Flood Potential Outlook
Issued by NWS Burlington, VT
Issued by NWS Burlington, VT
078 FGUS71 KBTV 142040 ESFBTV NYC019-031-033-089-VTC001-005-007-009-011-013-015-017-019-021-023- 027-150845- Winter/Spring Flood Potential Outlook National Weather Service Burlington VT 440 PM EDT Thu Mar 14 2024 ...Winter/Spring Flood Potential Outlook... This is the sixth flood outlook for the 2024 winter/spring flood season. Flood outlooks are issued bi-weekly by the National Weather Service in Burlington, Vermont to summarize the flood potential due to snowmelt and break up/formation of river ice across northern and central Vermont and northern New York. This outlook is valid for the two week period from March 14 to March 28, 2024. ...Overview... The potential for open water flooding through late March is below normal for the St. Lawrence Valley of New York and the northwestern Adirondacks. Elsewhere, across the Adirondacks, the Champlain Valley of Vermont and New York, and all of Vermont, the open water flooding threat is normal. A very localized area of Essex County New York has above normal flood potential. There is little to no river ice present, leading to a below normal to non existent threat for ice jams in the area over the next two weeks. March has begun unseasonably mild and wetter than normal across the region. March average temperature departures have ranged from +7 to +15F above normal. The above normal temperatures, increasing sun angle and melt runoff from precipitation events earlier this month has continued to deplete snow cover, even with the accumulating snow event for the higher elevations on March 9 and 10. The following is a summary of the conditions by region as of Thursday morning, March 14, 2024: ...St Lawrence Valley... .Flood Risk...Below normal .Snow Cover...Below normal, no snow cover .Water Equivalent...Below normal, none .Streamflows...Normal to above normal .Soil state...Above normal wetness .Groundwater...Normal to above normal .River Ice...None ...Northern Adirondacks... .Flood Risk...Below normal west, normal east .Snow Cover...Below normal, 1 to 3 inches in the lower slopes, to 4 to 7 inches in mid terrain and 1-2+ ft in the High Peaks above 3,000 feet .Water Equivalent...Below normal, 1 to 3 inches, mainly in mid terrain, with 4+ inches in the High Peaks above 3,000 feet. .Streamflows...Normal to much above normal .Soil state...Above normal wetness .Groundwater...Above normal .River Ice...Minimal coverage ...Champlain Valley... .Flood Risk...Near normal .Snow Cover...Below normal, no snow cover .Water Equivalent...Below normal, none to less than 1 inch .Streamflows...Normal to above normal .Soil state...Above normal wetness .Groundwater...Above normal .River Ice...None ...Central/northern Green Mountains and Upper CT River Valley... .Flood Risk...Near normal .Snow Cover...Below normal. Values ranging from a just a few inches along the Connecticut River, to 3 to 6 inches above 1500 feet .Water Equivalent...Below normal, ranging from 1 to 3 inches above 1500 feet .Streamflows...Above to much normal .Soil state...Above normal wetness .Groundwater...Normal to above normal .River Ice...Minimal coverage ...Southern VT and the adjacent Connecticut River Valley... .Flood Risk...Near normal .Snow Cover...Below normal, with less than 3 inches and large areas of bare ground in valleys/lower elevations, and 8 to 18 inches above 1500 feet .Water Equivalent...Below normal, less than an inch in the larger valleys, 1 to 4 inches in mid-terrain, and 4+ inches above 3,000 feet .Streamflows...Above to much above normal .Soil state...Above normal wetness .Groundwater...Near normal .River Ice...Minimal coverage ..Snow Depths and Water Equivalent... The unseasonably warm and rainy pattern which occurred over early March has led to below normal snow depths and water equivalents. Some snow was gained in the higher elevations this past week, but values remain below seasonal normals. ...River and River Ice Conditions... Daily and multi-day averaged streamflows remain at or above normal across the entire region. This is indicative of residual interflow and runoff from recent precipitation, and some surface recharge through snowmelt in the lower elevations. Given the recent warmth and rainfall, there is no notable river ice to speak of. No ice jams are currently reported. ...Soil Moisture and Groundwater Conditions... Moist soil moisture conditions have persisted across the region over the past two weeks. Some of the moist near-surface readings have occurred due to recent snowmelt recharge and rainfall, especially in the lower to mid elevations. This is supported by the latest groundwater data from the United States Geological Survey showing most values ranging through the mid to upper quartiles. ...Weather Outlook... Although the 6-10 day outlooks from NOAA`s Climate Prediction Center show near normal temperatures and precipitation, we return to above normal temperatures and precipitation in the 8-14 day range. This appears reasonable given the most recent forecasts of the North Atlantic Oscillation and the Pacific North America Index showing a more progressive weather pattern. Regardless, the most recent data suggests no large-scale, heavy rain/snow events are expected for the period giving confidence to the outlook as a whole. ...Summary... Based on the meteorological and hydrological information discussed above, the potential for open water flooding over the next two weeks is below normal for the St. Lawrence Valley of New York and northwestern Adirondacks. Elsewhere, across the northeastern Adirondacks, central and northern Vermont including the entire Champlain Valley and southern Vermont east of the Green Mountains, the open water flooding threat is normal. With little in the way of ice coverage and thickness on area rivers, the overall threat of ice jam flooding is below normal across far northern watersheds through mid March, in fact the threat for ice jam flooding has likely passed for this year. Finally, while the level on Lake Champlain remains about one foot above normal, a more normal flood threat is expected for the lake going forward into spring. It is important to remember that heavy rainfall can result in flooding at any time of year, even in areas that have little or no snow on the ground and overall predictability beyond 10 days is generally on the lower side of average. A graphic depicting the flood potential across the NWS Burlington service area is available online at: www.weather.gov/nerfc/springfloodpotential The next Winter/Spring Flood Potential Outlook will be issued by NWS Burlington on Thursday, March 28, 2024. For access to current weather conditions and forecasts, please visit our web site at www.weather.gov/btv. $$ Neiles