ENSO: La Nina-ish!
Latest CIC analog forecast: Now favoring a well-developed La Nina for northern hemisphere winter lingering through spring. Neutral ENSO is indicated middle of 2018 with a possible return to weak La Nina late next year.
Pictured: Climate Impact Company ENSO phase analog forecast.
United States: North/East cold ahead, settling North extended-range
Days: 1-5 (Dec. 3-7): Last of the real warm weather Monday ahead of a cold front as temperatures zoom to 20F above normal (again) from Oklahoma City to Chicago. Decent rainfall over the Upper Midwest/Great Lakes region develops changing over to snow west of a low pressure center in northeast Minnesota Monday afternoon. The snow zone lifts northeast into western Ontario on Tuesday. Expect 4-8 in. of snow for the Dakotas into Minnesota with this event. A squall line through the OH/TN Valley(s) tomorrow. Sprawling cold air for the Great Plains Tuesday moderating into Texas Tuesday night. There is no arctic air with this cold outbreak. Turning rainy and cool across southern Texas later this week.
Days 6-10 (Dec. 8-12): Feels like winter (finally) centered on the Midwest through next weekend with some moderation early the following week. The west/southwest Great Plains miss the cold air mass and Texas moderates quickly. The cold would be more widespread /effective with snow cover but only the Upper Midwest has snow cover to this point.
Days 11-15 (Dec. 13-17): The cold pattern is re-enforced early with more widespread snow cover developing mostly due to influence of the warm Great Lakes beneath the polar vortex. But the cold may be more choppy south of snow cover. Once again the southwest/south Great Plains into Texas tend to miss the cold and could be quite mild.
Week 3-4 (Dec. 17-23/24-30): Favoring cold adhering to snow cover in the far northern U.S. and Canada while south of snow cover the U.S. is warm. The caveat forecast is in the warmer direction.
Brazil/Argentina: Argentina TRYING to trend drier/hotter
Days: 1-5 (Dec. 3-7): Wet pattern across much of Brazil to Bolivia/Paraguay next 2-3 days. The wet weather remains stretched across south/southeast and central to east-central Brazil mid-to-late week. Argentina misses most of the rain. Becoming somewhat warmer than normal west/northwest Argentina this week otherwise cooler than normal temperatures prevail in the wet weather across Brazil and eastern Argentina due to a cold front.
Days 6-10 (Dec. 8-12): Wet weather in Brazil is less intense and lifts farther north during the period. Argentina tends to be dry. South and southeast Brazil also trend drier. Northeast Argentina to southeast Brazil are cool. Inland and western Argentina are hotter.
Days 11-15 (Dec. 13-17): Last week we mentioned a heat wave might develop in Argentina for mid-December and GFS indicates that scenario…dry ad hot! Wet belt is across north and northeast Brazil.
Week 3-4 (Dec. 17-23/24-30): Conflicting model forecasts suggesting potential extended-period of dryness and anomalous heat for Argentina OR a more transient pattern (but still drier than normal).
Europe: Storms Persist on South-Central Europe
Days: 1-5 (Dec. 3-7): Cool pattern across Southern Europe into midweek. Emerging somewhat warmer than normal temperatures U.K. to Poland/Germany into midweek. Later this week a major rain and wind storm into northwest Europe is expected.
Days 6-10 (Dec. 8-12): More sprawling chilly temperatures next weekend especially southern Europe. Â Seasonably cold and snowy across Northern Europe. Another major storm into U.K. and France featuring heavy rain and high wind late next weekend. The storm rolls east across the Mediterranean Sea early to middle next week bringing more cool temperatures to Southern Europe with heavy snows in the southern Europe mountain areas.
Days 11-15 (Dec. 13-17): The upper trough/stormy pattern anchors over South-central Europe. Â More heavy precipitation for Italy to Southeast Europe including heavy snow in mountain areas.
Week 3- Australia: Unusually cool this week but a hot reversal will follow
Days: 1-5 (Dec. 3-7): Week begins with locally heavy rain along the Queensland Coast. Low pressure area driving that rain move south toward Tasmania into midweek. Â Unusually cool trailing this East Coast frontal system. Temperatures are 10-20F below normal central and east continent through midweek. Another front brings more anomalous cool temperatures southern Australia late week. New South Wales observes rain from this next front on WED/THU.
Days 6-10 (Dec. 8-12): Much of the continent is dry. Trending much hotter west and central portions of Australia.
Days 11-15 (Dec. 13-17): Models are in disagreement. The GFS indicates profound continental-wide anomalous heat and dryness. Other models show a showery/cooler result for the south coast.
Week 3-4 (Dec. 17-23/24-30): Upper trough brings showers to east and southeast Australia during week 3. The trough shifts east and is replaced by a drier/hotter ridge week 4.
