Guest post by Paul Dorian
A colorful surface forecast map by the 12Z GFS for Saturday evening depicting a multi-hazard event with significant snow (blue) and ice (purple, pink) on the cold side of a powerful storm system and heavy rain (green, yellow) on the warm side where there will be a severe weather threat as well. Map courtesy NOAA/WPC, tropicaltidbits.com
Overview
A major storm is going to become a multi-hazard event for much of the eastern half of the nation during the next few days. The storm will begin to unfold on Friday in the south-central US and then trek northeast to a position near the Great Lakes by Saturday evening and then over New England on Sunday. Heavy rain and severe weather is likely to take place south and east of the storm track and significant snow and ice is likely to its north and west. The impact in the I-95 corridor will be to bring unusually warm conditions this weekend with highs generally in the 60’s and there will be some rainfall, stiff winds, and perhaps a heavy thunderstorm or two.
A widespread area of the nation will receive significant precipitation amounts during the upcoming event; map courtesy Weather Bell Analytics, NOAA/WPC
Details
There is likely to be a news making weather event over the next few days as a powerful storm system will impact a wide part of the eastern half of the nation. Surface low pressure will begin to form over Texas tomorrow night and then intensify as it pushes northeast on Saturday towards the Great Lakes and then it’ll slide into New England on Sunday. The upper-level wave of energy that will play a key role in the formation of this storm is now moving over California and heading southeast. By early Friday evening, there is likely to be a deep upper-level trough of low pressure near the New Mexico/Texas border region and this potent system will push to the northeast from there as we begin the weekend.
Strong support in the upper atmosphere (blue region) will help to spawn a strong system later tomorrow that will intensify on Saturday as it treks to the northeast. At the same time, strong upper-level ridging will develop along the eastern seaboard contributing to a major warm up in the I-95 corridor. Map courtesy NOAA, tropicaltidbits.com
On the warm side of the storm, heavy rain is likely and there can be a widespread severe weather outbreak from later tomorrow into Saturday night. Several key parameters will be coming together for this potential severe weather outbreak which will include the possibility of tornadoes. Low-level moisture will increase markedly on Friday in the southern US and this will combine with the negatively-tilted upper-level trough, deepening surface low pressure, and strong winds in the lower and middle parts of the atmosphere.
A severe weather threat will develop on Friday in the south-central US and then extend to the southeast US on Saturday with strong storms possible all the way into the Mid-Atlantic by Saturday night; maps courtesy NOAA/SPC
On the cold side of the storm, significant snow and ice is likely to fall in parts of the Midwest, Great Lakes and Northeast US. The warm up that intensifies in the eastern US this weekend will back off some early next week, but much of next week will remain well above normal for this time of year. There are some signs, however, for an overall pattern change to colder in the eastern US in about a week to ten days, but there will be quite a bit of warmth (and rain) to get through before that potential cool down.
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com
via Watts Up With That?
January 9, 2020 at 08:06PM
Iowa Climate Science Education 