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 EDT Tue March 25 2025 
 
6-10 DAY OUTLOOK FOR MAR 31 - APR 04, 2025 
 
The GEFS, ECENS and Canadian ensemble mean 500-hPa height forecasts are in fair  
agreement today over the forecast domain with regard to the overall synoptic  
pattern over North America, but the GEFS depicts stronger ridging over the  
southern Contiguous U.S. (CONUS) than the other two ensembles, decreasing  
forecast confidence particularly for the precipitation outlook where model  
solutions differ the most. Today’s 500-hPa manual blend height forecast depicts  
strong ridging over the Bering Sea, troughing and negative height anomalies  
over the North Pacific and extending over the northwestern CONUS and Northern  
Plains, and weak positive height anomalies for the rest of the CONUS, with the  
largest height departures (+60m) over the Mid-Atlantic. 
 
Above normal temperatures are favored over much of the CONUS associated with  
predicted weak to moderate anomalous ridging. Probabilities favoring above  
normal temperatures exceed 60% over parts of the southern CONUS. Below normal  
temperatures are slightly favored over portions of Oregon and northern  
California with persistent onshore flow and enhanced precipitation depicted by  
most forecast tools, as well as for portions of northern Michigan and New  
England. For Alaska, above normal temperatures are favored over the Aleutians  
and North Slope, in response to the strong Bering Sea ridge. In contrast, below  
normal temperatures are favored over Southeast Alaska due to predicted easterly  
surface flow. In Hawaii, above normal temperatures are strongly favored based  
on a consolidation of tools and the autoblend. 
 
Above normal precipitation is favored across most of the CONUS during the 6-10  
day outlook period. In the West, this is attributed to mid-level troughing and  
enhanced onshore flow. Forecast tools broadly indicate onshore flow with  
enhanced moisture transport into the West Coast, favoring above normal  
precipitation for much of the western CONUS, with >50% probabilities from  
northern Great Basin westward, with >70% chances indicated for a small portion  
of northern California. East of the Continental Divide, increasing Gulf  
moisture associated with the return flow around a surface anticyclone predicted  
off the Southeast coast and a series of disturbances moving across the Ohio  
Valley favors above normal precipitation for most of the Central and Eastern  
CONUS, particularly for portions of the Northeast U.S. (>50% probability) with  
a surface low exiting the region early in the forecast period. A weak tilt  
towards below normal precipitation is indicated for southeastern New Mexico,  
southern Texas, likely too far removed from large-scale storm tracks. In  
Alaska, most precipitation tools favor above normal precipitation across all  
but southernmost portions of the Mainland, the Alaska Peninsula, Aleutians, and  
Panhandle region where near to below normal precipitation is favored. In  
Hawaii, odds go from a slight tilt towards above normal precipitation for  
northwestern islands to a slight tilt towards below normal precipitation for  
the Big Island, based on a consolidation of tools and the autoblend. 
 
The official 6-10 day 500-hPa height blend consists of 33% of Today's 0z GFS  
Ensemble Mean centered on Day 8, 34% of Today's 0z European Ensemble Mean  
centered on Day 8, and 33% of Today's 0z Canadian Ensemble Mean centered on Day  
8  
  
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: About average, 3 out of 5. Fair  
agreement among models with regard to overall synoptic picture is offset by a  
large spread in solutions with placement and intensity of individual features. 
 
8-14 DAY OUTLOOK FOR APR 02 - 08 2025  
 
Like in the 6-10 day period, the models are in reasonable agreement regarding  
the week-2 mean circulation pattern, but the GEFS continues to favor stronger  
ridging over the southern CONUS, resulting in greater spread among forecast  
tools and decreased forecast confidence. The synoptic picture for North America  
during week-2 as depicted by the ECMWF, GEFS, and Canadian ensembles is little  
changed from the 6-10 day period, with the most notable changes being a  
decrease in amplitude for both the ridge over the Bering Sea and the trough  
over the West Coast. 
 
With a persistent synoptic pattern over North America, the week-2 temperature  
outlook is very similar to the 6-10 day period. Above normal temperatures  
continue to be favored for most of the CONUS east of the Rockies, with near to  
below normal temperatures indicated only for Maine. Probabilities continue to  
exceed 60% for much of the southern and southeastern CONUS. A slight tilt  
toward below normal temperatures remains over portions of the northwestern  
CONUS under continued moist onshore flow. In Alaska, a weakening of the ridge  
over the Bering Sea allows for increased easterly surface flow, tilting the  
odds towards below normal temperature for most of the state, with the exception  
of the western Aleutians, where the lingering ridge favors above normal  
temperatures. With continued positive SST anomalies in the region Hawaii  
continues to be strongly favored for above normal temperatures. 
 
With a persistence of synoptic features during the week-2 period, the  
precipitation outlook is also very similar to the 6-10 day period. With  
increasing spread in model solutions probabilities of above normal  
precipitation over the CONUS are generally weaker especially over the West  
Coast, while a large area of near normal precipitation is favored over the  
central CONUS due to contradictory guidance from forecast tools. Below normal  
precipitation remains slightly favored over portions of the Gulf Coast under  
continued positive height anomalies. In Alaska, the majority of objective  
guidance favors a similar precipitation pattern to that of the earlier 6-10 day  
period, with favored above normal precipitation over the northern and eastern  
Mainland, and near to below normal precipitation for the southwestern Mainland,  
the Alaska Peninsula and Aleutians, and parts of the Panhandle region. In  
Hawaii, above normal precipitation is favored for all of the islands except the  
Big Island where near normal precipitation is favored, based on a consolidation  
of tools and the autoblend. 
 
The official 8-14 day 500-hPa height blend consists of: 33% of Today's 0z GFS  
Ensemble Mean centered on Day 11, 34% of Today's 0z European Ensemble Mean  
centered on Day 11, and 33% of Today's 0z Canadian Ensemble Mean centered on  
Day 11  
 
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: About average, 3 out of 5, due to  
good overall agreement among model height forecasts offset by significant  
uncertainty in the surface temperature and precipitation fields, especially for  
Alaska. 
 
FORECASTER: Daniel Barandiaran 
 
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  
April 17. 
 
 
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:  
19590402 - 19850406 - 19590317 - 19720305 - 19890402 
 
 
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:  
19590404 - 19850403 - 19720305 - 19600403 - 19890402 
 
 
6-10 DAY OUTLOOK TABLE 
Outlook for Mar 31 - Apr 04, 2025 
 
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN    
WASHINGTON  N    A     OREGON      B    A     NRN CALIF   N    A      
SRN CALIF   A    A     IDAHO       N    A     NEVADA      A    A      
W MONTANA   A    A     E MONTANA   A    A     WYOMING     A    A      
UTAH        A    A     ARIZONA     A    A     COLORADO    A    A      
NEW MEXICO  A    N     N DAKOTA    A    A     S DAKOTA    A    A      
NEBRASKA    A    A     KANSAS      A    A     OKLAHOMA    A    A      
N TEXAS     A    N     S TEXAS     A    B     W TEXAS     A    B      
MINNESOTA   N    A     IOWA        A    A     MISSOURI    A    A      
ARKANSAS    A    A     LOUISIANA   A    A     WISCONSIN   N    A      
ILLINOIS    A    A     MISSISSIPPI A    A     MICHIGAN    N    A      
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    A      
TENNESSEE   A    A     ALABAMA     A    A     NEW YORK    N    A      
VERMONT     B    A     NEW HAMP    B    A     MAINE       B    A      
MASS        B    A     CONN        N    A     RHODE IS    N    A      
PENN        A    A     NEW JERSEY  A    A     W VIRGINIA  A    A      
MARYLAND    A    A     DELAWARE    A    A     VIRGINIA    A    A      
N CAROLINA  A    A     S CAROLINA  A    A     GEORGIA     A    A      
FL PNHDL    A    A     FL PENIN    A    A     AK N SLOPE  A    A      
AK ALEUTIAN A    B     AK WESTERN  N    A     AK INT BSN  B    A      
AK S INT    B    N     AK SO COAST B    B     AK PNHDL    B    B      
  
                            
 
8-14 DAY OUTLOOK TABLE 
Outlook for Apr 02 - 08 2025 
 
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN    
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   N    A      
SRN CALIF   A    A     IDAHO       N    A     NEVADA      N    A      
W MONTANA   N    A     E MONTANA   A    A     WYOMING     A    A      
UTAH        A    A     ARIZONA     A    N     COLORADO    A    N      
NEW MEXICO  A    N     N DAKOTA    A    A     S DAKOTA    A    A      
NEBRASKA    A    N     KANSAS      A    N     OKLAHOMA    A    N      
N TEXAS     A    N     S TEXAS     A    N     W TEXAS     A    N      
MINNESOTA   A    A     IOWA        A    A     MISSOURI    A    A      
ARKANSAS    A    N     LOUISIANA   A    N     WISCONSIN   A    A      
ILLINOIS    A    A     MISSISSIPPI A    N     MICHIGAN    A    A      
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    A      
TENNESSEE   A    A     ALABAMA     A    N     NEW YORK    A    A      
VERMONT     A    A     NEW HAMP    A    A     MAINE       N    A      
MASS        A    A     CONN        A    A     RHODE IS    A    A      
PENN        A    A     NEW JERSEY  A    A     W VIRGINIA  A    A      
MARYLAND    A    A     DELAWARE    A    A     VIRGINIA    A    A      
N CAROLINA  A    A     S CAROLINA  A    A     GEORGIA     A    A      
FL PNHDL    A    B     FL PENIN    A    B     AK N SLOPE  B    N      
AK ALEUTIAN N    N     AK WESTERN  B    N     AK INT BSN  B    N      
AK S INT    B    N     AK SO COAST B    N     AK PNHDL    B    N      
  
                           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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