US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 328 PM EST Mon Jan 24 2022 Valid Thursday January 27 2022 - Monday January 31 2022 Hazards: - Heavy precipitation across portions of the Pacific Northwest and the Northern Great Basin, Sun-Mon, Jan 30-Jan 31. - Heavy precipitation across portions of the Northeast, Sat, Jan 29. - Heavy rain across portions of the Pacific Northwest, Sun-Mon, Jan 30-Jan 31. - Heavy snow across portions of the Central Appalachians, Fri, Jan 28. - Heavy snow across portions of the Mid-Atlantic and the Northeast, Sat, Jan 29. - High winds across portions of the Northeast, Sat, Jan 29. - Much below normal temperatures across portions of the Mid-Atlantic, the Lower Mississippi Valley, the Central Appalachians, the Tennessee Valley, the Northeast, the Southern Appalachians, the Southeast, the Great Lakes, and the Ohio Valley, Sat-Sun, Jan 29-Jan 30. - Much below normal temperatures across portions of the Middle Mississippi Valley, the Great Lakes, and the Upper Mississippi Valley, Fri-Sat, Jan 28-Jan 29. - High significant wave heights for coastal portions of the Mid-Atlantic and the Northeast, Sat, Jan 29. - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Thu-Fri, Jan 27-Jan 28. - High winds across portions of the Alaska Panhandle and mainland Alaska, Thu-Fri, Jan 27-Jan 28. Detailed Summary: ...Key Messages for January 28-30 (Friday-Weekend) Winter Storm... Confidence is increasing that a significant winter storm will create considerable impacts Friday through the weekend from the Mid-Atlantic through the Northeast. While uncertainty continues with the track and intensity of this system, it is becoming more likely that it will bring significant snow, sleet, and freezing rain to the region, including the I-95 metropolitan areas. Hazardous travel conditions are possible due to the combination of snow, sleet, freezing rain, and wind. Close to the immediate Atlantic coastline, strong winds combined with high astronomical tides may lead to coastal flooding. Please continue to monitor for future updates as this system develops. ...Discussion... The final five days of January are likely to go out in an impactful way with strong upper level ridging over most of western North America and an expansive troughing pattern over eastern North America. Temperature-wise, this jet stream pattern favors bitterly cold temperatures residing along the Mississippi River and all the way to the East Coast. Coldest anomalies on Thursday start out in the Midwest and Great Lakes on Friday, then spread throughout the South and East by the weekend. The coldest daily anomalies look to range between 15 to 20 degrees below normal, with some locally colder spots possible. How long the cold lingers in the Northeast and northern Mid-Atlantic may be dependent upon fresh snowpack in parts of these regions. Speaking of "snowpack", latest ensemble guidance is coming into better agreement on a rapidly intensifying cyclone off the East Coast this Saturday that could generate heavy snowfall from the northern Mid-Atlantic to New England. While confidence in a storm is increasing, it remains to be seen how close to the shore the storm sets up, and how early it can develop along the coast. These more northern stream dependent storms tend to "favor" New England and points south to the coastal northern Mid-Atlantic where the storm's cold conveyor belt of heavy snow pivots overhead. This is generally where the Heavy Snow hazard has been drawn on the Hazards Chart today. However, should the storm form sooner, the storm could bring its swath of heavy snow farther south towards Maryland and Northern Virginia. This is shown on some ensemble members, but there are also other members that are far enough out to sea that the threat for heavy snow would be more confined over coastal New England. Residents in the Northeast will want to check in daily for the latest on this potential winter storm as additional changes to the forecast are likely given the lingering spread in ensemble guidance. Note that the immediate coast of New England is in a "heavy precipitation" hazard area. There are ensemble members that point to the storm tracking close enough to the Northeast coast that warm southeasterly low level flow would support a changeover to an icy wintry mix and/or all rain. Sea surface temperatures off the Northeast coast remain well above normal as well, giving additional weight to the concern for a transition zone from snow to rain along and east of I-95 in New England with a closer to the coast storm track. Should guidance indicate colder solutions or a more easterly track, it is well within reason to see the heavy precipitation area dropped and all of southern and coastal New England added to the Heavy Snow hazard area. In addition to the hazards from heavy snow, rapid intensification of this storm system provides higher confidence in strong winds and battering swells along the Northeast coast. Astronomical tides will be highest closer to the end of the month so there is a greater concern for beach erosion and storm surge, especially during high tides. Wind gusts in excess of 50 knots are also possible along the coast and potentially farther inland too, giving rise to a threat of power outages and downed trees. Add in the strong winds to areas where snow is falling heavily (1-2" per hour rates likely under the most intense bands), and visibility could be approaching zero with blizzard conditions possible for some. In the Northwest, a frontal system looks to deliver beneficial rain and mountain snow to the Northwest. While the locations forecast to see the heaviest totals reside in western Washington, western Oregon, and the Cascades, rainfall may extend as far south as parched northern California where any rainfall would be welcomed. Should precipitation totals trend up in parts of the northern Rockies or in Oregon and northern California, heavy precipitation or snowfall hazards may be necessary as January comes to a close. ...Alaska... An approaching occluded low pressure system is primed to direct deep Pacific moisture at the southeast Alaska coast and throughout much of the Panhandle to close out the week. Heavy mountain snow and coastal/valley rain is anticipated through the end of the week as well as strong wind gusts along the immediate coast of southeast Alaska. The upper low responsible for the unsettled weather may linger into the weekend, but eventually a building ridge over southwest Alaska should bring a brief stretch of drier weather to close out January for most of the state. The lone exceptions would be the Aleutians, where the storm track for additional North Pacific cyclones would track, and the southern half of the Panhandle. Mullinax