Stormy Monday, warmest week in 7 months ahead

I can smell rain in the air at the Weather Lab today.

A spectacular spring weekend in Minnesota delivered 72 degrees in the Twin Cities Sunday. Now another May low pressure system slides through with scattered to widespread rain and thunderstorms.

• Latest Twin Cities radar loop

• Latest Duluth radar loop

The heaviest rains favor northeast Minnesota where 1 to 2 inches could fall by Tuesday morning. Here's the two-day rainfall output from the National Oceanic and Atmospheric Administration's Weather Prediction Center.

A flash flood watch has been hoisted by the Duluth National Weather Service for the potential for 1 to 2 inches-plus rains through tonight. The most vulnerable areas to flooding? Along North Shore creeks and streams where multi-inch rains could cause rapid rises overnight.

 INCLUDING THE CITIES OF...ISABELLA...HIBBING...TWO HARBORS...GRAND MARAIS...DULUTH...CLOQUET

424 AM CDT MON MAY 19 2014

...FLASH FLOOD WATCH IN EFFECT FROM 4 PM CDT THIS AFTERNOON THROUGH TUESDAY AFTERNOON...

THE NATIONAL WEATHER SERVICE IN DULUTH HAS ISSUED A

* FLASH FLOOD WATCH FOR A PORTION OF NORTHEAST MINNESOTA...INCLUDING THE FOLLOWING AREAS...CARLTON/SOUTHERN ST. LOUIS...CENTRAL ST. LOUIS...NORTHERN COOK/NORTHERN LAKE...SOUTHERN COOK/LAKESHORE AND SOUTHERN LAKE/LAKESHORE.

* FROM 4 PM CDT THIS AFTERNOON THROUGH TUESDAY AFTERNOON

* A SLOW MOVING LOW PRESSURE SYSTEM WILL SWEEP AN ABUNDANT AMOUNT OF MOISTURE INTO THE REGION TODAY AND TONIGHT. RAIN WILL SPREAD INTO THE TWIN PORTS LATER THIS MORNING AND BECOME LOCALLY HEAVY IN THE LATE AFTERNOON AND CONTINUE THIS EVENING.

THUNDERSTORMS...AT TIMES...WILL PRODUCE HIGHER RAINFALL RATES. THE HEAVIEST RAIN WILL MOVE INTO THE ARROWHEAD LATE TODAY AND CONTINUE TONIGHT. AREAL AVERAGE RAINFALL AMOUNTS OF ONE TO TWO INCHES ARE EXPECTED WITH THE POTENTIAL FOR LOCALLY HIGHER

AMOUNTS IN THE ELEVATED TERRAIN ALONG THE NORTH SHORE OF LAKE SUPERIOR.

* AT THIS TIME IT IS EXPECTED THAT THE HIGHEST IMPACT WILL OCCUR ALONG THE NORTH SHORE AS THE ADDITIONAL EFFECTS OF TERRAIN LIFT WILL ENHANCE RUNOFF INTO AREA STREAMS AND RIVERS. WITHIN THE TWIN PORTS THE MAIN IMPACT SHOULD OCCUR THIS EVENING AS AREA ROADWAYS BECOME SUSCEPTIBLE TO LOCAL FLOODING AND STREAMS AND CREEKS RISE.

A few of the storms today over Minnesota could contain some hail and gusty winds, but most should stay below severe limits according to NOAA's Storm Prediction Center. There is a slight risk for severe storms over parts of Nebraska today.

Rain today, sun tomorrow

Our Monday soaker will be short lived. As low pressure slides east Tuesday, a bubble of June-like high pressure eases in from the west.

The high pressure system is the start of a significant change on the weather pattern this week. After months of riding the polar vortex to the north, it appears a semi-stable blocking pattern may shift and feature a "blocking high" set up over the Upper Midwest this week. Weather geeks call this an "Omega Block" since the pattern resembles the Greek letter Omega.

Here's a look at NOAA's Global Forecast System model upper air chart (500 millibars) for Saturday. The blocking high pressure ridge means Minnesota sits under a more favorable weather pattern for sunshine and warmer temps, while low pressure on the coasts delivers cooler wetter weather.

Instant June

What happens when a blocking high sets up overhead in late May? Several consecutive days of dry warmer weather. Here's a look at an increasingly favorable forecast for sunshine the coming week.

 Risk of a summery Memorial Day Weekend?

The first of the "Big 3" summer holiday weekends in Minnesota is almost here. That means three days of gray skies, temps in the 50s and a chilly rain for stoic and often weather fatalistic Minnesotans right?

Not this year.

It's still a little early for any good weather guarantees, but all signs point to a potentially favorable Memorial Day Weekend this year. The early read is for temps around 80 degrees, some sun with just a few hours of showers or a thunderstorm.

•  72 degrees high at Minneapolis-St. Paul International Airport Sunday

• 80 degrees possible Tuesday, and again Memorial Day Weekend

• May 3 average date of first 80 in spring in the Twin Cities

• Sept. 30 last 80 degree reading at MSP Airport

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Warmest week in over 7 months

Overall this looks like the warmest week in 7.5 months in Minnesota. We could have six or seven days at or above 70 in the next 10 days, and a few days in the 80s are possible.

The last time we had a stretch this warm was Sept. 26 through Oct. 2 when temps ran in the upper 70s and 80s.

Stock up the boat and fire up the grill.

We've earned it.