Category: Posts EN

Tropical Disturbance Has Gulf of Mexico Residents on Edge

Written by Team Morecast

 

An area of low pressure, which began as a cluster of thunderstorms over the Midwest several days ago, has now drifted into the northern Gulf of Mexico. Although it has not yet developed a defined center of circulation, the ingredients are coming together for significant strengthening. By the late week or this weekend, a tropical storm or even hurricane could be menacing the Gulf coast!

 

 

The low pressure area has a decent presentation on satellite imagery (notice the swirl of clouds in the animation above). It’s already producing torrential rains along the Gulf coast. These rains will continue to cause serious flooding issues as the low moves slowly west over the northern Gulf. Water temperatures in this area are very warm, in the upper 80s deg F (lower 30s deg C). Upper level winds are also quite favorable for tropical cyclone development. If the system can organize a bit more in its core, these ingredients will enable rapid intensification.

 

Model guidance is still somewhat undecided since the system remains poorly organized. Some guidance brings the storm to the west, some to the east. Likewise, intensity forecasts vary. However, there is starting to be some agreement on a track initially towards the west and then eventually north. A potential landfall looms along the coast of Louisiana by Saturday. As long the center organizes sufficiently into Thursday, that still leaves a 36+ hour window for rapid intensification. Some models even suggest the system could be a hurricane by early Saturday. Regardless of whether it’s a weak hurricane or a strong tropical storm, significant impacts can be expected in the form of flooding rains, damaging winds, and a life-threatening storm surge. The map above shows the area likely to see wind and rain hazards.

Heat Wave for the Ages Affecting Normally Mild Alaska

Written by Team Morecast

 

The Fourth of July is traditionally known as a warm weather holiday across much of the United States. For many it represents the beginning of the summer. Residents of Alaska usually enjoy relatively cool temps during the traditional fireworks shows. But this past Thursday was not only the hottest Independence Day on record for the northernmost state in the union. Several stations reported their warmest temperatures for any day ever!

 

 

The average high for early July in Anchorage, the largest city in Alaska, is in the mid-60s deg F (upper teens deg C). Located on the shores of the always-chilly Gulf of Alaska, it’s a rare summer day that approaches 80 deg (27 deg C), and the all-time record high for any day was 85 deg F (29.4 deg C). That is, until Thursday. The official high reached 90 deg F (32 deg C) in Anchorage, with several other stations across the southern part of the state setting new all-time high marks (see map above, courtesy of the National Weather Service).

 

A strong, persistent ridge of high pressure is responsible for the hot weather. Alaska has been well above normal for close to two months now. Average temps in June ran five degrees above normal. The hot pattern is expected to continue for the next several days; Anchorage was only spared another record-shattering high temperature on Friday by the cover provided by wildfire smoke descending on the city. More records are likely to fall through early next week.

Major Hurricane Barbara Spins Across the Eastern Pacific; Atlantic Basin Still Quiet

Written by Team Morecast

 

Residents along the Pacific and Atlantic coasts enjoyed a very quiet beginning to the 2019 hurricane season. June, the first month of the official hurricane season, is typically quiet anyway. However, this will be the first year since 2009 featuring no storm activity in the first five weeks of the season. It’s a different story in the eastern Pacific, though.

A tropical depression developed on Sunday over the open waters of the eastern Pacific and was named Barbara by the afternoon. Barbara has steadily gained strength and is now a major hurricane, producing sustained winds to 130 mph ( kph). That’s a potentially very dangerous storm. Fortunately Barbara is not projected to affect any land masses. The storm will continue to move west and northwest, eventually dissipating late this weekend into early next week.

 

 

No tropical activity has been detected in the Atlantic basin since Subtropical Storm Andrea’s brief existence in May. The ENSO (El Nino – Southern Oscillation) remains in the positive mode (see graphic above). In other words, warmer-than-normal water temperatures over the western Pacific are resulting in stronger winds aloft. These winds act to disrupt developing tropical cyclones over the Atlantic basin. However, the ENSO is only weakly positive, and is forecast to remain that way. In addition, water temperatures are quite warm (see map below), which could provide fuel for cyclones later in the season.

 

Windy Storms Roll Across Portions of the Plains, Potentially a Derecho Pattern

Written by Team Morecast

 

Heat and humidity lingering into the evening hours on Thursday over the Central Plains provided plenty of fuel for severe storms. These storms became a long-lived squall line that has produced damaging winds from Nebraska and Kansas to Illinois.

 

 

 

“Derecho” is the name given to a squall line that produces 60 mph (100 kph) winds continuously for a period of at least six hours. Meteorologists typically observe a handful every year, mainly during the summer. The radar signature of the mature derecho is known as a “bow” for its resemblance to the standard archery equipment (see radar imagery above). Some of the most destructive severe weather episodes in the U.S. have been derechos. The derecho that slammed the Midwest and Mid-Atlantic in July 2012 cost nearly $3 billion in damages!

 

 

The current squall line easily qualifies as a derecho in terms of wind damage reports and duration (see map above). The squall line spun together on Thursday evening along the western Kansas-Nebraska border. Within the first hour or two it was producing wind gusts commonly in the 80-100 mph (130-160 kph) range. Numerous trees were uprooted and power poles were snapped like twigs. As the night wore on, the derecho lost some energy, but was still producing sporadic reports of damage with gusts 60-70 mph (100-115 kph). These continued through the morning hours. As of Friday mid-afternoon, the line was still tracking through southern Illinois with a damaging wind potential headed for portions of Kentucky and Tennessee. The environment remains favorable for additional squall lines to develop tonight in the Plains and Midwest.