6-10 Day Narrative

129 
FXUS06 KWBC 192039
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST TUE FEBRUARY 19 2019
6-10 DAY OUTLOOK FOR FEB 25 - MAR 01, 2019
THE CANADIAN, GFS, AND ECMWF ENSEMBLE MEANS ARE IN EXCELLENT AGREEMENT WITH THE 
LONGWAVE 500-HPA PATTERN THROUGHOUT THE NORTHERN HEMISPHERE. THESE ENSEMBLE 
MEANS FEATURE A HIGHLY AMPLIFIED UPPER-LEVEL RIDGE OVER MAINLAND ALASKA DURING 
THIS 5-DAY PERIOD WITH A HIGH AMPLITUDE, POSITIVELY-TILTED, UPPER-LEVEL TROUGH 
EXTENDING FROM HUDSON BAY SOUTHWEST TO THE INTERIOR WEST. A SUBTROPICAL RIDGE 
IS FORECAST OVER THE CARIBBEAN ISLANDS. THE MANUAL, 500-HPA HEIGHT BLEND IS 
BASED PRIMARILY ON THE ENSEMBLE MEANS FROM THE GEFS AND ECMWF ENSEMBLES. BELOW 
NORMAL HEIGHTS ARE FAVORED FOR MUCH OF THE NORTH-CENTRAL CONUS, THE INTERIOR 
WEST, THE WESTERN ALEUTIANS, AND PARTS OF THE NORTHEAST. ABOVE NORMAL HEIGHTS 
ARE FORECAST FOR MAINLAND ALASKA, THE ALASKA PANHANDLE, AS WELL AS FROM THE 
GULF COAST OF THE CONUS, ACROSS THE SOUTHEAST, AND EXTENDING NORTHWARD TO 
SOUTHERN NEW ENGLAND.    
THE HIGH AMPLITUDE RIDGE OVER MAINLAND ALASKA AND ARCTIC HIGH PRESSURE CENTERED 
IN WESTERN CANADA ARE LIKELY TO MAINTAIN AN ANOMALOUSLY COLD PATTERN ACROSS 
MOST OF THE CENTRAL AND WESTERN CONUS. BELOW NORMAL TEMPERATURES ARE ALSO 
FAVORED TO EXTEND EASTWARD TO PARTS OF THE NORTHEAST WITH TIME BUT WITH 
RELATIVELY LOWER CONFIDENCE. THE HIGHEST ODDS FOR BELOW NORMAL TEMPERATURES 
(GREATER THAN 90 PERCENT) ARE FORECAST ACROSS THE NORTHERN AND CENTRAL GREAT 
PLAINS DUE TO EXCELLENT DYNAMICAL AND STATISTICAL TOOL AGREEMENT. THE SOUTHERN 
EXTENT OF THE ANOMALOUS COLD IS SOMEWHAT UNCERTAIN, BUT TELECONNECTIONS UPON 
THE LARGE POSITIVE 500-HPA CENTER OVER EASTERN MAINLAND ALASKA FAVOR BELOW 
NORMAL TEMPERATURES EXTENDING SOUTHWARD ACROSS THE SOUTHERN PLAINS. THE 
SUBTROPICAL RIDGE FORECAST OVER THE CARIBBEAN ISLANDS FAVORS ABOVE NORMAL 
TEMPERATURES FOR MUCH OF THE SOUTHEAST. ABOVE NORMAL TEMPERATURES ARE ALSO 
FAVORED FOR MAINLAND ALASKA AND THE ALEUTIANS UNDERNEATH ANOMALOUS RIDGING AND 
SOUTHERLY FLOW AHEAD OF A TROUGH FORECAST OVER THE WESTERN BERING SEA. HOWEVER, 
THERE ARE ENHANCED PROBABILITIES OF BELOW NORMAL TEMPERATURES FOR PARTS OF THE 
ALASKA PANHANDLE UNDERNEATH ANOMALOUS NORTHEASTERLY 500-HPA FLOW DOWNSTREAM OF 
THE RIDGE AXIS. 
ABOVE NORMAL PRECIPITATION IS FAVORED SOUTH AND EAST OF THE UPPER-LEVEL TROUGH 
AXIS ACROSS THE GULF COAST AND THE EASTERN SEABOARD. THE HIGHEST PROBABILITIES 
OF ABOVE NORMAL PRECIPITATION (GREATER THAN 60 PERCENT) ARE INDICATED FOR PARTS 
OF THE CENTRAL GULF COAST REGION NEAR A POTENTIAL MEAN FRONTAL BOUNDARY. 
POTENTIAL SHORTWAVE TROUGHS AND UPSLOPE FLOW TILT THE ODDS TO ABOVE NORMAL 
PRECIPITATION ACROSS PARTS OF THE NORTHERN AND CENTRAL PLAINS. BELOW NORMAL 
PRECIPITATION IS FAVORED ALONG THE WEST COAST AND SOUTHWEST DOWNSTREAM OF WEAK 
RIDGING OFF THE COAST. STRONG RIDGING AND ASSOCIATED OFFSHORE FLOW LEAD TO 
ENHANCED PROBABILITIES OF BELOW NORMAL PRECIPITATION FOR EASTERN PORTIONS OF 
MAINLAND ALASKA AND THE ALASKA PANHANDLE. CONVERSELY ABOVE NORMAL PRECIPITATION 
IS FAVORED FOR WESTERN ALASKA UNDERNEATH MOIST SOUTHERLY FLOW AHEAD OF THE 
TROUGH FORECAST OVER THE WESTERN BERING SEA.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 15% 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 6Z GFS CENTERED ON DAY 8, 35% OF TODAY'S 0Z 
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 10% OF TODAY'S OPERATIONAL 0Z ECMWF 
CENTERED ON DAY 8, AND 15% 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 THE ENSEMBLE MEANS IN A HIGHLY AMPLIFIED LONGWAVE PATTERN.
8-14 DAY OUTLOOK FOR FEB 27 - MAR 05, 2019 
THE ENSEMBLE MEANS MAINTAIN A HIGH AMPLITUDE LONGWAVE 500-HPA RIDGE OVER MUCH 
OF ALASKA DURING WEEK-2 WITH AN EASTWARD PROGRESSION OF AN ANOMALOUS TROUGH 
DOWNSTREAM ACROSS EAST-CENTRAL NORTH AMERICA. FARTHER TO THE SOUTH, LOW 
AMPLITUDE PACIFIC FLOW IS FORECAST TO UNDERCUT THE ALASKA RIDGE ACROSS MUCH OF 
THE WEST COAST OF THE CONUS (ALTHOUGH MODEL SPREAD AND UNCERTAINTY ARE 
RELATIVELY HIGH ACROSS THIS REGION). THE WEEK-2 MANUAL 500-HPA HEIGHT BLEND IS 
BASED ALMOST ENTIRELY ON THE ENSEMBLE MEAN SOLUTIONS FROM THE GEFS, ECMWF, AND 
CANADIAN MODELS. ABOVE NORMAL HEIGHTS ARE FAVORED ACROSS ALASKA (WITH THE 
EXCEPTION OF THE WESTERN ALEUTIANS). BELOW NORMAL HEIGHTS ARE FORECAST FROM THE 
NORTHERN ROCKIES EASTWARD ACROSS THE NORTHERN AND CENTRAL PLAINS, GREAT LAKES, 
AND PARTS OF THE NORTHEAST. NEAR TO SLIGHTLY ABOVE NORMAL HEIGHTS ARE FAVORED 
THE SOUTHERN TIER OF THE CONUS AND THE WEST COAST. 
BELOW NORMAL TEMPERATURES ARE LIKELY FOR MUCH OF THE CONUS DURING WEEK-2 
UNDERNEATH A MEAN ANOMALOUS TROUGH. THE HIGHEST PROBABILITIES OF BELOW NORMAL 
TEMPERATURES (GREATER THAN 90 PERCENT) CONTINUE FOR PARTS OF THE NORTH-CENTRAL 
CONUS NEAR THE PREDICTED MEAN TROUGH AXIS. LOWER ODDS FOR BELOW NORMAL 
TEMPERATURES ARE FORECAST ALONG THE WEST COAST DURING WEEK-2 COMPARED TO DAYS 
6-10 AS THIS REGION IS LIKELY TO EXPERIENCE A WARMING TREND. LOWER CONFIDENCE 
IN THE TEMPERATURE OUTLOOK ALSO EXISTS ACROSS THE SOUTHEAST AS MODEL SOLUTIONS 
VARY ON WHEN THE PERSISTENT, ANOMALOUS RIDGE WEAKENS. GIVEN THAT MEAN ABOVE 
NORMAL HEIGHTS ARE LIKELY ACROSS THE SOUTHEAST, NEAR TO ABOVE NORMAL 
TEMPERATURES ARE FAVORED FROM THE FLORIDA PENINSULA NORTHWARD TO THE CAROLINA 
COAST. DUE TO PERSISTENT ANOMALOUS RIDGING EXPECTED ACROSS MOST OF ALASKA, 
ABOVE NORMAL TEMPERATURES ARE FAVORED ACROSS THE MAINLAND AND THE ALEUTIANS. 
HOWEVER THERE ARE ENHANCED PROBABILITIES OF BELOW NORMAL TEMPERATURES ACROSS 
MUCH OF THE PANHANDLE UNDERNEATH ANOMALOUS NORTHEASTERLY 500-HPA FLOW AHEAD OF 
THE RIDGE AXIS. 
ABOVE NORMAL PRECIPITATION CONTINUES TO BE FAVORED ALONG THE EAST AND GULF 
COASTS IN ASSOCIATION WITH THE MEAN TROUGH PREDICTED ACROSS EAST-CENTRAL NORTH 
AMERICA. THE HIGHEST ODDS OF ABOVE NORMAL PRECIPITATION (GREATER THAN 50 
PERCENT) IS FORECAST FOR PARTS OF THE SOUTHEAST WHERE A FRONT IS LIKELY TO SLOW 
AND PERHAPS STALL DURING WEEK-2. NEAR TO BELOW NORMAL PRECIPITATION IS FAVORED 
THROUGHOUT THE MIDDLE AND UPPER MISSISSIPPI VALLEY AS WELL AS EASTERN PORTIONS 
OF THE NORTHERN AND CENTRAL PLAINS DUE TO A SPRAWLING AREA OF SURFACE HIGH 
PRESSURE EXPECTED ACROSS THESE REGIONS. HOWEVER, THERE IS A SLIGHT TILT IN THE 
ODDS FOR ABOVE NORMAL PRECIPITATION ACROSS THE NORTHERN HIGH PLAINS RELATED TO 
POTENTIAL UPSLOPE FLOW. DYNAMICAL AND STATISTICAL MODEL GUIDANCE ARE IN 
RELATIVELY GOOD AGREEMENT IN FAVORING BELOW NORMAL PRECIPITATION ACROSS THE 
DESERT SOUTHWEST AS WELL AS THE PACIFIC NORTHWEST. HOWEVER, NEAR TO ABOVE 
NORMAL PRECIPITATION IS FAVORED FOR NORTHERN CALIFORNIA DUE TO THE POTENTIAL 
FOR PACIFIC FLOW TO UNDERCUT STRONG RIDGING FARTHER TO THE NORTH OVER ALASKA. 
THE PREDICTED ALASKAN RIDGE FAVORS BELOW NORMAL PRECIPITATION ACROSS THE ALASKA 
PANHANDLE AND MOST OF EASTERN MAINLAND ALASKA. FORECAST ANOMALOUS SOUTHERLY 
FLOW BEHIND THE RIDGE AXIS LEADS TO CONTINUED ELEVATED PROBABILITIES OF ABOVE 
NORMAL PRECIPITATION FOR WESTERN ALASKA.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 15% OF TODAY'S 0Z GFS 
ENSEMBLE MEAN CENTERED ON DAY 11, 30% OF TODAY'S 6Z GFS ENSEMBLE MEAN 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 15% OF TODAY'S 0Z CANADIAN 
ENSEMBLE MEAN CENTERED ON DAY 11 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO VERY 
GOOD AGREEMENT AMONG THE TEMPERATURE TOOLS OVER THE NORTH-CENTRAL CONUS AND 
MOST OF ALASKA OFFSET BY MODEL UNCERTAINTY AS TO THE SOUTHERN EXTENT OF THE 
TROUGH OVER EAST-CENTRAL NORTH AMERICA AS WELL AS UNCERTAINTY RELATED TO THE 
EXTENT OF UNDERCUTTING PACIFIC FLOW OVER THE WESTERN CONUS.
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 
FEBRUARY 21.
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: 
20010208 - 19850303 - 20060218 - 20090213 - 19530301
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: 
20010209 - 20060218 - 19850303 - 20090213 - 19530301
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR FEB 25 - MAR 01, 2019
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN   
WASHINGTON  B    B     OREGON      B    B     NRN CALIF   B    B     
SRN CALIF   B    B     IDAHO       B    N     NEVADA      B    B     
W MONTANA   B    A     E MONTANA   B    A     WYOMING     B    A     
UTAH        B    N     ARIZONA     B    B     COLORADO    B    A     
NEW MEXICO  B    B     N DAKOTA    B    N     S DAKOTA    B    A     
NEBRASKA    B    A     KANSAS      B    N     OKLAHOMA    B    N     
N TEXAS     B    N     S TEXAS     B    A     W TEXAS     B    B     
MINNESOTA   B    N     IOWA        B    A     MISSOURI    B    N     
ARKANSAS    B    N     LOUISIANA   N    A     WISCONSIN   B    A     
ILLINOIS    B    N     MISSISSIPPI N    A     MICHIGAN    B    A     
INDIANA     B    N     OHIO        B    N     KENTUCKY    B    N     
TENNESSEE   N    A     ALABAMA     A    A     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        N    A     NEW JERSEY  N    A     W VIRGINIA  N    A     
MARYLAND    N    A     DELAWARE    N    A     VIRGINIA    N    A     
N CAROLINA  N    A     S CAROLINA  A    A     GEORGIA     A    A     
FL PNHDL    A    A     FL PENIN    A    A     AK N SLOPE  A    N     
AK ALEUTIAN A    A     AK WESTERN  A    A     AK INT BSN  A    B     
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    B    B     
 
                           
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR FEB 27 - MAR 05, 2019
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN   
WASHINGTON  B    B     OREGON      B    B     NRN CALIF   B    N     
SRN CALIF   B    B     IDAHO       B    B     NEVADA      B    B     
W MONTANA   B    N     E MONTANA   B    A     WYOMING     B    N     
UTAH        B    B     ARIZONA     B    B     COLORADO    B    N     
NEW MEXICO  B    B     N DAKOTA    B    B     S DAKOTA    B    B     
NEBRASKA    B    B     KANSAS      B    B     OKLAHOMA    B    B     
N TEXAS     B    N     S TEXAS     B    A     W TEXAS     B    N     
MINNESOTA   B    B     IOWA        B    B     MISSOURI    B    B     
ARKANSAS    B    N     LOUISIANA   B    A     WISCONSIN   B    B     
ILLINOIS    B    B     MISSISSIPPI B    A     MICHIGAN    B    N     
INDIANA     B    N     OHIO        B    N     KENTUCKY    B    N     
TENNESSEE   B    N     ALABAMA     B    A     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    N    A     FL PENIN    A    A     AK N SLOPE  A    N     
AK ALEUTIAN A    A     AK WESTERN  A    A     AK INT BSN  A    B     
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    B    B     
 
                           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.
$$