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Prognostic Meteorological Discussion (PMD)

Issued by National Weather Service (NWS)

                            
000
FXUS06 KWBC 132003
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST TUE NOVEMBER 13 2018

6-10 DAY OUTLOOK FOR NOV 19 - 23 2018

TODAY'S MODEL ENSEMBLE MEANS GENERALLY PREDICT AN AMPLIFIED 500-HPA CIRCULATION 
PATTERN OVER NORTH AMERICA IN THE 6-10 DAY PERIOD. AN AMPLIFIED MEAN TROUGH IS 
FORECAST TO PROGRESS OFF THE EAST COAST OF NORTH AMERICA. LOW AMPLITUDE FLOW IS 
GENERALLY FORECAST ACROSS MUCH OF THE WESTERN AND CENTRAL CONUS CORRESPONDING 
TO AN EXPECTED RIDGE OVER THE WESTERN CONUS. FARTHER TO THE NORTH, A MEAN 
TROUGH IS EXPECTED OVER MAINLAND ALASKA WHILE A RIDGE IS FORECAST UPSTREAM OVER 
THE WESTERN BERING SEA. TODAY'S MANUAL 500-HPA HEIGHT BLEND IS BASED PRIMARILY 
ON THE ENSEMBLE MEANS FROM THE ECMWF AND GEFS MODEL SUITES. THE RESULTANT 
MANUAL BLEND INDICATES NEAR TO ABOVE NORMAL 500-HPA HEIGHTS OVER MUCH OF THE 
NORTHWESTERN AND NORTH-CENTRAL CONUS. BELOW NORMAL 500-HPA HEIGHTS ARE FORECAST 
OVER THE EASTERN AND SOUTHWESTERN CONUS. 

MEAN TROUGHING OVER NORTHEASTERN NORTH AMERICA SUPPORTS ENHANCED PROBABILITIES 
OF BELOW NORMAL TEMPERATURES ACROSS MUCH OF THE EASTERN CONUS AND THE 
MISSISSIPPI VALLEY, EXCEPT FOR PARTS OF THE FLORIDA PENINSULA. ABOVE NORMAL 
500-HPA HEIGHTS GENERALLY FAVOR ABOVE NORMAL TEMPERATURES OVER THE WEST 
EXTENDING EASTWARD TO PARTS OF THE CENTRAL AND SOUTHERN ROCKIES. ABOVE NORMAL 
TEMPERATURES ARE MOST LIKELY OVER ALASKA, AHEAD OF A TROUGH PREDICTED OVER THE 
GULF OF ALASKA. 

BELOW NORMAL PRECIPITATION IS FAVORED ACROSS MUCH OF THE NORTHERN CONUS AS MEAN 
SURFACE HIGH PRESSURE IS EXPECTED TO DOMINATE MUCH OF THE COUNTRY. HOWEVER, 
ABOVE NORMAL PRECIPITATION IS FAVORED FOR THE SOUTHWESTERN CONUS AND THE 
SOUTHERN PLAINS AHEAD OF THE TROUGHING OVER THE EASTERN PACIFIC AND DUE TO 
MOISTURE FLOW FROM THE GULF OF MEXICO. ABOVE NORMAL PRECIPITATION IS MOST 
LIKELY FOR ALASKA, AHEAD OF A PREDICTED 500-HPA TROUGH AND SOUTHEASTERLY FLOW 
FROM THE STORM SYSTEM OVER THE GULF OF ALASKA. 

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, 20% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 8, 20% OF 
TODAY'S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, AND 20% OF YESTERDAY'S 
OPERATIONAL 12Z ECMWF CENTERED ON DAY 7 
 

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO GOOD 
AGREEMENT ON A HIGH AMPLITUDE PATTERN IN THE PERIOD, OFFSET BY INCREASING 
UNCERTAINTY REGARDING A POTENTIAL PATTERN TRANSITION AS TIME PROGRESSES.


8-14 DAY OUTLOOK FOR NOV 21 - 27 2018 

DURING THE WEEK-2 PERIOD, THE FORECAST MODELS GENERALLY INDICATE A TRANSITIONAL 
PATTERN ACROSS MUCH OF THE FORECAST DOMAIN CHARACTERIZED BY HIGH UNCERTAINTY. 
GENERALLY, LOW AMPLITUDE MEAN 500-HPA FLOW IS FORECAST OVER MUCH OF THE CONUS 
CONSISTENT WITH A POTENTIAL PATTERN CHANGE. A FAIRLY AMPLIFIED PATTERN IS 
EXPECTED OVER THE ALASKA SECTOR PUNCTUATED BY A MEAN TROUGH FORECAST OVER THE 
BERING SEA AND MAINLAND ALASKA AND RIDGING PREDICTED OVER THE WESTERN BERING 
SEA. ENSEMBLE MEAN GFS AND ECMWF MODEL SOLUTIONS ARE IN AGREEMENT IN 
FORECASTING MEAN TROUGH DEVELOPMENT ACROSS THE WESTERN CONUS. THE MANUAL BLEND 
CHART DEPICTS NEAR TO SLIGHTLY ABOVE NORMAL HEIGHTS ACROSS MUCH OF THE 
NORTHWESTERN AND NORTH-CENTRAL CONUS CONSISTENT WITH A LOWER AMPLITUDE PATTERN. 
BELOW NORMAL HEIGHTS ARE INDICATED FOR THE EASTERN AND SOUTHWESTERN CONUS.

BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE NORTHEASTERN CONUS DUE TO 
RESIDUAL TROUGHING ACROSS EASTERN NORTH AMERICA. ABOVE NORMAL TEMPERATURES ARE 
FAVORED OVER THE SOUTH-CENTRAL AND SOUTHEASTERN CONUS IN ASSOCIATION WITH 
PREDICTED LOW AMPLITUDE FLOW. ENHANCED PROBABILITIES OF ABOVE NORMAL 
TEMPERATURES ARE ALSO INDICATED FOR THE WESTERN COASTS OF THE CONUS, MUCH OF 
MAINLAND ALASKA, THE ALEUTIANS, AND THE ALASKA PANHANDLE DUE TO SOUTHERLY LOWER 
LEVEL WINDS AND ABOVE NORMAL SSTS IN ADJACENT WATERS. LARGE AREAS OF NEAR 
NORMAL ARE FAVORED FOR THE REST OF THE CONUS.

PREDICTED MEAN SURFACE HIGH PRESSURE OVER THE INTERIOR WESTERN CONUS LEADS TO 
FAVORED NEAR TO BELOW NORMAL PRECIPITATION FOR THE NORTHWESTERN CONUS. THERE 
ARE ENHANCED PROBABILITIES OF ABOVE NORMAL PRECIPITATION ACROSS MUCH OF THE 
CENTRAL AND EASTERN CONUS DUE TO THE POTENTIAL ADVECTION OF MOISTURE FROM THE 
GULF OF MEXICO UNDERNEATH MEAN SOUTHERLY/SOUTHWESTERLY LOW LEVEL FLOW. 
DYNAMICAL MODEL GUIDANCE FROM BOTH THE GEFS AND ECMWF ENSEMBLES ALSO FAVOR 
ABOVE NORMAL PRECIPITATION FOR THE SOUTHWEST CONUS, SUGGESTIVE OF A POTENTIALLY 
ACTIVE SOUTHERN STREAM DURING THIS PERIOD. ABOVE NORMAL PRECIPITATION IS MOST 
LIKELY FOR ALASKA IN ASSOCIATION WITH A MEAN TROUGH OVER OVER THE BERING SEA. 

THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 20% OF TODAY'S 0Z GFS 
ENSEMBLE MEAN CENTERED ON DAY 11, 20% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED 
ON DAY 11, 20% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11, 20% OF 
TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 20% 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 
UNCERTAINTY IN ASSOCIATION WITH A POTENTIAL PATTERN CHANGE DURING THE PERIOD. 

FORECASTER: QIN Z

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 
NOVEMBER 15.

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: 
19761127 - 19931027 - 19641119 - 19571121 - 20021126


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: 
19761126 - 19931026 - 19641119 - 20021126 - 19571121


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 19 - 23 2018

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN   
WASHINGTON  A    B     OREGON      A    B     NRN CALIF   A    A     
SRN CALIF   A    A     IDAHO       N    B     NEVADA      A    A     
W MONTANA   N    B     E MONTANA   N    B     WYOMING     N    B     
UTAH        A    N     ARIZONA     A    A     COLORADO    N    N     
NEW MEXICO  N    N     N DAKOTA    N    B     S DAKOTA    N    B     
NEBRASKA    N    N     KANSAS      N    N     OKLAHOMA    B    A     
N TEXAS     B    A     S TEXAS     N    A     W TEXAS     N    A     
MINNESOTA   B    B     IOWA        B    B     MISSOURI    B    N     
ARKANSAS    B    A     LOUISIANA   N    A     WISCONSIN   B    B     
ILLINOIS    B    B     MISSISSIPPI N    A     MICHIGAN    B    B     
INDIANA     B    B     OHIO        B    B     KENTUCKY    B    B     
TENNESSEE   B    B     ALABAMA     N    N     NEW YORK    B    B     
VERMONT     B    B     NEW HAMP    B    B     MAINE       B    B     
MASS        B    B     CONN        B    B     RHODE IS    B    B     
PENN        B    B     NEW JERSEY  B    B     W VIRGINIA  B    B     
MARYLAND    B    B     DELAWARE    B    B     VIRGINIA    B    B     
N CAROLINA  B    B     S CAROLINA  B    N     GEORGIA     N    N     
FL PNHDL    N    A     FL PENIN    A    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 NOV 21 - 27 2018

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

$$