Prognostic Discussion for Monthly Outlook 
NWS Climate Prediction Center College Park MD 
830 AM EDT Thu Sep 15 2022 
 
 
30-DAY OUTLOOK DISCUSSION FOR OCTOBER 2022 
 
A review of background climate conditions continues to show established La Nina 
conditions which are forecast to remain in place at least into the upcoming 
winter months. Both the Nino4 and Nino3.4 latest sea surface temperature (SST) 
values remain near -1.0 degrees C and tropical atmospheric conditions (i.e., 
convection/rainfall, low-level and upper-level winds) continue to be consistent 
with La Nina. Although this is a monthly outlook and impacts from La Nina to 
the mid-latitudes are generally weak at this time of the year, the La Nina base 
state was considered in the October monthly outlook to some degree. 
 
The MJO signal is not particularly coherent especially in certain indices such 
as the RMM index which is being heavily influenced by interference from ongoing 
La Nina conditions. Some predictions of other variables such as 200-hPa 
velocity potential show some potential for more MJO organization as we enter 
the month of October with the enhanced convective phase located in Phases 
1-2-3. This may promote enhanced convection to develop in the Central America 
and Caribbean region at a time of the year when primary tropical cyclone 
development begins to shift from the eastern and central Atlantic westward to 
these areas. 
 
In addition to the considerations noted above, dynamical model guidance from 
the North American Multi-Model Ensemble (NMME), Copernicus model suite (C3S) 
and extended (30-day) ensemble model systems from the CFS, ECMWF and GEFS that 
target the Week 3-4 period were utilized in preparing the outlook. 
 
The October 2022 temperature outlook depicts favored above-normal monthly mean 
temperatures for the majority of the CONUS with the only exception being the 
far Pacific Northwest. The greatest odds are forecast for an area from the 
central Rockies to the central Plains where the anomalously warm signal was 
most consistent amongst all the forecast tools and potential La Nina influence. 
The Week 3-4 dynamical model guidance and multiple linear regression forecast 
tool (ENSO, MJO, trend as predictors) supported a warmer than average start to 
October across the CONUS associated with forecast ridging and northward shifted 
westerlies. For Alaska, the signals  overall were quite weak and conflicting. 
Slight tilts toward above-normal (below-normal) temperatures are depicted for 
coastal northwest Alaska (south-central Alaska) driven primarily by long-term 
trends (model guidance). 
 
For the October 2022 precipitation outlook, elevated odds for below-normal 
monthly total precipitation amounts is depicted from north-central California 
eastward across the central Rockies to the central and southern Plains and 
parts of the central Mississippi and Ohio Valley's. The La Nina base state, 
dynamical model guidance and long term trends  contributed to this outlook. A 
slight tilt toward above-normal precipitation is shown for parts of Washington 
and the Alaska panhandle associated with model guidance and potential La Nina 
impacts. Probabilities in all locations are modest due to the low 
predictability common during this time of the year. 
 
Considerations of tropical moisture from the Gulf of Mexico or Caribbean Sea 
region related to any potential intraseasonal influence noted above resulted in 
an Equal Chances (EC) forecast for parts of the Gulf coast and Southeast 
despite considerable forecast guidance favoring drier-than-normal 
precipitation. There were weak and conflicting signals  for mainland Alaska so 
EC is currently forecast in this area. 
 
FORECASTER: Jon Gottschalck 
 
The climatic normals are based on conditions between 1991 and 2020, following 
the World Meteorological Organization convention of using the most recent 3 
complete decades as the climate reference period.  The probability anomalies 
for temperature and precipitation based on these new normals better represent 
shorter term climatic anomalies than the forecasts based on older normals. 
 
An updated monthly outlook... for Oct will be issued on Fri September 30 2022 
 
These outlooks are based on departures from the 1991-2020 base period. 
$$