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FXUS06 KWBC 011901
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE SEPTEMBER 01 2015

6-10 DAY OUTLOOK FOR SEP 07 - 11 2015

TODAY`S MODEL SOLUTIONS ARE IN FAIR AGREEMENT ON THE PREDICTED 500-HPA FLOW
PATTERN OVER NORTH AMERICA AND VICINITY. THE ENSEMBLE MEAN SOLUTIONS FROM THE
GFS, ECMWF, AND CANADIAN FORECAST TROUGHS OVER THE BERING SEA OR WESTERN ALASKA
AND OVER THE NORTHWESTERN CONUS. 500-HPA RIDGING IS PREDICTED FOR THE SOUTHERN
HIGH PLAINS. UNCERTAINTY IS HIGH REGARDING A SHORTWAVE TROUGH PREDICTED
DOWNSTREAM OF THE FORECAST RIDGE CENTER. TODAY`S ECMWF-BASED SOLUTIONS PREDICT
THIS SHORTWAVE TROUGH TO BE OVER THE SOUTHEASTERN CONUS WHILE TODAY`S GFS-BASED
SOLUTIONS FORECAST IT TO BE OVER THE GULF COAST REGION. UNCERTAINTY IS ALSO
HIGH REGARDING THE TROUGH OVER THE NORTHWESTERN CONUS AS THE DETERMINISTIC 0Z
ECMWF FORECASTS THE TROUGH AXIS OVER THE PACIFIC NORTHWEST WHILE THE
DETERMINISTIC 6Z GFS PREDICTS THE TROUGH TO BE NEAR THE NORTHERN ROCKIES OR
NORTHERN HIGH PLAINS. TODAY`S 0Z ECMWF ENSEMBLE MEAN IS THE LARGEST COMPONENT
OF THE OFFICIAL 500-HPA MANUAL HEIGHT BLEND DUE, IN PART, TO CONSIDERATIONS OF
RECENT SKILL. HOWEVER, SIGNIFICANT CONTRIBUTIONS FROM THE GFS AND CANADIAN ARE
ALSO PRESENT. THE RESULTANT HEIGHT BLEND DEPICTS ABOVE NORMAL 500-HPA HEIGHTS
OVER THE NORTHEASTERN CONUS AND PARTS OF ALASKA AND NEAR NORMAL HEIGHTS
ELSEWHERE.

BELOW NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE NORTHERN ROCKIES AND
NORTHERN HIGH PLAINS IN ASSOCIATION WITH A TROUGH PREDICTED OVER THE
NORTHWESTERN CONUS. ABOVE NORMAL TEMPERATURES ARE FAVORED AHEAD OF THIS TROUGH
OVER MOST OF THE EASTERN AND SOUTH-CENTRAL CONUS. ENHANCED PROBABILITIES OF
ABOVE NORMAL TEMPERATURES ARE ALSO INDICATED FOR MUCH OF ALASKA AHEAD OF THE
TROUGH PREDICTED OVER THE BERING SEA. PROBABILITIES OF ABOVE NORMAL
TEMPERATURES ARE ENHANCED ALONG THE WEST COAST OF THE CONUS DUE IN PART TO
ABOVE NORMAL SSTS CURRENTLY OBSERVED IN ADJACENT WATERS.

THERE ARE ENHANCED PROBABILITIES OF ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE
NORTHERN AND CENTRAL PLAINS AND MISSISSIPPI VALLEY AHEAD OF THE TROUGH
PREDICTED OVER THE NORTHWESTERN CONUS. PREDICTIONS FROM THE GFS ENSEMBLE
MEMBERS ALSO FAVOR ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE SOUTHWESTERN
CONUS. FARTHER TO THE EAST, BELOW MEDIAN PRECIPITATION IS SLIGHTLY FAVORED FOR
PARTS OF SOUTHERN TEXAS UNDERNEATH FORECAST RIDGING. THERE ARE ENHANCED
PROBABILITIES OF BELOW MEDIAN PRECIPITATION FOR THE NORTHWESTERN CONUS
CONSISTENT WITH GEFS REFORECAST GUIDANCE. PRECIPITATION ESTIMATES FROM THE GFS
AND ECMWF ENSEMBLE MEMBERS ALSO FAVOR BELOW MEDIAN PRECIPITATION FOR SOUTHERN
NEW ENGLAND AND PARTS OF THE NORTHERN MID ATLANTIC REGION. CONVERSELY, ABOVE
MEDIAN PRECIPITATION IS FAVORED FOR MUCH OF THE SOUTHEASTERN CONUS DUE TO A
FORECAST SHORTWAVE TROUGH IN THE VICINITY. ENHANCED PROBABILITIES OF ABOVE
MEDIAN PRECIPITATION ARE ALSO INDICATED FOR SOUTHERN ALASKA AHEAD OF A TROUGH
PREDICTED OF THE BERING SEA.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 10% OF TODAY`S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 10% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 10%
OF TODAY`S OPERATIONAL 6Z GFS CENTERED ON DAY 8, 20% OF TODAY`S 0Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 8, 15% OF YESTERDAY`S 12Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 7, 15% OF TODAY`S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, 5% OF
YESTERDAY`S OPERATIONAL 12Z ECMWF CENTERED ON DAY 7, AND 15% 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
FAIRLY LARGE DISAGREEMENTS AMONG THE DETERMINISTIC GFS AND ECMWF SOLUTIONS.

8-14 DAY OUTLOOK FOR SEP 09 - 15 2015

TODAY`S WEEK TWO MODEL SOLUTIONS EXHIBIT LARGE SPREAD AND UNCERTAINTY FOR MUCH
OF THE FORECAST DOMAIN. THE ENSEMBLE MEAN SOLUTIONS GENERALLY FORECAST MOSTLY
LOW AMPLITUDE FLOW ACROSS MUCH OF THE NORTHERN TIER OF THE CONUS DUE, IN PART,
TO LARGE SPREAD AMONG THE MODELS BEING AVERAGED TOGETHER. THE GFS AND CANADIAN
ENSEMBLE MEANS FORECAST A WEAK TROUGH CENTERED NEAR THE GREAT LAKES REGION
WHILE THE 0Z ECMWF ENSEMBLE MEAN HAS MOSTLY ZONAL FLOW ACROSS THE NORTHERN
TIER. FARTHER TO THE SOUTH, WEAK RIDGING IS FORECAST OVER MUCH OF THE SOUTHERN
TIER OF THE CONUS. HOWEVER, A WEAKNESS IN THE SUBTROPICAL RIDGE IS FORECAST BY
THE GFS ENSEMBLE MEAN SOLUTIONS NEAR THE GULF COAST. AGREEMENT IS SOMEWHAT
BETTER OVER ALASKA, AS MOST MODEL SOLUTIONS AGREE IN FORECASTING A TROUGH NEAR
THE WESTERN PART OF THE STATE AND A RIDGE NEAR THE PANHANDLE. DUE TO LARGE
DISAGREEMENTS AMONG THE DETERMINISTIC GFS SOLUTIONS, TODAY`S WEEK TWO MANUAL
HEIGHT BLEND CONSISTS PRIMARILY OF THE ENSEMBLE MEAN SOLUTIONS.

BELOW NORMAL TEMPERATURES ARE FAVORED FOR PARTS OF THE NORTH CENTRAL CONUS
REPRESENTING A COMPROMISE BETWEEN THE ECMWF- AND GFS-BASED SOLUTIONS AND
CONSISTENT WITH TELECONNECTIONS FROM AN UPSTREAM RIDGE PREDICTED NEAR THE
ALASKA PANHANDLE. CONVERSELY, GEFS REFORECAST GUIDANCE AND BIAS CORRECTED
TEMPERATURES FROM THE ECMWF ENSEMBLE MEMBERS FAVOR ABOVE NORMAL TEMPERATURES
FOR THE WEST COAST AS WELL AS THE SOUTHERN TIER OF THE CONUS. PREDICTIONS FROM
THE ECMWF ENSEMBLE MEMBERS ALSO FAVOR ABOVE NORMAL TEMPERATURES ALONG THE
EASTERN SEABOARD. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MOST OF SOUTHERN
ALASKA AHEAD OF A TROUGH PREDICTED OVER THE BERING SEA.

FORECASTS FROM THE GFS AND ECMWF ENSEMBLE MEMBERS FAVOR ABOVE MEDIAN
PRECIPITATION FOR MOST OF THE EASTERN HALF AND SOUTHERN TIER OF THE CONUS.
THERE ARE ENHANCED PROBABILITIES OF ABOVE MEDIAN PRECIPITATION FOR MUCH OF
SOUTHERN ALASKA IN ASSOCIATION WITH THE TROUGH PREDICTED OVER THE BERING SEA.
BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE NORTHWESTERN CONUS CONSISTENT
WITH GEFS REFORECAST GUIDANCE.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 20% 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 6Z GFS CENTERED ON DAY 11, 25% OF TODAY`S 0Z
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 10% OF YESTERDAY`S 12Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 10, AND 15% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN
CENTERED ON DAY 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: BELOW AVERAGE, 2 OUT OF 5, DUE
TO LARGE MODEL SPREAD AND UNCERTAINTY.

FORECASTER: SCOTT HANDEL

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
SEPTEMBER 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:
19830906 - 19520905 - 19690812 - 20000907 - 19600830


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:
19600901 - 19830906 - 19690812 - 20040914 - 19690817


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 07 - 11 2015

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 09 - 15 2015

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    B     OREGON      A    B     NRN CALIF   A    N
SRN CALIF   A    N     IDAHO       A    B     NEVADA      A    N
W MONTANA   N    B     E MONTANA   B    N     WYOMING     N    N
UTAH        A    A     ARIZONA     A    A     COLORADO    N    A
NEW MEXICO  A    A     N DAKOTA    B    A     S DAKOTA    B    A
NEBRASKA    B    A     KANSAS      N    A     OKLAHOMA    N    A
N TEXAS     A    A     S TEXAS     A    A     W TEXAS     A    A
MINNESOTA   B    A     IOWA        B    A     MISSOURI    N    A
ARKANSAS    A    A     LOUISIANA   A    A     WISCONSIN   B    A
ILLINOIS    N    A     MISSISSIPPI A    A     MICHIGAN    N    A
INDIANA     N    A     OHIO        N    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    A     AK N SLOPE  N    N
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    N

                           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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