Friday, July 16, 2010

7/16/10: Friday's Weather Report

Issued at 8:00 PM CDT, Friday, July 16th, 2010

Note: One year ago Today our high temperature at Duluth, Minnesota was just 60 degrees!

Weather tidbits for Duluth, Minnesota.
Source: NWS Duluth, MN.

*Average monthly temperature (ending on the 15th) 69.3 degrees or 4.4 degrees Above Normal

*9 days so far this month with a high temperature of at least 80 degrees

*Monthly precipitation total (ending on the 15th) 1.45" or 0.66" Below Normal

*Precipitation total since January 1st, 2010: 15.85" or 0.81" Above Normal

*Precipitation total since June 1st, 2010: 6.70" or 0.34" Above Normal

30 Day Outlook for August 2010...Issued by the Climate Predictions Center on Thursday, July 15th, 2010.

*For Duluth: 40% chance for Above Normal Temperatures with Equal Chances for Above Normal, Normal, or Below Normal Precipitation.

90 day Outlook for August through October 2010...Issued by the Climate Prediction Center on Thursday, July 15th, 2010.

*For Duluth: 33% chance for Above Normal Temperatures with Equal Chances for Above Normal, Normal, or Below Normal Precipitation.

Note: Only one month so far in 2010 at Duluth, Minnesota has been below normal in the temperature department...And even that month wasn't that much below normal.

January 2010: 2.2 degrees Above Average
February 2010: 0.7 degrees Above Average
March 2010: 11.6 degrees Above Average
April 2010: 7.1 degrees Above Average
May 2010: 2.0 degrees Above Average
June 2010: 0.1 degrees Below Normal

Forecast Discussion for Northeast Minnesota and Northwest Wisconsin

Today's Weather:

A very nice mid-July day with partly cloudy to mostly sunny skies with highs in the upper 70s to middle 80s with comfortable amounts of humidity with dewpoints generally in the 50s to around 60 degrees. Winds Today were out of the west or northwest at 10-20 mph with a few higher gusts. Surface map This Evening featured a warm front extending from the Western Dakotas to Northern Iowa.

This Evening's Upper Level Analysis:

Northwest 500 mb flow was in place over the Upper Midwest This Evening per water vapor satellite imagery and RUC model analysis. A strong upper level low continued to spin slowly toward the south/east across Northcentral Ontario Province This Evening well the next system set to impact the Upper Midwest was currently over Western Canada and the Pacific Northwest. 850 mb temperatures as of 7 PM ranged from +13/+18 degrees from north to south across our local area. A surge of hot air was advecting E/NE off the Northern Rockies/Western High Plains This Evening with H85 temperatures of +24/+35 degrees C which is leading to 90+ degree temperatures from the Western Dakotas back through the Northern Rockies late Today.


Clear to partly cloudy skies will be the rule across Northern Minnesota and Northwest Wisconsin Tonight with low temperatures in the 50s to around 60 degrees. Winds will be out of the north or west under 15 mph.

Saturday and Saturday Night:

Some quick changes will take place during this period. Saturday Morning will feature partly cloudy skies with low humidity along with west or north winds across our area...Then, by Saturday Afternoon moisture will start to increase from southwest to northeast as a southerly flow sets-up out ahead of an area of low pressure which will move into the Upper Midwest later in the day. A warm front extending east-southeast of that surface low will begin to creep north out of Southern Minnesota and is expected to reach Central areas of Minnesota by late Saturday Afternoon. Dewpoints by Saturday Afternoon and Saturday Night will climb into the 58-65 degree range over most of our area, but a pocket of 65-70 degree dewpoints will likely occur along and south of a line from Brainerd to Hinckley to Hayward. 850 mb td's are expected to rise to between +8/+13 degrees C during this period with PWS increasing to between 1.00"-1.50".

An area of extreme instability with CAPES of 4000-5500 j/kg will cover portions of Western-Southern Minnesota and adjacent areas of the Dakotas, Nebraska, and Iowa by Saturday Afternoon with some of this instability getting pulled NE into our area with CAPES by Saturday Afternoon/Evening ranging from 1000-2500 j/kg around Northern Minnesota and Northwest Wisconsin, there is a chance for even higher instability to get pulled northeast into Western-Southern parts of our local area by late Saturday with CAPES possibly as high as 3000-3500 j/kg! Lifted Indices throughout our local area will decrease to around -2/-6 degrees C from Saturday Afternoon into Saturday Night.

We should see the development of scattered showers and thunderstorms by Saturday Afternoon across Northern and Eastcentral Minnesota and also in Northwest Wisconsin as the axis of deeper moisture and higher instability advect E/NE into our local area. The threat for additional showers and thunderstorms will then linger into Saturday Night as low pressure along with it's warm front, cold front, and trough push through the Upper Midwest.

All but the Arrowhead of Minnesota is currently in a SLIGHT RISK for Severe Thunderstorms Saturday Afternoon and Saturday Night per Storm Prediction Center, with the area from Cass Lake and Walker down through Leader and Brainerd, east through Aitkin and McGregor, Hinckley and Pine City under a MODERATE RISK for Severe Thunderstorms.

40-50 knots of shear are forecast throughout our area Saturday and Saturday Night with 500 mb winds up to 50 knots from the west-northwest while 850 mb winds veer to the southwest, and possibly even the S/SW. Surface winds will gradually back toward the south or southeast during the day Saturday. Ample amounts of speed shear and directional wind shear should be in place especially by late in the day Saturday and this could lead to supercell thunderstorm development, especially in Western-Southern portions of our area.

A few things to keep an eye on for Saturday will include the timing of the surface low and warm front...Some of the models are trending slower with this system which would mean that most of the activity for our area could hold off until Saturday Evening or Overnight which would limit the threat for supercell thunderstorms. Also, the placement of the warm front by late Saturday Afternoon...If this boundary stays over Southern Minnesota, which is possible...Then this would mean a lesser threat of supercells up around our area. Also, the presence of a cap...Right now it looks like 700 mb temperatures will be around +8/+10 degrees C around our area, +12/+14 degrees C across the Southern half of Minnesota. 850 mb temperatures will range from around +22 degrees C around the Brainerd Lakes area with cooler readings north of the Iron Range. If this cap holds, then this too would lessen the threat for severe weather across the Upper Midwest.

The main threats if thunderstorms become severe Saturday Afternoon and Saturday Night will be from large hail and damaging winds, but there will be a risk for isolated tornadoes as well...Especially between the hours of 4PM-9PM...At this time it would appear that the tornado risk would include Cass, Crow Wing, Aitkin and Pine Counties in Minnesota and Burnett County in Northwest Wisconsin.

People in Northern Minnesota and Northwest Wisconsin should be alert of changing weather conditions Tomorrow Afternoon and Tomorrow Night, portions of our local area could be under severe thunderstorm and or tornado watches/warnings at some point between late Tomorrow and Tomorrow Night.

High temperatures on Saturday will be in the 70s and 80s with lows Saturday Night in the 50s and 60s. Winds will be out of the south, west, or east at 10-20 mph.

Extended Forecast:

Low pressure pulls off to our east on Sunday. Could see some lingering showers Sunday Morning in Eastern Minnesota and Northwest Wisconsin, otherwise things look dry from Sunday Afternoon through Sunday Night with highs in the 70s and lows in the 50s.

Next week will be quite active at times across the Northern and Central Plains as well as the Upper Midwest...A warm front will develop most likely in Nebraska and Iowa with strong jet stream energy found along and north of that front with building heat south of the front. Clusters of severe thunderstorms and heavy rainfall will likely develop along and north of this warm front for most of next week...Right now it looks like the best threat for seeing this activity will be to our south until around mid or late week when the warm front could start to lift north and closer to our local area.

High temperatures on Monday will be in the 70s to lower 80s with lows Monday Night in the 50s to around 60 degrees.

5 Day Forecast for Duluth/Superior

.Tonight... Mostly clear. Low 55 to 60. Wind north to northwest at 5 to 15 mph.

Saturday... Partly to mostly cloudy. Late Afternoon showers or thunderstorms possible. High 79 to 84. Wind west at 5 to 15 mph becoming south during the Afternoon. Chance of rain 30%.

.Saturday Night... Scattered showers or thunderstorms possible. Mostly cloudy. Low 58 to 63. Wind variable at 5 to 15 mph. Chance of rain 40%.

.Sunday... Showers possible early. Partly to mostly cloudy. High 70 to 75. Chance of rain 20%.

.Sunday Night... Partly cloudy. Low 53 to 58.

.Monday... Partly cloudy. High 72 to 77.

.Monday Night... Partly cloudy. Low 55 to 60.

.Tuesday... Partly sunny. High 73 to 78.

Normal High Temperature Tomorrow 77 degrees

Normal Low Temperature Tomorrow 55 degrees