Prognostic Meteorological Discussion
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FXUS06 KWBC 272001
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST THU NOVEMBER 27 2014

6-10 DAY OUTLOOK FOR DEC 03 - 07 2014

THERE IS CONSIDERABLE DISAGREEMENT AMONG THE ENSEMBLE MEANS OF THE VARIOUS
MODELS ON THE IMPORTANT 500-HPA FEATURES AFFECTING THE CONUS IN THE 6-10 DAY
PERIOD. AT ISSUE IS THE FORECAST EVOLUTION OF A TROUGH EXPECTED TO BE OFF THE
WEST COAST OF THE CONUS NEAR THE START OF THE 6-10 DAY PERIOD. THE GFS AND
CANADIAN MODELS SHOW A PROGRESSIVE TROUGH STALLING OVER THE SOUTHWESTERN CONUS,
RESULTING IN A SPLIT FLOW ON THE 6-10 DAY MEAN. THE ECMWF, ON THE OTHER HAND,
KEEPS THE TROUGH OFF SHORE AND PHASED WITH THE NORTHERN STREAM. THE FORECAST
FOR THE NORTHERN STREAM IS IN REASONABLE AGREEMENT, WITH ALL MODELS PREDICTING
ABOVE-NORMAL 500-HPA HEIGHTS BETWEEN 30 AND 50 DEGREES NORTH LATITUDE, AND
BELOW-NORMAL HEIGHTS FARTHER NORTH. THIS GIVES A POSITIVE AO/NAO LOOK TO THE
FLOW PATTERN AND A STRONG JET JUST NORTH OF THE U.S./CANADIAN BORDER. THE
500-HPA HEIGHTS OVER ALASKA ARE MOSTLY FORECAST TO BE NEAR TO BELOW NORMAL WITH
A TROUGH OVER THE WESTERN PART OF THE STATE.

IN SPITE OF REASONABLE AGREEMENT ON THE 500-HPA CIRCULATION ELSEWHERE, THE
DIFFERENT SOLUTIONS OVER THE SOUTHWEST HAVE WIDESPREAD INFLUENCE ON THE
TEMPERATURE AND PRECIPITATION PATTERNS FOR MOST OF THE CONUS. THE SPLIT FLOW OF
THE GEFS AND CANADIAN MODELS WOULD PROVIDE MOISTURE TO THE WESTERN CONUS NEAR
THE TROUGH, AND PROVIDE FOR MORE MOISTURE IN THE SOUTHWEST FLOW AHEAD OF THE
SOUTHERN STREAM TROUGH IN THE CENTRAL AND EASTERN CONUS. THE ECMWF KEEPS THE
FLOW MORE ZONAL AND WITH LESS CERTAINTY IN ITS PRECIPITATION SYSTEMS. THE POOR
AGREEMENT AMONG TODAY`S MODELS RESULTS IN CONSIDERABLE REVISIONS TO THE
FORECAST RELATIVE TO YESTERDAY`S OUTLOOK. THE GEFS SOLUTION WAS SLIGHTLY
FAVORED IN TODAY`S BLEND DUE TO IT`S AGREEMENT WITH THE CANADIAN ENSEMBLES.

THE MODELS CONTINUE TO FAVOR ABOVE-NORMAL 500-HPA HEIGHTS OVER MUCH OF THE
COUNTRY LEADING TO ENHANCED CHANCES OF ABOVE-NORMAL TEMPERATURES FOR MOST OF
THE CONUS. LOW LEVEL TEMPERATURE FORECASTS FROM THE GEFS CONTINUE TO SUGGEST
THAT SHALLOW COLD AIR MASSES WILL ELEVATE CHANCES FOR BELOW-NORMAL TEMPERATURES
NEAR THE NORTHERN GREAT PLAINS. TEMPERATURES IN ALASKA ARE WARMER TODAY THAN
INDICATED ON YESTERDAY`S OUTLOOK, WITH ABOVE-NORMAL TEMPERATURES FAVORED FOR
THE SOUTHERN PART OF THE STATE, AND THE CHANCES OF NEAR- TO BELOW-NORMAL
TEMPERATURES SLIGHTLY ELEVATED IN THE NORTH.

THE PRECIPITATION OUTLOOK REFLECTS THE GEFS AND CANADIAN SOLUTIONS FAVORING A
TROUGH OVER THE SOUTHWEST IN THE 6-10 DAY PERIOD WITH LOW CONFIDENCE. THE
CHANCES FOR ABOVE-MEDIAN PRECIPITATION AMOUNTS ARE ELEVATED FOR MUCH OF THE
SOUTHWESTERN CONUS NEAR AND AHEAD OF THE ANTICIPATED SOUTHERN STREAM TROUGH.
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 NEAR TO BELOW-MEDIAN PRECIPITATION AMOUNTS FOR THE PACIFIC NORTHWEST,
NORTHERN ROCKIES AND NORTHERN GREAT PLAINS. THE GEFS FAVORS A STORM TRACK
STRETCHING FROM TEXAS TO THE SAINT LAWRENCE VALLEY, HOWEVER THE FORECAST WAS
ADJUSTED TO REFLECT THE DRIER CONDITIONS SUGGESTED BY THE ANALOGS AND OTHER
TOOLS, AND INDICATES ONLY MINIMALLY ENHANCED CHANCES FOR ABOVE-MEDIAN
PRECIPITATION.

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: BELOW AVERAGE, 2 OUT OF 5, DUE TO
POOR MODEL AGREEMENT ON THE 500-HPA HEIGHTS OVER THE SOUTHWEST CONUS.

8-14 DAY OUTLOOK FOR DEC 05 - 11 2014

THE AGREEMENT AMONG MODELS FOR THE MEAN 500-HPA HEIGHTS IN THE 8-14 DAY PERIOD
IS POOR. THE GEFS MODELS PREDICT A SPLIT FLOW OVER WESTERN NORTH AMERICA, WITH
A TROUGH IN THE SOUTHERN JET OVER THE SOUTHWEST AND A RIDGE DIRECTLY NORTH OF
IT OVER WESTERN NORTH AMERICA. THE ECMWF KEEPS THE FLOW ZONAL WITH ONLY A WEAK
SOUTHERN STREAM AND INTENSIFIED WESTERLIES TO THE NORTH OF THE U.S.- CANADIAN
BORDER. THE CANADIAN ENSEMBLE MEAN IS SIMILAR TO THE GEFS, BUT WITH HIGHER
AMPLITUDE IN THE NORTHERN STREAM, LEADING TO A FAIRLY DEEP EASTERN TROUGH. AS
IN THE 6-10 DAY PERIOD, THE GEFS SOLUTION WAS SLIGHTLY FAVORED.

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, WITH NEAR NORMAL TEMPERATURES FAVORED IN THE
REGIONS MOST INFLUENCED BY THE EASTERN TROUGH.

THE POSSIBILITY OF A SOUTHERN STREAM TROUGH IN THE SOUTHWESTERN CONUS ELEVATES
CHANCES FOR ABOVE-MEDIAN PRECIPITATION AMOUNTS FROM CENTRAL ARIZONA THROUGH
TEXAS, ALTHOUGH THE CONFIDENCE IN THIS FORECAST IS LOW.  RELATIVELY DRY
NORTHWEST 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 GEFS REFORECAST INDICATES SLIGHTLY ELEVATED
CHANCES FOR ABOVE-MEDIAN PRECIPITATION IN THE NORTHEASTERN CONUS WITH
PROBABILITIES ADJUSTED SLIGHTLY TOWARD HIGHER PRECIPITATION AMOUNTS FOR
CONSISTENCY WITH THE 6-10 DAY FORECAST. THE BUILDING WESTERN RIDGE INCREASES
CHANCES FOR ABOVE-MEDIAN PRECIPITATION IN EASTERN ALASKA AS IT DIVERTS THE
PACIFIC STORM TRACK NORTHWARD.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 50% OF TODAY`S 6Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 40% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON
DAY 11, 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 POOR MODEL AGREEMENT.

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 - 19931107 - 19911202 - 20081203


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:
19721128 - 19931106 - 19581202 - 19761201 - 20061203


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR DEC 03 - 07 2014

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    B     OREGON      A    B     NRN CALIF   A    N
SRN CALIF   A    A     IDAHO       N    B     NEVADA      A    A
W MONTANA   B    B     E MONTANA   B    B     WYOMING     N    B
UTAH        A    A     ARIZONA     A    A     COLORADO    A    A
NEW MEXICO  A    A     N DAKOTA    B    B     S DAKOTA    N    B
NEBRASKA    N    B     KANSAS      A    N     OKLAHOMA    A    N
N TEXAS     A    A     S TEXAS     A    A     W TEXAS     A    A
MINNESOTA   B    B     IOWA        N    B     MISSOURI    A    N
ARKANSAS    A    N     LOUISIANA   A    N     WISCONSIN   N    N
ILLINOIS    A    N     MISSISSIPPI A    B     MICHIGAN    N    A
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    A
TENNESSEE   A    N     ALABAMA     A    B     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        A    A     NEW JERSEY  A    A     W VIRGINIA  A    A
MARYLAND    A    A     DELAWARE    A    A     VIRGINIA    A    A
N CAROLINA  A    A     S CAROLINA  A    N     GEORGIA     A    N
FL PNHDL    A    B     FL PENIN    A    N     AK N SLOPE  N    B
AK ALEUTIAN A    N     AK WESTERN  N    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 05 - 11 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    B     NEVADA      A    B
W MONTANA   A    B     E MONTANA   A    B     WYOMING     A    B
UTAH        A    N     ARIZONA     A    A     COLORADO    A    N
NEW MEXICO  A    A     N DAKOTA    A    B     S DAKOTA    A    B
NEBRASKA    A    B     KANSAS      A    B     OKLAHOMA    A    N
N TEXAS     N    N     S TEXAS     N    A     W TEXAS     A    A
MINNESOTA   N    B     IOWA        A    B     MISSOURI    A    B
ARKANSAS    N    B     LOUISIANA   N    B     WISCONSIN   N    B
ILLINOIS    A    N     MISSISSIPPI N    B     MICHIGAN    N    N
INDIANA     A    N     OHIO        A    A     KENTUCKY    A    N
TENNESSEE   A    N     ALABAMA     N    B     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        A    A     NEW JERSEY  A    A     W VIRGINIA  A    A
MARYLAND    A    A     DELAWARE    A    A     VIRGINIA    A    A
N CAROLINA  A    A     S CAROLINA  A    N     GEORGIA     A    N
FL PNHDL    N    N     FL PENIN    N    N     AK N SLOPE  N    N
AK ALEUTIAN A    B     AK WESTERN  A    B     AK INT BSN  N    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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