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FXUS06 KWBC 181914
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU SEPTEMBER 18 2014

6-10 DAY OUTLOOK FOR SEP 24 - 28 2014

THERE IS FAIR TO POOR AGREEMENT AMONG TODAY`S ENSEMBLE MEAN FORECASTS OF 6-10
DAY 500-HPA HEIGHTS OVER NORTH AMERICA AND VICINITY. MODELS AGREE ON THE
PREDICTION OF A TROUGH OVER ALASKA. DOWNSTREAM, TODAY`S GFS-BASED SOLUTIONS
FORECAST A TROUGH OVER THE NORTHWESTERN CONUS WHILE THE 0Z ECMWF DETERMINISTIC
AND ENSEMBLE MEAN KEEP THIS FEATURE MOSTLY OFF THE COAST. FARTHER TO THE EAST,
MOST MODEL SOLUTIONS DEPICT A RIDGE OVER THE GREAT LAKES REGION. THERE IS
CONSIDERABLE SPREAD AMONG THE INDIVIDUAL ENSEMBLE MEMBERS OVER MUCH OF THE
CONUS. THEREFORE, TODAY`S OFFICIAL 500-HPA HEIGHT BLEND IS BASED PRIMARILY ON
THE ENSEMBLE MEAN SOLUTIONS.

ABOVE-NORMAL TEMPERATURES ARE FAVORED FROM THE SOUTHWESTERN CONUS TO THE
NORTHERN PLAINS AHEAD OF A TROUGH PREDICTED NEAR THE NORTHWESTERN CONUS.
BELOW-NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE MID-ATLANTIC REGION IN
ASSOCIATION WITH PREDICTED MEAN NORTHEASTERLY SURFACE FLOW. THE ODDS OF
ABOVE-NORMAL TEMPERATURES ARE ELEVATED FOR SOUTHERN FLORIDA AND PARTS OF THE
GULF COAST CONSISTENT WITH ABOVE NORMAL SEA SURFACE TEMPERATURES IN THE REGION
AND BIAS CORRECTED TEMPERATURES FROM THE 0Z ECMWF ENSEMBLES. ABOVE-NORMAL
TEMPERATURES ARE ALSO FAVORED FOR THE ALASKA PANHANDLE AHEAD OF A PREDICTED
TROUGH. BELOW-NORMAL TEMPERATURE PROBABILITIES ARE ENHANCED FOR PARTS OF
NORTHERN ALASKA NEAR THE TROUGH AXIS. PROBABILITIES OF ABOVE-NORMAL
TEMPERATURES ARE ELEVATED FOR THE ALEUTIANS CONSISTENT WITH BIAS CORRECTED
TEMPERATURES FROM THE ECMWF ENSEMBLES AND WITH ABOVE NORMAL SEA SURFACE
TEMPERATURES IN ADJACENT WATERS.

MODELS HAVE TRENDED WETTER FOR THE PACIFIC NORTHWEST IN ASSOCIATION WITH A
PREDICTED TROUGH. THEREFORE, PROBABILITIES OF ABOVE MEDIAN-PRECIPITATION WERE
INCREASED FOR THIS AREA RELATIVE TO YESTERDAY`S OUTLOOK. AN ANTICIPATED FRONT
AND MEAN EASTERLY FLOW ENHANCES PROBABILITIES FOR ABOVE-MEDIAN PRECIPITATION
AMOUNTS OVER FLORIDA AND THE GULF COAST REGION. PREDICTED SURFACE HIGH PRESSURE
FAVORS BELOW-MEDIAN PRECIPITATION FOR MUCH OF THE NORTHEASTERN CONUS.
ABOVE-MEDIAN PRECIPITATION IS FAVORED FOR MUCH OF THE SOUTHERN AND CENTRAL HIGH
PLAINS, MUCH OF THE SOUTHERN ROCKIES, AND PARTS OF THE CENTRAL ROCKIES AND
SOUTHWEST CONSISTENT WITH GEFS REFORECAST GUIDANCE. THERE ARE ELEVATED
PROBABILITIES OF ABOVE-MEDIAN PRECIPITATION FOR PARTS OF THE ALASKA PANHANDLE
AHEAD OF A PREDICTED TROUGH. BELOW-MEDIAN PRECIPITATION IS FAVORED FOR MUCH OF
THE REMAINDER OF ALASKA NEAR AND WEST OF THE PREDICTED TROUGH AXIS.

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


MODEL OF THE DAY: 0Z ECMWF ENSEMBLE MEAN AND 0Z GFS ENSEMBLE MEAN (TIED)

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, DUE TO
LARGE MODEL SPREAD OVER MUCH OF THE FORECAST DOMAIN.

8-14 DAY OUTLOOK FOR SEP 26 - OCT 02, 2014

DURING THE WEEK TWO PERIOD, TODAY`S MODEL ENSEMBLES EXHIBIT HIGH SPREAD OVER
MUCH OF THE FORECAST DOMAIN INDICATING HIGH UNCERTAINTY AMONG THE MODEL
SOLUTIONS. TODAY`S ENSEMBLE MEAN SOLUTIONS FORECAST A TROUGH OVER ALASKA.
RELATIVELY LOW-AMPLITUDE FLOW IS FORECAST BY THE ECMWF AND CANADIAN ENSEMBLE
MEANS OVER MUCH OF THE CONUS DUE, IN PART, TO LARGE VARIATIONS AMONG THE
COMPONENT ENSEMBLE MEMBERS BEING AVERAGED TOGETHER. TODAY`S GFS-BASED SOLUTIONS
PREDICT MORE AMPLIFIED SOLUTIONS THAN THE ECMWF AND CANADIAN ENSEMBLE MEANS AND
FORECAST A TROUGH OVER THE ROCKIES WITH RIDGING OVER THE EASTERN CONUS. THIS
WOULD REPRESENT A SIGNIFICANT PATTERN CHANGE FROM THAT FORECAST EARLIER THIS
WEEK. THUS, CONFIDENCE REMAINS LOW IN TODAY`S OUTLOOK PACKAGE. DUE TO LARGE
UNCERTAINTIES AMONG INDIVIDUAL ENSEMBLE MEMBERS, TODAY`S WEEK TWO MANUAL HEIGHT
BLEND CONSISTS PRIMARILY OF THE ENSEMBLE MEAN SOLUTIONS.

ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE EASTERN CONUS DUE TO
PREDICTED RIDGING. ENHANCED PROBABILITIES OF ABOVE-NORMAL TEMPERATURES ARE ALSO
INDICATED FOR MOST OF CALIFORNIA, UNDERNEATH PREDICTED POSITIVE 500-HPA HEIGHT
ANOMALIES. NEAR-NORMAL TEMPERATURES ARE FAVORED FOR THE PACIFIC NORTHWEST AND
MUCH OF THE INTERMOUNTAIN WEST IN ASSOCIATION WITH A PREDICTED TROUGH. FOR
ALASKA, TEMPERATURE ANOMALIES FOR THE 8-14 DAY PERIOD ARE EXPECTED TO BE
SIMILAR TO THOSE IN THE 6-10 DAY PERIOD.

THE PRECIPITATION FORECAST FOR THE 8-14 DAY PERIOD FAVORS ABOVE-MEDIAN
PRECIPITATION FOR THE PACIFIC NORTHWEST, ROCKIES, AND MUCH OF THE PLAINS IN
ASSOCIATION WITH A TROUGH PREDICTED OVER THE ROCKIES IN THE MANUAL BLEND.
BELOW-MEDIAN PRECIPITATION PROBABILITIES ARE ENHANCED FOR MUCH OF THE NORTHEAST
CONUS DUE TO PREDICTED MEAN SURFACE HIGH PRESSURE. ABOVE-MEDIAN PRECIPITATION
PROBABILITIES ARE ENHANCED FOR FLORIDA AND THE GULF COAST REGION DUE TO
PREDICTED MEAN EASTERLY SURFACE FLOW. MOIST FLOW AHEAD OF A TROUGH OVER THE
EASTERN NORTH PACIFIC FAVORS ABOVE-MEDIAN PRECIPITATION FOR THE ALASKA
PANHANDLE. BELOW-MEDIAN PRECIPITATION PROBABILITIES ARE ENHANCED FOR MUCH OF
THE REMAINDER OF ALASKA SIMILAR TO THAT PREDICTED IN THE 6 TO 10 DAY PERIOD.

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, 10% OF TODAY`S OPERATIONAL 0Z GFS CENTERED ON DAY 11, 10% OF TODAY`S
OPERATIONAL 6Z GFS CENTERED ON DAY 11, 20% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, 15% OF YESTERDAY`S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON
DAY 10, AND 5% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: MUCH BELOW AVERAGE, 1 OUT OF 5,
DUE TO HIGH SPREAD AMONG TODAY`S ENSEMBLE MEMBERS AND POOR CONTINUITY BETWEEN
TODAY`S AND YESTERDAY`S FORECAST TOOLS

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
OCTOBER 16

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:
19550910 - 19950910 - 19790920 - 20080916 - 19841001


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:
19550910 - 19790919 - 19840930 - 19560916 - 19950911


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 24 - 28 2014

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 26 - OCT 02, 2014

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

$$




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