Meteorologist Paul Douglas writes about Minnesota weather daily, trying to go beyond the "highs" and "lows" of the weather story to discuss current trends and some of the how's and why's of meteorology. Rarely is our weather dull - every day is a new forecast challenge. Why is the weather doing what it's doing? Is climate change a real concern, and if so, how will my family be affected? Climate is flavoring all weather now, and I'll include links to timely stories that resonate with me.
Saturday, April 18, 2015
Somewhat Soggy Sunday; Turning Breezy and Cooler
April 16th, 2014
YIKES!! Here's a scary image from last year! I snapped this on April 16th, 2014 during a late spring snow event... Let's hope that doesn't happen again!
Snowfall Analysis April 18th, 2014
This is a look at the snow depth analysis from April 18th, 2014. Note the strip of heavier snowfall from western Minnesota to the northeastern part of the state and northern Wisconsin. St. Cloud, MN ended up with 8.5" of snow from that storm, Duluth had 7.2" and the Twin Cities only saw 0.3".
Memories of March By Todd Nelson
The sweet smell of freshly cut grass returned to a neighborhoods near you... I heard the low hum of a few distant law mowers on Saturday and I've never been so happy! I even had a tough time resisting the urge to poke my nose outside, hope you enjoyed it!
Highs drop from the 60s and 70s that we had on Friday and Saturday to the 40s and 50s through the week ahead. It comes by way of a slow moving storm system that has brought some soaking rains and a few rumbles to the Upper Midwest. The heaviest rains end by midday Sunday, but winds pick up late in day out of the Northwest and temperatures begin to tumble.
The storm system will be in no hurry to move east of the Great Lakes. We'll endure several days of cooler, breezy weather this week. There may even be a few wet snowflakes mixing in with the lingering precipitation up north Monday night. The weather this week may bring back a few memories of March, but we're doing much better than we did last April when we saw 7" of snow!
April average 2.4" in the Twin Cities, so far we've seen 0.3". I guess I could do without any more snow this year. At this point, I'd rather mow my lawn rather than shovel the driveway!
SATURDAY NIGHT: Rain/rumbles of thunder likely. Low: 49. Winds: ESE 15mph.
SUNDAY: Wet start. Drier and windier by the afternoon/evening. High: 61. Winds: SSE turning NW 10-15.
SUNDAY NIGHT: Mostly cloudy with a few lingering sprinkles/light rain showers. Low: 40. Winds: NW 10-15
MONDAY: Breezy & cooler with a rain/snow mix up north. High: 48
TUESDAY: A few AM flakes up north. Still breezy and cool. Wake-up: 33. High: 49
WEDNESDAY: Mix of clouds and sun. Still breezy. Wake-up: 32. High: 48
THURSDAY: More sun, light jacket worty. Wake-up: 31. High: 49
FRIDAY: Less wind, a little warmer. Wake-up: 33 High: 53
SATURDAY: Hints of April return! Wake-up: 38. High: 56.
This Day in Weather History April 19th
1928: Chilly air moves across the region with a record low of 19 at the Twin Cities.
1893: Heavy snowstorm at Bird Island that would last until the 21st. 17 inches of snow fell with drifts 3 to 4 feet high.
1820: A tornado hits the camp that would soon become Ft. Snelling. This was the first tornado ever reported in Minnesota and it damaged the roof of a barracks, with no one injured.
Average High/Low for Minneapolis April 19th
Average High: 60F (Record: 87F set in 1985) Average Low: 39F (Record: 19F set in 1928)
Sunrise/Sunset Times for Minneapolis April 19th
Sunrise: 6:10am Sunset: 8:13pm
Moon Phase for April 19th at Midnight 1.5 Days Since New Moon
Minneapolis Temperature Trend
Our brief flirtation with May weather comes to an end this week as temperatures settle into more March-like levels. It appears we slowly climb out of cooler weather and get 'close' to average by the end of the month.
Take a look at the simulated radar as the storm system pushes through the Upper Midwest from late Saturday through midday Monday. Note that the bulk of the precipitation comes through Friday night/early Saturday, while lingering sprinkles/light rain showers continue Sunday/Monday. Also note the light blue (snow) that shows up across far northern Minnesota through the first half of Monday.
Sunday Weather Outlook
The heaviest/steadiest rain will begin to shift east through the second half of the day. Cloudy skies will persists through the afternoon/evening with a few lingering sprinkles/light rain showers.
It'll be a soggy start on Sunday with areas of steady AM rain tapering to lingering sprinkles/light rain showers through the afternoon/evening. Temperatures will cool into the 50s & 60s for highs on Sunday rather than the 60s and 70s that we've been seeing over the past several days. Note the wind speeds picking up across the Dakotas and western Minnesota by late in the day. Winds will be quite breezy later and stay breezy through the first half of next week
The precipitation potential from PM Friday through midday Tuesday suggests as much as 0.50" to 1.0"+ across much of Minnesota, the heaviest of which looks to fall across northern/northeastern Minnesota.
It doesn't look like much, but as temperatures cool on the backside of the storm system, snow potential looks to increase a little. Snowfall accumulations look fairly light across the northern part of the state, but there could be up to 1" or 2" of slush in spots through midday Tuesday.
National Weather Outlook
Weather conditions over the last several days have been very active in the middle part of the country. A large area of low pressure has been kicking out heavy snow across the Intermountain-west, while folks in the Plains have been dealing with severe storms and heavy rain. The storm finally makes a move towards the Great Lakes/Northeast through the late weekend/early next week time frame. Strong/severe thunderstorm potential will begin to shift east with the storm into early next week as well.
Severe Threat Sunday
...SUMMARY... THUNDERSTORMS -- SOME CAPABLE OF PRODUCING LARGE HAIL AND LOCALLY DAMAGING WINDS -- WILL BE POSSIBLE FROM EASTERN PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS EASTWARD ACROSS THE MID SOUTH AND SOUTHEAST ON SUNDAY. ...SYNOPSIS... COMPLEX EVOLUTION OF THE UPPER FLOW FIELD ACROSS THE U.S. IS PROGGED SUN...AS MULTIPLE SHORTER-WAVELENGTH LOWS/TROUGHS BETWEEN THE ROCKIES AND THE APPALACHIANS GRADUALLY EVOLVE INTO A MORE CONSOLIDATED/EXPANSIVE TROUGH ACROSS THIS AREA BY THE END OF THE PERIOD. MEANWHILE...RIDGING WILL PREVAIL OVER BOTH THE W AND E COASTS. AT THE SURFACE...EVOLUTION OF THE PATTERN WILL BE SIMILARLY COMPLEX...AS A COLD FRONT SWEEPS SEWD ACROSS THE PLAINS WITH TIME WHILE A WARM FRONT SHIFTS NEWD ACROSS THE ERN STATES. A WEAKER LOW AND ITS PARENT UPPER FEATURE SHIFTING OUT OF ERN OK INTO THE OZARKS VICINITY WILL ALSO PLAY A ROLE IN THE CONVECTIVE FORECAST THIS PERIOD. ...SERN KS/ERN OK/E TX INTO THE LOWER MS VALLEY... CONVECTION IS PROGGED TO INCREASE ACROSS SERN KS/ERN OK/THE ARKLATEX REGION DURING THE AFTERNOON...AS HEATING/DESTABILIZATION INCREASE THROUGH THE DAY AHEAD OF AN ESEWD-MOVING VORT MAX PROGGED TO BE CROSSING THIS AREA. WITH ENHANCED FLOW FIELD ALOFT ASSOCIATED WITH THIS FEATURE SPREADING ACROSS THE OZARKS/ARKLATEX VICINITY DURING THE AFTERNOON...DEVELOPING STORMS SHOULD ORGANIZE/BECOME SEVERE...WITH HAIL AND DAMAGING WINDS THE PRIMARY THREATS. GREATEST INSTABILITY IS FORECAST FROM ROUGHLY CENTRAL AR SWWD INTO E TX...WHERE MIXED-LAYER CAPE IN EXCESS OF 3000 J/KG WILL BE POSSIBLE. THOUGH CAPPING SHOULD LIMIT STORM COVERAGE WITH SWWD EXTENT INTO TX...THE ENVIRONMENT WILL BE SUPPORTIVE OF LARGE SUPERCELLS CAPABLE OF PRODUCING VERY LARGE HAIL ACROSS THIS AREA. WITH TIME...STORMS SHOULD SPREAD ACROSS AR/SRN MO/LA...REACHING THE LOWER MS VALLEY THROUGH THE EVENING...WITH SOME SEVERE RISK LIKELY TO LINGER INTO THE OVERNIGHT HOURS. ...THE MID SOUTH AND SOUTHEAST STATES... WIDESPREAD ONGOING CONVECTION IS FORECAST ACROSS PARTS OF KY/TN AND INTO GA AND THE CAROLINAS...WHICH SHOULD SPREAD ENEWD WITH TIME. THOUGH THIS CONVECTION/CLOUD COVER SHOULD LIMIT DESTABILIZATION POTENTIAL IN THESE AREAS...AFTERNOON STORM INTENSIFICATION APPEARS POSSIBLE FROM PARTS OF SRN KY/TN AND INTO GA...WHERE AT LEAST SOME HEATING/DESTABILIZATION IS EXPECTED. THOUGH SOMEWHAT UNIDIRECTIONAL...THE FLOW FIELD ACROSS THIS AREA WILL BE STRONG ENOUGH TO SUPPORT ORGANIZED STORMS/STORM CLUSTERS -- ALONG WITH ATTENDANT RISK FOR HAIL AND DAMAGING WINDS. STORMS ARE EXPECTED TO SPREAD NEWD WITH TIME ACROSS GA AND INTO SC AND POSSIBLY PARTS OF NC THROUGH THE EVENING...WITH SEVERE RISK LIKELY TO PERSIST THROUGH SUNSET. WHILE A HIGHER-PROBABILITY RISK AREA MAY BE REQUIRED IN LATER OUTLOOKS ACROSS PARTS OF THIS AREA...QUESTIONS REGARDING DEGREE OF DESTABILIZATION DUE TO PRIOR/ONGOING CONVECTION PRECLUDE ADDITION OF ENHANCED RISK ATTM.
Severe Threat Monday
...SUMMARY... SCATTERED THUNDERSTORMS WITH POTENTIAL FOR HAIL AND DAMAGING WIND GUSTS WILL BE POSSIBLE ON MONDAY FROM THE CENTRAL APPALACHIAN MOUNTAINS SOUTHWARD ACROSS THE MID-ATLANTIC INTO THE CAROLINAS AND GEORGIA. ...MID-ATLANTIC/CAROLINAS/SE GA... AN UPPER-LEVEL TROUGH IS FORECAST TO MOVE EWD ACROSS THE MS VALLEY ON MONDAY AS A LEAD SHORTWAVE TROUGH MOVES INTO THE CNTRL APPALACHIAN MTNS. AT THE SFC...A PRE-FRONTAL TROUGH IS FORECAST TO MOVE INTO THE FOOTHILLS OF THE APPALACHIAN MTNS WITH A COLD FRONT ACROSS THE OH AN TN VALLEYS. SFC DEWPOINTS IN THE LOWER TO MID 60S F FROM SRN VA SWD INTO THE CAROLINAS SHOULD RESULT IN POCKETS OF MODERATE INSTABILITY MONDAY AFTERNOON WITH SCATTERED THUNDERSTORMS DEVELOPING ALONG THE CORRIDOR OF INSTABILITY. GFS FORECAST SOUNDINGS FROM RICHMOND VA SSWWD TO COLUMBIA SC AT 21Z MONDAY SHOW MLCAPE IN THE 1000 TO 1500 J/KG RANGE WITH STEEP LOW-LEVEL LAPSE RATES AND UNIDIRECTIONAL WIND PROFILES. ALTHOUGH DEEP-LAYER SHEAR MAY BE MARGINAL FOR SUPERCELLS...THE ENVIRONMENT SHOULD SUPPORT MULTICELL DEVELOPMENT WITH WIND-DAMAGE POTENTIAL. HAIL WILL ALSO BE POSSIBLE WITH THE STRONGER UPDRAFTS IN AREAS THAT HEAT UP THE MOST. A MARGINAL SEVERE THREAT MAY ALSO DEVELOP ACROSS PARTS OF THE CNTRL APPALACHIAN MTNS MONDAY AFTERNOON BUT WEAKER INSTABILITY SHOULD KEEP ANY POTENTIAL FOR STRONG WIND GUSTS AND HAIL RELATIVELY ISOLATED THERE.
According to NOAA's HPC, the rainfall potential through PM Tuesday suggests 1" to 3"+ across parts of the Eastern U.S. The heaviest looks to fall along and just east of the Appalachians into the Northeast with 2" to nearly 4"+ possible!
The image below is the 500mb vorticity (spin) map for this Wednesday. This particular map can help pick out weather features, particularly areas of low pressure. Note the large circular area over the Great Lakes Region/Northeastern quadrant of the nation. This is part of the same storm system that has been causing all the issues in the central part of the country over the past several days. It appears that it won't be in any hurry to exit the area and will have an impact on our weather through much of next week.
Cool End to April
The area of low pressure mentioned above looks to be responsible for some cooler than average conditions into the end of the month. The 8 to 14 day temperature outlook takes us through the end of the month...
Thanks for checking in and have a great rest of your weekend. Don't forget to follow me on Twitter @TNelsonWX