Two Atlantic disturbances to watch; Guchol hits Japan; extreme heat in Colorado

An area of low pressure and heavy thunderstorms has developed over Western and Central Caribbean, and this disturbance will need to be watched for development as it moves northwest at 5 - 10 mph and enters the Gulf of Mexico late this week. The disturbance is poorly organized, and its modest area of heavy thunderstorms is bringing rains to Jamaica, the Cayman Islands, South Florida, the Southern Bahamas, and Cuba today. Wind shear is a moderate to high 20 - 30 knots over the region, and the shear is predicted to remain in the moderate to high range for the next three days along the disturbance's path. Water vapor satellite loops show a region of dry air over the Southern Gulf of Mexico and Yucatan Peninsula; strong upper-level winds out of the southwest are bringing some of this dry air into the vicinity of the disturbance, which is interfering with development. NHC is giving the disturbance a 10% chance of developing into a tropical depression by Thursday morning. None of the computer models is showing development of the disturbance into a tropical depression, but I wouldn't be surprised to see the system grow in size and potential for development over the next few days. There are currently no hurricane hunter missions scheduled to investigate.


Figure 1. Morning satellite image of the tropical disturbance near Cuba.

North Atlantic Invest 95L headed out to sea
A well-organized low pressure system with a closed surface circulation but little heavy thunderstorm activity (Invest 95L) is over the open Atlantic between Bermuda and Canada. This storm doesn't have enough heavy thunderstorms to deserve a name, but has a 50% chance of doing so before hitting colder waters on Wednesday, according to NHC. 95L is headed northeast out to sea, and will not trouble any land areas.


Figure 2. Tropical Storm Guchol as seen from NASA's Aqua satellite on June 19, 2012, as the storm approached Japan. Image credit: NASA.

Tropical Storm Guchol hits Japan
Tropical Storm Guchol made landfall in Japan's southern Wakayama prefecture near 9 UTC Tuesday morning. The Japan Times reports that the storm has injured five people, and 83,000 people have been evacuated. Guchol is the first June tropical cyclone to hit Japan since 2004. Tokyo recorded sustained winds of 56 mph, gusting to 76 mph, at 10:47pm local time (9:47 am EDT.) A wind gust of 74 mph was recorded at Shizuhama at 8:21 pm local time. The main threat from Guchol is heavy rain. The storm is expected to dump rains in excess of 400 mm (15.7") in the Tokai region, and 250 mm (9.8") inches near Tokyo. Japan is also watching Tropical Storm Talim, which is expected to pass along the length of the country Thursday and Friday. Talim's rains could cause considerable trouble, as they will fall on soils already saturated by the passage of Tropical Storm Guchol.

Intense heat in Colorado
One of the warmest days in Eastern Colorado history was observed Monday. According to wunderground's weather historian Christopher C. Burt, Denver had a daily record high of 100°F, but Wray, near the Kansas-Nebraska border, reached 109°. This was just short of its all-time record (for any month) of 110°F set in July 1934, and just 5° shy of the all-time state of Colorado record of 114°F set at Las Animas and Sedgwick on July 25, 1952. Lamar in Southeast Colorado hit 108°F yesterday, just 3° short of its all-time record of 111°F set in July 1934. Sterling, the in the far Northeast part of the state, hit 108°F, which may be its all-time heat record. The intense heat yesterday was accompanied by some very dry air. The humidity in Broomfield, CO fell to 4% for more than six hours on Monday. The hot, dry weather made firefighting efforts difficult for the massive wildfire burning 15 miles west of Fort Collins, CO. This fire is the third largest and most destructive fire in Colorado history. Firefighters have achieved 50% containment of the blaze.

Jeff Masters