Clipper System Today

AN ACTIVE STORM TRACK INTO THE PACIFIC NORTHWEST WILL CONTINUE THROUGH NEXT WEEK WITH REPEATED WEATHER SYSTEMS HITTING THE COAST. A CLIPPER SYSTEM WILL BRING ACCUMULATING SNOW TO THE NORTHERN PLAINS AND UPPER MIDWEST TODAY, MOVING EASTWARD INTO THE NORTHEASTERN U.S. BY FRIDAY. STRONG HIGH PRESSURE THEN SETTLES OVER THE GREAT LAKES AND NEW ENGLAND THIS WEEKEND. THIS HIGH MOVES INTO EASTERN CANADA BY EARLY/MID-NEX WEEK, WHICH SHOULD PROMOTE MOSTLY FAIR WEATHER ACROSS THE EASTENR PART OF THE COUNTRY. HOWEVER, SOME WEAK SYSTEMS MAY STILL PASS THROUGH WITH SOME PERIODS OF RAIN/SNOW. SOME BELOW NORMAL TEMPERATURES WILL SPREAD ACROSS THE CENTRAL/EASTERN U.S. LATE THIS WEEK INTO THIS WEEKEND, COLDEST IN THE NORTH. ABOVE NORMAL TEMPERATURES WILL SPREAD EASTWARD ACROSS THE CONTINENTAL U.S. NEXT WEEK AS AN UPPER LEVEL RIDGE WILL BUILD EASTWARD.

EAST: A clipper system will bring snow through the Great Lakes and Northeast today and Friday, with some lake-effect snow showers over the weekend behind this system. Otherwise, the weekend and early next week will feature relatively quiet weather across the Eastern U.S as an area of high pressure settles in. Precipitation may redevelop through the middle to end of next week, but confidence is low on the track and strength of any following systems, especially around the Great Lakes and Northeast. Above normal temperatures will lead to much of this precipitation falling as rain.

Temperatures:
– Temperatures will fall to near to below average following a cold front today and Friday, coolest in northern areas.
– Cold anomalies peak this weekend and Monday, with all areas seeing below normal temperatures. Peak cold anomalies may reach 15-20 degrees in the Northeast.
– A warming trend is then expected for mid to late next week, as most areas warm back above normal, especially in western/northern areas.
– By the end of the following week, temperature anomalies may reach 15-20 degrees above normal.

CENTRAL: A clipper system will move southeast through the Northern Plains and Upper Midwest today and will bring a swath of accumulating snow to North Dakota, Minnesota, and Wisconsin into the Great Lakes. Another clipper may bring an additional round of light snow Friday and Saturday for parts of the Dakotas and Minnesota. Drier conditions will return for the second half of the weekend and into early next week as a strong high builds into the region. Additional storm systems could return during the middle to end of next week, but confidence is low regarding the track and development of any systems. Warmer air will move in later next week, will limit snow potential, and will lead to more rain potential.

Temperatures:
– Below normal temperatures from the Northern Plains through the Upper Mississippi Valley through Saturday.
– The cold temperatures will peak on Friday where parts of the north will be up to 15 degrees below normal.
– Central/southern parts of the region will fall slightly below normal on Friday and Saturday before rebounding.
– Temperatures will warm above normal by Sunday across the Plains and closer to normal near the Mississippi Valley.
– Next week above normal warmth will take over for all areas. Temperatures may rise to 15 degrees above normal across central and northern parts of the region by mid to late next week.

WEST: Additional rounds of rain and mountain snow look to build into the Pacific Northwest Thursday through the weekend. The Southwest and Great Basin will stay dry as a ridge of high pressure dominates through the weekend. Next week, active weather will continue at times across the Pacific Northwest, with some reaching further south into California and the Great Basin as the ridge of high pressure breaks down some. Repeated weather systems will impact the Pacific Northwest through the following week, leading to a wet and snow pattern for many areas.

Temperatures: 
– Temperatures on the order of 5-10 degrees above normal will be common across the region through the forecast period.
– Some areas along/east of the Rockies may reach up to 10-15 degrees above normal next week.
– Temperatures begin to moderate a bit by the middle of the following week, with some seasonal temperatures appearing. Most areas will continue to trend mild, however.

TROPICAL:
No tropical activity expected to impact the US through the forecast period. 

MODEL DISCUSSION:
– High-res models preferred through today.
– A blend of ECMWF/GFS is then favored through the weekend.
– Ensemble guidance is favored next week due to model disagreement regarding additional the strength of Pacific low pressure systems and development of systems impacting the Central and Eastern US.

Forecaster: Michael Hansen