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FXUS06 KWBC 172001
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 17 2018

6-10 DAY OUTLOOK FOR JAN 23 - 27 2018

TODAY`S ENSEMBLE MEAN SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT ON THE EXPECTED
500-HPA FLOW PATTERN OVER THE FORECAST DOMAIN. ALL OF TODAY`S MODEL SOLUTIONS
FORECAST A RIDGE OVER THE WESTERN ALEUTIANS AND TROUGH OVER MUCH OF MAINLAND
ALASKA. RIDGING IS EXPECTED FARTHER TO THE EAST OVER WESTERN CANADA AND TO THE
SOUTH WELL OFF THE COAST OF CALIFORNIA. A BROAD TROUGH IS PREDICTED BY MOST
SOLUTIONS OVER THE WEST-CENTRAL CONUS. HOWEVER, THE DETERMINISTIC 0Z AND 6Z GFS
PROGRESS THIS TROUGH FARTHER TO THE EAST OVER THE CENTRAL CONUS. RIDGING IS
LIKELY OVER THE CARIBBEAN EXTENDING TO PARTS OF THE SOUTHEASTERN CONUS.
ENSEMBLE SPREAD IS RELATIVELY LOW OVER THE EASTERN CONUS BUT MODERATE FOR THE
WESTERN CONUS AND ALASKA. TODAY`S MANUAL 500-HPA BLEND IS BASED PRIMARILY ON
THE ENSEMBLE MEANS FROM THE CANADIAN, EUROPEAN, AND GEFS MODEL SUITES. THE
RESULTANT MANUAL BLEND DEPICTS BELOW NORMAL HEIGHTS OVER MOST OF MAINLAND
ALASKA, THE ALASKA PANHANDLE, AND MOST OF THE NORTHWESTERN AND WEST-CENTRAL
CONUS. ABOVE NORMAL HEIGHTS ARE EXPECTED FOR MUCH OF THE EASTERN THIRD OF THE
CONUS, THE ALEUTIANS, EXTREME WESTERN MAINLAND ALASKA, AND PARTS OF CALIFORNIA.

THE TROUGH OVER MAINLAND ALASKA LEADS TO ENHANCED PROBABILITIES OF BELOW NORMAL
TEMPERATURES ACROSS ALASKA. BELOW NORMAL TEMPERATURES ARE ALSO FAVORED ACROSS
MUCH OF THE WESTERN CONUS AND THE NORTHERN PLAINS UNDERNEATH CYCLONIC FLOW AND
NEAR TO BELOW NORMAL HEIGHTS. RIDGING AND ABOVE NORMAL HEIGHTS TO THE EAST OF
THIS TROUGH FAVOR ABOVE NORMAL TEMPERATURES FOR MUCH OF THE EASTERN CONUS.

THE POTENTIAL FOR SHORTWAVE TROUGHS TO MOVE INTO THE WESTERN CONUS FROM THE
PACIFIC LEADS TO ENHANCED PROBABILITIES OF ABOVE NORMAL PRECIPITATION ACROSS
MUCH OF THE NORTHWESTERN CONUS EXTENDING EASTWARD TO THE NORTHERN AND CENTRAL
ROCKIES. MOIST FLOW AHEAD OF THE LONGWAVE TROUGH OVER THE WEST-CENTRAL CONUS
FAVORS ABOVE NORMAL PRECIPITATION FOR MUCH OF THE EASTERN CONUS. BELOW NORMAL
PRECIPITATION IS LIKELY FOR MUCH OF WESTERN AND CENTRAL ALASKA UNDERNEATH
NORTHEASTERLY LOW LEVEL FLOW. BELOW NORMAL PRECIPITATION IS FAVORED FOR PARTS
OF THE SOUTHWESTERN CONUS CONSISTENT WITH DYNAMICAL MODEL GUIDANCE FROM THE
GEFS AND ECMWF ENSEMBLES AS WELL AS ANALOGS FROM THE MANUAL BLEND.

THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 15% OF TODAY`S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 15% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED
ON DAY 8, 5% OF TODAY`S OPERATIONAL 0Z GFS CENTERED ON DAY 8, 25% OF TODAY`S 0Z
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF YESTERDAY`S 12Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 7, 10% OF TODAY`S OPERATIONAL 0Z ECMWF CENTERED
ON DAY 8, 20% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 5% OF
YESTERDAY`S 12Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 7


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO FAIRLY
GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS OFFSET BY POOR AGREEMENT AMONG
THE TELECONNECTIONS FROM THE VARIOUS HEIGHT ANOMALY CENTERS DEPICTED IN THE
MANUAL 500-HPA HEIGHT BLEND.

8-14 DAY OUTLOOK FOR JAN 25 - 31 2018

DURING THE WEEK-2 PERIOD, TODAY`S MODELS DEPICT INCREASED 500-HPA SPREAD AND
UNCERTAINTY ACROSS MUCH OF THE FORECAST DOMAIN. A MEAN TROUGH IS FORECAST TO
PERSIST OVER MUCH OF MAINLAND ALASKA WITH RIDGES PREDICTED ON EITHER SIDE OF
THIS FEATURE OVER THE ALEUTIANS AND WESTERN CANADA. FARTHER TO THE SOUTH,
RIDGING IS FORECAST OFF THE WEST COAST OF THE CONUS WHILE SHALLOW, CYCLONIC
FLOW IS DEPICTED FROM THE GREAT LAKES SOUTHWESTWARD TO THE SOUTHWESTERN CONUS.
A RIDGE IS EXPECTED OVER THE CARIBBEAN EXTENDING TO PARTS OF THE SOUTHEASTERN
CONUS. ENSEMBLE SPREAD IS RELATIVELY HIGH OVER THE WESTERN CONUS AND SUCCESSIVE
RUNS OF THE DETERMINISTIC GFS VARY GREATLY ON THE POSITION OF A LONGWAVE TROUGH
OVER THE CONUS. DUE TO THESE UNCERTAINTIES, THE MANUAL 500-HPA HEIGHT BLEND IS
BASED ALMOST ENTIRELY ON THE ENSEMBLE MEAN SOLUTIONS. ABOVE NORMAL HEIGHTS ARE
EXPECTED FOR THE EASTERN THIRD OF THE CONUS, THE ALEUTIANS, EXTREME WESTERN
MAINLAND ALASKA, AND MUCH OF CALIFORNIA. BELOW NORMAL HEIGHTS ARE FORECAST FOR
SOUTHEASTERN MAINLAND ALASKA AND THE ALASKA PANHANDLE.

THE TROUGH OVER ALASKA LEADS TO ENHANCED PROBABILITIES OF BELOW NORMAL
TEMPERATURES ACROSS THE STATE. ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES OF
ABOVE NORMAL TEMPERATURES ACROSS MUCH OF THE EASTERN CONUS. BELOW NORMAL
TEMPERATURES ARE FAVORED FOR MUCH OF THE NORTHWESTERN CONUS UNDERNEATH NEAR TO
BELOW NORMAL HEIGHTS. PROBABILITIES OF ABOVE NORMAL TEMPERATURES ARE SLIGHTLY
ELEVATED FOR PARTS OF THE SOUTHWESTERN CONUS IN ASSOCIATION WITH ABOVE NORMAL
HEIGHTS.

MOIST FLOW AHEAD OF A TROUGH OVER THE CENTRAL CONUS INCREASES PROBABILITIES OF
ABOVE NORMAL PRECIPITATION OVER MUCH OF THE EASTERN HALF OF THE CONUS. ABOVE
NORMAL PRECIPITATION IS ALSO FAVORED FOR THE NORTHWESTERN CONUS AND PARTS OF
THE ALASKA PANHANDLE DUE TO THE POTENTIAL FOR ENHANCED PACIFIC FLOW. DYNAMICAL
MODEL GUIDANCE FROM THE ECMWF AND GEFS ENSEMBLE MEMBERS FAVOR BELOW NORMAL
PRECIPITATION FOR PARTS OF THE SOUTHWESTERN CONUS. BELOW NORMAL PRECIPITATION
IS ALSO FAVORED FOR PARTS OF WESTERN MAINLAND ALASKA UNDERNEATH MEAN
NORTHEASTERLY LOW LEVEL FLOW.

THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 20% OF TODAY`S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 15% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED
ON DAY 11, 5% OF TODAY`S OPERATIONAL 6Z GFS CENTERED ON DAY 11, 30% OF TODAY`S
0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 5% OF YESTERDAY`S 12Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 10, 20% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 5% OF YESTERDAY`S 12Z CANADIAN ENSEMBLE MEAN CENTERED
ON DAY 10


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, DUE TO
RELATIVELY HIGH MODEL SPREAD AND POOR AGREEMENT AMONG THE SURFACE TOOLS.

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 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:
20010120 - 19860124 - 20030104 - 20060104 - 19980125


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:
20010120 - 19950119 - 19941229 - 19810123 - 20060102


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 23 - 27 2018

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   B    A
SRN CALIF   N    B     IDAHO       B    A     NEVADA      B    A
W MONTANA   B    A     E MONTANA   B    A     WYOMING     B    A
UTAH        B    A     ARIZONA     N    B     COLORADO    B    N
NEW MEXICO  N    B     N DAKOTA    B    A     S DAKOTA    B    A
NEBRASKA    B    A     KANSAS      N    N     OKLAHOMA    N    N
N TEXAS     N    A     S TEXAS     N    A     W TEXAS     N    N
MINNESOTA   N    A     IOWA        N    A     MISSOURI    N    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    A    A
VERMONT     A    A     NEW HAMP    A    A     MAINE       A    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    N     FL PENIN    A    N     AK N SLOPE  B    N
AK ALEUTIAN B    B     AK WESTERN  B    B     AK INT BSN  B    B
AK S INT    B    B     AK SO COAST B    B     AK PNHDL    B    N



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 25 - 31 2018

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   N    B
SRN CALIF   N    B     IDAHO       B    A     NEVADA      N    B
W MONTANA   B    A     E MONTANA   B    A     WYOMING     B    N
UTAH        N    N     ARIZONA     N    B     COLORADO    N    N
NEW MEXICO  N    N     N DAKOTA    N    N     S DAKOTA    N    A
NEBRASKA    N    N     KANSAS      N    N     OKLAHOMA    N    A
N TEXAS     N    A     S TEXAS     N    A     W TEXAS     N    N
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    A    A
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    A
TENNESSEE   A    A     ALABAMA     A    A     NEW YORK    A    A
VERMONT     A    A     NEW HAMP    A    A     MAINE       A    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    A     FL PENIN    A    N     AK N SLOPE  B    N
AK ALEUTIAN B    N     AK WESTERN  B    B     AK INT BSN  B    N
AK S INT    B    N     AK SO COAST B    N     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.

$$




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