The Groundhog Lied
After a mostly quiet first half of winter - storms are ramping up. Fluke or trend? The beginning of the end of the drought? All good questions. I'm encouraged by what I see on the maps. Remember, every extra hour you spend gritting your teeth on slushy freeways in the coming weeks means more water in our lakes and on our farms.
Late March & April will be critical, after deep frost leaves the ground. Will big, wet storms keep coming like clockwork? The pattern looks wetter, but we're not out of the (dry/dusty) woods just yet. It will be a slow recovery, if it comes.
The groundhog meant well, but the "6 more weeks of winter" forecast is pure fantasy, at least for Minnesota. Today may be the last single-digit high of winter; a subzero start Wednesday morning could leave you with a tingling, Yukon brain-freeze.
A digging trough of low pressure, a wrinkle of cold, unstable Pacific air, will eject a series of storms across the Plains. A plowable snowfall is expected Thursday night into Friday - but this won't be The Big One. Another storm arrives Monday, maybe a few more inches; probably not a Crippling Whopper.
Latest 1981-2010 climate data shows average winter snowfall of 54.4 inches for MSP.
We may come close.
Projected Snowfall Amounts. I have a sudden urge to ski Nebraska, as much as 15" from Thursday's storm. The surge of energy and moisture will weaken slightly as it pushes northeast, but the GFS is still suggesting some 3-6" amounts over central and southern Minnesota; more as you head south toward Iowa. I still think it will be plowable, but not The Big One.
European Solution. The ECMWF is printing out just over half an inch (liquid) Thursday night into Friday, which should be all snow. The next storm early next week may produce even more precipitation, but I expect a wet, slushy accumulation, possibly a few hours of mixed precipitation or rain.
Monday Slop-Storm? It's early - this thing is still 6 days away. But the ECMWF model shows a storm near Omaha by midday Monday, with the rain-snow line pushing across central Minnesota. I'm also concerned about the "dreaded dry tongue", sometimes called the "dry slot", a surge of dry, desert air pushing in from the south, which may cut off the heaviest precipitation by Monday night. Again, the details on next week's storm are still (very) sketchy.
* the latest Drought Outlook from NOAA is here.
- Precipitation deficits (negative departures from normal) over the past eight and one-half months are in excess of ten inches in some southwest and south central Minnesota counties. Somewhat smaller, but still significant, precipitation shortfalls were reported across Minnesota over the past six months.
- As of late autumn, the soil moisture content in the plant rooting zone was near all-time low levels at many locations.
- The liquid content of our present snowpack is unremarkable when compared with winters of the past. Snow water equivalence estimates across Minnesota range from zero to three inches in most places.
- The soil moisture situation will remain mostly unchanged until spring because the deeply frozen soil (18-36 inches) assures that only a fraction of the overwinter precipitation will make it into the ground.
- When the soils thaw, and if the spring rains come, the dry plant rooting zone will claim "first mortgage" on water infiltration. This means that spring recharge of unconfined aquifers will be less than typically expected. Water table well levels, and base flow to surface water systems, will be slow to react.
- Without abundant spring rains, a number of critical drought issues involving agriculture, forestry, horticulture, tourism, and public water supply will begin to emerge.
Photo credit above: "A boy digs around a car marked with a sign on a street in Windsor Locks, Conn., Saturday, Feb. 9, 2013. A behemoth storm packing hurricane-force wind gusts and blizzard conditions swept through the Northeast overnight." Photo: Jessica Hill, ASSOCIATED PRESS - AP
Photo credit above: "Storm-destroyed house in Ortley Beach. N.J.Gov. Christie, in efforts to rebuild at the Shore, sees environmental factors as irrelevant." MICHAEL S. WIRTZ / Staff