Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000 FXUS63 KOAX 170841 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 241 AM CST Fri Feb 17 2017 .SHORT TERM...
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(today through Sunday) Issued at 241 AM CST Fri Feb 17 2017 A temporary rex block will continue over the Plains into the weekend with a cutoff cyclone moving slowly across the Gulf Coast and an upper-level ridge over the central and northern Plains. This will continue to provide record setting warmth to the area. Surface low pressure, the reflection of a shortwave trough moving into southern Canada, will move across the Dakotas today with a surface trough dropping through the CWA. Along and ahead of the trough the surface to 850 mb flow will turn southwest allowing for good mixing within the 850 mb thermal ridge. This should allow for highs today to be 3 to 6 degrees warmer than we saw on Thu with record highs likely at KOMA/KLNK. The trough will pass tonight with a surface ridge over the area on Sat. With full sunshine and a very dry atmosphere in place we should again see good mixing with highs still making it into the 60s. Height falls moving into the west coast tonight will eventually emerge onto the Plains Sunday into Monday. Deep southerly flow ahead of the trough will likely lead to some increase in clouds on Sunday. Nevertheless with a very warm atmosphere in place we should still see highs reach the mid 60s most areas. .LONG TERM...(Sunday night through Thursday) Issued at 241 AM CST Fri Feb 17 2017 Moisture will continue to increase on Sunday night associated with a 40-50 kt low-level jet. Isentropic upglide within this jet may lead to a few showers overnight /although the moisture depth is pretty marginal/. Lapse rates do steepen overnight Sunday and thus isolated thunder was added to the forecast. The better lapse rates do shift east during the day on Monday, but the synoptic- scale forcing does increase during the day with the passage of the front and upper level trough. Thus we removed the thunder mention during the day on Monday, but scattered showers, especially in the eastern CWA appear possible. Behind this system we will likely see record highs again on Tuesday. The 850 mb flow becomes west, which should lead to great mixing yielding highs in the lower 70s. Warm temperatures appear to continue into Wednesday although highs are likely to be a touch cooler after another weak boundary on Tuesday night. The upper level flow then becomes southwest toward the end of the period with the chance for rain increasing toward next Thursday with some cooler temperatures.
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&& .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1114 PM CST Thu Feb 16 2017 LLWS at KLNK/KOMA through about 11-13z with winds at 2000 feet from 240-250 degrees at 30-35 knots. VFR conditions otherwise. && .FIRE WEATHER...
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Issued at 241 AM CST Fri Feb 17 2017 Very high fire danger is expected today. The most critical area will be just ahead of an advancing surface trough over southeast Nebraska. Here afternoon dewpoints will likely drop into the upper 20s, and with highs in the lower to mid 70s we will see minimum RH values of <=20% for a couple of hours. The limiting factor for the issuance of a RFW is the wind. Southwest winds of 10 to 20 mph are expected, but we should generally not see the wind speeds of 25+ mph in this area of minimum RH. Nevertheless given the fuels and very low RH, any fires that occur will have the potential to be difficult to control. Low RH is again expected on Saturday with some improvement on Sunday. Tuesday is another potential very high fire weather period day as well.
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&& .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ SHORT TERM...Boustead LONG TERM...Boustead AVIATION...DeWald FIRE WEATHER...Boustead

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