Update: Spring Rain Coming to the Lower 48

April 4, 2013 by   - () Comments Off on Update: Spring Rain Coming to the Lower 48

The Northeast: Light precipitation, on the order of a few tenths of an inch, fell on most locations from Pennsylvania and New Jersey northeastward to the Canadian border, with totals approaching an inch in a few locales. Nonetheless, parts of the lower Northeast have received 2 to 4 inches less precipitation than normal since the beginning of the year, so abnormal dryness was expanded into these regions. Similar deficits have been recorded in some areas farther north in New England, but with snowpack still melting and streamflows remaining fairly robust, D0 was not introduced there.

The Southeast: Areas of ongoing dryness from North Carolina southwestward into central Georgia generally recorded 0.5 to 1.5 inches of rain, with the larger amounts falling across Georgia and western South Carolina. Drought designations were unchanged in these areas.

Farther south, only isolated light rain fell on southeastern Georgia and the Florida Peninsula, leading to some expansion of moderate drought in east-central and southeastern Florida. Many locations on the Florida Peninsula are 4 to 8 inches below normal since the beginning of the year, and a couple of wildfires have been reported in Collier and Miami-Dade Counties in southern Florida.

The Upper Midwest: Only a few tenths of an inch of precipitation were reported in a few areas from Illinois and Iowa northward through the Great Lakes region and Minnesota, keeping dryness and drought unchanged from last week. Most of central and northern Illinois, southern Wisconsin, central and northern Iowa, and southwestern Minnesota received no measurable precipitation.

The Lower Mississippi Valley/Delta region: No appreciable precipitation fell on the Louisiana Bayou last week. Over the last six months, this region has received 8 to locally 16 inches less precipitation than normal, with deficits of 1 to locally 4 inches accumulating in the last 30 days. As a result, abnormal dryness was introduced in the region this week.

The Plains: Precipitation totals exceeding one inch were widespread from northeastern Texas and northwestern Louisiana northward through southwestern Missouri and part of southeastern Kansas. Some of the northern reaches of this area, extending as far south as central Arkansas and east-central Oklahoma, measured 2 to 4 inches of rain. As a result, drought classifications improved in several areas which were generally in the D0 to D2 range last week.

Elsewhere, most locations in the central Plains received anywhere from a few tenths of an inch to slightly over an inch while only isolated measurable precipitation was reported in central and southern Texas, the High Plains, and the northern Great Plains. Some areas of degradation were introduced in roughly the southwestern half of Texas and the northwestern Plains, but conditions remained essentially unchanged in most areas.

The Rockies and Intermountain West: Scattered light precipitation fell on the northern half of the Plains and central sections of the Intermountain West, including most of the Great Basin. Most other locations reported no measurable precipitation. D0 conditions were extended into southeastern Washington, where precipitation shortfalls now exceed 2 inches since the beginning of the year, with deficits reaching up to 6 inches in some of the higher elevations. In other areas, dryness and drought remained the same as last week.

The West: Generally 1 to 2 inches of precipitation fell from southwestern Oregon southward through northern California and the Sierra Nevada, with a few locations reporting larger totals in the southernmost Cascades. Meanwhile, a few tenths of an inch were recorded in the Pacific Northwest to the west of the Cascades and across central and southwestern California. Southeastern California recorded little or no precipitation.

The precipitation that fell did not change conditions in existing areas of dryness and drought. Farther north, however, parts of western Oregon and southwestern Washington eastward to near the foothills of the Cascades reported their driest start to a calendar year on record. To wit, abnormal dryness was expanded into this region despite a fairly robust snowpack in most of the Cascades to the east of this region.

Hawaii and Alaska: Most locations in southern Kauai reported 1 to locally 5 inches of rain this past week, but only scattered amounts exceeding 0.5 inch were reported in other parts of the state currently experiencing dryness and drought. Impact assessments from recent precipitation indicated that former D1 conditions had improved on part of the southern Big Island, and areas of improvement were also noted in parts of the western Big Island where D2 to D3 conditions had prevailed, particularly along and near the coast. In addition, recent rains appear to have improved conditions on parts of Lanai.

The few tenths of an inch of precipitation that fell on the areas of dryness and drought in Alaska were not enough to significantly change conditions, and this week the assessment remains the same as last week.

Looking Ahead:  The next 5 days (April 4–8) are expected to be dry in the desert Southwest, southern sections of the Rockies and High Plains, and the central and southern parts of Texas. Most of the contiguous 48 states, however, should receive at least light precipitation, with 0.25 to 1.5 inches forecast for much of the country. Higher totals, generally 1.5 to 3.5 inches, are anticipated in the Pacific Northwest and in the Southeast from the lower Delmarva Peninsula southwestward through northern Florida.

For the ensuing 5 days (April 9–13), the odds favor below-median precipitation from the Rockies westward to the Pacific Coast, except along the northern tier of this region. In contrast, above-median amounts are favored from central Texas, the east-central Great Plains, and the upper Midwest eastward to near the Atlantic Coast, excluding the immediate Coastal Plain and most of Florida.


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