#ColoradoRiver District’s annual seminar #crdseminar #COriver

Beginnings. Photo: Brent Gardner-Smith/Aspen Journalism

I’m heading to Grand Junction for the Colorado River Districts annual seminar. Follow along using Twitter hash tag #crdseminar. I think the seminar is going to be a hoot with all the Colorado River news of late.

#SeamanFire update

Outline of the watershed above Seaman Reservoir via CoCoRaHS and the Colorado Climate Center. The Seaman Fire is pinned near the S. side.

Noah from the Colorado Climate Center sent along this information about the Seaman Fire near Seaman Reservoir. I asked if the fire was in the Seaman Reservoir watershed which is Greeley’s water supply. It is. If it gets over the hill Fort Collins’ and other municipal supplies can be affected from burn scar runoff:

Yes, but just over the hill puts it into another watershed of the main branch of the Poudre. Check out the CoCoRaHS watershed map to see how Seaman is in the HUC [watershed] for Rabbit Creek –North Fork Cache La Poudre and just south of the reservoir – up the hillside – is the Gordon Creek-Cache La Poudre River.

[Link to the CoCoRaHS mapping tool: https://cocorahs.erams.com/locations/seaman%20reservoir,%20co

Seaman Reservoir upstream of confluence of the North Fork of the Cache la Poudre River. Photo credit Greg Hobbs.

#Drought news: Light rain this past week in central #Colorado

Click here to go to the US Drought Monitor website. Here’s an excerpt:

Summary

A stalled cold front draped across the southern Plains, middle Mississippi and Ohio Valleys, and mid-Atlantic, plus ample Gulf moisture from Tropical Storm Gordon, was the focal point for moderate to heavy showers and thunderstorms. Widespread amounts of 2-4 inches, with locally 6-12 inches, were common in the southern and central Great Plains, along the Gulf Coast (Gordon), in the lower and middle Mississippi, Tennessee, and Ohio Valleys, western Great Lakes region, and the mid-Atlantic. Similar to last week, additional improvements were made in the Midwest, but this week, major modifications (improvements) were also done in the southern Plains (especially Texas) and lower Mississippi Valley. Elsewhere, little or no precipitation fell across the western third of the Nation, although some light showers finally dampened western Washington. In addition, the northern Plains, parts of the Southeast (Georgia and Carolinas), and extreme northern New England saw little or no rain. Temperatures averaged below-normal across the middle third of the Nation and in New England, and above-normal in most of the West, Southeast, and mid-Atlantic…

High Plains

Generally little or no precipitation fell across the western High Plains while light rains (0.5-1 inch) fell on parts of North Dakota, southeastern South Dakota, eastern Nebraska, most of Kansas, and central Colorado. Scattered locations in extreme southeastern SD, northeastern NE, and eastern KS received more (1.5-3 inches, locally to 7 inches in southeastern KS), but most of this rain fell on non-drought areas. An exception to this was north-central and southeastern Kansas where a 1-cat improvement was made, but unfortunately missed most of the core D2-D4 area in northeastern Kansas (again). Kansas pastures and ranges have also improved, with a NASS/USDA Aug. 12 value of 35% poor or very poor versus a Sep. 9 value of 20%. Subnormal weekly temperatures (anomalies of -2 to -6 degF) in the central Plains also eased evaporative demands. In contrast, drier and warmer weather in the Dakotas have steadily lowered moisture and growing conditions. Under half of normal 30- and 60-day precipitation has fallen on parts of North and South Dakota, and field reports are indicating declining farming, ranching (no forages to graze), and hydrologic (shallow wells and small ponds drying up) conditions. The NASS/USDA poor and very poor pasture conditions for ND and SD have slowly climbed from 7 and 10%, respectively, on July 29, to both at 25% on Sep. 9. Accordingly, D0-D2 was expanded into the driest areas, and a D3 was added in McHenry County, ND, where the field reports and drought tools lined up…

West

Warmer weather returned to the Northwest after two consecutive weeks of near or subnormal temperatures. Deteriorations in this week’s dry areas were limited to an expansion of D1 into central Washington’s Chelan and Kittitas Counties (2, 3, and 4-month SPEIs -1 to -1.5); a slight increase in D3 in Oregon’s northern Harney and Malheur Counties (soil moisture models, EDDI > 6 weeks, Vegetation Health, VegDRI, low stream flows); reassessment of northern California (D0-D2 shifted eastward into Siskiyou and Modoc Counties); D2 expanded into southern Idaho (Oneida County) with similar conditions in bordering northern Utah (Box Elder County); D3 expanded in southeastern CA due to the weak to non-existent summer monsoon rains. In contrast, improvements were made in central Arizona (courtesy of the Flagstaff WFO) that noted the past 8 weeks have seen well above-normal monsoon rains (in some areas 40-70% of average ANNUAL rainfall) in central Yavapai County and the Mogollon Rim region; and in eastern New Mexico that received significant rains (but less than neighboring west Texas) – with some improvements to Colfax and Mora Counties [D3 to D2], San Miguel and Guadalupe Counties [D2 to D1], DeBaca and Chavez Counties [D3 to D2], and Roosevelt County [D1 to D0]. Conversely, some D2 was added into eastern Otero County, NM, and northeastern Hudspeth County, TX, after a reassessment of conditions. The rest of the West was left untouched as the Pacific Northwest awaits the start of its wet (Fall) season…

Looking Ahead

For the ensuing 5 days (September 13-17), the focus will be on Hurricane Florence’s landfall and where it tracks thereafter. As of Wednesday afternoon, the most likely scenario is landfall near the NC-SC border, with the hurricane slowing down and dropping catastrophic amounts of rain (over 20 inches near landfall), with possible devastating floods in parts of the Southeast and mid-Atlantic. The 5-day QPF targets the Carolinas and Virginia with 4-10 inches, with heavy rains moving northward into the Northeast during Days 6-7. Elsewhere, a tropical disturbance is expected to move into the western Gulf from the Caribbean, dumping more heavy rain (2-6 inches) on the southern half of Texas. Pacific systems traversing along the US-Canada border may drop light to moderate amounts from Washington to Minnesota. Little or no precipitation is expected elsewhere. Temperatures should average below-normal in the Far West, northern Rockies, and Texas, and above-normal from the Southwest northeastward into New England.

For the CPC 6-10 day extended range outlook (Sep. 18-22), the odds favor above-normal precipitation in the northern half of the Plains, in the eastern quarter of the country (from Florence), and northwestern Alaska. Chances are good for subnormal precipitation in most of the West, south-central Plains, lower and middle Mississippi Valleys, and southern Alaska. Above-normal temperatures are likely in the southern and eastern sections of the U.S. and most of Alaska, with subnormal readings limited to the Northwest and northern Rockies and Plains.