Prognostic Meteorological Discussion
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FXUS06 KWBC 282001
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST FRI NOVEMBER 28 2014

6-10 DAY OUTLOOK FOR DEC 04 - 08 2014

THE AGREEMENT AMONG THE ENSEMBLE MEANS OF THE VARIOUS MODELS IS A BIT BETTER
TODAY THAN ON YESTERDAY`S RUNS. AS IN YESTERDAY`S FORECAST, THE MODELS AGREE
WELL ON THE NORTHERN STREAM FLOW PATTERN BUT DISAGREE ON A SOUTHERN-STREAM
TROUGH FORECAST TO INFLUENCE THE SOUTH-CENTRAL CONUS WITHIN THE 6-10 DAY
PERIOD. THE GEFS AND CANADIAN MODELS TEND TO FORECAST A SPLIT FLOW, WITH A
TROUGH OVER THE SOUTHWESTERN CONUS UNDERNEATH A NORTHERN STREAM RIDGE. THE
ECMWF ENSEMBLES KEEP THE SOUTHERN STREAM MORE INTACT WITH A NORTHERN-STREAM
TROUGH FORECAST TO BE WELL OFF THE COAST IN THE EASTERN NORTH PACIFIC. TODAY`S
ECMWF SHOWS MORE HINTS OF AN ACTIVE SOUTHERN STREAM THAN IT DID ON YESTERDAY`S
PRODUCING A SLIGHTLY BETTER CONSENSUS WITH THE GEFS ON THE LIKELY TEMPERATURE
AND PRECIPITATION ANOMALIES OVER THE CONUS WITHIN THE 6-10 DAY PERIOD. THE
CANADIAN MODEL RESEMBLES THE GEFS SOLUTION, LEADING TO HIGHER WEIGHTS GIVEN TO
THE GEFS ENSEMBLE IN TODAY`S BLEND.

ABOVE-NORMAL 500-HPA HEIGHTS ARE FORECAST OVER MUCH OF THE COUNTRY LEADING TO
ENHANCED CHANCES OF ABOVE-NORMAL TEMPERATURES FOR MOST OF THE CONUS. THE
500-HPA HEIGHT ANOMALIES OVER THE EASTERN CONUS ARE SOMEWHAT HIGHER IN TODAY`S
ENSEMBLE MEANS, BUT TEMPERATURE FORECASTS FROM THE GEFS CONTINUE TO SUGGEST
ENHANCED CHANCES FOR NEAR-NORMAL TEMPERATURES ALONG THE U.S. - CANADIAN BORDER
FROM THE GREAT LAKES EASTWARD ASSOCIATED WITH THE POSSIBILITY OF AN EASTERN
TROUGH.  A RIDGE EXTENDS FROM THE WEST COAST OF CANADA INTO EASTERN ALASKA,
INCREASING CHANCES FOR ABOVE-NORMAL TEMPERATURES IN THE SOUTHERN PART OF THE
STATE, BUT HEIGHTS ARE PREDICTED TO BE BELOW NORMAL, SO NEAR-NORMAL
TEMPERATURES ARE FAVORED FOR NORTHERN ALASKA.

THE CHANCES FOR ABOVE-MEDIAN PRECIPITATION AMOUNTS ARE ELEVATED FOR PARTS OF
THE SOUTHWESTERN CONUS NEAR AND AHEAD OF THE ANTICIPATED SOUTHERN STREAM
TROUGH. THE GEFS IS QUITE CONFIDENT FOR ABOVE-MEDIAN PRECIPITATION AMOUNTS NEAR
TEXAS, HOWEVER PROBABILITIES ARE KEPT FAIRLY LOW CONSIDERING THE WEAKER
SOUTHERN JET PREDICTED BY THE ECMWF. AS IN YESTERDAY`S MODEL RUNS, THE GEFS
ENSEMBLES CONTINUE TO SUGGEST ENHANCED CHANCES OF ABOVE-MEDIAN PRECIPITATION
FROM TEXAS NORTHEASTWARD TO PARTS OF NEW ENGLAND. THE PREDICTION OF A
DEVELOPING RIDGE OVER THE WEST COAST OF CANADA SUGGESTS A NORTHERLY
DISPLACEMENT OF THE PACIFIC STORM TRACK WITH ENHANCED CHANCES FOR ABOVE-MEDIAN
PRECIPITATION AMOUNTS IN SOUTHEASTERN ALASKA, AND ELEVATED CHANCES OF
BELOW-MEDIAN PRECIPITATION AMOUNTS FOR THE PACIFIC NORTHWEST, NORTHERN ROCKIES
AND NORTHERN GREAT PLAINS.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 40% OF TODAY`S 6Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 30% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8,
10% OF TODAY`S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, AND 20% OF TODAY`S 0Z
CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8


MODEL OF THE DAY: 6Z GEFS ENSEMBLE MEAN

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: NEAR AVERAGE, 3 OUT OF 5, DUE TO
GOOD MODEL AGREEMENT BUT WITH CONTINUED DISAGREEMENT ON THE STRENGTH OF
SOUTHERN STREAM DISTURBANCES.

8-14 DAY OUTLOOK FOR DEC 06 - 12 2014

THE AGREEMENT AMONG MODELS FOR THE MEAN 500-HPA HEIGHTS IN THE 8-14 DAY PERIOD
CONTINUES TO BE QUITE POOR. AT ISSUE IS THE STRENGTH OF THE TROUGH FORECAST TO
BE OVER THE EASTERN CONUS, AND THE STRENGTH OF A SOUTHERN-STREAM TROUGH
EXPECTED OVER THE SOUTHWESTERN CONUS. THE GEFS CONTINUES TO SUGGEST A
PRONOUNCED SPLIT FLOW OVER WESTERN NORTH AMERICA, WITH A TROUGH IN THE SOUTHERN
JET OVER THE SOUTHWEST AND A RIDGE TO ITS NORTH OVER WESTERN NORTH AMERICA. THE
ECMWF KEEPS ONLY A WEAK SOUTHERN STREAM IN MOSTLY ZONAL FLOW. THE CANADIAN
ENSEMBLE MEAN IS SIMILAR TO THE GEFS, BUT WITH HIGHER AMPLITUDE IN THE NORTHERN
STREAM, LEADING TO A FAIRLY DEEP EASTERN TROUGH. THE DETERMINISTIC GFS RUNS
ALSO SUGGEST A DEEPER EASTERN TROUGH THAN THE GEFS.

MOST ENSEMBLES FAVOR ABOVE-NORMAL 500-HPA HEIGHTS OVER MUCH OF NORTH AMERICA,
ENHANCING CHANCES FOR ABOVE-NORMAL TEMPERATURES THROUGHOUT THE CONUS.
PROBABILITIES ARE NOT HIGH, IN VIEW OF THE POSSIBILITY OF HIGHER AMPLITUDE FLOW
SUGGESTED BY THE CANADIAN MODEL AND THE DETERMINISTIC GFS. NEAR-NORMAL
TEMPERATURES ARE FAVORED IN THE NORTHEAST CONUS CLOSEST TO THE TROUGH AXIS
PREDICTED BY THE GEFS AND CANADIAN MODELS.

TODAY`S 8-14 DAY PRECIPITATION OUTLOOK WAS REVISED CONSIDERABLY FROM
YESTERDAY`S OUTLOOK IN PARTS OF THE EAST CENTRAL CONUS, REFLECTING THE BETTER
MODEL AGREEMENT ON THE POSSIBLE TRACK OF MOISTURE ASSOCIATED WITH THE SOUTHERN
JET. THE PRECIPITATION FORECASTS FROM TODAY`S GEFS REFORECAST ARE MORE
CONSISTENT BETWEEN THE 6-10 AND 8-14 DAY PERIODS THAN YESTERDAY`S RUNS. THE
BETTER CONSISTENCY INCREASES THE CONFIDENCE SOMEWHAT IN THE PREDICTIONS SINCE
IT SUGGESTS A MORE STABLE PATTERN. TODAY`S FORECAST SUGGESTS ENHANCED CHANCES
FOR ABOVE-MEDIAN PRECIPITATION ASSOCIATED WITH THE SOUTHERN JET FROM TEXAS TO
PARTS OF THE MID-ATLANTIC STATES. RELATIVELY DRY NORTHWESTLY FLOW IS EXPECTED
OVER MUCH OF THE CENTRAL CONUS, WHICH TOGETHER WITH THE NORTHERN-STREAM RIDGE
SHOULD INCREASE THE CHANCES FOR BELOW-MEDIAN PRECIPITATION ACROSS THE REMAINDER
OF THE CENTRAL AND WESTERN CONUS EXCEPT FOR PARTS OF WASHINGTON STATE. THE
EXPECTED WESTERN RIDGE INCREASES CHANCES FOR ABOVE-MEDIAN PRECIPITATION IN
CENTRAL AND SOUTHEASTERN ALASKA AS IT DIVERTS THE PACIFIC STORM TRACK NORTHWARD.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 40% OF TODAY`S 6Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 30% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON
DAY 11, AND 30% 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 UNCERTAINTY IN THE STRENGTH OF THE SOUTHERN STREAM TROUGH AND THE AMPLITUDE
OF A POSSIBLE TROUGH OVER THE EASTERN CONUS.

FORECASTER: DAVE UNGER

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:
19721129 - 19581203 - 19931108 - 19601109 - 20021205


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:
19721129 - 19581202 - 19931107 - 19961111 - 19641122


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR DEC 04 - 08 2014

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    B     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    B
UTAH        A    N     ARIZONA     A    A     COLORADO    A    A
NEW MEXICO  A    A     N DAKOTA    A    B     S DAKOTA    A    B
NEBRASKA    A    N     KANSAS      A    A     OKLAHOMA    A    A
N TEXAS     A    A     S TEXAS     A    A     W TEXAS     A    A
MINNESOTA   A    B     IOWA        A    N     MISSOURI    A    A
ARKANSAS    A    A     LOUISIANA   A    N     WISCONSIN   A    B
ILLINOIS    A    A     MISSISSIPPI A    N     MICHIGAN    N    N
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    A
TENNESSEE   A    A     ALABAMA     A    B     NEW YORK    A    A
VERMONT     N    N     NEW HAMP    A    A     MAINE       N    N
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    N     VIRGINIA    A    N
N CAROLINA  A    N     S CAROLINA  A    B     GEORGIA     A    B
FL PNHDL    A    B     FL PENIN    A    N     AK N SLOPE  N    B
AK ALEUTIAN A    N     AK WESTERN  A    B     AK INT BSN  N    B
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    A    A



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR DEC 06 - 12 2014

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