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FXUS06 KWBC 171901
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT WED SEPTEMBER 17 2014

6-10 DAY OUTLOOK FOR SEP 23 - 27 2014

THERE IS FAIR 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 DEEP TROUGH OVER THE EASTERN NORTH PACIFIC, SOUTH OF ALASKA. A RIDGE IS
PREDICTED OVER WESTERN NORTH AMERICA. DOWNSTREAM FROM THESE FEATURES, THE
ENSEMBLE MEANS PREDICT A WEAK TROUGH OVER THE EASTERN CONUS. THERE IS
CONSIDERABLE SPREAD AMONG THE INDIVIDUAL ENSEMBLE MEMBERS OVER MOST OF THE
CONUS. THEREFORE, TODAY`S OFFICIAL 500-HPA HEIGHT BLEND IS BASED PRIMARILY ON
THE ENSEMBLE MEAN SOLUTIONS.

THE RIDGE FORECAST OVER THE WESTERN CONUS FAVORS ABOVE-NORMAL TEMPERATURES FROM
THE NORTHERN PLAINS TO THE WEST COAST. BELOW-NORMAL TEMPERATURES ARE FAVORED
FOR THE NORTHEASTERN CONUS DUE A TROUGH PREDICTED OVER THE EASTERN CONUS.
BELOW-NORMAL TEMPERATURE PROBABILITIES ARE ALSO ENHANCED FOR PARTS OF THE
SOUTHERN HIGH PLAINS DUE TO A POTENTIAL INFLUX OF MOISTURE INTO THIS REGION.
THE ODDS OF ABOVE-NORMAL TEMPERATURES ARE ELEVATED FOR MUCH OF FLORIDA AND THE
GULF COAST CONSISTENT WITH ABOVE NORMAL SEA SURFACE TEMPERATURES IN THE REGION.
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.

THE TROUGH OVER THE EASTERN CONUS ENHANCES PROBABILITIES FOR ABOVE-MEDIAN
PRECIPITATION AMOUNTS OVER PARTS OF THE SOUTHEASTERN CONUS. SUBSIDENCE BEHIND
THE PREDICTED EASTERN CONUS TROUGH FAVORS BELOW-MEDIAN PRECIPITATION FOR THE
MIDWEST AND INTERIOR NORTHEAST. THE PREDICTED WESTERN RIDGE ENHANCES CHANCES
FOR BELOW-MEDIAN PRECIPITATION FOR PARTS OF THE NORTHERN INTERMOUNTAIN WEST.
ABOVE-MEDIAN PRECIPITATION IS FAVORED FOR THE SOUTHERN HIGH PLAINS, 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 SOUTHEASTERN AND NORTHEASTERN ALASKA AHEAD OF A
PREDICTED TROUGH. BELOW-MEDIAN PRECIPITATION IS FAVORED FOR MUCH OF
SOUTHWESTERN ALASKA BEHIND THE PREDICTED TROUGH AXIS.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 10% 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 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


MODEL OF THE DAY: 0Z ECMWF ENSEMBLE MEAN

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO FAIRLY
GOOD AGREEMENT AMONG THE FORECAST TOOLS OFFSET BY LARGE MODEL SPREAD OVER MOST
OF THE CONUS.

8-14 DAY OUTLOOK FOR SEP 25 - OCT 01, 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 ENSEMBLE MEANS OVER MUCH OF
THE CONUS DUE, IN PART, TO LARGE VARIATIONS AMONG THE COMPONENT ENSEMBLE
MEMBERS BEING AVERAGED TOGETHER. THE 0Z AND 6Z DETERMINISTIC GFS PREDICT MORE
AMPLIFIED PATTERNS THAN THE ENSEMBLE MEANS WITH A TROUGH OVER THE EASTERN OR
EAST-CENTRAL CONUS. HOWEVER, RUN TO RUN CONSISTENCY IS POOR AS THE 12Z
DETERMINISTIC GFS IS OUT OF PHASE WITH THE PREVIOUS RUNS AND PREDICTS AN
AMPLIFIED TROUGH OVER THE WESTERN CONUS AND A RIDGE OVER THE EAST. 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 THE WESTERN CONUS, NORTHERN PLAINS,
AND MUCH OF THE NORTHEAST UNDERNEATH PREDICTED NEAR TO POSITIVE 500-HPA HEIGHT
ANOMALIES. NEAR-NORMAL TEMPERATURES ARE FAVORED FROM THE SOUTHERN HIGH PLAINS
TO THE MID ATLANTIC CONSISTENT WITH GEFS REFORECAST GUIDANCE. ELSEWHERE,
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 PARTS OF THE SOUTHEASTERN CONUS AHEAD OF A TROUGH PREDICTED
OVER THE EASTERN CONUS IN THE MANUAL BLEND. BELOW-MEDIAN PRECIPITATION
PROBABILITIES ARE ENHANCED FOR PARTS OF THE TENNESSEE AND OHIO VALLEYS TO THE
MID-ATLANTIC CONSISTENT WITH GEFS REFORECAST AND NAEFS GUIDANCE. MODELS HAVE
TRENDED WETTER OVER THE NORTHERN PLAINS RESULTING IN INCREASES IN ABOVE-MEDIAN
PRECIPITATION PROBABILITIES FOR THIS REGION RELATIVE TO YESTERDAY`S OUTLOOK.
ABOVE-MEDIAN PRECIPITATION PROBABILITIES ARE ALSO ENHANCED FOR PARTS OF THE
SOUTHERN HIGH PLAINS CONSISTENT WITH NAEFS AND GEFS REFORECAST GUIDANCE. NEAR-
TO BELOW-MEDIAN PRECIPITATION PROBABILITIES ARE ENHANCED FOR MUCH OF THE FAR
WEST UNDERNEATH PREDICTED POSITIVE 500-HPA HEIGHT ANOMALIES. 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 SOUTHWESTERN ALASKA BEHIND A PREDICTED TROUGH AXIS.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 15% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 20% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY
11, 5% OF TODAY`S OPERATIONAL 0Z GFS CENTERED ON DAY 11, 10% OF TODAY`S
OPERATIONAL 6Z GFS CENTERED ON DAY 11, 25% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, 15% OF YESTERDAY`S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON
DAY 10, AND 10% 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
SEPTEMBER 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:
19550910 - 20080916 - 19730916 - 19790920 - 19950911


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 - 19790918 - 19840930 - 19950911 - 20080917


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

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 25 - OCT 01, 2014

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