Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks 
NWS Climate Prediction Center College Park, MD 
300 PM EST Thu February 25 2021 
 
6-10 DAY OUTLOOK FOR MAR 03 - 07 2021 
 
Today's model forecasts are in general agreement regarding the 500-hPa  
circulation pattern across North America and surrounding regions during the  
6-10 day period. Troughing is forecast over Mainland Alaska extending southward  
across the Gulf of Alaska, while ridging is predicted over most of the CONUS in  
most model solutions. The manual height blend depicts negative 500-hPa height  
anomalies over most of Alaska except for parts of the Aleutians. Near to below  
normal 500-hPa heights are predicted over the Pacific Coast, and positive  
500-hPa height anomalies are predicted across the remainder of the CONUS. 
 
Below normal temperatures are likely over the Pacific coastal states of the  
CONUS, related to troughing over the Gulf of Alaska. Above normal temperatures  
are likely over much of the central and eastern CONUS, under near to above  
normal 500-hPa heights. Probabilities of below-normal temperatures are enhanced  
across Alaska, except for the western Aleutians, under predicted negative  
500-hPa height anomalies. 
 
Above normal precipitation is favored over northern and central portions of the  
Pacific Coast due to the potential emergence of shortwaves ahead of a trough  
over the Gulf of Alaska. Chances of below normal precipitation are enhanced for  
the remainder of the CONUS under near to above normal 500-hPa heights, except  
for parts of the Northeast where above normal precipitation is favored,  
consistent with operational Autoblend and ERF Consolidation tools.  Near to  
above normal precipitation is likely across Alaska, under enhanced westerly  
flow. 
 
The official 6-10 day 500-hPa height blend consists of 10% of Today's 6z GFS  
Ensemble Mean centered on Day 8, 60% of Today's GFS Superensemble Mean centered  
on Day 8, 20% of Today's 0z European Ensemble Mean centered on Day 8, and 10%  
of Today's 0z Canadian Ensemble Mean centered on Day 8  
  
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: Below average, 2 out of 5, due to  
only fair agreement among the model circulation forecasts, offset by  
differences among temperature and precipitation forecasts.  
 
8-14 DAY OUTLOOK FOR MAR 05 - 11 2021  
 
The main features of the predicted circulation pattern for the 6-10 day period  
persist into the week 2 period in the manual 500-hPa height blend. A trough and  
below normal 500-hPa heights are depicted over the western CONUS.  Ridging and  
positive 500-hPa height anomalies are forecast over most of the central and the  
eastern CONUS. A trough is forecast over the Bering Sea, and below normal  
500-hPa heights and enhanced westerly flow are expected over much of Mainland  
Alaska. 
 
The temperature pattern forecast for the week 2 period is similar to the 6-10  
day outlook period. Enhanced probabilities of below normal temperatures are  
forecast for the western CONUS, due to the predicted trough and associated  
negative 500-hPa height anomalies. Above normal temperatures are favored over  
most of the central and eastern CONUS, as in the 6-10 day period forecast,   
under positive 500-hPa height anomalies.  Enhanced probabilities of  below  
normal temperatures are indicated for the Alaska Mainland, under negative  
500-hPa height anomalies.  
 
Above normal precipitation is favored over parts of California and western  
Nevada, ahead of a predicted trough. Near to below normal precipitation is  
favored over most of the remainder of the CONUS, except for parts of the Upper  
and Middle Mississippi Valley, the Upper Great Lakes, and the Ohio Valley,  
where above normal precipitation is likely, consistent with operational  
Autoblend and ERF Consolidation tools and supported by most dynamical model  
forecasts. Enhanced probabilities of above normal precipitation are favored  
over most of Alaska in week 2, under persistent westerly mid-level flow. 
 
The official 8-14 day 500-hPa height blend consists of: 10% of Today's 0z GFS  
Ensemble Mean centered on Day 11, 40% of Today's 6z GFS Ensemble Mean centered  
on Day 11, 40% of Today's 0z European Ensemble Mean centered on Day 11, and 10%  
of Today's 0z Canadian Ensemble Mean centered on Day 11  
 
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Below average, 2 out of 5, due to  
only fair agreement among the model circulation, temperature, and precipitation  
forecasts, offset by increasing uncertainty and model spread.  
 
FORECASTER: Luke H 
 
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 1981-2010 base period means for  
temperature...precipitation...and 500-hpa heights as reference in the climate  
outlooks. 
 
The next set of long-lead monthly and seasonal outlooks will be released on  
March 18. 
 
 
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:  
19530304 - 19850301 - 19670214 - 19530227 - 20040306 
 
 
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:  
19530304 - 19850228 - 19550308 - 19530227 - 19670213 
 
 
6-10 DAY OUTLOOK TABLE 
Outlook for Mar 03 - 07 2021 
 
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN    
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   B    A      
SRN CALIF   N    B     IDAHO       N    B     NEVADA      N    B      
W MONTANA   N    B     E MONTANA   A    B     WYOMING     A    B      
UTAH        N    B     ARIZONA     N    B     COLORADO    A    B      
NEW MEXICO  N    B     N DAKOTA    A    B     S DAKOTA    A    B      
NEBRASKA    A    B     KANSAS      A    B     OKLAHOMA    A    B      
N TEXAS     A    B     S TEXAS     A    B     W TEXAS     A    B      
MINNESOTA   A    B     IOWA        A    B     MISSOURI    A    B      
ARKANSAS    A    B     LOUISIANA   A    B     WISCONSIN   A    B      
ILLINOIS    A    B     MISSISSIPPI A    B     MICHIGAN    A    B      
INDIANA     A    B     OHIO        A    B     KENTUCKY    A    B      
TENNESSEE   A    B     ALABAMA     A    B     NEW YORK    A    N      
VERMONT     A    A     NEW HAMP    A    A     MAINE       N    A      
MASS        A    A     CONN        A    N     RHODE IS    A    N      
PENN        A    B     NEW JERSEY  A    N     W VIRGINIA  A    B      
MARYLAND    A    B     DELAWARE    A    N     VIRGINIA    A    B      
N CAROLINA  A    N     S CAROLINA  A    N     GEORGIA     A    B      
FL PNHDL    A    B     FL PENIN    A    N     AK N SLOPE  B    A      
AK ALEUTIAN B    A     AK WESTERN  B    A     AK INT BSN  B    A      
AK S INT    B    A     AK SO COAST B    A     AK PNHDL    B    N      
  
                            
 
8-14 DAY OUTLOOK TABLE 
Outlook for Mar 05 - 11 2021 
 
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN    
WASHINGTON  B    N     OREGON      B    N     NRN CALIF   B    A      
SRN CALIF   B    N     IDAHO       B    N     NEVADA      B    N      
W MONTANA   B    B     E MONTANA   N    B     WYOMING     B    B      
UTAH        B    N     ARIZONA     A    B     COLORADO    A    B      
NEW MEXICO  A    B     N DAKOTA    A    B     S DAKOTA    A    N      
NEBRASKA    A    N     KANSAS      A    B     OKLAHOMA    A    B      
N TEXAS     A    B     S TEXAS     A    B     W TEXAS     A    B      
MINNESOTA   A    A     IOWA        A    A     MISSOURI    A    A      
ARKANSAS    A    N     LOUISIANA   A    B     WISCONSIN   A    A      
ILLINOIS    A    A     MISSISSIPPI A    B     MICHIGAN    A    A      
INDIANA     A    N     OHIO        A    B     KENTUCKY    A    B      
TENNESSEE   A    B     ALABAMA     A    B     NEW YORK    A    N      
VERMONT     A    N     NEW HAMP    A    N     MAINE       A    N      
MASS        A    N     CONN        A    N     RHODE IS    A    N      
PENN        A    B     NEW JERSEY  A    N     W VIRGINIA  A    B      
MARYLAND    A    B     DELAWARE    A    B     VIRGINIA    A    B      
N CAROLINA  A    B     S CAROLINA  A    B     GEORGIA     A    B      
FL PNHDL    A    B     FL PENIN    A    B     AK N SLOPE  B    A      
AK ALEUTIAN N    A     AK WESTERN  B    A     AK INT BSN  B    A      
AK S INT    B    A     AK SO COAST B    A     AK PNHDL    B    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. 
 
$$