HDR1012000170101210961200WEEKLY WEATHER AND CROP BULLETIN National Weather Summary Volume 83, No. 49 December 1 - 7, 1996 For additional information, call (202) 720-7917. Highlights: A strong west-to-east jet stream added to recent precipitation surpluses in the Northwest. Downslope winds eroded snow cover on the northern High Plains and delivered mild, dry conditions to the central and southern Plains. Late in the week, back-to-back storms embedded in the fast-moving air flow dropped light snow on the Midwest, but intensified over the Northeast, depositing heavy snow from northeastern Pennsylvania into New England. Arctic air, scoured out east of the Rockies by the persistent Pacific fetch, lost its 3-week grip. As a result, temperatures averaged within a few degrees of normal nationwide. Early in the week, a moisture-laden storm tracked northeastward through the Great Lakes region, soaking the East Coast States. On December 1-2, 24-hour rainfalls topped 2 inches in locations such as Hartford, CT and Binghamton, NY. Many Northeastern basins overflowed in the storm's wake, including the Connecticut River, which crested on December 5 at 2.5 feet above flood stage at Hartford and 1.4 feet above flood stage at Middletown, CT. Farther south, areas from southern Georgia to central Florida weathered strong thunderstorms, but experienced relief from recent dryness. On Sunday, daily-record rainfall totaled 0.58 inches in Orlando, FL. By midweek, a powerful winter storm (minimum central pressure of at least 28.17 inches, or 954 millibars) developed over the Gulf of Alaska, hurling relentless moisture at the Northwest. Cool air cloaked the West prior to the moisture's arrival, resulting in daily-record lows in locations such as Eureka, CA (34 degrees F on Monday) and Tooele, UT (11 degrees F on Tuesday). Snow continued to blanket the interior Northwest. Weekly totals in eastern Washington included 12.7 inches in Spokane and 6.8 inches in Yakima. Heavy rain continued to lash western Oregon, where 192-hour (November 30 - December 8) totals reached 13.03 inches in Brookings and 9.79 inches in Florence, and shifted into northern California. Totals included 8.17 inches at Blue Canyon, in the Sierra Nevada foothills, and 7.52 inches in Eureka during the same 8-day period. In Oregon, annual rainfall records were eclipsed in Portland (formerly 51.09 inches in 1950) and Eugene (65.56 inches in 1995). Heavy snow fell from the Sierra Nevada to the Rockies, including valley floor locations such as Elko, NV (17.5 inches) and Salt Lake City, UT (14.2 inches). Light snow fell frequently across the Midwest, boosting weekly snowfall to 8.7 inches in Cedar Rapids, IA, 5.1 inches in Moline, IL, and 4.1 inches in LaCrosse, WI. Farther east, snow fell on December 5-6 and 7-8. The two-storm snowfall topped 30 inches in parts of western Massachusetts, leaving a 25-inch depth by December 8 in Worthington. The earlier storm dumped snow as far south as the Middle Atlantic piedmont, while the latter system reached into Maine. Both storms produced coastal wind gusts in excess of 50 mph. Meanwhile, strong thunderstorms again swept across northern and central Florida. Orlando posted another daily-rainfall record on Saturday, as 1.46 inches fell. Farther west, the mercury soared to 91 degrees F in Brownsville, TX, only their fourth occurrence of 90-degree heat during December. Farther north, bitterly cold air began to build again across interior Alaska. Weekly temperatures averaged more than 20 degrees F below normal in McGrath, including a low of -43 degrees F on December 7. NATIONAL AGRICULTURAL SUMMARY December 2 - 8, 1996 HIGHLIGHTS: Heavy rains and high winds along the Pacific Northwest caused flooding and limited the number of days suitable for fieldwork. In the Northern States, early snow accumulation and the lateness of small grain seedings raised some producers' concern. Light snowfall and frozen soil across the Great Lakes region brought an end to fieldwork. The lack of moisture in the central High Plains was a potential problem for late-planted wheat. Cold, wet weather slowed the cotton harvest in the Southern Great Plains, where wheat conditions improved from the recent moisture. Heavy snowfall across the Northeast slowed harvest activity and fieldwork. Excessive rainfall in the mid-Atlantic restricted harvest activity but improved small grain and pasture conditions. Rains across the Southeast stopped field operations and limited cotton harvest activity. Beneficial rain in Florida aided plants recovering from recent wind damage, but slowed some vegetable harvest for the holiday markets. Cool nights and cloudy conditions have helped citrus trees harden up, with most of the early fruit reported in good condition and coloring well. Movement of early tangerines and tangelos is increasing for the Christmas trade.