Friday Daily Weather Summary

ONLINE DAILY WEATHER SUMMARY

Friday, 30 April 1999

COOL, WET WEATHER IN THE SOUTHEAST
MORE SMILES IN FLORIDA
PLEASANT WEATHER ACROSS THE NATION'S MIDSECTION
A WINTRY WESTERN STORM SYSTEM
UPPER AIR
YESTERDAY'S TEMPERATURE EXTREMES IN THE LOWER 48
ALASKAN WEATHER
HAWAIIAN WEATHER
MAY DAY
IN THE NIGHT SKY
A TIME OUT
HISTORICAL WEATHER EVENTS

COOL, WET WEATHER IN THE SOUTHEAST -- A cool pool of air moved southward along the Appalachians over the last several days. As of Thursday, a region of clouds, rain and low temperatures were found across the Carolinas, extending into adjoining portions of Georgia. Afternoon high temperatures across the Carolinas on Thursday were on the order of 20 degrees below the average high temperatures for this time of year.

A northeasterly onshore wind also contributed to the damp, chilly feeling across the Southeast. The winds were circulating around a low pressure system that was developing off the South Carolina coast. Gale warnings were posted for the Carolina coast south of Cape Hatteras for winds between 39 and 54 mph. The onshore winds also necessitated heavy surf advisories for the entire North and South Carolina coast and much of the Georgia coast. The occurrence of a high astronomical "spring" tide because of the full moon compounds the problem of potential coastal flooding and erosion.

The storm system is expected to continue to remain well off the coast as of Friday morning. Widespread rain is anticipated to continue across the Carolinas.

MORE SMILES IN FLORIDA -- Following months of very little precipitation, Florida continued to receive more much-needed rain from showers and thunderstorms on Thursday. Interestingly, the 1.23 inches of rain that fell at Orlando on Wednesday was a 24 hour record rainfall for the date. However, thunderstorms produced wind damage across the western portions of the Florida Panhandle and adjacent counties in southern Alabama on Thursday afternoon. Winds gusted to 60 mph. Golfball sized hail was also reported. These thunderstorms were associated with a cold front that passed across the area.

PLEASANT WEATHER ACROSS THE NATION'S MIDSECTION -- A large, sprawling ridge of high pressure centered over Lake Superior produced pleasant, cloud-free weather across a large portion of the country extending from the Northeast to the western high Plains and from the Canadian border south to the Tennessee and lower Mississippi Valleys. High temperatures across northern Minnesota were in the mid to upper 70s, some 15 degrees above the climatological high temperatures for the date.

Thursday afternoon's high temperature at New Orleans (Audubon Park) tied the daily record at 91 degrees.

A WINTRY WESTERN STORM SYSTEM -- A large complex low pressure system with multiple low pressure center were found across the southwestern portion of the country on Thursday night. Individual low pressure centers were located over western New Mexico, Colorado, Utah and northern California. These lows are rotating in a counterclockwise direction around an upper air circulation feature associated with a cold pool of air.

The weather has been unseasonably chilly across the Southwest. Much of the region from southern California into Arizona and Nevada experienced high temperatures on Thursday afternoon that were roughly 20 degrees below the long-term averages for this time of year. Near the center of this pool of cold air and associated low pressure complex, the high temperature on Thursday afternoon at Las Vegas, NV was only 56 degrees, setting a record low maximum temperature for the date. Farther to the north, the overnight low temperature at Pendleton, OR reached a record-tying low of 32 degrees.

Widely scattered precipitation was also found with these low pressure systems. Rain and high altitude snow were found over the southern Rockies of New Mexico, stretching northward into Colorado and westward through southern Wyoming and into northern portions of Utah and Nevada. Some of the precipitation has been heavy, especially in Colorado, where in addition to the lifting into the storm system, orographic lifting took place as easterly upslope winds confronted the Front Range. By Thursday afternoon, record rains fell at Colorado Springs as 1.57 inches was collected and at Pueblo, with 0.77 inches being recorded. During the 24 hours ending on Thursday afternoon, 4.10 inches of rain fell at Colorado Springs. During a six-hour interval ending early Thursday, Cripple Creek had received 8 inches of snow.

Thunderstorms were also forming over eastern New Mexico and moving into west Texas on Thursday night. Some of these thunderstorms were producing large hail and some may contain tornadoes, according to Doppler radar estimates.

This system is not expected to change much by early Friday. Widespread rain and mountain snow is expected. Winter storm warnings were issued for the accumulation of more than a foot of snow by late Friday at elevations above 8500 feet in the Sangre de Cristo Mountains of southern Colorado. Strong winds along the coast prompted gale warnings for the coast between Point Arena, CA and Cape Blanco, OR.

UPPER AIR --The 500 and 300 mb constant pressure charts for 00Z Friday contained a mid and upper tropospheric wind regime that was quite similar to 24 hours earlier. At both levels, the winds circulate in a clockwise fashion around a large height ridge over the northern Plains, flanked by counterclockwise flow around height troughs on the East and West coasts. This type of exaggerated wind flow pattern, often called an "omega block", is a result of a warm pool of air that has been displaced poleward and that has become flanked by cold pools of air that have moved equatorward. The pattern has the appearance of the Greek letter omega and this regime would cause storms to be carried around the periphery of the ridge, resulting in "blocking".

The 300 mb trough over southern Nevada reflects the cold air associated with the surface storm system over Nevada. The upper tropospheric trough over the Middle Atlantic states corresponds to the cold pool of air over the Carolinas. In-between, the center of the 300 mb ridge over the Dakotas is directly related to the warm conditions over the upper Mississippi Valley.

YESTERDAY'S TEMPERATURE EXTREMES IN THE LOWER 48 -- The lowest temperature on Thursday was 19 degrees at Saranac Lake, NY, while the day's high was 91 degrees at Houston, TX and Lake Charles, New Orleans and New Iberia, LA.

ALASKAN WEATHER -- A large storm system situated over Far Eastern Russia the weather across western Alaska on Thursday afternoon. This low pressure system had an accompanying occluded front that curled eastward over the Seward Peninsula before turning south to cross the Yukon-Kuskokwim Delta and reach a point of occlusion near Bristol Bay. A warm front continued southward across the Alaska Peninsula, while a cold front swung westward along the Aleutians. The frontal bands from another storm in the southern Gulf of Alaska spread clouds across the Panhandle.

Whatever precipitation that fell across Alaska on Thursday was relatively light, with less than several hundredths of a inch. However, Saint Paul Island, Nome and Yakutat had over a tenth of an inch.

Weak high pressure extended northeastward from over the North Pacific toward the vicinity of Kodiak Island and then into portions of interior and south central Alaska.

The lowest overnight temperature across the state as of Thursday was 9 degrees below zero at Nuiqsut. The highest midafternoon temperature was 55 degrees at Dutch Harbor.

HAWAIIAN WEATHER --Light trade winds and pleasant trade weather continued over the islands on Thursday. However, an upper level low, coupled with a surface front located to the northwest of Hawaii is expected to locally disrupt the trade winds by Saturday. With weaker trade winds afternoon convective showers should be more widespread.

IN THE NIGHT SKY -- Today the moon reaches the full moon phase at 1455 Z. The April moon is often called the "Grass Moon" or the "Egg Moon".

MAY DAY -- Tomorrow is May Day, which is a welcome to "the merry month of May"! Apparently the name comes from "Maius", named for "Maia", in Roman mythology, the goddess of increase and growth of plants. An alternate is that it is from the Latin "Maiores", meaning elders, who were celebrated during this month. May Day or Beltane is also close to the traditional "cross quarter" day, roughly halfway between the vernal equinox and the summer solstice. This day was a great Celtic festival including bonfires, May Poles and May Queens.

A TIME OUT -- Today's Daily Weather Summary discussion is the final one for the spring 1999 course. An abbreviated daily summary will appear next week. Starting Monday, 10 May and running through the summer, the Online Weather Daily Summary will contain only the selected Historical Weather Events for that day. Current weather data will be available on the homepage as usual. If you are looking for an alternative description of daily weather, you could try:

http://www.usatoday.com/weather/wlead.htm

HISTORICAL WEATHER EVENTS - 30 April

From the files of the Aviation Weather Center, Kansas City, MO and Intellicast

...1852...A tornado, following the same track as the famous "Tri-state Tornado" of 1925, struck the town of New Harmony IN. Just sixteen persons were killed by the twister, due to the sparse settlement. The "Tri-state Tornado" killed 695 persons. (David Ludlum)
...1924...A major tornado outbreak occurred from Alabama to Virginia. Twenty tornadoes were of F2 intensity or greater. A total of 111 people were killed and over 1100 were injured. A F4 tornado tore through Steedman and Horrell Hill, SC. Fifty five people were killed from this tornado. (Intellicast)
...1953...Jeffersonville and Warner Robbins, GA were hit by a tornado rated F4 on the Fujita scale and having a width of approximately 300 yards. Warner Robbins Air Force Base was severely damaged, as barracks were leveled. Nineteen people were killed, 300 injured, and total damage was 15 million dollars. (The Weather Channel) (Intellicast)
...1986...The driest January through April period in the history of Birmingham, AL came to a close. Total rainfall for the period was 6.00 inches, compared with a normal of 21.46 inches. The previous record drought for this period was 10.72 inches in 1972. (Intellicast)
...1987...Thunderstorms developing along a cold front produced severe weather in Idaho, Utah, Wyoming and Montana. Thunderstorms produced wind gusts to 100 mph in Lincoln, Mineral and Sanders counties. Twenty-three cities in the central and southeastern U.S. reported record high temperatures for the date. Memphis, TN was the hot spot in the nation with a record high of 94 degrees. (The National Weather Summary) (Storm Data)
...1988...A cold front produced high winds in the southwestern U.S. Winds gusting to 90 mph in southwestern Utah downed power lines, and damaged trees and outbuildings. The high winds also downed power lines in Nevada, completely knocking out power in the town of Henderson. (The National Weather Summary) (Storm Data)
...1989...Thunderstorms produced severe weather in central and eastern Texas. Hail three inches in diameter was reported at Cool, and thunderstorm winds gusted to 80 mph at Hillsboro. For the first time of record Oklahoma City went through the entire month of April without a single thunderstorm. (The National Weather Summary) (Storm Data) (The Weather Channel)
...1990...Late afternoon and evening thunderstorms produced severe weather in southern Virginia and the Carolinas, with tennis ball size hail reported southeast of Chesnee, SC. Thunderstorms moving over Chesapeake Bay flooded U.S. Highway 50 on Kent Island, MD with several inches of water resulting in a seventeen-mile long traffic jam. (The National Weather Summary) (Storm Data)
...1991...Memphis, TN set a new monthly rainfall record for April with 17.13 inches of rain. The old record was 13.90 inches set back in 1877. (Intellicast)
...1992...The past month was 0.3 degrees below normal at Raleigh, NC, ending an amazingly long streak of 27 consecutive months of normal or above normal temperatures. The streak began in January 1990. The previous record streak of 11 months extended from July 1912 to May 1913.
The heat was definitely on in the central US. The following cities set record high temperatures not only for the date but for the month of April as well: Valentine, NE 100 degrees, North Platte, NE 98 degrees, Colorado Springs, CO 87 degrees, Denver, CO 90 degrees, Casper, WY 84 degrees, and Cheyenne, WY 83 degrees. (Intellicast)

1 May

...1854...After 66 hours of steady rain, the Connecticut River reached a level of nearly twenty-nine feet (28 feet 10.5 inches) at Hartford, CT (the highest level of record up until that time). The record height was reached in the midst of a great New England flood which followed sixty-six hours of steady rain. (David Ludlum) (Intellicast)
...1883...At Cape Lookout, NC, a storm tide swept over the island drowning sheep and cattle. (Intellicast)
...1895...An F5 tornado nearly one mile wide cut a 22 mile path through Sedgwick and Harvey Counties in Kansas. 8 people were killed and 25 were injured. 25 farms were "completely devastated" and a few "entirely vanished". (Intellicast)
...1933...The most deadly tornado in Louisiana's history struck Minden. Twenty eight people were killed and 400 were injured. 500 homes were damaged or destroyed with 1.3 million dollars in damage. The tornado reportedly sounded like "mad lions on a speeding train". (Intellicast)
...1935...Snow, ice and sleet brought winter back to parts of southeast Minnesota. Minneapolis received three inches of snow to tie their May record which was established in 1892. (1st-2nd) (The Weather Channel)
...1954...The temperature at Polebridge, MT dipped to 5 degrees below zero to establish a state record for the month of May. (The Weather Channel)
...1967...A full blizzard was in progress across the Dakotas. Wind gusts reached 70 mph at Dickinson, ND. 16 inches of snow fell at Lemmon, SD and 30 inches was reported in the Northern Black Hills. Frequent vivid lightning displays also accompanied this storm. (Intellicast)
...1987...Thunderstorms produced large hail and heavy rain in Texas. Baseball size hail pounded Dublin, and 3.75 inches of rain soaked Brady. (The National Weather Summary) (Storm Data)
...1988...Strong southerly winds ahead of a cold front crossing the Rocky Mountain Region gusted to 90 mph at Lamar, CO. High winds created blinding dust storms in eastern Colorado, closing roads around Limon. (The National Weather Summary) (Storm Data)
...1989...Thunderstorms produced heavy rain in the southeastern U.S. Rainfall totals of 1.84 inches at Charlotte, NC and 2.86 inches at Atlanta, GA were records for the date. Strong thunderstorm winds uprooted trees in Twiggs County, GA. (The National Weather Summary) (Storm Data)
...1990...Thunderstorms produced severe weather from northern Alabama to North Carolina. There were sixty-three reports of large hail or damaging winds, with hail four inches in diameter reported near Cartersville, GA. Ten cities in the southeastern U.S. reported record high temperatures for the date as readings warmed into the 90s. Jacksonville, FL reported a record high of 96 degrees. Late night thunderstorms over central Texas produced up to ten inches of rain in southern Kimble County and northern Edwards County. (The National Weather Summary) (Storm Data)

2 May

...1762...A tornado struck Port Royal Island, SC. It left a path 400 yards wide, tore up trees by the roots, and carried away houses and bridges. (Intellicast)
...1899...A storm buried Havre, MT under 24.8 inches of snow, an all-time record for that location. The water equivalent of 2.48 inches was a record 24 hour total for the month of May. (The Weather Channel)
...1920...A swarm of tornadoes in Rogers, Mayes and Cherokee Counties in Oklahoma killed 64 persons. Peggs, OK was completely destroyed by an F4 tornado. Seventy one people were killed which was 30 percent of the town's population. (David Ludlum) (Intellicast)
...1929...Virginia's worst tornado disaster occurred. Six tornadoes, two of which were west of the Blue Mountains, killed 22 people. Twelve children and a teacher were killed at Rye Cove, in Scott County. Four schools were destroyed by the storms. (The Weather Channel)
...1954...A major late season snowstorm struck the Arrowhead of Minnesota, leaving 18 inches of new snow at Virginia. (Intellicast)
...1983...Severe thunderstorms spawned twenty tornadoes across Michigan, Ohio, Pennsylvania and New York State. The tornadoes caused five deaths. Five were F2 tornadoes and one was a F3 tornado in New York with 3 people killed. A large part of the small town of Boonville was demolished with a damage total of $15 million in the town alone. Golfball size hail accumulated to a depth of 6 inches at Pine City. (The Weather Channel) (Intellicast)
...1987...Thunderstorms in the Lower Mississippi Valley produced golf ball size hail in northern Louisiana, and wind gusts to 77 mph at Lake Providence, LA. Thunderstorms in Arkansas produced 4.20 inches of rain at Arkadelphia and 4.00 inches at Bismarck. (Storm Data) (The National Weather Summary)
...1988...A powerful storm produced snow and high winds in the Central Rockies and the Central High Plains Region. Snowfall totals in Colorado ranged up to 12 inches at Strasburg, and winds in southeastern Colorado gusted to 87 mph at Lamar. Snow and high winds created blizzard conditions in eastern Colorado and southeastern Wyoming. (The National Weather Summary) (Storm Data)
...1989...Thunderstorms developing to the north of a warm front produced severe weather in Oklahoma and Texas. There were 93 reports of severe weather. Thunderstorm winds gusted to 80 mph at Beattie, and baseball size hail was reported at Ranger and Breckenridge. Juneau, AK reported a record high temperature of 72 degrees while Honolulu equaled their record low for the month of May with a reading of 60 degrees. (The National Weather Summary) (Storm Data)
...1990...Fourteen cities in Florida, Georgia and South Carolina reported record high temperatures for the date as readings soared into the 90s. Tampa, FL reported a record high of 97 degrees, and Fort Stewart, GA was the hot spot in the nation with a reading of 100 degrees.
Thunderstorms produced severe weather from northeastern Texas to western Arkansas during the evening and early nighttime hours. Thunderstorms spawned a tornado which injured thirteen persons at Paris, TX, and produced baseball size hail at Rio Vista, TX. Thunderstorm rains of four to seven inches caused flash flooding in west central Arkansas, southern and eastern Oklahoma, and northern Texas. (The National Weather Summary) (Storm Data)