Friday, July 21, 2017

Humid through Saturday with showers/t-storms possible at times (Risk of a few strong/severe storms through Saturday evening)

/Issued 4:50 PM CDT, Friday, July 21, 2017/

Yellow polygons=Active Severe Thunderstorm Warnings as of 4:50 PM CDT.

Note:  Storms are moving toward the south/east but could start to drop more to the south following the axis of higher instability which is down near the Brainerd Lakes area late this afternoon.  Not as much instability farther east so it remains to be seen if these storms hold together the farther east they get.


Severe Thunderstorm Watch (Blue area on map) until 11 PM CDT tonight.




18z NAM 500mb forecast valid for Saturday afternoon

Weather Synopsis

Low level moisture has increased over most of the Northland today as southerly flow develops ahead of a low pressure system which was over the northern Plains.  Dew points this afternoon were generally in the 60s in our area with even higher dew points in the low-mid 70s just west/south of the Northland.  A mix of sun/clouds across the area today with showers and thunderstorms at times across far northern Minnesota.  Highs today ranged from around 70 near Lake Superior to the upper 70s and lower 80s away from the lake.

Through Saturday evening there will be chances for showers and thunderstorms as the system currently to our west moves toward the east.  A few different boundaries will affect us providing more lift in the atmosphere, this combined with a more potent disturbance which approaches from the NW on Saturday will keep the threat for convection going at least through Saturday evening.  This activity should remain scattered, so not everyone in the Northland will get wet, but the potential is there for showers and thunderstorms to move through at times with heavy rain and frequent lightning.  In addition, there is also a risk of a few strong to severe thunderstorms tonight and Saturday with strong mid and upper level winds over the upper Midwest.  Damaging wind gusts looks to be the main hazard in our area with the secondary threat coming from large hail of quarter size or larger.

Lows tonight will be in the 50s and 60s with highs Saturday in the 70s and 80s with cooler temperatures near Lake Superior.

Forecast for Duluth and Superior

.Tonight...  Partly to mostly cloudy.  Scattered showers or thunderstorms possible.  Low 58 to 62.  Wind east at 10 to 20 mph.

.Saturday...  Partly to mostly cloudy.  Scattered showers or thunderstorms possible.  High 71 to 76 but cooler near Lake Superior.  Wind east to southeast at 10 to 20 mph.

.Sunday...  Partly to mostly cloudy.  High near 70.  Wind north at 10 to 15 mph.

Normal temperatures for Saturday

High:  77
Low:   56

Sunrise Saturday:  5:37 AM CDT
Sunset Saturday:   8:52 PM CDT