Updraft: April 9, 2012 Archive

Wild weather week ahead: Fire & frost; Much needed rainfall late week?

Posted at 8:51 AM on April 9, 2012 by Paul Huttner

Freeze warnings in effect tonight for all of central & southern Minnesota

27 - 32 degrees in the metro early Tuesday morning

Cover up any sensitive plants & flowers you want to save

Red Flag Warnings - Extreme fire danger again today

Coolest Twins Home Opener so far at Target Field today

Much needed rainfall on the horizon Thursday-Sunday?

Source: NWS

From Fire to Frost:

This is going to be one of those weeks in Minnesota that may leave you scratching your head, or at least wondering where on earth we live anyway.

Fire? Frost? Puddles all in the same week? Yup!

Let's sart with high fire danger. When I was in Arizona working weather at the ABC affiliate in Tucson for 9 years "Red Flag Warnings" were common features in my weathercasts.

In Minnesota, people ask me what that means.

A "Red Flag Warning" is issued by the NWS for any combination of weather factors that promote rapid wildfire growth.

-High winds (usually over 15-25 mph)
-Low relative humidity (Under 15 - 25%)
-Warm temperatures (Often over 70 degrees)

The specific criteria can vary depending on topography, vegetation etc.

With tinder dry brush and soils in Minnesota right now, wildfire danger is listed as "extreme according to the Minnesota DNR.

The air mass over Minnesota is as dry as the air in the desert southwest today. Dew points in Minnesota re in the teens, the same as places like Tucson today!

This is not the best week to burn anything outdoors. As we discovered Sunday with the wildfire near Nimrod in Wadena County, any fires that do start will spread rapidly today.

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
400 AM CDT MON APR 9 2012

...ANOTHER DAY OF DANGEROUS WILDFIRE CONDITIONS..MAINLY ACROSS
PARTS OF SOUTHERN INTO WEST CENTRAL MINNESOTA...

.TODAY MARKS AN UNPRECEDENTED FOURTH CONSECUTIVE DAY OF RED FLAG WARNINGS FOR AT LEAST PORTIONS OF THE AREA. TEMPERATURES WILL BE AROUND 10 DEGREES COLDER THAN YESTERDAY...BUT RELATIVE HUMIDITY THIS AFTERNOON WILL DIP TO AROUND 25 PERCENT IN MUCH OF SOUTHERN AND WEST CENTRAL MINNESOTA. NORTHWEST WINDS WILL INCREASE BEHIND A COLD FRONT WHICH WILL DROP ACROSS THE AREA EARLY THIS MORNING. BY NOON WINDS WILL BE AROUND 20 MPH WITH GUSTS AROUND 30 MPH. RED FLAG WARNINGS ARE POSTED THIS AFTERNOON AND EARLY EVENING FOR AREAS ROUGHLY SOUTH OF A LINE FROM MONTEVIDEO TO OWATONNA.

Frosty night: Freeze warnings in April:

We're not used to seeing "freeze warnings" in April in Minnesota. That's because it usually freezes this time of year, and it's really not a big deal in most years.

But this is not "most years."

Our record warm March has our landscape looking more like early May. Most native plants will be fine in tonight's freeze. But any tender flowers or any sensitive plants you may have put in to get a jump on this year's garden will freeze tonight. Cover them up if you want to see them last.

A desert dry air mass will chill rapidly after sunset tonight, and freezing temps should cover most all of Minnesota by morning. Even the inner Twin Cities should dip to or below freezing Tuesday morning, and the outer suburbs could see several hours below 28 degrees.

Source: NWS

Some frost may also linger Wednesday morning.

Pattern Change: Precious rainfall ahead?

Our tinder box weather pattern will change late this week.

A series of low pressure systems will push toward Minnesota starting on Thursday. Several waves of much needed rainfall may arrive as early as Thursday PM & evening, and last through the weekend.

Early indications are that much of central and Minnesota may pick up 1" to 2"+ worth of precious April showers by late Sunday.

Source: ISU

There will also be a thunder threat, and at least some severe weather can't be ruled out for parts of southern Minnesota this weekend. A bigger severe weather outbreak is possible in the central plains this weekend.

Source: NOAA SPC

Coolest Twins opener so far:

Twins & Yankees in 2010
Photo by Paul Huttner-MPR News

Bring your jacket if you're heading out to Target Field today. This will be the coolest home opener in the brief weather history of Target Field.

2010: Sunny - 68 degrees (April 12th vs. Boston Red Sox)

2011: Sunny 64 degrees (April 8th vs. Oakland A's)

2102: Sunny & windy near 50 degrees (Today vs. Los Angeles Angels)

Sunshine will offset the cool temps in the upper 40s today if you're sitting in left field or down the 3rd base line in the outfield today. Gusty NW winds will be blowing out toward right center today. Watch to see it the flags over the left field roofline and in right field near Target Plaza are blowing in the same direction today.

The infamous "Target Field Eddy" may be knocking some balls down in the outfield today. But if any get launched in the right spots, the gusty winds could help carry them out this afternoon.

Play Ball!

PH

A "25-Day" forecast?

Posted at 12:03 PM on April 9, 2012 by Paul Huttner (5 Comments)

Heres' a new one.

Accuweather will soon start issuing a "25-day forecast."

That's right, we're talking a specific detailed forecast on temps, rain/snow etc 25 days in advance.

"AccuWeather.com released a 25-Day Forecast that can help users make informed decisions about long-term plans. The AccuWeather 25-Day Forecast shows you the trends in temperature, precipitation and more, along with the forecast for a particular day.

For each day in the 25-day Forecast, you can see the forecasted high and low temperatures, the AccuWeather RealFeel® temperature, sky conditions and chance of precipitation, wind speed and direction, rain, snow and ice amounts, thunderstorm probability, cloud cover and UV index."
Source: Accuweather.com

Here's the forecast for the Twin Cities. Notice there is no mention of rain Thursday, Friday, or Saturday.

Source: Accuweather.com

Put me in the skeptical camp as to the value of this latest venture.

Forecasts beyond 5-7 days show little skill over "chance" or 50%. To put precip totals on a forecast 25 days out? Good luck with that.

The Washington Post's Capital Weather Gang seems to agree with the notion that this is more of a headline grab, and less about weather science.

"No it's not an April Fools' joke: Accuweather is pushing the limits of weather forecasting and issuing detailed predictions extending 25 days into the future effective today.

Consider me highly skeptical about their value.

Nevermind, the skill in forecasts rapidly deteriorates beyond 5-7 days and is typically no better than judging what the weather will be based on climatology (historical averages). Today, AccuWeather delivers the forecast out to Saturday, April 28 to every zip code in the U.S.

For Washington, D.C. on 4/28, we should expect mostly cloudy skies with "showers around" and a high of 64 and low of 46. But don't worry, if you buy this unrealistically precise forecast, just two hundredths of an inch of rain will fall - your outdoor picnic won't be washed out.

Let's get real for a second: I can hardly say with a lot of confidence whether 0.02" is a good rainfall prediction for today much less more than three weeks from now."
Source: Washington Post - Captial Weather Gang

What do you think? Do these kinds of forecast have any value to you as a user?

PH

(5 Comments)