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FXUS06 KWBC 172011
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST WED DECEMBER 17 2014

6-10 DAY OUTLOOK FOR DEC 23 - 27 2014

TODAY`S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE 500-HPA HEIGHT PATTERN
FORECAST FOR THE 6-10 DAY PERIOD. ALL MODELS ARE FORECASTING A BUILDING RIDGE
OVER THE NORTHEAST PACIFIC AND ALASKA. COMPARED WITH YESTERDAY`S FORECAST, THE
DOWNSTREAM TROUGH SHIFTED EASTWARD PREDICTED OVER THE EASTERN CONUS. POSITIVE
500-HPA HEIGHT ANOMALIES ARE FORECAST ALONG THE WEST COAST, NEGATIVE 500-HPA
HEIGHT ANOMALIES ARE FORECAST FROM THE ROCKIES TO THE EAST COAST. THE ENSEMBLE
SPAGHETTI DIAGRAMS INDICATE MODERATE SPREAD ACROSS THE FORECAST DOMAIN. TODAY`S
OFFICIAL 500-HPA HEIGHT MANUAL BLEND INCLUDED THE OPERATIONAL EUROPEAN MODEL
SINCE IT IS CONSISTENT WITH THE ENSEMBLE MEAN SOLUTIONS.

ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR THE WESTERN AND NORTHEASTERN CONUS
NEAR THE FORECAST RIDGE AND AHEAD OF THE TROUGH, RESPECTIVELY. BELOW-NORMAL
TEMPERATURES ARE EXPECTED OVER THE NORTHERN PLAINS AS MUCH COLDER TEMPERATURES
ARE FORECAST TO ENTER THIS REGION BY DAY 8. WITH SST ANOMALIES BELOW-NORMAL IN
THE EASTERN GULF OF MEXICO, BELOW-NORMAL TEMPERATURES ARE FAVORED FOR FLORIDA.
ABOVE-NORMAL TEMPERATURE PROBABILITIES ARE ENHANCED FOR ALASKA, AND THE
ALEUTIANS IN ASSOCIATION WITH THE SURFACE SOUTHWESTERLY FLOW, EAST OF THE LOW
PRESSURE SYSTEM OVER THE BERING SEA.

WITH A STRONG PACIFIC JET NEAR THE NORTHWEST COAST, ABOVE-MEDIAN PRECIPITATION
IS FAVORED FROM THE PACIFIC NORTHWEST TO THE NORTHERN ROCKIES AND NORTHERN
GREAT PLAINS. ABOVE-MEDIAN PRECIPITATION IS PREDICTED OVER THE GREAT LAKES,
OHIO VALLEY AND ATLANTIC COAST STATES IN ASSOCIATION WITH THE ACTIVE
LOWER-LEVEL JET AHEAD OF THE TROUGH. BELOW-MEDIAN PRECIPITATION CHANCES ARE
ENHANCED FOR THE SOUTHWESTERN CONUS AND WEST GULF COAST, UNDER THE INFLUENCE OF
THE RIDGE NEAR THE WEST COAST. ABOVE-MEDIAN PRECIPITATION CHANCES ARE ENHANCED
FOR WESTERN ALASKA AND THE ALEUTIANS, NEAR AND AHEAD OF THE PREDICTED TROUGH
OVER THE NORTH PACIFIC. BELOW-MEDIAN PRECIPITATION CHANCES ARE ENHANCED FOR
EASTERN ALASKA, AND THE PANHANDLE IN ASSOCIATION WITH THE RIDGE FORECAST OFF
THE WEST COAST OF NORTH AMERICA.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 20% OF TODAY`S 6Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 20% OF YESTERDAY`S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 7,
20% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 20% OF YESTERDAY`S
12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 7, AND 20% OF TODAY`S OPERATIONAL 0Z
ECMWF CENTERED ON DAY 8


MODEL OF THE DAY: NO PREFERENCE

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO GOOD
AGREEMENT AMONG ENSEMBLE MEANS, OFFSET BY UNCERTAINTY WHEN COLDER TEMPERATURE
ENTER THE CONUS.

8-14 DAY OUTLOOK FOR DEC 25 - 31 2014

THE ENSEMBLE MEAN PREDICTIONS OF THE 500-HPA HEIGHT PATTERN FOR THE WEEK-2
PERIOD ARE IN FAIR AGREEMENT OVER NORTH AMERICA. A RIDGE IS PREDICTED OVER THE
GULF OF ALASKA, ASSOCIATED WITH POSITIVE 500-HPA HEIGHT ANOMALIES OFF THE WEST
COAST. A HIGHLY AMPLITUDE TROUGH IS ANTICIPATED OVER THE EASTERN CONUS, WITH
NEGATIVE 500-HPA HEIGHT ANOMALIES ACROSS MOST OF THE CONUS. THE ENSEMBLE
SPAGHETTI DIAGRAMS INDICATE MODERATE SPREAD ACROSS THE FORECAST DOMAIN.

THERE ARE ENHANCED PROBABILITIES FOR NEAR- TO ABOVE-NORMAL TEMPERATURES FOR THE
SOUTHWESTERN CONUS, AHEAD OF THE RIDGE OFF THE WEST COAST. BELOW-NORMAL
TEMPERATURES ARE FAVORED FOR MUCH OF THE NORTHERN, CENTRAL AND EASTERN CONUS
EXCEPT FOR NEW ENGLAND. THERE ARE ENHANCED PROBABILITIES FOR NEAR- TO
ABOVE-NORMAL TEMPERATURES FOR ALASKA RELATED TO THE SOUTHWESTERLY WINDS, EAST
OF THE SURFACE LOW PRESSURE OVER THE BERING SEA.

BELOW-MEDIAN PRECIPITATION IS FAVORED FOR THE WESTERN CONUS IN ASSOCIATION WITH
THE FORECAST RIDGE OFF THE WEST COAST. NEAR- TO ABOVE-MEDIAN PRECIPITATION IS
FAVORED FOR THE NORTHERN AND CENTRAL ROCKIES, THE NORTHERN GREAT PLAINS, THE
GREAT LAKES AND THE NEW ENGLAND, CONSISTENT WITH THE BIAS CORRECTED
PRECIPITATION FROM THE ECMWF ENSEMBLES AND GFS ENSEMBLES.  ABOVE-MEDIAN
PRECIPITATION IS ALSO FAVORED FOR THE SOUTHEASTERN CONUS AHEAD OF THE TROUGH.
THERE ARE ENHANCED PROBABILITIES OF NEAR- TO ABOVE-MEDIAN PRECIPITATION FOR
WESTERN ALASKA AND THE ALEUTIANS. BELOW-MEDIAN PRECIPITATION IS FAVORED FOR
EASTERN ALASKA AND THE PANHANDLE.

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


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOUT AVERAGE, 3 OUT OF 5, DUE
TO FAIR MODEL AGREEMENT WITH SOME DISAGREEMENT BETWEEN TOOLS FROM THE ECMWF AND
GEFS ENSEMBLES.

FORECASTER: QIN GINGER ZHANG

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
DECEMBER 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:
19911230 - 19931215 - 19871128 - 19591225 - 20031224


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:
19911230 - 19931214 - 19871127 - 19591225 - 20031224


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR DEC 23 - 27 2014

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR DEC 25 - 31 2014

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