Very Cool Weather Moving in the Upper Midwest and the Great Lakes Today...Severe Weather for the Northeast over the Next Few Days

An unusual highly amplified summer jet stream pattern will produce very cool temperatures tonight through Wednesday for the upper Midwest and the Great Lakes. Temperatures will be 15 to 20 degrees below normal today through Wednesday from eastern Montana to Wisconsin. High temperatures will rise into only the upper 50s with showers in northern Minnesota on Monday. Sunshine will return to northern Minnesota on Tuesday and Wednesday with highs only in the 60s to near 70. A strong upper-level low pressure system across Ontario combined with a strong ridge in the western United States will produce this unusual cool weather. The ridge in the west will produce unusual heat in the Northwest for the next few days with highs in the 90s to near 100 across interior portions of Oregon, Washington and Idaho. This highly amplified and intense upper-flow is not normally found this far south in summer, it normally does not occur across the northern United States until early fall. The combination of a strong jet steam flow, humid air from the south and cool air from the north will produce an extended period of heavy thunderstorms that will likely be severe in some locations beginning today and lasting until Tuesday across the Great Lakes, the northern Ohio Valley and into the Northeast and Mid-Atlantic by Monday and Tuesday. The greatest chance for severe thunderstorms and isolated tornadoes will be from central New York State to southern Illinois Sunday night and throughout the day on Monday. More than 4 inches of rain is expected in parts of the Northeast including New York City. With cool, Canadian high pressure in control, the weather will be sunny and pleasant Wednesday through Saturday across the Great Lakes and the Northeast.
George Wright is a Certified Consulting Meteorologist for Wright Weather Consulting, LLC. Visit our website at WrightWeather.com. Follow George Wright on Twitter @gwweather.

Arthur is Forecast to Strengthen to a Category 2 Storm by Friday Morning...

Hurricane Arthur continues to slowly intensify as it moves to the north-northeast this evening. Maximum winds are now at 90 mph and some strengthening is expected over the next 24 hours.  It is forecast to make landfall Friday morning along the Outer Banks of North Carolina with sustained winds of 96 to 110 mph (Category 2 intensity).  The storm is then forecast to be ejected to the northeast by an upper trough taking it out to sea sparing any direct impacts for New York City or Long Island.  However, the storm is forecast to produce tropical storm conditions and up to 4 inches of rain near Cape Cod and southeastern Rhode Island Friday evening.  A Severe Thunderstorm Watch is in effect for the New York City metro area and across a large portion of the Northeast.  Much nicer weather will follow this holiday weekend. Have a great Fourth of July.  
George Wright is a Certified Consulting Meteorologist for Wright Weather Consulting, LLC. Visit our website at WrightWeather.com. Follow George Wright on Twitter @gwweather.

Latest bulletin on Arthur:

BULLETIN
HURRICANE ARTHUR ADVISORY NUMBER  12...CORRECTED
NWS NATIONAL HURRICANE CENTER MIAMI FL AL012014
500 PM EDT THU JUL 03 2014
CORRECTED FOR PRESSURE IN SUMMARY TABLE
...EYE OF ARTHUR NEARING THE COAST OF NORTH CAROLINA...
SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...33.4N 77.9W
ABOUT 35 MI...55 KM S OF CAPE FEAR NORTH CAROLINA
ABOUT 185 MI...300 KM SW OF CAPE HATTERAS NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...90 MPH...150 KM/H
PRESENT MOVEMENT...NNE OR 20 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...977 MB...28.85 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...
A TROPICAL STORM WARNING HAS BEEN ISSUED FOR NANTUCKET ISLAND
AND FOR CAPE COD FROM PROVINCETOWN TO CHATHAM.
ENVIRONMENT CANADA HAS ISSUED A TROPICAL STORM WATCH FOR NOVA
SCOTIA FROM PORT MAITLAND EASTWARD AND NORTHWARD TO POINT ACONI.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT...
A HURRICANE WARNING IS IN EFFECT FOR...
* SURF CITY NORTH CAROLINA TO THE NORTH CAROLINA/VIRGINIA BORDER
* PAMLICO SOUND
* EASTERN ALBEMARLE SOUND
A HURRICANE WATCH IS IN EFFECT FOR...
* LITTLE RIVER INLET TO SOUTH OF SURF CITY
A TROPICAL STORM WARNING IS IN EFFECT FOR...
* SOUTH SANTEE RIVER SOUTH CAROLINA TO SOUTH OF SURF CITY
* THE NORTH CAROLINA/VIRGINIA BORDER TO CAPE CHARLES LIGHT
VIRGINIA...INCLUDING THE MOUTH OF THE CHESAPEAKE BAY
* WESTERN ALBEMARLE SOUND
* NANTUCKET

* CAPE COD FROM PROVINCETOWN TO CHATHAM