/Issued 5:03 PM CDT, Thursday, May 25, 2017/
Surface map valid for Friday afternoon. Red line=Warm front. Blue line=Cold front.
12z European Ensemble model.
Weather Tidbits for Duluth, Minnesota
-Going into today (May 25th) The average temperature for the month of May was 48.8 degrees; -1.7 degrees below normal. May 2017 will likely be a below average temperature month. This will be the first below average May since 2013, and the first below average temperature month since April 2016.
-No 80 degree days this month -- This is the first May since 2011 without at least one 80 degree day. Dating back to 2000, there have been 7 Mays with zero 80 degree days. 2011, 2008, 2006, 2005, 2004, 2003 and 2001. Of those 7, only 2 were followed by a cooler than normal summer (June-August) The most recent was in 2008, and prior to that 2004.
Upper level trough has moved off to the east today while a brief upper level ridge moves over the upper Midwest. Temperatures over most of the Northland were close to normal to slightly above normal on this 25th day of May with highs in the mid to upper 60s, even a few lower 70s in parts of northwest Wisconsin. Of course the exception to this was near Lake Superior as the wind direction remained out of the east today which kept temperatures in the 50s. Skies across the Northland were partly to mostly cloudy today.
Our weather for tonight through Friday evening will be controlled by an area of low pressure which will be centered off to our northwest while a warm front and cold front attached to this low move through the Northland -- Moisture will be on the increase tonight as PWATS increase to around 1.00" to as high as 1.25" while dew points Friday afternoon climb into the 50s over parts of the Northland.
There will likely be a couple rounds of rain showers that'll move through the Northland beginning this evening, and then continuing through Friday evening. The rain tonight will generally be on the light side and not everyone will get wet, this rain will be caused by deeper moisture which will advect into our area during the night.
The showers Friday may be a little heavier but again not all of us will get wet.
Instability is forecast to increase Friday afternoon with a corridor of CAPE in the 300-800 j/kg range over parts of north central and east central Minnesota. This coupled with steepening mid level lapse rates should be enough to produce a few thunderstorms in the aforementioned areas Friday. Severe weather is not expected but the thunderstorms could produce some small hail or gusty winds along with occasional lightning especially in the afternoon/early evening hours.
It'll be milder tonight than it has been in previous nights with lows in the 40s to mid 50s. Friday's high temperatures are forecast to be in the 60s and 70s with 50s near Lake Superior.
...Memorial Day weekend...
Note: The average high temperature is ~66 degrees from Saturday through Monday.
Saturday still looks like the drier day of the 3-day weekend. Highs Saturday are forecast to be around 70-72 degrees in Duluth with a westerly wind for a change!
Scattered showers and a few thunderstorms Sunday with more scattered showers Memorial Day. The coolest day will be on Monday with highs near 60 degrees in Duluth, while highs Sunday range from 63 to 67 degrees. Winds Sunday and Monday will be out of the north or northwest.
Forecast for Duluth and Superior
.Tonight... A few showers at times. Partly to mostly cloudy. Low 43 to 48. Wind east at 10 to 15 mph.
.Friday... Scattered showers. Mostly cloudy. High 60 to 65, cooler near Lake Superior. Wind east to southeast at 10 to 15 mph.
Normal temperatures for Friday
Sunrise Friday: 5:22 AM CDT
Sunset Friday: 8:49 PM CDT