Updraft: July 14, 2011 Archive

Rainy Thursday; Scattered Friday; Heat kicks in Saturday

Posted at 8:30 AM on July 14, 2011 by Paul Huttner
Filed under: Heat, Rainfall

Rain is moving across much of Minnesota as expected today. The good news is the potential for flooding; multi inch rain totals appears lower than yesterday. The "bad" news is, it's still going to rain most everywhere today, but the rain is timely and needed in some areas.

-Latest Twin Cities radar loop

Surface chart shows rain shield moving through Minnesota Thursday.

Most of the rain has been "garden variety" so far, but there have been a few bands of heavier rainfall. Doppler storm total rainfall and surface reports indicate 1" to 2" bands from near Fergus Falls through Wadena, Brainerd, to Cloquet.

Patches of heavy rain have also fallen near Montevideo (1.5") and in southwest Minnesota.

In the metro rain will favor the morning and midday hours, and a general .50" is likely with some isolated 1" totals likely today.

Scattered showers linger Friday:

The chance for scattered showers and T-Storms will linger through Friday and into early Saturday. As hot high pressure builds in overhead Saturday, an atmospheric "cap" should put the lid on T-Storms for a few days.

SPC maintains a slight risk for severe storms Friday, but does not sound overly concerned about intensity and coverage.

...UPPER MS VALLEY TO CENTRAL HIGH PLAINS...

ONE OR TWO MCS MAY BE ONGOING AT BEGINNING OF PERIOD OVER PORTIONS
DAKOTAS/MN...MOVING GENERALLY EWD WITH POTENTIAL FOR ISOLATED HAIL.
AS LLJ WEAKENS THROUGHOUT MORNING...THIS CONVECTION SHOULD DO LIKEWISE. REJUVENATION AND/OR ADDITIONAL TSTM DEVELOPMENT ISPOSSIBLE DURING AFTERNOON ALONG NEARBY SECTIONS OF FRONTAL ZONE AND SWWD PAST SFC LOW...RESULTING IN SCATTERED TSTMS IN BANDS AND
CLUSTERS.

Saturday: Heat kicks in:

The real headline of this forecast period continues to be the heat wave setting up for the rest of July.

Model trends continue to indicate a string of days in the mid to upper 90s next week, with high dew points in the 70s pushing heat index values into the 100 range.

Keep the umbrella handy today!

PH

A solid week of 90-degree heat? Summer's hottest air ahead.

Posted at 5:30 PM on July 14, 2011 by Paul Huttner
Filed under: Heat

Get ready for some persistent intense heat. The hottest air of the summer is on the way over the next week.

A large hot high pressure dome will expand over Minnesota and the Midwest this weekend. All indications are the pattern will persist right through next week.

The Twin Cities and much of Minnesota could see at least 7 consecutive days with daily high temperatures at or above 90 degrees starting Saturday. High temperatures will likely soar above 90 degrees in much of Minnesota from Saturday through next Friday. Heat index values could soar into the 100 range!

There are signs a cool front may bring some temporary relief by next weekend.

The chart below tracks forecast temperatures at MSP Airport over the next 7 days from various models.

Sunday may be the hottest day, when highs could push 100 in much of southern Minnesota.

While 7 days is a long stretch of 90 degree temps, it would not be a record breaker.

Hot nights too!

One feature of the coming heat wave will be hot overnight temperatures. For several consecutive nights temperatures may not drop below 75 degrees in the metro...and there could be a few nights with overnight "low" temperatures near 80 degrees!

One aspect of the record Chicago heat wave in 1995 that killed over 700 people was that nighttime temps did not dip below 80 in much of the city for days. It was so hot at night that people's bodies just did not have the chance to cool off, and many died in apartments without air conditioning.

Another factor was the urban heat island effect. Days of sun and temps near 100 baked buildings (many red brick apartments) to well over 125 degrees. If you didn't have A/C, you just had now way of cooling off. The red brick "reraditiated" heat at night, and temperatures in the city could not fall.

I covered the heat wave in 1995 in Chicago as a meteorologist for WGN TV.

WGN Morning News Team in the mid-'90s. (Gotta love that 'stache!)

It was a lesson in establishing "cooling centers" where people who did not have A/C could gather to cool off, and for checking on the elderly and others who could not care for themselves.

In the heat waves of the 1930's my parents recall sleeping with hundreds of others by Lake Calhoun and other Minneapolis lakes to cool off at night in the pre A/C days.

People sleeping outside near Minneapolis lakes in the heat waves of the 1930's.

Stay cool when the heat builds this weekend!

PH