Here a compilation of 7 strange weather phenomena that baffled meteorologists this week.
And there are more to come.
The final full week of July has featured several unusual weather events. Among them are several rainfall extremes, strange tropical cyclone interactions and out-of-season conditions.
A downpour that had a 0.1-percent chance of happening in Harrisburg, Pennsylvania
Harrisburg International Airport received 4.27 inches of rain in a single hour, from 5:56 to 6:56 p.m. EDT. A rainfall event of this magnitude in Harrisburg has just a 0.1-percent chance of happening in a given year, according to NOAA.
This now stands as the wettest July day on record, and the fifth-wettest day overall for any month of the year at that location. This downpour was extremely localized. Harrisburg’s Capital City Airport, just a few miles to the northwest, saw less than a half-inch of rain during the same evening.
Third time in 140 years: Rain in downtown Lor Angeles on July 24
A trace of rain was recorded in downtown Los Angeles on July 24. Only three other times in history has any rain been observed there on July 24. A trace was also recorded on July 24 in 1954, 1941 and 1910.
— NWS Los Angeles (@NWSLosAngeles) July 24, 2017
July is the driest month of the year in Los Angeles as the jet stream moves far to the north, taking the storm track away from California.
Hurricane swallows up another hurricane: Fujiwhara effect x 2
I’ve been discussing the Fujiwhara effect in the Pacific Ocean. It’s an uncommon event during which one low pressure area swallows up another one. Typhoon Noru and now former Tropical Storm Kulap have already done the Fujiwhara dance in the western Pacific earlier this week. Now, the Fujiwhara effect is forecast to take place in the eastern Pacific between Irwin and Hilary through this weekend.
Observing a single Fujiwhara event is a rarity in a given year, so having this occur twice in a matter of days is exceptional.
No measurable rain in Seattle this month, A new record for the city
Wet days are not a common occurrence in Seattle during July since it’s typically the driest month of the year. The dryness this month, however, has a chance to enter the record books for Sea-Tac airport. No measurable rain has been observed there through July 28, and none is in the forecast through Wednesday, August 2.
Top 5 Seattle dry streaks
1. 51 days 7/7-8/26,1951
2. 48 7/23-9/8,2012
3. 45 9/1-10/15,1991
4. 42 7/17-8/27,1986
5. 41 6/18-today#wawx
— NWS Seattle (@NWSSeattle) July 28, 2017
Seattle is in the midst of its fifth-longest dry streak on record at 41 days through Friday.
Fall temperatures recorded in New England
The weather in New England on Monday afternoon resembled something you might imagine occurring in fall or spring. At 1 p.m. EDT, Boston was just 58 degrees with light rain and winds gusting to 26 mph.
That temperature was only four degrees warmer than the daily record low for July 24, which is 54 degrees.
Rare cold front in the South in July
The South will have a late-July treat this weekend as a cold front sweeps away the typical summer humidity currently in place. Cold front passages are a fairly rare occurrence in the South during mid-summer, because the jet stream is usually bottled up near the Canadian border and rarely takes the sharp dive southward that is needed for a cold front to penetrate into the southern states.
Dew points in the 70s are typical in the Southeast during July. This weekend, dew points in parts of the Southeast will drop into the 50s and 60s.
South Florida July is too hot
July is on track to be the warmest month on record for Miami, where temperatures have had a rough time dropping below the 80 degree mark. The number of nights that Miami has failed to fall below 81 degrees stands at 22 through July 28.
With the exception of one day, every day in July has peaked over 91 degrees even with rainfall being nearly twice the average for the month.
Indeed some strange weather phenomena going on in the USA this week.