Wednesday, August 24, 2016

Fire and Rain

A lot of attention is being paid to the tropical Atlantic where Fiona is now history, Gaston is strengthening, and a third disturbance, which could end up being Hermine, is being watched closely. Although there were five previous systems, including two hurricanes (Alex and Earl), only two, Bonnie in late May and Colin in early June, directly affected any part of the U.S., mostly with heavy rain.

In the meantime, resident of south-central Louisiana are still trying to clean up after a no-name tropical-like system dumped two feet of rain on them just 10 days ago.

7-day precipitation for Louisiana ending August 16. However, most of this fell in just two days (August 12-13).

The public and the news media don't get quite as excited about things when they aren't being talked about days in advanced (hyped, if you wish), and don't seem as interested in the aftermath when there is no "name" (e.g. Katrina, Sandy, Andrew) to blame it on. With or without a name, the destruction is the same.

Flooding in Baton Rouge.
Credit: U.S. Department of Agriculture -

In Louisiana an estimated 60,000+ homes are damaged, to say nothing of businesses, schools, and other buildings. The US Coast Guard, National Guard, local emergency responders, and citizens helped rescue more than 30,000 residents and 1,400 animals. Thirteen people lost their lives in the flooding. At least 7,000 people are in shelters, and more than 100,000 people in the state have registered for federal emergency aid. Twenty parishes (counties) have been declared federal disaster areas.

Two photos showing flooding in a Baton Rouge neighborhood on August 14 (top) and five days later on August 19.
Credit:Twitter @JesseWeather

In the western U.S. wildfires have been in the news. Much of the west, but California in particular, is tinder dry, and wildfires are everywhere.

Almost all of the western states are dealing with fires at the present time.  Large fire activity picked up with seven new large fires reported Monday. Currently, 32 large fires have burned more than a half million acres. Some of these fires have been burning for well over a month. The fires have destroyed numerous homes, disrupted truck and rail transportation, and caused air quality issues throughout the west.

Although fire activity is high, the number of fires and the acres involved are less than last year. According the the National Interagency Fire Center, the states currently reporting large fires and their number are: California (6), Colorado (1), Idaho (7), Montana (2), Nevada (1), Oklahoma (1), Oregon (5), Utah (6), Washington (6), and  Wyoming (6).

In Alaska 52 wildfires are currently being monitored. Alaska wildfires have burned more than 384,000 acres, substantially less than last year.

Active Alaskan wildfires as of 8/24/2016.
Credit: University of Alaska Fairbanks Arctic Region Supercomputing Center as part of the UAF SMOKE forecast project.
The outlook for the next month or so is for continued above normal fire risk in California and a return to normal fire risk in the intermountain west.

While Louisiana residents continue to recover from the rain and flooding almost two weeks ago, they are also keeping a watchful eye on the developments in the Atlantic. The tropical disturbance now labeled #99L is showing signs of organization and there is a 50 to 80 percent likelihood it will develop into a tropical cyclone in the next 3 to 5 days. It is way to early to determine a confident track for this potential cyclone, so those with interest from the Gulf Coast to the Florida east coast should be staying abreast of the latest information and advisories from the National Hurricane Center.

Friday, August 12, 2016

Louisiana Deluge

A flooding disaster of major proportions is underway in Louisiana and is likely to get worse over the next few days.

As of early Friday morning up to 15 inches of rain had accumulated during  the preceding 24 hrs. A westward moving low pressure system that is tropical in nature had been producing torrential rains from western Mississippi through eastern and  south-central Louisiana.

24-hour precipitation valid at 7:00 a.m. CDT 8/12/2016

Amounts reported by CoCoRaHS observers topped 11 inches this morning, and a late report at 7:00 p.m. tonight reported 14.65 inches (this is likely a 36 hour total).

CoCoRaHS reports >7.00 inches for Louisiana and Mississippi 8/12/2016

The U.S. Cooperative observer in Livingston, LA reported 10.55 inches of rain this morning, and then  another 6.54 inches as of 3:00 p.m. this afternoon. The observer reported rainfall rates of 3 inches  per hour for an extended period this morning. Rainfall totals exceeding 20 inches will be common by Saturday morning across Louisiana.

The low pressure system responsible for this rain has been hanging along the Gulf coast the past several days and become somewhat more organized as it drifted east. It was located over western Mississippi this morning, and slowly drifted westward during the day today.

Surface map at 1:00 p.m. CDT 8/12/2016 showing low pressure center over western Mississippi.

Visible satellite image for Louisiana at 4:15 p.m. CDT 8/12/2016. The bulging clouds over north-central Louisiana are indicative of strong convection.
 The low is expected to eventually begin drifting to the east and northeast this weekend. The potential for additional heavy rain remains high through the weekend.

Excessive rainfall outlook for the period from 7:00 a.m. CDT Saturday 8/13 to 7:00 a.m. CDT Sunday 8/14/2016.

The 3-day Quantitative Precipitation Forecast for the period from 7:00 p.m. CDT Friday, 8/12 to 7:00 p.m. CDT Monday, 8/15/2016.

Flooding is extensive. Rivers and streams rose rapidly with the high rainfall rates. Numerous rivers in southeast Louisiana and southern Mississippi were overflowing their banks and threatening widespread flooding and most rivers are expected to reach major flooding levels.

River levels and forecasts for southwest Mississippi and southwest Louisiana.
There have been two fatalities reported as a result of the flooding, and another person was reported missing at the time of this writing. Louisiana Gov. John Bel Edwards declared a state of emergency today because of the severe flooding and additional heavy rain expected.

Update Saturday, August 13  10:30 a.m.

Here are two-day rainfall totals for Louisiana. Radar rainfall estimate of 27.47" near Brownfields, LA corresponds well with observed rainfall.

48 hour rainfall totals for stations reporting >10" in Louisiana for period ending 7:00 a.m. CDT August 13.