speed of about 10 meters per second. A balloon sounding of the upper atmosphere taken at 3 pm local time at a nearby station (Al-Midinah) found that the bottom 1000 meters of the atmosphere was 97°F (36°C) or warmer. Thus, the thunderstorms' raindrops would have been subjected to 100 seconds of some very hot air on the way to the surface, likely warming them above 100°F by the time they hit the ground. A classic 1948 study of raindrops found that, in many cases, raindrop temperatures start off cold in the first few minutes of a rain shower, then warm up to within 1°C (1.8°F) of the air temperature within a few minutes. With the air temperature a sizzling 109°F (43°C) at the time of the June 4 thunderstorm in Mekkah, the raindrops could easily have been heated to a temperature of over 105°F (41°C) by the time they reached the surface!
How hot can it be and still rain?
If substantial amounts of liquid water are present on the Earth, the planet will experience rain, as long as some mechanism to lift the warm, moist air and cause condensation can be found. If the climate continues to warm as expected, we should see an increasing number of cases where it rains at temperatures well above 100°F. On Saturday, June 2, the temperature in Mekkah hit 51.4°C (124.5°F), a new record for the city, and just 1.1°F (0.6°C) below the all-time hottest temperature record for Saudi Arabia (125.6°F, or 52°C, recorded at Jeddah on June 22, 2010.) I expect that 20 - 40 years from now, we'll begin seeing occasional cases where rain falls at a temperature above 117°F (47°C) in the desert regions of North Africa and the Middle East.
I'll have a new post by Friday afternoon.
Jeff Masters
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A crossover is what the Euro hints there?
It only came back 5 mb. weaker than the 18Z. :P
Good morning all.
And that's the weather/farm report from East Texas.
What is it with all these beautiful storms with amazing structures in the West/Plains? We just get a bunch of black clouds here in the East...
By Jamie Dupree
After recent revelations of internal budget mismanagement, the National Weather Service is proposing a plan to furlough all of its employees in coming months, in case a deal cannot be reached with Congress to move around money to help make up a $26 million budget shortfall.
"This would require each employee to be furloughed for 13 days, or the equivalent of at least one full pay period," read a fact sheet from the Commerce Department, which oversees the Weather Service.
Even as they notified workers about the possibility, officials acknowledged that such furloughs "would potentially impact critical weather operations including those at the National Hurricane Center and Storm Prediction Center, during the peak of hurricane season."
The hurricane season began June 1; the furloughs would take place between mid-July and the end of September, normally an active time for tropical weather systems.
Certainly one way to grab some attention in the Congress - and the public at large - is to threaten to short staff the Hurricane Center during the summer.
The announcement angered leaders of the union for Weather Service employees, as they argued workers should not be penalized for the mistakes of upper management.
"Their misguided plan to furlough all agency employees is another example of the short-sighted thinking that has put them in such dire straits," said union president Dan Sobien.
"National Weather Service employees are paying for the mistakes of the agency’s leadership," Sobien added.
The move comes less than two weeks after the head of the National Weather Service suddenly retired, as an internal investigation showed that money had been diverted to weather forecasting field offices without the approval of Congress.
There was no evidence that the money had been pocketed for personal gain - instead, it was simply used to fund operations at local National Weather Service offices, by stripping money from other weather facilities.
While that might sound kosher to some outside of government, the cold truth is that no one other than the Congress can "reprogram" budget funds, one reason the Congress is demanding more answers before signing off on any deal.
So far, the Commerce Department has not released details of how it would move around money, but it would have to be done most likely before the end of June.
"It is the Department’s hope to work with the Congress to achieve this outcome," Commerce officials said in a document which was released yesterday by the National Weather Service Employees Organization.
"For years, NWSEO warned Congress that the NWS budget was underfunded," said Sobien, the union president.
I believe its depicting a large cluster of convection around Central America that extends from the EPAC and into the western Caribbean due to the monsoonal trough. On the eastern end of the convection a low spins up and become dominant which lead to development in the NW caribbean by the GFS. However the ECWMF shows a dominant low in the EPAC which get shoved ENE towards the Gulf which it spins up. Let see what camp the other models support the GFS or ECWMF.
This is something I've experienced with NASA. I would be surprised if they weren't payed at some point after the furlough. Most likely the NWS employees will get a payed vacation out of this...if it happens. Usually the threat alone kicks Congress into doing it's job.
i know >:|
I think it has to do with the drier air causing LP supercells etc and with the fact that is flatter out there so you can see further.
Here in GA, if that storm was 1 mile from me, it would just look like a mass of gray over the trees.
And the 6z gfs came in 500mb weaker and a lot broader.
It is not as tight and so looks weaker
hopefully, it would be terrible if they had a furlough on a major hurricane landfall day, or on a major severe weather day.
At least we shouldnt have too many more severe weather events but the Northern tier of the country is still fair game for strong storms.
And if we had a landfalling hurricane, with the NHC, SPC, and local NWS offices out of service, there would be no flood warnings, tornado warnings, and hurricane warnings etc would have to be issued in advance.
I dont see congress letting that happen.
CNN says she it a tropical storm.
Maybe that was Sanvu
right this is what I think
we will have Chris in the Caribbean. starts off of the Monsoon trough, it breaks off heads N being just NE of Hon/Nic, he will continue off in a NNE-ENE direction Towards Cuba,Florida,Bahamas direction and out. while that happens a peice of monsoon trough in the EPac breakes off, continues on a W-WNW path and forms Carlotta. she then starts to move N, makes landfall, crosses over, and be comes Debby in the GOM and heads ENE-E following Chris. JMO
They send me something in 36 hrs. I don't know what.
right right now that build up of convection over the SW caribbean and Colombia and Venezuela it is part of the monsoon trough that is what will trigger the development
Nice swath on rain for Florida yesterday with some more to come today which is a good thing.
On the tropics front, really interesting to see the ITCZ finally fire up and start it's slow climb northward towards the Caribbean island chain over the next two months peaking in August and September. Mother Nature is like that every year; it was pretty clear out there for the past several weeks, and now like a switch was thrown, the ITCZ has activated in earnest. Time to start keeping a close eye on the long term models and waves emerging from Africa. But do not get too excited yet; sheer is way too high out in the Central Atlantic and nothing brewing closer to home at the moment.
Link
Have a Great Weekend Folks.........WW.
SOME LOCALLY HEAVY RAINFALL IS A GOOD BET.
IN THIS TROPICAL LIKE SITUATION...A DOUBLING OF THOSE
AMOUNTS IS VERY POSSIBLE. DESPITE THE ON-GOING DRY SPELL AND WE ARE
IN THE GROWING SEASON...EXCESSIVE RAINFALL COULD STILL PRODUCE SOME
EPISODES OF FLOODING.
and then hits the Carolinas:
and then the NE:
although i am not so sure it is tropical when it hits the NE.
The system is finally moving up in time as it now exits the carribean at 240hrs.
and Carlotta is missing
True. But still, I want to see a storm like that!
It's weird, none of the local forecasters have mentioned that we could receive 2-4 inches of rain. They're just suggesting off and on showers the next few days.
the HPC has the 3.8 bullseye over N GA, and the NWS Peachtree City Forecast Discussion talks about the rain.
Maybe the local mets are just not into giving rainfall totals yet on steady rain events.
By tonight i think they will begin to mention rainfall totals given that this is the next system to affect the GA area.
GFS AND ECMWF MODEL FORECASTS SHOW THE MONSOON TROUGH BECOMING
MORE ACTIVE AND EXTENDING FURTHER W TO AROUND 120W-125W OVER THE
WEEKEND...WITH LONG TERM 5-7 DAY FORECASTS HINTING AT POSSIBLE
TROPICAL CYCLONE GENESIS OCCURRING S OF MEXICO BETWEEN 100W-105W.
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