Preview of NWS' New Version of Forecast
This preview is not operational and should not be used for support decisions.

Prognostic Meteorological Discussion (PMD)

Issued by National Weather Service (NWS)

                            
000
FXUS06 KWBC 162002
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST WED JANUARY 16 2019

6-10 DAY OUTLOOK FOR JAN 22 - 26 2019

THE ENSEMBLE MEANS ARE GENERALLY IN GOOD AGREEMENT IN PREDICTING HIGHLY 
AMPLIFIED 500-HPA FLOW ACROSS MUCH OF THE FORECAST DOMAIN. A CLOSED MID-LEVEL 
LOW IS FORECAST OVER THE ALEUTIANS. STRONG RIDGING IS ANTICIPATED FARTHER TO 
THE EAST ACROSS MUCH OF MAINLAND ALASKA, EXTENDING SOUTHWARD OVER THE EASTERN 
PACIFIC OFF THE WEST COAST OF THE CONUS. DOWNSTREAM, AMPLIFIED CYCLONIC FLOW IS 
EXPECTED ACROSS MUCH OF THE EASTERN TWO-THIRDS OF THE CONUS. A TROUGH IS 
FORECAST TO EXIT THE NORTHEAST NEAR THE BEGINNING OF THE PERIOD AND A STRONG 
TROUGH IS PREDICTED TO RELOAD BEHIND IT ACROSS MUCH OF THE CENTRAL CONUS. THE 
500-HPA MANUAL HEIGHT BLEND, BASED PRIMARILY ON THE ENSEMBLE MEAN SOLUTIONS 
FROM THE GEFS AND ECMWF MODELS, FAVORS BELOW NORMAL HEIGHTS FOR THE ALEUTIANS, 
AS WELL AS FOR MOST OF THE CONUS BETWEEN THE ROCKIES AND THE APPALACHIANS. 
ABOVE NORMAL HEIGHTS ARE INDICATED FOR MOST OF MAINLAND ALASKA, THE ALASKA 
PANHANDLE, THE WESTERN CONUS, AND PARTS OF THE EASTERN SEABOARD.

THE AMPLIFIED, CYCLONIC FLOW FORECAST OVER MUCH OF NORTH AMERICA FAVORS BELOW 
NORMAL TEMPERATURES FOR MOST OF THE CONUS FROM THE GREAT BASIN EASTWARD TO THE 
APPALACHIANS. PROBABILITIES OF BELOW NORMAL TEMPERATURES ARE THE HIGHEST FOR 
THE EAST-CENTRAL CONUS NEAR THE PREDICTED MEAN LONG-WAVE TROUGH AXIS AND FOR 
PARTS OF THE CENTRAL AND SOUTHERN ROCKIES UNDERNEATH ANOMALOUS NORTHERLY 
MID-LEVEL FLOW. SNOW COVER CONSIDERATIONS CONTRIBUTED TO INCREASING 
PROBABILITIES OF BELOW NORMAL TEMPERATURES FOR PARTS OF THE MIDDLE MISSISSIPPI 
VALLEY. RIDGING AND ASSOCIATED ABOVE NORMAL HEIGHTS LEAD TO SLIGHTLY ENHANCED 
PROBABILITIES OF ABOVE NORMAL TEMPERATURES ALONG PARTS OF THE CALIFORNIA COAST. 
ABOVE NORMAL TEMPERATURES ARE ALSO FAVORED FOR MOST OF ALASKA DUE TO PREDICTED 
RIDGING, ABOVE NORMAL HEIGHTS ACROSS MUCH OF THE MAINLAND AND THE PANHANDLE, 
AND SOUTHERLY FLOW AHEAD OF A TROUGH PREDICTED OVER THE ALEUTIANS.  

ABOVE NORMAL PRECIPITATION IS FAVORED FOR MUCH OF THE EASTERN CONUS AHEAD OF A 
MEAN TROUGH PREDICTED OVER THE CENTRAL CONUS. THERE ARE SLIGHTLY ENHANCED 
PROBABILITIES OF BELOW NORMAL PRECIPITATION FARTHER TO THE WEST FOR PARTS OF 
THE SOUTHERN PLAINS, CONSISTENT WITH PRECIPITATION ESTIMATES FROM THE GEFS AND 
CANADIAN ENSEMBLES. ABOVE NORMAL PRECIPITATION IS FAVORED FOR MUCH OF THE 
NORTHERN AND CENTRAL HIGH PLAINS DUE TO THE POTENTIAL PROGRESSION OF SHORTWAVE 
ENERGY AROUND THE PERIPHERY OF MEAN CYCLONIC FLOW PREDICTED OVER MUCH OF NORTH 
AMERICA. THERE ARE INCREASED ODDS OF BELOW NORMAL PRECIPITATION FOR THE 
SOUTHWEST EXTENDING NORTHWARD TO THE PACIFIC NORTHWEST DUE TO A PREDICTED 
AMPLIFIED RIDGE OFF THE WEST COAST OF THE CONUS. THERE ARE ENHANCED 
PROBABILITIES OF ABOVE NORMAL PRECIPITATION FOR ALASKA AHEAD OF A MEAN 500-HPA 
TROUGH PREDICTED NEAR THE ALEUTIANS. 

THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 20% OF TODAY'S 0Z GFS 
ENSEMBLE MEAN CENTERED ON DAY 8, 20% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED 
ON DAY 8, 5% OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 8, 10% OF TODAY'S 
OPERATIONAL 6Z GFS CENTERED ON DAY 8, 30% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN 
CENTERED ON DAY 8, 10% OF TODAY'S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, AND 
5% 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, DUE TO 
GOOD AGREEMENT AMONG 500-HPA HEIGHT, TEMPERATURE, AND PRECIPITATION GUIDANCE 
ACROSS MUCH OF THE FORECAST DOMAIN.


8-14 DAY OUTLOOK FOR JAN 24 - 30 2019 

THE ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT IN PREDICTING A HIGHLY 
AMPLIFIED MEAN 500-HPA TROUGH CENTERED FROM THE GREAT LAKES TO THE MISSISSIPPI 
VALLEY AND EXTENDING ACROSS MUCH OF THE CONUS. UPSTREAM, STRONG RIDGING IS 
PREDICTED OFF THE WEST COAST OF THE CONUS EXTENDING NORTHWARD TO MAINLAND 
ALASKA. A MEAN TROUGH IS FORECAST TO PERSIST OVER THE WESTERN ALEUTIANS, BUT 
WITH REDUCED AMPLITUDE RELATIVE TO THE 6-10 DAY PERIOD. CONVERSELY, MEAN 
RIDGING IS FORECAST OVER THE NORTH ATLANTIC. THE AO INDEX, AS PREDICTED BY MOST 
OF THE GEFS ENSEMBLE MEMBERS, IS FORECAST TO TREND STRONGLY NEGATIVE DURING THE 
WEEK-2 PERIOD, CONSISTENT WITH TROUGH DEVELOPMENT ACROSS MUCH OF THE CONUS. THE 
MANUAL 500-HPA BLEND, BASED PRIMARILY ON THE ENSEMBLE MEANS FROM THE GEFS AND 
ECMWF MODELS, FEATURES BELOW TO MUCH BELOW NORMAL HEIGHTS ACROSS THE CONUS EAST 
OF THE ROCKIES. ABOVE NORMAL HEIGHTS ARE INDICATED ACROSS ALASKA AND PARTS OF 
THE WESTERN CONUS. 

THE AMPLIFIED TROUGH FORECAST OVER MUCH OF NORTH AMERICA LEADS TO ENHANCED 
PROBABILITIES OF BELOW NORMAL TEMPERATURES FOR MOST OF THE CONUS. THE HIGHEST 
PROBABILITIES OF BELOW NORMAL TEMPERATURES ARE INDICATED FOR THE EAST-CENTRAL 
CONUS NEAR THE PREDICTED MEAN TROUGH AXIS. ABOVE NORMAL TEMPERATURES ARE 
SLIGHTLY FAVORED FOR THE CALIFORNIA COAST UNDERNEATH PREDICTED ABOVE NORMAL 
500-HPA HEIGHTS. RIDGING AND SOUTHERLY FLOW AHEAD OF A MEAN TROUGH NEAR THE 
WESTERN ALEUTIANS LEADS TO ENHANCED PROBABILITIES OF ABOVE NORMAL TEMPERATURES 
FOR ALASKA. 

THE PRECIPITATION PATTERN FOR THE WEEK-2 PERIOD IS SIMILAR TO THAT PREDICTED 
FOR THE 6-10 DAY PERIOD. ABOVE NORMAL PRECIPITATION IS FAVORED FOR MUCH OF THE 
EASTERN AND NORTH-CENTRAL CONUS UNDERNEATH MEAN CYCLONIC FLOW. DYNAMICAL MODEL 
GUIDANCE SUPPORTS SLIGHTLY ENHANCED PROBABILITIES OF BELOW NORMAL PRECIPITATION 
FOR PARTS OF THE SOUTHERN PLAINS TO PARTS OF THE LOWER AND MIDDLE MISSISSIPPI 
VALLEY. AN AMPLIFIED RIDGE PREDICTED OFF THE WEST COAST OF THE CONUS LEADS TO 
INCREASED ODDS OF BELOW NORMAL PRECIPITATION FROM THE SOUTHWESTERN CONUS 
NORTHWARD TO THE PACIFIC NORTHWEST. CONVERSELY, MOIST SOUTHERLY FLOW AHEAD OF A 
MEAN TROUGH NEAR THE ALEUTIANS LEADS TO INCREASED CHANCES OF ABOVE NORMAL 
PRECIPITATION ACROSS MOST OF ALASKA. 

THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 25% OF TODAY'S 0Z GFS 
ENSEMBLE MEAN CENTERED ON DAY 11, 25% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED 
ON DAY 11, 5% OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 11, 5% OF TODAY'S 
OPERATIONAL 6Z GFS CENTERED ON DAY 11, 35% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN 
CENTERED ON DAY 11, AND 5% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 
11 


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: MUCH ABOVE AVERAGE, 5 OUT OF 5, 
DUE TO GOOD AGREEMENT ON A HIGH AMPLITUDE PATTERN.



FORECASTER: SCOTT 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 
JANUARY 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: 
19941231 - 20050127 - 20010124 - 19810123 - 19830130


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: 
19941231 - 20050126 - 20010124 - 19780111 - 19940125


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 22 - 26 2019

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN   
WASHINGTON  N    B     OREGON      N    B     NRN CALIF   N    B     
SRN CALIF   N    B     IDAHO       B    B     NEVADA      B    B     
W MONTANA   N    A     E MONTANA   N    A     WYOMING     B    A     
UTAH        B    B     ARIZONA     B    B     COLORADO    B    A     
NEW MEXICO  B    N     N DAKOTA    B    A     S DAKOTA    B    A     
NEBRASKA    B    A     KANSAS      B    N     OKLAHOMA    B    B     
N TEXAS     B    B     S TEXAS     B    B     W TEXAS     B    N     
MINNESOTA   B    A     IOWA        B    A     MISSOURI    B    A     
ARKANSAS    B    A     LOUISIANA   B    A     WISCONSIN   B    A     
ILLINOIS    B    A     MISSISSIPPI B    A     MICHIGAN    B    A     
INDIANA     B    A     OHIO        B    A     KENTUCKY    B    A     
TENNESSEE   B    A     ALABAMA     B    A     NEW YORK    B    A     
VERMONT     B    A     NEW HAMP    N    A     MAINE       N    A     
MASS        N    A     CONN        N    A     RHODE IS    N    A     
PENN        B    A     NEW JERSEY  N    A     W VIRGINIA  B    A     
MARYLAND    B    A     DELAWARE    N    A     VIRGINIA    B    A     
N CAROLINA  N    A     S CAROLINA  N    A     GEORGIA     B    A     
FL PNHDL    B    A     FL PENIN    B    A     AK N SLOPE  N    A     
AK ALEUTIAN A    A     AK WESTERN  A    A     AK INT BSN  A    A     
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    A    A     
 
                           

8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 24 - 30 2019

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN   
WASHINGTON  B    B     OREGON      B    B     NRN CALIF   N    B     
SRN CALIF   N    B     IDAHO       B    B     NEVADA      B    B     
W MONTANA   B    A     E MONTANA   B    A     WYOMING     B    A     
UTAH        B    B     ARIZONA     B    B     COLORADO    B    A     
NEW MEXICO  B    B     N DAKOTA    B    A     S DAKOTA    B    A     
NEBRASKA    B    A     KANSAS      B    B     OKLAHOMA    B    B     
N TEXAS     B    B     S TEXAS     B    B     W TEXAS     B    B     
MINNESOTA   B    A     IOWA        B    A     MISSOURI    B    B     
ARKANSAS    B    B     LOUISIANA   B    N     WISCONSIN   B    A     
ILLINOIS    B    N     MISSISSIPPI B    N     MICHIGAN    B    A     
INDIANA     B    A     OHIO        B    A     KENTUCKY    B    A     
TENNESSEE   B    N     ALABAMA     B    N     NEW YORK    B    A     
VERMONT     B    A     NEW HAMP    B    A     MAINE       B    A     
MASS        B    A     CONN        B    A     RHODE IS    B    A     
PENN        B    A     NEW JERSEY  B    A     W VIRGINIA  B    A     
MARYLAND    B    A     DELAWARE    B    A     VIRGINIA    B    A     
N CAROLINA  B    A     S CAROLINA  B    A     GEORGIA     B    A     
FL PNHDL    B    A     FL PENIN    B    A     AK N SLOPE  A    A     
AK ALEUTIAN A    A     AK WESTERN  A    A     AK INT BSN  A    A     
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    A    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.

$$