WELCOME TO OCTOBER -- The name "October" given to this month is derived from "Octo", the Latin word for the number eight, representing the eighth month of the year in the old Roman calendar, which started in March.
WEATHER OVER THE WEEKEND -- Much of the nation experienced relatively tranquil weather over the weekend, essentially devoid of severe thunderstorm activity. The one major exception was across Florida and along the East Coast, where clouds, rain and winds made for a relatively chilly and soggy weekend.
One storm system was found along the New England coast on Friday morning. Coastal rain continued until Saturday, as the low pressure center moved eastward out over the Atlantic Ocean. By Sunday morning, another low pressure system had developed and intensified offshore of the Middle Atlantic coast. A relatively tight pressure gradient developed, resulting in strong winds with speeds of 25 to 30 mph coming onshore along the coast. These winds also caused high seas and some coastal flooding.
Farther south, a stationary front that stretched across Florida continued to produce rainshowers and thunderstorms through Saturday. Several low pressure disturbances formed along the front, enhancing the precipitation. Thunderstorm winds downed some trees in the northern Florida Keys on Friday evening. With the cooling effect of afternoon showers, the record low temperature for the date was tied on Friday afternoon in Miami with 71 degrees. By Sunday morning, the front had drifted southward as a cold front, but residual showers remained in the easterly wind flow across south Florida. In part as a result of the clouds and rain, high temperatures on Saturday across Florida and the Carolinas were on the order of 10 degrees below average. On Saturday, Key West set a record low of 71 degrees. Saturday's high temperature in Miami was only 78 degrees, a low high temperature record. Other record low high temperatures were established at Hollywood (65 degrees) Ft. Lauderdale (69 degrees) and Miami Beach (70 degrees). In addition, a record 3.22 inches of rain fell at Miami and 2.42 inches at Palm Beach on Saturday. Unseasonably chilly conditions continued along the Eastern Seaboard and portions of the Gulf Coast on Sunday afternoon, where high temperatures were on the order of 10 to 15 degrees below the average highs for the date
The nation's midsection was dominated by a large high pressure system that drifted eastward across the Great Lakes and the Midwest. On Friday morning, this cool high pressure center was located over western Lake Superior, and by evening it was centered over the lake. As a result, high temperatures across the Ohio Valley were 10 degrees below average on Friday. This high remained relatively stationary over the northern Lakes and the Midwest on Saturday. By Sunday morning, the high had split, with one center remaining over Lower Michigan, while the other center was located over the St. Lawrence Valley. With relatively clear skies and weak winds under high pressure, overnight cooling caused extensive dense fog and low clouds to form across the region. However, by midday temperatures rose and winds helped dissipate the fog.
A nearly stationary front that was located across the northern Rockies and western portions of the northern Plains on Friday morning drifted eastward over the weekend. As of Friday morning, the front with several weak low pressure centers stretched from northeastern Montana southwestward into northwest Nevada. On Saturday this front drifted slowly eastward across the Dakotas and Nebraska as a cold front. However, this front was more of a shift in the wind direction, as warmer air was found to the west of the front on Saturday afternoon. Southerly winds were found to the east and south of the front, while weak northerly winds were prevalent to the north and west. Some widely scattered light rain was associated with this front.
The West remained unseasonably warm over the weekend. On Friday, high temperatures across the Rockies were as much as 20 degrees above the average highs on Friday. High temperature records were either tied or set in Arizona at Coolidge (108 degrees), Winslow (91 degrees), Page (91 degrees) and Prescott (88 degrees); in Wyoming at Sheridan (92 degrees), Wheatland (91 degrees), Worland (90 degrees) and Riverton (86 degrees); in Utah at Springville (90 degrees) in Colorado at Alamosa (88 degrees) and at Wells, NV (86 degrees). On Saturday, the largest temperature departures were found across the northern Plains, where highs were on the order of 15 degrees above the average highs. With the development of an offshore wind along the California coast, much of California and portions of Oregon warmed on Sunday. Afternoon high temperatures on Sunday from the northern Plains westward across the Rockies and the Great Basin to the Pacific Coast ranged from 10 to 20 degrees above the average highs for the end of September. Record high temperatures were reported across California on Sunday, to include Pasadena (106 degrees), Gilroy (104 degrees), Escondido (103 degrees), Salinas (98 degrees), San Francisco (96 degrees Downtown and 94 degrees at the Airport), San Jose (94 degrees) and Monterey (93 degrees).
WEATHER FOR THE START OF THE NEW WEEK -- The following highlights of the national weather have been extracted from the surface weather map for late Sunday night.
A low pressure system located off the coast east of the Del-Mar-Va Peninsula continued to spread clouds, rain and windy conditions over the Middle Atlantic and southern New England states. A large area of rain extended northward from the Chesapeake Bay to near Cape Cod. Northeasterly winds spiraling around the low produced an onshore component of the winds. Gale warnings for winds between 39 to 54 mph were in effect into Monday for marine interests along the coast from Cape Hatteras, NC northward to Provincetown, MA. A wind advisory was also posted for Nantucket Island, MA. Heavy surf advisories remained in effect for some of the east-facing beaches along the Atlantic coast, extending from Jupiter Inlet northward to Flagler Beach in Florida, and from Cape Hatteras, NC to Fenwick Island, DE. For a time, a coastal flood watch was in effect for the Maryland coast near Ocean City.
The storm system is expected to continue to move toward the northeast, remaining at sea. The precipitation associated with this system should diminish on Monday. Between 0.5 and 1.0 inches of rain could fall in the 24 hours ending on Monday evening along the coast from the Del-Mar-Va Peninsula northeastward to Cape Cod.
A large high pressure center located over the Mississippi Valley continued to dominated the weather across the Midwest and Southeast. With cool high pressure stretching eastward from the Mississippi Valley, overnight temperatures are expected to drop with radiative cooling. There are frost advisories for portions of south central New York State, northern Pennsylvania and the Blue Ridge to include eastern West Virginia, western Virginia and North Carolina.
Thunderstorms continued across southern Florida to the north of the stationary front that was located over Cuba. As many as three waterspouts were observed off the Florida Keys late Sunday afternoon. Most of the rain activity should diminish on Monday. Less than 0.2 inches of rain could fall by Monday evening.
A weak cold front was passing across the upper Mississippi Valley into the western Great Lakes. Some light and widely scattered rainshowers were moving across northern Lake Michigan and the Upper Peninsula ahead of the storm. The front is expected to dissipate by Monday morning. A second cold front along the Canadian border should move across the Plains during the week.
Increased clouds, along with some rain and winds associated with the remnants of former Hurricane Juliette (see below) were spreading into the Southwest. A wind advisory had been in effect for southern Arizona late Sunday afternoon and evening as winds were gusting to 40 mph. Southerly winds were expecting to bring more moisture northward from Juliette. As much as one inch of rain could fall across portions of northwest Mexico south of the border.
TEMPERATURE EXTREMES ACROSS THE LOWER 48 -- On Sunday, the lowest temperature reported in the continental U.S. was 17 degrees at Wisdom, MT, while Sunday's highest temperature was 113 degrees at Death Valley, CA.
ALASKAN WEATHER -- A broad area of low pressure was moving eastward across the central Bering Sea, accompanied by an occluded front that stretched southeastward across the western portions of the Alaska Peninsula. A weak trough of low pressure extended southward across the northern Gulf of Alaska from the vicinity of the Kenai Peninsula. A weak stationary front extended from the northern Bering Sea southeastward across western and south central Alaska before curving to the northeast across eastern Alaska. To the north, a ridge of high pressure was centered over the Chukchi Sea and extended eastward along the North Slope toward the Beaufort Sea and southeastward into interior Alaska. Petersburg received 3.50 inches of rain in the 24 hours ending on Sunday. Klawok (2.72 inches), Ketchikan (1.93 inches) and Wrangell (1.39 inches) also received significant rain. Some of the first snow of the season was reported across interior Alaska at Bettles, Fairbanks, Nenana and Tanana.
The lowest overnight temperature in Alaska as of Sunday was 17 degrees at Barrow and the midafternoon highest statewide temperature was 57 degrees at Cordova.
HAWAIIAN WEATHER -- A weak cold front with a band of clouds and showers was trailing from a midlatitude storm system southward to within approximately 150 miles north of Kauai. This southward moving front and accompanying showers are expected to pass across the Aloha State by Tuesday. High pressure to the northwest of the islands is expected to drift southward behind the front. As a result, the trade winds are expected to weaken slightly following the passage of the front.
EYE ON THE TROPICS -- In the eastern North Pacific, Hurricane Juliette, which reached major hurricane status as a Category 4 hurricane on the Saffir-Simpson Hurricane Intensity Scale last week, finally has dissipated. On Friday Juliette grazed Cabo San Lucas at the southern end of Baja California before weakening to a tropical storm as winds decreased to below 75 mph. On Saturday, Juliette made landfall along the Baja coast to the northwest of Cabo San Lucas and then appeared to dissipate. Juliette reorganized when it moved out over the Gulf of California. The last advisory for this system was issued by the National Hurricane Center on Sunday evening. At that time, tropical depression Juliette had maximum sustained surface winds of 30 mph and was located over the Gulf of California approximately 25 miles north of Tiburon Island, Mexico. Movement was to the north-northwest at 12 mph. Estimated central pressure at sea level was 1005 mb.
THE END OF A SEASON -- If you live in the northern portion of the country, the growing season may have already come to an end as cold air masses have moved southeastward from Canada. However, some delightful October days should remain. Read the optional Monday Supplemental Information concerning the end of the growing season and "Indian Summer".
From the files of the Aviation Weather Center, Kansas City, MO and Intellicast