November 2023 - Page 2 of 3 - Climate Impact Company

11/20/2023, 4:23 pm EST

El Nino Should Peak Next Month; Mature Phase Q1/2024

The Nino SSTA regions (and subsurface equatorial Pacific Ocean) indicate a warming trend in the already very warm central and east-central Pacific equatorial region (Nino34 and Nino4). Implied is an approaching peak of El Nino forecast by most dynamic models in December or January followed by weakening El Nino the first half of 2024.

11/19/2023, 4:09 pm EST

More East Australia Heavy Rains

Heavy rain along a low-pressure trough stretches through East Australia today. The wet pattern has no end in sight as a supporting upper-level low-pressure area coupled with the surface trough persists the remainder of November. Forecast models are in good agreement on a widespread 2-6-inch rainfall for Eastern Australia through the next 15 days.

11/19/2023, 1:10 pm EST

Europe Flips Wet Extremes for Cold

November 2023 has produced a soaking wet climate across much of Europe. In the wet zone, rainfall amount has ranged from 3 to 23 in. during the past 30 days according to NOAA/CPC. The super upper trough causing the heavy rain reorientates shifting eastward this week and amplifying across Europe to bring early season cold in the 6-10-day period.

11/17/2023, 8:03 am EST

Texas Cold Risk Vs. ENSO Phase

The ERCOT ice storm “Uri” occurred February 13-17, 2021, during a La Nina winter. During the past 30 years, coldest risk during winter in Dallas, TX strongly favors presence of La Nina. The bias appears in each month of meteorological winter.

11/16/2023, 10:44 am EST

Comparing NOAA and Climate Impact Company U.S. Winter 2023-24 Outlook

A review of the just-issued NOAA/CPC long-lead probabilistic climate forecast for DEC-23 and DEC/JAN/FEB 2023-24 with the anomaly projections from Climate Impact Company plus initial insight into the summer 2024 forecast. NOAA and CIC are similarly warm in the East for winter 2023-24 while CIC is colder West. Both forecasts agree on a vigorous (mostly) Southern U.S. storm track.

11/15/2023, 12:34 pm EST

Impressive Cold Pattern Change in U.S. Based on 12Z GFS

The GFS continues to trend colder in the medium range forecast for the U.S. valid the last third of November. The colder support from climate signals is becoming evident for central North America via negative phase of the West and East Pacific oscillations.

11/15/2023, 12:30 pm EST

Unexpected Wet Regime Develops Across Australia

Last week widespread wet weather was observed across Australia. The wet weather is a surprise given the dry climate usually produced by El Nino and certainly evident in October. Latest week 2-4 forecast for Australia maintains the wetter than normal regime into December.

11/15/2023, 8:38 am EST

Why El Nino 2023 Climate is Weaker than Historical Average

The rainfall pattern in the tropics across the Pacific Ocean with all El Nino’s since 2000 during AUG/SEP/OCT has produced typical heavy thunderstorm activity and attendant rainfall across the central and east-central Pacific. To compensate, the far western tropical Pacific/Indonesia observes atmospheric subsidence and a dry climate. The vertical air motion difference between the sinking air over Indonesia and rising air near and east of the Dateline drives the El Nino climate. In 2023, the pattern described is not present.

11/14/2023, 8:51 am EST

Late Season Tropical Threats Brewing in the North Atlantic Basin

Late season subtropical/tropical trouble is brewing in the North Atlantic basin. A subtropical storm is possible east-northeast of Florida late this week while a full-blown tropical cyclone emerges in the Caribbean Sea.

11/14/2023, 5:14 am EST

Subtropical Ridge Split: Wetter Medium-range Forecasts for Central Brazil

Most evident in the 6-10-day period, the subtropical ridge delivering a hot and mostly dry 1-5-day forecast splits in the 6-10-day period to allow tropical moisture to shift across Central Brazil in a forecast change. In the 11-15-day period, Central Brazil trends wetter for the same reason.

11/13/2023, 1:27 pm EST

12Z GFS South America Forecast is Wetter Central Brazil

The subtropical ridge over Southeast Brazil edges eastward in the 6-10-day period which allows a moisture feed from the deep tropics into central continent and a wetter forecast change.

11/09/2023, 2:09 pm EST

Despite Strong El Nino Nino34 SSTA Signature, Multivariate ENSO Index Shifts Back to Neutral ENSO Phase

In October 2023, the Nino34 SSTA index was +1.59C which eclipses the +1.50C threshold for strong oceanic El Nino classification. However, the response of the atmospheric climate pattern to the El Nino warming is weak yielding neutral multivariate ENSO index (MEI = +0.3) during SEP/OCT 2023. Preliminary investigation reveals this is a first-time occurrence for a strong oceanic El Nino.