/Issued 4:36 PM CDT, Wednesday, October 2, 2013/
-Differences continue to show up regarding the storm set to arrive on Friday. The track and speed of this storm is handled differently by the NAM, GFS, and EURO Today.
The image below is the 700mb relative humidity forecast valid at 7 AM Saturday. The darker colors represent a dry slot which would end the rain at least for a time where-ever this dry slot ends up. According to the 18z NAM the dry slot Saturday AM would extend from North Central and Eastern Minnesota, far Western Wisconsin, and Southern Minnesota.
-Here’s the 12z GFS model’s take on where the dry slot will be located Saturday AM. Way down in Eastern Nebraska/Western Iowa. Quite the difference!
-Surface map valid for Saturday Morning. A strong area of low pressure located along the Iowa/Minnesota border. Green lines on the map represent wind, and the tighter they are the more wind there is. Could have 30-40 mph wind gusts out of the ENE in the Twin Ports Friday into Saturday. (Source, Weather Prediction Center)
-Surface map for Sunday Morning shows the area of low pressure centered over Northern Wisconsin. Slower storm movement like what this map shows means that rain would linger into Sunday. (Source, Weather Prediction Center)
*By Sunday, much of Minnesota and Wisconsin will have picked up 1-2″ of rain with locally higher amounts of 3-4″ possible, especially over Southern Minnesota and Central Wisconsin. (Source, Weather Prediction Center)
*Storm track forecast ending at 7 AM Saturday. Note how large the circle is come 12z (7am Saturday) Surface low could be anywhere from Eastern South Dakota to Southern Iowa. (Source, Weather Prediction Center)
*September 2013 ended up being the 11th warmest and the 12th driest on record at Duluth, while International Falls tied for their 8th warmest September on record. (Source, NWS Duluth, MN)
*We hit triple digits Today! 100 days so far this year with a high temperature of at least 70F at Duluth. Well above the average of 85. I think were done with the 70s now until spring 2014, but then again I said that just a few days ago.
Today’s Weather Summary for Northeast Minnesota and Northwest Wisconsin
Low pressure averaging 1009mb was over Southern/Eastern South Dakota as of 4 PM with a warm front across Northern Iowa with a trough stretching from Southeast North Dakota to Northeast Minnesota. Most of Today was nice with plenty of sunshine and high temperatures in the 60s and 70s. Clouds did increase though during the Afternoon and some rain has been hitting parts of the Northland as a 25-35 knot southerly low level jet aids in a warm/moist advection pattern. A wide range in dew points across Minnesota Today with 30s in the NE part of the state and 50s in SW Minnesota. Winds were out of the south, north, or east at 5 to 15 mph.
Forecast Discussion for Northeast Minnesota and Northwest Wisconsin
Short Term Forecast – Confidence: High.
Tonight (October 2)
A warm front well to our south combined with low pressure in Eastern South Dakota and an upper level disturbance tracking ENE out of Nebraska will lead to some rain across the Northland Tonight. The greatest chance for rain will occur This Evening. After Midnight most of the rain (if any is leftover) should be concentrated in Northern Wisconsin and Eastern Minnesota. Could be an isolated thunderstorm as well Tonight mainly in East Central Minnesota into Northern Wisconsin. Lows will be in the 40s and 50s with winds out of the east at 5 to 15 mph.
Thursday and Thursday Night (October 3)
Surface pattern changes little as a warm front remains over Northern Iowa – Southern Minnesota vicinity while a weak lead low heads ENE along that boundary while a stronger system starts to take shape over the Rockies. Rain is possible at times Tomorrow and Tomorrow Night with an isolated threat for thunderstorms from Eastern Minnesota through Northern Wisconsin. Highs will be in the 50s and 60s with lows in the 40s and 50s. North or east winds are forecast at 5 to 15 mph with higher gusts possible.
Extended Forecast – Confidence: Medium.
Friday through Sunday (October 4-6)
A strong fall storm is still expected to hit the Upper Midwest during this period, but there are differences that continue to show up in the computer models in regards to the storm track, also with the speed of which this storm moves through. NAM continues to be quicker compared to the GFS, CANADIAN, and EURO models. A digging storm like this usually leads to a slower moving storm, so will see if the NAM starts to trend toward a slower solution during the next 12-24 hours.
Rain will occur at times from Friday through Sunday. Can’t rule out a few thunderstorms either, especially Friday into early Saturday across East Central Minnesota and Northern Wisconsin. The potential for any frozen precipitation in the Northland still looks pretty low with the greater potential for snow remaining over portions of the Western High Plains and Northern Plains.
High temperatures will be in the 40s and 50s through this period with a few 60s possible in far Southern areas on Friday. Lows Friday Night will be in the 40s and 50s. Lows Saturday Night will be in the 30s and 40s.
*Enhanced severe thunderstorm risk for Friday across South Central Minnesota, Southwest Wisconsin, down through Iowa and Eastern Nebraska. (Source, NWS/Storm Prediction Center) Note: Slight (5%) chance comes as far north as Duluth on Friday. That’s certainly a possibility depending on the track of the low. Farther north=a better chance for storms over parts of our area.
*Here’s the tornado ingredients map valid for late Friday Afternoon. Lines up nicely with the outlook above. Supercells could develop Friday Afternoon/Night with large hail, damaging winds, and possibly even a few tornadoes in the risk area. (Source, 15z SREF model)
Long Range Forecast – Confidence: Medium.
Early next week (7th-8th) looks generally dry at this time. Chances for rain could return during the 9th-12th time frame as another trough and possible storm come out of the Western/Southwest U.S. Near normal temperatures are forecast during this period.
5 DAY FORECAST FOR DULUTH/SUPERIOR
.Tonight… Rain, especially before Midnight. Considerable cloudiness. Low 48 to 53. Wind east at 10 to 15 mph.
.Thursday… Occasional showers possible. Considerable cloudiness. High 53 to 58. Wind east to northeast at 10 to 20 mph.
.Thursday Night… Showers possible. Mostly cloudy. Low 48 to 53. Wind east to northeast at 10 to 20 mph.
.Friday… Breezy. Mostly cloudy. Showers possible. High 50 to 55. Wind east at 15 to 25 mph with higher gusts possible.
.Friday Night… Breezy. Rain possible. Low 45 to 50. Wind east at 15 to 25 mph with higher gusts possible.
.Saturday… Breezy. Rain possible. High 45 to 50. Wind east at 15 to 25 mph with higher gusts possible.
.Saturday Night… Rain possible. Low 38 to 43.
.Sunday… Mostly cloudy. Showers possible. High 43 to 48.
Normal temperatures for Today
Sunrise Thursday: 7:10 AM CDT
Sunset Thursday: 6:44 PM CDT