####018019396#### FGUS73 KGID 141242 ESFGID NEC129-NEC175-NEC077-NEC125-NEC163-NEC093-NEC019-NEC079-NEC019- KSC147-KSC163-051800- PROBABILISTIC HYDROLOGIC OUTLOOK NATIONAL WEATHER SERVICE Hastings NE 741 AM CDT Thu Mar 14 2024 ...2024 Spring Flood and Water Resources Outlook Number 3... This outlook is for the Hastings Hydrologic Service Area (HSA). In South Central Nebraska this outlook includes the Platte...Loup...Little Blue...and Republican Rivers and their tributaries. In North Central Kansas...the Solomon River and its tributaries are included. ...The potential for spring flooding is generally below average across the majority of the area... ...Hydrologic Outlook...March 15th Through June 14th... Spring flood outlooks are routinely issued from February through March to give advanced notice of possible flooding. They are based on soil moisture, snowpack magnitude, stream flow conditions, and the long range forecast of future precipitation patterns. The precipitation outlook through the end of March generally favors above normal precipitation and then trends towards equal chances thereafter as we head through April, May, and into early June. Therefore, overall through most of the spring we don't see strong signals one way or the other regarding expected precipitation relative to normal. Therefore, it may be difficult for some of our area to climb out of the drought this spring (despite official drought outlooks leaning toward improvement). There are several primary factors leading to our below average threat for spring flooding. - The local snowpack is negligible to non-existent. - The mountain snowpack in the Platte River Basin is near normal, but there is plenty of reservoir capacity. - Lake McConaughy is just over 60 percent capacity and has plenty of storage space available. - Soil moisture is drier than normal in many locations given the ongoing moderate to severe drought. We do have some locations that have come out of the drought, but even in these areas soil moisture is just near normal at best. Consequently, the soil is still capable of absorbing plenty of moisture thus limiting spring flood potential. - Current streamflow on our biggest rivers is averaging near normal to below normal. - The longer range outlook of April through June indicates equal chances with no strong indicators one way or the other. It is important to mention that isolated or localized flooding is still possible even in dry years and when the overall risk of widespread flooding is low. Isolated heavy spring thunderstorms will still be capable of producing localized areas of flooding. ...Climatological Review ("Meteorological Winter 2023-24 Precipitation Review)... Following is an overview/recap of precipitation trends across the NWS Hastings coverage area during the recently-ended "meteorological winter" 2023-24 season (which consisted of the calendar months of Dec-Jan-Feb). Please note that our 30-county coverage area includes 24 counties in central/south central Nebraska and six counties in north central Kansas. As evidenced in the data presented in the table below (and supported by AHPS precipitation analysis), this meteorological winter featured modestly above normal precipitation across nearly our entire coverage area (despite the last three weeks of February actually being very dry). More specifically, most of our area received somewhere between 2.00-4.00" of seasonal precipitation (including melted snow). This equates to most of our receiving 100-200 percent of normal for the winter season. Although much of this precipitation fell as snow during January, quite a bit of it actually fell as rain during December and early February. Although not a large/significant difference, the overall- wettest locations mainly favored eastern/southern portions of our area, with the overall-driest locations mainly concentrated in western/northern counties. In fact, of mainly our far western coverage area (including Furnas County) actually received slightly below normal winter precipitation. Per official NWS cooperative observer and airport stations, a few of the wettest locations in our area from Dec-Feb included: Plainville KS 4WNW (5.17"), Smith Center KS (5.03") and Hebron (4.42"). In fact, this ended up being the 2nd- wettest winter on record at both the Plainville and Smith Center stations. Meanwhile, a few of the driest official observation sites in our area this winter ended up being: Cambridge (1.51"), Edison (1.97") and Greeley (2.04"). -- Meteorological Winter 2023-24 Drought Recap (per weekly updates by the U.S. Drought Monitor/USDM): Thanks to the aforementioned above normal precipitation this winter (and in particular the fact that much of it fell as rain and efficiently soaked into the soil), there was an unusually- significant improvement in drought categories across much of our coverage area from Dec-Feb. At the start of December, 64% of our coverage area was under drought categories ranging from Moderate (D1) to Exceptional (D4), including 36% of the area in worst-off D3+D4 (primarily focused east of Highway 281 in Nebraska and also in parts of north central Kansas). However, the winter months only brought gradual improvement, and as of the Feb. 29th USDM issuance our entire coverage area is void of all Extreme (D3) and Exceptional (D4) Drought categories. That being said, half of our area remains under Moderate (D1) or Severe (D2) drought, with D2 dominating most local Nebraska counties along/east of Highway 281. In the "best news of all" department, 31% of our coverage area is currently indicated to be void of all drought categories whatsoever (even Abnormally Dry D0), including large parts of several counties mainly west of the Highway 281 corridor. The table below highlights precipitation totals and departures from normal/percent of normal for meteorological winter 2023-24, covering Dec. 1 - Feb. 29. Data is shown for just a small sampling of official NWS cooperative observers representing various parts of our area, along with a few primary airport sites. Location Precip Departure Percent of North Central KS Dec 1-Feb 29 from Normal Normal --------------- -------- ------ --------- Beloit 4.03 +1.49 159 Phillipsburg 3.07 +0.79 134 Plainville 4WNW 5.17 +2.75 214 Smith Center 5.03 +2.95 242 Location Precip Departure Percent of South Central NE Dec 1-Feb 29 from Normal Normal --------------- -------- ------ --------- Cambridge 1.51 -0.21 88 Elwood 8S 2.08 +0.41 124 Grand Island Arpt 3.50 +1.31 160 Hastings Airport 3.28 +1.12 152 Hebron 4.42 +1.75 166 Holdrege 2.80 +0.84 143 Kearney Airport 2.51 +0.73 141 Lexington 6SSE 2.24 +0.70 145 Ord 2.93 +0.95 148 Osceola 3.78 +1.25 149 Superior 3.61 +1.07 142 St. Paul 2.33 +0.22 110 York 3N 3.59 +0.82 130 ...Weather/Climatological Outlook For The Next Week Through The Next Three Months... It's now time to switch gears and look ahead to expected weather conditions over the next several days and expected climate trends over the next several months: The next week (through March 21): According to our latest official 7-day forecast, the vast majority of the upcoming week will week will be dry. The only exceptions are right away today/Thursday (areas of light rain) and perhaps again around next Wednesday-Thursday (March 20-21), when our next/highly uncertain rain chances might enter the picture. Temperature-wise, seasonable highs mainly in the 50s/60s will prevail through this next week. Two weeks out (March 21-27): Looking out just a bit farther in time, the latest 8-14 day outlook from the Climate Prediction Center (CPC) calls for near-normal temperatures across most of our area, with a slight lean toward cooler than normal especially north of Interstate 80. Precipitation- wise, our entire area features a slight lean toward above normal amounts. Meteorological Spring (March-May): Turning to the meteorological spring months of March-April-May as a whole, the latest Climate Prediction Center (CPC) three-month outlook (issued Feb. 15th) indicates a slight lean toward above normal precipitation (primarily driven by expectations of a somewhat- wet March), along with "Equal chances" for temperatures to be above normal, below normal or near normal. This means that there are no clear signals in current longer-range forecast data to lean toward one of these outcomes over another. Based on 30-year normals, total March-May precipitation across the NWS Hastings coverage area typically ranges from 7-10", with the lowest amounts generally west of Highway 183 and highest amounts near the Highway 81 corridor. U.S. Seasonal Drought Outlook (updated by CPC on Feb. 29th and valid through the end of May): Going hand in hand with the aforementioned slight lean toward above normal precipitation this spring, this outlook indicates that those parts of our coverage area currently under any drought category (Moderate Drought D1 or worse), will either see some improvement or perhaps have drought removed altogether. (The longer range forecasts issued by CPC and referenced in the preceding paragraphs are based on output from various forecast models, as well as forecaster expertise, and take into consideration ongoing global/tropical atmospheric and oceanic states, recent trends in observed data, soil moisture conditions, etc. More information about these longer-range forecasts can be obtained from the CPC web site at: https://www.cpc.ncep.noaa.gov) ...Long Range Probabilistic Outlooks... In Table 1 below...the current (CS) and historical (HS) or normal probabilities of exceeding minor...moderate...and major flood stages are listed for the valid time period. CS values indicate the probability of reaching a flood category based on current conditions. HS values indicate the probability of reaching a flood category based on historical or normal conditions. When the value of CS is more than HS...the probability of exceeding that level is higher than normal. When the value of CS is less than HS...the probability of exceeding that level is lower than normal. ...Table 1--Probabilities for minor...moderate and major flooding... Valid Period: 03/16/2024 - 06/14/2024 : Current and Historical : Chances of Exceeding : Flood Categories : as a Percentage (%) Categorical : Flood Stages (FT) : Minor Moderate Major Location Minor Mod Major : CS HS CS HS CS HS -------- ----- ----- ----- : --- --- --- --- --- --- :Little Blue River Deweese 10.0 16.0 17.0 : 28 40 <5 6 <5 5 :North Fork Solomon Glade 11.0 16.0 18.0 : 6 15 <5 8 <5 <5 :Bow Creek Stockton 9.0 12.0 13.6 : 11 23 <5 7 <5 <5 :Platte River Darr 11.5 12.5 13.0 : 31 34 23 26 15 16 Overton 7.5 12.0 14.0 : 27 30 <5 5 <5 <5 Kearney 7.0 8.0 9.0 : 17 18 8 8 <5 <5 :Wood River Gibbon 15.0 16.0 16.5 : 29 36 24 32 21 25 Alda 10.0 11.0 12.2 : 36 44 33 37 22 28 Wood River Divers 19.5 20.5 21.5 : 8 24 6 13 5 10 :Platte River Grand Island 6.5 7.0 7.5 : 32 32 19 25 17 18 :South Loup River Ravenna 5.0 8.0 10.0 : 38 45 9 14 4 5 :Mud Creek Sweetwater 16.5 18.0 21.0 : 12 27 6 10 <5 <5 :South Loup River Saint Michael 9.5 14.0 17.0 : 19 26 5 7 <5 <5 :Middle Loup River Saint Paul 8.0 10.0 12.0 : 5 9 <5 7 <5 <5 :North Loup River Saint Paul 7.0 10.0 12.0 : <5 6 <5 <5 <5 <5 :Cedar River Fullerton 9.0 15.0 18.0 : <5 6 <5 <5 <5 <5 :Loup River Genoa 10.5 12.0 13.0 : 6 11 <5 6 <5 <5 :Beaver Creek Genoa 15.0 17.0 19.0 : 12 18 8 9 <5 <5 Legend CS = Conditional Simulation (Current Outlook) HS = Historical Simulation FT = Feet In Table 2 below...the 95 through 5 percent columns indicate the probability of exceeding the listed stage levels (FT) for the valid time period. ...Table 2--Exceedance Probabilities... Chance of Exceeding Stages at Specific Locations Valid Period: 03/16/2024 - 06/14/2024 Location 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Little Blue River Deweese 3.1 3.9 4.5 7.8 10.6 12.5 13.7 :North Fork Solomon Glade 2.9 2.9 3.2 5.3 8.5 10.0 13.4 :Bow Creek Stockton 4.3 4.3 4.4 4.7 7.1 9.3 11.2 :Platte River Darr 6.8 7.6 8.5 10.4 12.5 15.2 16.3 Overton 3.8 3.9 4.4 5.7 7.8 10.8 11.9 Kearney 3.1 3.2 3.5 4.6 6.1 7.9 8.3 :Wood River Gibbon 4.2 4.2 5.1 9.8 15.9 17.6 18.3 Alda 4.5 4.5 5.0 8.5 12.1 13.0 13.4 Wood River Divers 10.9 10.9 12.0 14.8 17.5 19.2 21.4 :Platte River Grand Island 3.9 4.0 4.2 5.3 6.8 8.2 9.1 :South Loup River Ravenna 3.0 3.1 3.8 4.9 5.4 7.7 10.0 :Mud Creek Sweetwater 6.0 6.9 10.4 12.5 15.2 16.7 18.4 :South Loup River Saint Michael 2.8 3.1 3.9 6.5 8.5 12.1 13.9 :Middle Loup River Saint Paul 1.3 1.5 2.4 3.5 5.1 5.7 8.1 :North Loup River Saint Paul 2.8 3.0 3.6 4.1 4.8 5.4 6.4 :Cedar River Fullerton 2.5 2.7 3.7 5.5 6.5 7.6 8.3 :Loup River Genoa 5.2 5.2 5.9 6.7 8.0 8.8 10.7 :Beaver Creek Genoa 3.9 4.1 6.2 9.5 12.5 15.6 18.4 In Table 3 below...the 95 through 5 percent columns indicate the probability of falling below the listed stage levels (FT) for the valid time period. ...Table 3--Nonexceedance Probabilities... Chance of Falling Below Stages at Specific Locations Valid Period: 03/16/2024 - 06/14/2024 Location 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Little Blue River Deweese 2.4 2.4 2.3 2.2 2.2 2.1 2.1 :North Fork Solomon Glade 2.6 2.5 2.4 2.3 2.2 2.1 2.1 :Bow Creek Stockton 4.2 4.2 4.1 4.1 4.1 4.0 4.0 :Platte River Darr 4.9 3.6 3.0 3.0 3.0 3.0 3.0 Overton 2.8 2.7 2.7 2.5 2.5 2.5 2.5 Kearney 2.9 2.8 2.4 2.2 2.2 2.1 2.1 :Wood River Gibbon 4.2 4.1 4.1 4.1 4.1 4.1 4.1 Alda 4.4 4.4 4.4 4.4 4.3 4.3 4.3 Wood River Divers 10.9 10.9 10.8 10.8 10.7 10.7 10.7 :Platte River Grand Island 3.6 3.6 3.5 3.2 3.2 3.2 3.2 :South Loup River Ravenna 2.8 2.8 2.7 2.7 2.6 2.6 2.6 :Mud Creek Sweetwater 5.6 5.6 5.5 5.4 5.2 5.2 5.2 :South Loup River Saint Michael 2.3 2.2 2.1 2.1 1.9 1.8 1.8 :Middle Loup River Saint Paul 1.0 0.9 0.7 0.3 0.0 0.0 0.0 :North Loup River Saint Paul 2.6 2.5 2.4 2.3 2.1 2.0 2.0 :Cedar River Fullerton 2.2 2.2 2.1 2.0 1.9 1.9 1.9 :Loup River Genoa 3.9 3.9 3.9 3.9 3.9 3.9 3.9 :Beaver Creek Genoa 3.2 3.2 3.1 3.1 3.0 3.0 2.9 These long-range probabilistic outlooks contain forecast values that are calculated using multiple season scenarios from 30 or more years of climatological data...including current conditions of the river...soil moisture...snow cover...and 30 to 90 day long-range outlooks of temperature and precipitation. By providing a range of probabilities...the level of risk associated with long-range planning decisions can be determined. These probabilistic forecasts are part of the National Weather Service's advanced hydrologic prediction service. ...Future Outlooks... This marks the final Spring Flood Outlook for 2024. && Visit our local NWS office website for current weather/hydrological and climate information for South Central Nebraska and North Central Kansas at: https://www.weather.gov/hastings Additional climate information for the region can be obtained from the High Plains Regional Climate Center: https://hprcc.unl.edu Additional information on climatological outlooks can be found from the Climate Prediction Center: https://www.cpc.ncep.noaa.gov Further information on drought conditions can be obtained at: https://droughtmonitor.unl.edu https://www.drought.gov https://drought.unl.edu Information on mountain snowpack can be found at: https://www.nrcs.usda.gov/resources/data-and-reports/snow-and-water- interactive-map NWS AHPS precipitation analysis maps can be found at: https://water.weather.gov/precip National snow analysis page can be found at: https://www.nohrsc.noaa.gov Soil Moisture: https://www.cpc.ncep.noaa.gov/products/Soilmst_Monitoring Reservoir Levels: www.usbr.gov/gp/hydromet/curres_google.htm For training on NWS river forecast graphics: www.youtube.com/watch?v=psIByj8EZY0Visit our web site weather.gov/gid for more weather and water information. The next outlook will be issued $$ Wesely/Pfannkuch