Friday Daily Weather Summary

ONLINE DAILY WEATHER SUMMARY

Friday, 17 September 1999

FLOYD WEAKENS ON ITS WAY TO NEW ENGLAND
TRANQUIL WEATHER CONTINUES ACROSS THE NATION
MORE THUNDERSTORMS FOR THE SOUTHWEST
YESTERDAY'S TEMPERATURE EXTREMES IN THE LOWER 48
ALASKAN WEATHER
HAWAIIAN WEATHER
EYE ON THE TROPICS
REPORT FROM THE FIELD
A POSTSCRIPT
HISTORICAL WEATHER EVENTS

FLOYD WEAKENS ON ITS WAY TO NEW ENGLAND -- Floyd, at one time approaching a rare opportunity to become a category five hurricane, was moving quickly across New England as a tropical storm on Thursday night. Earlier in the afternoon, Hurricane Floyd was downgraded to tropical storm status as the sustained near-surface winds fell below 75 mph. As of late Thursday night, Tropical Storm Floyd was moving to the northeast at 35 mph passing a point approximately 25 miles east of Hartford, CT. Winds were 60 mph and central pressure was 980 mb (28.94 inches of mercury).

The Thursday night surface weather analyses show a large precipitation shield associated with Floyd and a mid-latitude frontal system was found across essentially all of New England and much of New York State, along with adjoining portions of Pennsylvania and New Jersey. These maps also depict a vigorous circulation regime as numerous concentric and tightly packed isobars appeared centered on southern New England.

After making landfall along the barrier islands of North Carolina, the tight circulation around Floyd began to become somewhat disorganized as the system began to accelerate as it moved to the north-northeast. Wind gusts that had been measured to 105 mph diminished, while heavy rains and windy conditions continued along the Eastern Seaboard. Winds caused tree damage and downed power lines across New England, where 29,000 customers remained without power on Thursday night. Rainfall records were set at several locations across the Northeast. At Philadelphia, 6.60 inches had fallen by early evening, setting an all-time record for any 24 hour period, and eclipsing pervious records set 101 years ago. Other daily records were set well before local midnight at Newark, NJ (6.14 inches), Central Park in New York City (4.79 inches) and Bridgeport, CT (2.74 inches). Wilmington, NC had a storm total of more than 19 inches. Some of the reservoirs in the Northeast that had experienced near-record low levels because of the protracted drought were replenished by late Thursday. Some dams were in danger of failing. Numerous flash flood watches and warnings remained in effect from the Carolinas north to Maine.

By Friday morning, the remnants of Floyd are expected to curve toward the east-northeast, reaching southern Maine. By then, Floyd should lose its tropical characteristics as it merges with the mid-latitude frontal system. The area of precipitation is expected to shift also. Tropical storm warnings continued in effect along the coast from Sandy Hook, NJ to the Merrimack River, MA, including Long Island Sound. Wind advisories also remained in effect for New York State as winds remained above 40 mph in some areas.

TRANQUIL WEATHER CONTINUES ACROSS THE NATION -- With the exception of the precipitation shield associated with Tropical Storm Floyd in the Northeast and scattered thunderstorms in the Southwest, much of the nation experienced pleasant weather once again on Thursday. A sprawling high pressure center located over Wisconsin produced relatively cloud-free skies from the Great Lakes south to the Gulf coast and westward from the Appalachians to the West Coast where several weak regions of low pressure were situated. On Thursday morning record low temperatures were set for the date at St. Joseph, MO (38 degrees.), Austin, TX (54 degrees) and Orlando, FL (68 degrees). Record high temperatures were set on Thursday afternoon at Dayton Beach, FL (93 degrees).and Miami Beach (92 degrees).

Little change in this picture is expected into Friday. As a result of the cool air mass, coupled with clear skies and weak winds near the center of the high, frost advisories have been posted for portions of northern Wisconsin and northern Lower Michigan for Thursday night and Friday morning.

MORE THUNDERSTORMS FOR THE SOUTHWEST -- Widely scattered thunderstorms were found across the Four Corners area of the Southwest on Thursday. Some of these thunderstorms, especially near Phoenix, AZ became severe as high winds and large hail were reported.

TEMPERATURE EXTREMES ACROSS THE CONTINENTAL US -- Thursday's lowest temperature was 26 degrees at Stanley, ID. Thursday's highest temperature was 108 degrees at Death Valley, CA and Lake Havasu City, AZ.

ALASKAN WEATHER -- A large complex storm system to the southwest of the mainland spread clouds, precipitation and windy weather across a large portion of southern Alaska on Thursday night. This storm system contained three separate low pressure centers, with one center located over the eastern Aleutians, a second over the Alaska Peninsula, and the third over the North Pacific Ocean south of Unalaska. Windy conditions were reported during the day for the Pribilofs, the Aleutians and Kodiak Island, where a wind advisory had been posted for gusts to 40 mph, along with nearly one inch of rain by early afternoon. A high wind watch was also reported along the eastern Gulf Coast.

Skies cleared across the northern half of Alaska on Thursday afternoon. However, earlier, light freezing drizzle was reported at Barrow on Thursday morning.

The lowest overnight temperature in Alaska on Thursday morning was 27 degrees at Barrow and Deadhorse, while the mid-afternoon highest statewide temperature was 61 degrees at McGrath, Koyuk and Unalakleet.

HAWAIIAN WEATHER -- The large ridge of high pressure located to the north of Hawaii that has provided moderate trade winds across the islands is expected to remain relatively stationary and show little change in strength through the beginning of the weekend. Increased winds may develop at the start of next week, as the high is forecast to intensify. As a result, wind speeds should remain relatively constant along with typical trade showers.

EYE ON THE TROPICS -- Hurricane Gert, a category four hurricane on the Saffir-Simpson Hurricane Intensity Scale, continued to move toward the west-northwest across the tropical Atlantic. As of early Friday morning, Gert was located approximately 1100 miles south-southeast of Bermuda and had sustained winds of approximately 135 mph. While movement was toward the west-northwest at 10 mph, Gert is expected to turn toward the northwest on Friday.

REPORT FROM THE FIELD -- Melissa Ficek of Online Weather Studies Central reported that moderate to heavy rains associated with Hurricane Floyd fell almost continuously from Wednesday afternoon through Thursday afternoon as the hurricane passed to the east of Washington, DC. Thick clouds made for a dark day, while the rains were also driven by winds gusting to 40 mph. Many of the area schools were canceled on Thursday and the subway system was packed.

A POSTSCRIPT -- Weather satellite monitoring of Hurricane Floyd was in jeopardy for a time on Thursday as Floyd approached the Wallops Island, VA receiving station where most of the satellite images from the geosynchronous satellite positioned over the western Atlantic are received, processed and retransmitted. Winds associated with Floyd were not sufficiently strong to require securing the satellite receiving antennae in a safe position that would not permit reception of data from the satellite.

HISTORICAL WEATHER EVENTS - 17 September

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

...1932...Concord, NH was drenched with 5.97 inches of rain in 24 hours to establish a record for that location (16th- 17th). (The Weather Channel)
...1963...Nearly two and a half inches of rain fell at Yuma, AZ in 24 hours. This rain, from Tropical Storm Katherina, was the most intense rain for Yuma during the period between 1909 and 1977. (The Weather Channel)
...1965...A storm produced a band of heavy snow across parts of Wyoming. Totals of 23 inches at Rawlins and 20.7 inches at Lander easily surpassed previous snowfall record totals for so early in the season. (15th-17th) (The Weather Channel)
...1971...Boulder, CO was buried under 21 inches of snow and Denver recorded 15.6 inches. Damage to trees and power lines was extensive due to the wet nature of the snow. Record breaking cold followed the snow.
...1987...Thunderstorms produced large hail, damaging winds, and heavy rain in the northeastern U.S. Heavy rain in southwestern Pennsylvania forced evacuation of twenty homes along Four Mile Run Creek, near Darlington. Harrisburg, PA established a record for the date with 2.11 inches of rain. A cold front in the central U.S. brought freezing temperatures to parts of Montana and Wyoming. (The National Weather Summary) (Storm Data)
...1988...Early in the morning a tornado hit Kelly Air Force Base in San Antonio, TX injuring three persons and causing twenty-eight million dollars damage. A second tornado on the northwest side of San Antonio caused six million dollars damage, and a third tornado in Bexar County killed one person and injured another. Thunderstorms associated with Hurricane Gilbert spawned a total of forty-seven tornadoes in a two day period, with forty of those tornadoes in central and south central Texas. (Storm Data) (The National Weather Summary)
...1989...Hurricane Hugo hit the Virgin Islands, producing wind gusts to 97 mph at Saint Croix. Hurricane Hugo passed directly over the island of Saint Croix causing complete devastation and essentially cutting off the island from communications. A storm surge of five to seven feet occurred at Saint Croix. The only rain gauge left operating, at Caneel Bay, indicated 9.40 inches in 24 hours. Hurricane Hugo claimed the lives of three persons at Saint Croix, and caused more than 500 million dollars damage. A ship, Nightcap, in the harbor of Culebra, measured wind gusts as high as 170 mph.
A cold front brought high winds to the Great Basin and the Rocky Mountain Region, and thunderstorms along the cold front produced wind gusts to 66 mph at Yellowstone Park, WY. (Storm Data) (The National Weather Summary)

18 September

...1926...The great "Miami Hurricane" produced winds reaching 138 mph which drove ocean waters into the Biscayne Bay drowning 135 persons. The eye of the hurricane passed over Miami, at which time the barometric pressure reached 27.61 inches. Tides up to twelve feet high accompanied the hurricane, which claimed a total of 372 lives. (David Ludlum) (The Weather Channel)
...1987...Early morning thunderstorms in northern Texas produced wind gusts to 65 mph at Sulphur Springs, and 2.50 inches of rain in one hour at Commerce, which caused widespread street flooding. Bonham, TX received 4.50 inches of rain which also resulted in widespread street flooding as Pig Branch overflowed its banks. (Storm Data) (The National Weather Summary)
...1988...A strong cold front produced severe thunderstorms in the north central U.S. High winds behind the cold front gusted to 92 mph at Fort Collins, CO, and up to a foot of snow blanketed the mountains of Montana, with seven inches reported at Great Falls. High winds in Colorado caused three million dollars damage. (Storm Data) (The National Weather Summary)
Old typhoons never die - they just become extratropical and head for the Bay! A potent low, formerly Typhoon Hal produced record setting winds of 75 mph with gusts to 96 mph at Cold Bay, AK. (Intellicast)
...1989...Hurricane Hugo hit Puerto Rico, producing wind gusts to 92 mph at San Juan, and wind gusts to 120 mph at Roosevelt Roads. Hugo produced a storm surge of four to six feet, and northeastern sections of the island were deluged with more than ten inches of rain. Hugo claimed the lives of a dozen persons in Puerto Rico, and caused a billion dollars damage, including 100 million dollars damage to crops. Thunderstorms representing what remained of Hurricane Octave continued to bring heavy rain to the valleys of northern California. Heavier 24 hour rainfall totals included 3.15 inches at Redding, and 2.66 inches at Red Bluff. (The National Weather Summary) (Storm Data)
...1991...2.4 inches of snow fell at Duluth, MN to set a new record for September. (Intellicast)

19 September

...1947...The eye of a hurricane passed directly over New Orleans, and the barometric pressure dipped to 28.61 inches. The hurricane killed fifty-one persons, and caused 110 million dollars damage. It produced wind gusts to 155 mph while making landfall over Fort Lauderdale FL two days earlier. (David Ludlum) (The Weather Channel)
...1955...Hurricane Ione made landfall near Morehead City, NC with winds over 100 mph. 16.63 inches of rain fell at Maysville, NC. Forty blocks of New Bern, NC were underwater at one point. Seven people lost their lives and total damage was $88 million. This was the third hurricane to cross eastern North Carolina in 5 weeks. (Intellicast)
...1967...Hurricane Beulah deluged Brownsville, TX with 12.19 inches of rain in 24 hours, to establish a record for that location. Hurricane Beulah made landfall on the 20th near the mouth of the Rio Grande River, where a wind gust to 135 mph was reported by a ship in the port. (19th-20th) (The Weather Channel)
...1983...New York City had a record 92 degrees while snows fell out west. Fourteen inches of snow fell just south of Great Falls, MT (19-20 September). Temperatures fall to a 6 degrees below zero at West Yellowstone, MT following the snow. (Intellicast)
...1987...Cool autumn-like weather invaded the Central Rockies. Temperatures dipped into the 30s and 40s, with readings in the teens and 20s reported in the higher elevations. Gunnison, CO was the cold spot in the nation with a morning low of 15 degrees. (The National Weather Summary)
...1988...Thunderstorms developing along a fast moving cold front produced severe weather in Wisconsin, Illinois, Indiana and Michigan. Eight tornadoes were reported, including five in Indiana. Thunderstorm winds gusted to 74 mph at Wabash, IN. Winds associated with the cold front itself gusted to 69 mph at Kenosha, WI. (The National Weather Summary) (Storm Data)
...1989...Showers and thunderstorms produced heavy rain in the Middle and Northern Atlantic Coast Region. Cape Hatteras, NC was deluged with nearly 3.50 inches of rain in three hours. Syracuse, NY reported 1.77 inches of rain, a record for the date, and Chatham, NJ reported an all-time record of 3.45 inches in one day. Hurricane Hugo headed for the Bahamas, and Tropical Storm Iris, following close on its heels, strengthened to near hurricane force. (The National Weather Summary)