Sunday, July 25, 2010

7/25/10: Sunday's Weather Report

Issued at 2:23 PM CDT, Sunday, July 25th, 2010

Weather History:

On this date in 1989, a record high temperature of 89 degrees occurred at Duluth, Minnesota.

Weather tidbits:

*2nd wettest July so far at International Falls, Minnesota. 8.31" of rain has fallen at International Falls, MN thru July 24th, 2010. This is 5.64" Above the normal amount of 2.67"! The wettest July on record occurred in 1966 when 9.52" of rain fell. There is a chance that July 2010 will go down as the wettest of all time at International Falls Minnesota.

Rainfall totals from Saturday, July 24th, 2010. Source: NWS Duluth, MN.

St. Louis County:

Duluth MN: 0.44"

Hibbing MN: 0.21"

Crow Wing County:

Brainerd MN: 0.13"

Ashland County:

Butternut WI: 0.27"

Sawyer County:

Hayward WI: 0.43"

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

High pressure of 1020 mb was centered along the Minnesota-Wisconsin border as of mid-Afternoon. Mostly sunny skies with very pleasant temperatures covered our local area Today with highs in the upper 70s to lower 80s with comfortable amounts of humidity as dewpoints were only in the 50-55 degree range This Afternoon with PWS around 0.70". Winds Today were variable under 15 mph.

Today's Upper Level Analysis:

W/NW 500 mb flow was in place over the Upper Midwest Today per water vapor satellite imagery and RUC model analysis. A potent upper level low/upper level trough was progressing east-southeast through Eastern Ontario/Western Quebec Province Today while another strong upper level low covered the Northwest Territories, Northern Alberta and Northern Saskatchewan Province Canada Today per water vapor satellite imagery. Note: The 500 mb low in Northwest Canada Today has prompted the issuance of severe thunderstorm watches/warnings as far north as the Northwest Territories Today, per Envrionment Canada.


High pressure will slide off to our south-east with mostly clear skies prevailing in Northern Minnesota and Northwest Wisconsin. Lows will be in the 50s to lower 60s, perhaps a few 40s in the typical cool spots. Winds Tonight will be variable under 15 mph.

Monday and Monday Night:

Southerly flow will become established across our area during this period which will start to pump more moisture into the Upper Midwest. Dewpoints should climb into the 60s in most areas Tomorrow and Tomorrow Night with PWS climbing to around 1.00". A cold front will remain well to our west-northwest Monday and Monday Night, but a warm/moist advection pattern aided by a 25-35 knot SW 850 mb jet out ahead of that boundary could cause scattered showers and thunderstorms at times across Northern Minnesota, especially by Monday Afternoon and or Monday Night.

There will be sufficient instability and shear in place...CAPES around 1500 j/kg, Lifted Indices around -3 degrees C, and 0-6 KM Bulk Shear and Effective Bulk Shear of 30-35 knots to warrant a risk for isolated severe thunderstorms Monday Night especially in Koochiching, Northern Itasca, and Northern St. Louis Counties MN...Large hail and damaging winds along with localized heavy downpours and dangerous lightning strikes will be possible from thunderstorms/severe storms if they do develop.

Partly-mostly sunny skies are expected on Monday with highs mainly in the 80s, lows Tomorrow Night will be mainly in the 60s with partly-mostly cloudy skies. Winds during this period will be out of the south or southwest at 10-25 mph.

Extended Forecast:

A cold front will settle south/east through Northern Minnesota and Northwest Wisconsin from Tuesday into Tuesday Night. The latest set of forecast models are indicating that there will be quite a bit of instability, moisture and shear in place along and ahead of this front on Tuesday which will result in a risk for severe thunderstorms across our local area.

CAPES Tuesday Afternoon are forecast to range from 1500-2500 j/kg with Lifted Indices from -3/-6 degrees C. 30-40 knots of 0-6 KM Bulk Shear and Effective Bulk Shear are forecast per 09z SREF model along with around 40-50 knots of westerly winds at 500 mb while 850 mb winds veer more southwesterly. Large hail and damaging winds will be the primary threats, but with the shear in place and the change of wind directions with height, there will be a risk for isolated supercells and an isolated tornado threat, especially over Central-Eastern portions of Minnesota late Tuesday Afternoon or Tuesday Evening.

High temperatures on Tuesday will be in the 70s and 80s with dewpoints in the 60s to near 70 degrees and PWS of 1.25-1.75", the high moisture content in the atmosphere will also lead to a heavy rain risk in our area. Lows Tuesday Night will be in the 50s and 60s.

Wednesday and Wednesday Night look drier as Tuesday's cold front pushes south/east of our area allowing winds to swing around to the northwest which will usher in cooler/drier and more stable conditions. Highs on Wednesday will generally be in the 70s with lows Wednesday Night in the 40s and 50s.

5 Day Forecast for Duluth/Superior

.Tonight... Mostly clear. Low 56 to 61. Wind variable around 12 mph.

.Monday... Mostly sunny. Warm. Turning more humid. High 81 to 86. Wind south to southwest at 10 to 20 mph.

.Monday Night... Partly cloudy. Mild and humid. Low 62 to 67.

.Tuesday... Humid. Scattered showers and thunderstorms developing, especially during the Afternoon. A few storms could be severe. Variable cloudiness. High 80 to 85. Chance of rain 40%.

.Tuesday Night... Scattered showers or thunderstorms mainly during the Evening. Partly to mostly cloudy. Low 58 to 63. Chance of rain 40%.

.Wednesday... Partly cloudy, less humid. High 75 to 80.

.Wednesday Night... Mostly clear. Low 53 to 58.

.Thursday... Partly cloudy. High 75 to 80.

Normal High Temperature Today 77 degrees

Normal Low Temperature Today 56 degrees