Longer range: Potentially wet system early next week tugs chilly air in for Thanksgiving (a week from Thursday)

WGN WEATHER HEADLINES

AN EARLY PEEK AT SOME MODEL PROJECTIONS

For Thanksgiving, 2023 which takes place a week from this Thursday

  • We have a way to go before THANKGIVING DAY, 2023 ARRIVES a week from this Thursday. But, the early read on potential Thanksgiving weather in Chicago suggests it’s to be a chilly day with highs here projected at 40 degrees after morning lows in the 20s. There’s a growing model consensus the city is likely to be entering a colder than normal weather pattern from Thanksgiving day (a week from this Thursday) through the full holiday weekend which follows.
  • A wet, early week storm system may precede the Thanksgiving chill — a system which could sweep the Midwest and Chicago in the Monday/Tuesday time frame— details of which will become clearer as we get closer to the event. There are, as is generally the case at this distance in times, disparities in model handling of the system. But, on one point, most major medium-range forecast models agree — a colder pattern seems to be taking shape from mid next week forward into the following week.
  • One thing which is interesting about the potential system early next week: it arrives in a chillier environment than others this fall. That this is the case means we start watching carefully to see if any snow begins to show up with such disturbances as we get closer to these events. Don’t see definitive evidence of such a scenario with that system in Chicago at this point. But, it’s prudent to watch the evolution of the forecasts on such systems as we move deeper in autumn and approach the winter season.

CHECK OUT THE TRANSITION FROM THIS WEEK’S DAY 1 TO 5 ABOVE NORMAL TEMP REGIME to BELOW NORMAL TEMPS

Projection off three different computer forecast models

  • You see that as you move from Days 1 to 5 to Days 5 to 10 and Days 10 to 15 in the forecast maps posted below that temps descend into below normal territory from the mild temp pattern we’re witnessing this week.
  • Forecast panels from three forecast models appear here. The first set forecasts is off the European Centre’s global ensemble model — the second from the National Weather Service’s “GEFS” global ensemble forecast and a third set comes from Environment Canada’s global ensemble model.
  • Of the three models, the Canadian ensemble is MOST AGGRESSIVE in bringing colder than normal weather into a huge swath of the Lower 48 in the 10 to 15 day time frame. But all models are on the same track on the projected change.

THE PREDICTED PRECIP PATTERN FOR THE WEST AND SOUTHWEST OVER THE COMING TEN DAYS

The predicted precip pattern for the west and southeast over the coming 10 days has, in many respects, “El Niño” written all over it

  • THE NWS BLENDED MODEL ESTIMATE PRECIP TALLIES THROUGH THE END OF NEXT WEEK are paralleling the frequently observed precip distributions seen in the West, the Gulf Coast and the Southeast during El Niño cool/cold seasons, aren’t they?
  • Big rains show up in current projections out past 10 days for the West and South based on the array of computer model forecasts averaged and depicted in NWS “blended model” rainfall estimates issued Tuesday morning and covering the period through the end of next week.
  • Should these rains materialize as projected across the Mississippi River Delta area and along the Gulf Coast extending into the Southeast U.S. region, they would occur in an area which has been in the grip of “severe” to “extreme” and “exceptional drought” conditions.

CLICK TO ENLARGE