Climate Prediction Center - 6-10 and 8-14 Day Prognostic Discussions

Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks 
NWS Climate Prediction Center College Park, MD 
300 PM EST Mon January 20 2025 
 
6-10 DAY OUTLOOK FOR JAN 26 - 30 2025 
 
The dynamical models are in good agreement regarding the mid-level height  
pattern across North America during the 6 to 10 day period. Mid-level troughs  
are forecast across Alaska and northeastern North America. Mid-level ridging is  
forecast across the Northwest contiguous United States (CONUS). However, a  
cut-off mid-level low is forecast to undercut the ridge in the southwestern  
CONUS. This will briefly increase chances for precipitation in this region. In  
the Southeast, positive mid-level heights are generally forecast. 
 
Below-normal temperatures are forecast for the western CONUS during the 6-10  
day period. The strongest probabilities are on the backside of the mid-level  
cut-off low over the southwestern CONUS where chances exceed 70% for  
below-normal temperatures. Further east, the temperature forecast is less  
certain and a broad area of near-normal is forecast across much of the eastern  
CONUS. Along the Gulf Coast, there are increased chances for above-normal  
temperatures with better agreement among the tools for weak mid-level positive  
height anomalies to develop. In the Upper Mississippi Valley, low snow pack and  
zonal flow increases chances for above-normal temperatures in the region. In  
Alaska, deep troughing is forecast with the trough axis across western Mainland  
which increases chances for below-normal temperatures across much of Mainland  
Alaska. Above-normal temperatures are favored in Southeast Alaska. For Hawaii,  
above-normal temperatures are strongly favored across the archipelago. 
 
Due to the cut-off low pressure in the Southwest, progressing east with time  
during the forecast period, above-normal precipitation is forecast in the Four  
Corners region. Chances of above-normal precipitation stretch into the southern  
Plains and Lower Mississippi Valley, where return flow off the Gulf of Mexico  
will influence precipitation chances in these regions. Below-normal  
precipitation is favored for areas from Northern California through the  
Northwest and then east into the Upper Mississippi Valley with the northern  
stream jet displaced north and no southern stream interaction. Above-normal  
precipitation is favored in Alaska ahead of the mid-level trough. Likewise,  
above-normal precipitation is favored in Hawaii, consistent with dynamical  
guidance. 
 
The official 6-10 day 500-hPa height blend consists of 30% of Today's 6z GFS  
Ensemble Mean centered on Day 8, 45% of Today's 0z European Ensemble Mean  
centered on Day 8, and 25% of Today's 0z Canadian Ensemble Mean centered on Day  
8  
  
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: Above-Average, 4 out of 5. Good  
agreement among the dynamical and statistical tools is offset by a progressive  
pattern. 
 
8-14 DAY OUTLOOK FOR JAN 28 - FEB 03, 2025  
 
The week-2 mid-level height pattern forecasts from the dynamical models remain  
in fair agreement. Mid-level troughing and negative 500-hPa height anomalies  
remain forecast across Alaska and nearly all of Canada. Near to above-normal  
500-hPa heights are forecast in much of the CONUS. The cutoff mid-level low in  
the Southwest during the 6-10 day period is favored to progress east and weaken  
as it moves over the Southern Rockies with mid-level ridging developing along  
the California coastline.  
 
As mid-level ridging builds into the West, a warming trend is forecast,  
displacing the below-normal temperatures forecast during the 6-10 day period  
with near- to above-normal temperatures across much for the West, excluding  
parts of the Southwest where the strongest probabilitiesfor below-normal  
temperatures were forecast in the prior period. East of the Rockies, generally  
a slight tilt towards above-normal temperatures is forecast consistent with the  
dynamical guidance. There is fair agreement among the models for these warmer  
conditions during the week-2 period. Some lingering below-normal temperatures  
are favored in parts of the Northeast where the ECENS maintains weak troughing  
early in the period. In Alaska, below-normal temperatures are forecast during  
week-2 consistent with the mid-level trough over the state. In Hawaii,  
above-normal temperatures are strongly favored consistent with all the  
available guidance. 
 
Above-normal precipitation is favored in parts of the Southern Plains and Lower  
Mississippi Valley associated with a shortwave trough and return flow off the  
Gulf of Mexico. The moisture may spread eastward with time to the Atlantic and  
into the Northeast, therefore slight chances for above-normal precipitation are  
favored for these regions. A swath of below-normal precipitation is favored for  
California and Southern Oregon east into the Central Plains. These areas are  
favored to be displaced from the storm track that is slowly shifting south out  
of Canada into Washington and Montana where a slight tilt towards above-normal  
precipitation is favored. In Alaska, above-normal precipitation is favored  
across much of the state. In Hawaii, a slight tilt towards above-normal  
precipitation is favored. 
 
The official 8-14 day 500-hPa height blend consists of: 30% of Today's 6z GFS  
Ensemble Mean centered on Day 11, 40% of Today's 0z European Ensemble Mean  
centered on Day 11, and 30% of Today's 0z Canadian Ensemble Mean centered on  
Day 11  
 
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Average, 3 out of 5, Fair  
agreement among the dynamical guidance is offset by low probabilities and a  
more zonal flow pattern. 
 
FORECASTER: Ryan Bolt 
 
Notes: 
 
 
Automated forecasts are issued on Saturday and Sunday. Occasionally manual  
intervention is necessary to address quality control and consistency issues. In  
these cases, forecasts are manually drawn but a full discussion is not issued. 
 
 
The notation for the categorical forecast indicated on the maps is the same as  
that in the tables: A-above   N-near normal   B-below 
 
 
The temperature map shows regions with > 33% chance of being warmer (orange,  
"A"), colder (blue, "B"), or close to (unshaded, "N"). Historical average  
values for the calendar period of the forecast (dashes, "f").  Labels on the  
shaded lines give the probability (> 33%) of the more likely category (B or A).  
 Probability of N is always < 40%. 
 
 
The precipitation map shows regions with > 33% chance of being wetter (green,  
"A"), drier (tan, "B"), or close to (unshaded, "n"). Historical median values  
for the calendar period of the forecast (dashes, "inches").  Labels on the  
shaded lines give the probability (> 33%) of the more likely category (B or A).  
 Probability of N is always < 40%. 
 
 
In the southwest and other climatologically dry regions - there will be a  
greater than 33.3% chance of no precipitation and occasionally even a normal  
(i.e. Median) value of zero - especially during the dry seasons.  In such cases  
a forecast of near normal is effectively a forecast of little or no  
precipitation. 
 
 
The climate prediction center uses 1991-2020 base period means as reference in  
the climate outlooks. 
 
The next set of long-lead monthly and seasonal outlooks will be released on  
February 20. 
 
 
Analogs to the 5 day mean observed pattern centered 3 days ago (D-3) 
for the region from 20N to 70N latitude and 175E to 60W longitude 
include the 5 day periods centered on the following dates:  
19671231 - 20080120 - 19940201 - 19910122 - 19850130 
 
 
Analogs to the 7 day mean observed pattern centered 4 days ago (D-4) 
for the region from 20N to 70N latitude and 175E to 60W longitude 
include the 7 day periods centered on the following dates:  
19671230 - 19940131 - 20080119 - 19620111 - 19850130 
 
 
6-10 DAY OUTLOOK TABLE 
Outlook for Jan 26 - 30 2025 
 
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN    
WASHINGTON  B    B     OREGON      B    B     NRN CALIF   B    B      
SRN CALIF   B    A     IDAHO       B    B     NEVADA      B    B      
W MONTANA   B    B     E MONTANA   B    B     WYOMING     B    B      
UTAH        B    A     ARIZONA     B    A     COLORADO    B    A      
NEW MEXICO  B    A     N DAKOTA    A    B     S DAKOTA    N    B      
NEBRASKA    N    B     KANSAS      B    A     OKLAHOMA    B    A      
N TEXAS     N    A     S TEXAS     A    A     W TEXAS     B    A      
MINNESOTA   A    B     IOWA        A    B     MISSOURI    N    A      
ARKANSAS    N    A     LOUISIANA   A    A     WISCONSIN   A    B      
ILLINOIS    N    N     MISSISSIPPI A    A     MICHIGAN    N    N      
INDIANA     N    N     OHIO        N    A     KENTUCKY    N    A      
TENNESSEE   N    A     ALABAMA     A    A     NEW YORK    N    N      
VERMONT     N    N     NEW HAMP    N    N     MAINE       N    N      
MASS        N    N     CONN        N    N     RHODE IS    N    N      
PENN        N    A     NEW JERSEY  N    N     W VIRGINIA  N    A      
MARYLAND    N    N     DELAWARE    N    N     VIRGINIA    N    A      
N CAROLINA  N    A     S CAROLINA  N    A     GEORGIA     N    A      
FL PNHDL    A    A     FL PENIN    A    B     AK N SLOPE  B    A      
AK ALEUTIAN B    A     AK WESTERN  B    A     AK INT BSN  B    A      
AK S INT    N    A     AK SO COAST A    A     AK PNHDL    A    A      
  
                            
 
8-14 DAY OUTLOOK TABLE 
Outlook for Jan 28 - Feb 03, 2025 
 
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN    
WASHINGTON  N    A     OREGON      N    B     NRN CALIF   N    B      
SRN CALIF   B    B     IDAHO       A    B     NEVADA      A    B      
W MONTANA   N    A     E MONTANA   A    N     WYOMING     N    B      
UTAH        N    B     ARIZONA     B    N     COLORADO    N    N      
NEW MEXICO  B    N     N DAKOTA    A    N     S DAKOTA    A    N      
NEBRASKA    A    B     KANSAS      A    N     OKLAHOMA    A    A      
N TEXAS     A    A     S TEXAS     A    A     W TEXAS     A    A      
MINNESOTA   A    N     IOWA        A    N     MISSOURI    A    N      
ARKANSAS    A    A     LOUISIANA   A    A     WISCONSIN   A    N      
ILLINOIS    A    N     MISSISSIPPI A    A     MICHIGAN    A    N      
INDIANA     A    N     OHIO        N    N     KENTUCKY    A    A      
TENNESSEE   A    A     ALABAMA     A    A     NEW YORK    N    A      
VERMONT     B    A     NEW HAMP    B    N     MAINE       B    A      
MASS        B    N     CONN        B    N     RHODE IS    B    N      
PENN        N    N     NEW JERSEY  B    N     W VIRGINIA  N    A      
MARYLAND    N    N     DELAWARE    N    N     VIRGINIA    N    A      
N CAROLINA  A    A     S CAROLINA  A    A     GEORGIA     A    A      
FL PNHDL    A    A     FL PENIN    A    N     AK N SLOPE  B    A      
AK ALEUTIAN B    A     AK WESTERN  B    N     AK INT BSN  B    A      
AK S INT    B    A     AK SO COAST B    A     AK PNHDL    N    A      
  
                           LEGEND 
TEMPS WITH RESPECT TO NORMAL     PCPN WITH RESPECT TO MEDIAN 
A - ABOVE   N  - NEAR NORMAL     A - ABOVE   N - NEAR MEDIAN 
B - BELOW                        B - BELOW 
  
THE FORECAST CLASSES REPRESENT AVERAGES FOR EACH STATE. NORMAL 
VALUES - WHICH MAY VARY WIDELY ACROSS SOME STATES - ARE 
AVAILABLE FROM YOUR LOCAL WEATHER SERVICE FORECAST OFFICE. 
  
FOR ADDITIONAL INFORMATION SEE MESSAGE FXUS06 KWBC - ON AWIPS AS 
PMDMRD. 
 
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