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FXUS06 KWBC 271902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU AUGUST 27 2015

6-10 DAY OUTLOOK FOR SEP 02 - 06 2015

TODAY`S ENSEMBLE MEAN AND DETERMINISTIC SOLUTIONS ARE IN GOOD AGREEMENT ON
THE 500-HPA MEAN CIRCULATION PATTERN FORECAST OVER MOST OF THE NORTH AMERICA
DOMAIN FOR THE 6-10 DAY PERIOD. TROUGHS ARE PREDICTED JUST WEST OF THE BERING
SEA AND ALONG THE WEST COAST OF THE CONTINENT, WHILE ANOMALOUS RIDGING IS
EXPECTED OVER THE EASTERN AND CENTRAL CONUS. TODAY`S MANUAL BLEND CHART
INDICATES BELOW-NORMAL HEIGHTS FOR THE WESTERN CONUS AND NEAR TO ABOVE-NORMAL
HEIGHTS OVER THE EASTERN CONUS. TODAY`S MANUAL 500-HPA HEIGHT BLEND IS COMPOSED
PRIMARILY OF THE ENSEMBLE MEAN SOLUTIONS AND BASED LARGELY ON CONSIDERATIONS OF
RECENT SKILL AND ON ANALOG CORRELATIONS, WHICH MEASURE HOW CLOSELY THE MODEL
SOLUTIONS RESEMBLE CASES THAT HAVE OCCURRED IN THE PAST. THE ENSEMBLE SPAGHETTI
DIAGRAMS INDICATE LOW TO MODERATE SPREAD ACROSS THE MAJORITY OF THE FORECAST
DOMAIN.

BELOW-NORMAL 500-HPA HEIGHTS INCREASE THE CHANCES FOR NEAR TO BELOW-NORMAL
TEMPERATURES FOR THE WESTERN CONUS. NEAR TO ABOVE-NORMAL MEAN TEMPERATURES ARE
FAVORED OVER THE CENTRAL AND EASTERN CONUS, AS WELL AS WESTERN ALASKA AND THE
ALEUTIANS, CONSISTENT WITH GEFS REFORECAST GUIDANCE.

TROUGHING ALONG THE WEST COAST AND SOUTHWESTERLY ANOMALOUS FLOW ENHANCE CHANCES
OF ABOVE-MEDIAN PRECIPITATION AMOUNTS FROM THE PACIFIC NORTHWEST TO THE UPPER
MISSISSIPPI VALLEY. RIDGING ENHANCES CHANCES OF NEAR TO BELOW MEDIAN
PRECIPITATION FOR THE SOUTHERN GREAT PLAINS, THE UPPER GREAT LAKES AND NEW
ENGLAND. THERE ARE ENHANCED CHANCES OF BELOW MEDIAN PRECIPITATION FOR EASTERN
ALASKA, WITH ABOVE MEDIAN PRECIPITATION FOR WESTERN ALASKA IN CONSISTENT WITH
PRECIPITATION ESTIMATES FROM THE GEFS AND ECMWF ENSEMBLE MEMBERS. ABOVE-MEDIAN
PRECIPITATION AMOUNTS ARE FAVORED FOR THE SOUTHEAST COAST DUE TO THE POSSIBLE
INFLUENCE OF PRECIPITATION ASSOCIATED WITH TROPICAL STORM ERIKA.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 10% 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 0Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 8, 10% OF YESTERDAY`S 12Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 7, AND 20% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY
8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG THE TEMPERATURE TOOLS OFFSET BY LARGE UNCERTAINTY IN THE
PRECIPITATION OUTLOOKS ACROSS THE EASTERN CONUS.

8-14 DAY OUTLOOK FOR SEP 04 - 10 2015

TODAY`S ENSEMBLE MEAN AND DETERMINISTIC SOLUTIONS ARE IN GOOD AGREEMENT ON THE
500-HPA MEAN CIRCULATION PATTERN FORECAST OVER MOST OF NORTH AMERICA FOR THE
WEEK-2 PERIOD. THE PREDICTED CIRCULATION PATTERN IS SIMILAR TO THAT EXPECTED
FOR THE 6-10 DAY PERIOD. TROUGHS ARE PREDICTED JUST WEST OF THE BERING SEA AND
ALONG THE WEST COAST OF THE CONTINENT, WITH RIDGING OVER THE EAST-CENTRAL CONUS.

THE EXPECTED TEMPERATURE ANOMALY PATTERNS FOR WEEK-2 ARE SIMILAR TO THOSE
PREDICTED FOR DAYS 6-10. BELOW-NORMAL 500-HPA HEIGHTS INCREASE THE CHANCES FOR
NEAR TO BELOW-NORMAL TEMPERATURES FOR THE WESTERN CONUS. ABOVE-NORMAL MEAN
TEMPERATURES ARE EXPECTED OVER THE CENTRAL AND EASTERN CONUS, AS WELL AS
WESTERN ALASKA AND THE ALEUTIANS, CONSISTENT WITH GEFS REFORECAST GUIDANCE.

SOUTHWESTERLY ANOMALOUS FLOW AND TROUGHING FAVOR ABOVE-MEDIAN PRECIPITATION
AMOUNTS FROM THE PACIFIC NORTHWEST TO THE NORTHERN ROCKIES. SHORT WAVE
DISTURBANCES ARE EXPECTED NEAR THE NORTHERN EXTENT OF THE DOWNSTREAM RIDGE,
ENHANCING CHANGES FOR ABOVE-MEDIAN PRECIPITATION FOR THE NORTHERN PLAINS, THE
UPPER AND MIDDLE MISSISSIPPI VALLEY, THE GREAT LAKES, THE OHIO VALLEY, AND THE
TENNESSEE VALLEY. ABOVE-MEDIAN PRECIPITATION AMOUNTS ARE FAVORED FOR THE EAST
COAST DUE TO THE POSSIBLE INFLUENCE OF PRECIPITATION ASSOCIATED WITH TROPICAL
STORM ERIKA. THERE ARE ENHANCED CHANCES OF BELOW MEDIAN PRECIPITATION FOR
MAINE, SOUTHERN TEXAS AND THE ALASKAN PANHANDLE, WITH ABOVE MEDIAN
PRECIPITATION FOR NORTHERN ALASKA IN CONSISTENT WITH PRECIPITATION ESTIMATES
FROM THE GEFS AND ECMWF ENSEMBLE MEMBERS.

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


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOUT AVERAGE, 3 OUT OF 5, DUE
TO GOOD AGREEMENT AMONG THE TEMPERATURE TOOLS OFFSET BY LARGE UNCERTAINTY IN
THE PRECIPITATION OUTLOOKS ACROSS THE EASTERN CONUS.

FORECASTER: LUKE HE

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:
19850825 - 19970821 - 19970910 - 19540829 - 19940907


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:
19850825 - 19970820 - 19540829 - 20050830 - 19940907


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 02 - 06 2015

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 04 - 10 2015

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

$$



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