Prognostic Meteorological Discussion
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FXUS06 KWBC 202019
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 20 2014

6-10 DAY OUTLOOK FOR NOV 26 - 30 2014

TODAYS MODELS ARE IN GOOD AGREEMENT ON THE 500-HPA CIRCULATION PATTERN
FORECAST OVER NORTH AMERICA. MOST OF TODAYS MODELS PREDICT A DEEP TROUGH
CENTERED OVER MUCH OF THE EASTERN CONUS, AND ANOMALOUS RIDGING IN THE WESTERN
HALF OF THE CONUS. TODAYS 0Z ECMWF ENSEMBLE INDICATES LESS ANOMALOUS RIDGING
IN THE WESTERN U.S. THE 0Z DETERMINISTIC ECMWF IS THE OUTLIER TODAY,
FORECASTING NEGATIVE HEIGHT ANOMALIES EVERYWHERE IN THE CONUS, EXCEPT FOR THE
WEST COAST. SINCE THE GFS ENSEMBLE HAS SHOWN BETTER RUN-TO-RUN CONSISTENCY OVER
THE PAST SEVERAL DAYS, IT WAS GIVEN THE MOST WEIGHT IN TODAYS MANUAL 500-HPA
HEIGHT BLEND. IN ADDITION TELECONNECTIONS OFF OF A NEGATIVE HEIGHT ANOMALY
CENTER IN THE EASTERN PACIFIC AND A POSITIVE HEIGHT ANOMALY CENTER IN THE
ATLANTIC INDICATE A 6-10 DAY PATTERN THAT CLOSELY RESEMBLES THE GFS ENSEMBLE
FORECAST.

ABOVE NORMAL HEIGHTS OVER ALASKA INCREASE THE CHANCES FOR ABOVE NORMAL
TEMPERATURES THROUGHOUT THE STATE. ANOMALOUS RIDGING ALSO INCREASES THE
LIKELIHOOD OF ABOVE NORMAL TEMPERATURES IN THE WESTERN CONUS, ESPECIALLY OVER
COASTAL CA WHERE OFFSHORE, DOWNSLOPING WINDS STRONGLY FAVOR ABOVE NORMAL
TEMPERATURES. BELOW NORMAL TEMPERATURES ARE FAVORED OVER MUCH OF THE REMAINDER
OF THE CONUS DUE TO ANOMALOUS NORTHERLY FLOW AND ANOMALOUSLY HIGH SNOW COVER.

ANOMALOUS LOW-LEVEL SOUTHERLY FLOW INCREASES THE CHANCES FOR ABOVE MEDIAN
PRECIPITATION OVER ALASKA. STORM SYSTEM ACTIVITY EXPECTED TO ENTER THE NORTHERN
CONUS FROM CANADA FAVORS ABOVE MEDIAN PRECIPITATION IN THE NORTHERN PLAINS INTO
THE GREAT LAKES REGION. ANOMALOUSLY HIGH SURFACE PRESSURE FROM THE WESTERN U.S.
INTO THE SOUTHERN PLAINS, SOUTHEAST, AND OHIO AND TENNESSEE VALLEYS FAVORS
BELOW MEDIAN PRECIPITATION FOR THOSE AREAS.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 45% OF TODAY`S 6Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 35% OF TODAY`S OPERATIONAL 6Z GFS CENTERED ON DAY 8, AND 20%
OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8


MODEL OF THE DAY: 6Z GEFS MEAN

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD MODEL AGREEMENT, A FAIRLY AMPLIFIED PATTERN, AND FAIRLY GOOD AGREEMENT
AMONG THE TOOLS.

8-14 DAY OUTLOOK FOR NOV 28 - DEC 04, 2014

BY THE WEEK-2 PERIOD, THE 500-HPA PATTERN IS EXPECTED TO BE SHIFTED EASTWARD
FROM THAT FORECAST FOR THE 6-10 DAY PERIOD, AND BECOME MUCH LESS CERTAIN.
TODAYS 6Z GFS ENSEMBLE AND 0Z CANADIAN ENSEMBLE ARE OUT OF PHASE. THE GFS
ENSEMBLE INDICATES NEGATIVE HEIGHT ANOMALIES FOR THE WEST COAST AND POSITIVE
HEIGHT ANOMALIES OVER MUCH OF THE CONUS, WHILE THE CANADIAN ENSEMBLE INDICATES
POSITIVE HEIGHT ANOMALIES OFF THE WEST COAST AND NEGATIVE HEIGHT ANOMALIES
THROUGHOUT MOST OF THE CONUS. TODAYS 0Z ECMWF ENSEMBLE MEAN IS SOMEWHERE IN
BETWEEN, AND AS SUCH WAS FAVORED IN TODAYS WEEK-2 MANUAL 500-HPA HEIGHT BLEND.
THE TEMPERATURE PROBABILITY FORECAST IS FAIRLY SIMILAR TO THAT IN THE 6-10 DAY
PERIOD, EXCEPT PROBABILITIES ARE LOWER DUE TO INCREASED UNCERTAINTY. SINCE
ANOMALOUS LOW-LEVEL SOUTHERLY FLOW IS FORECAST TO DECREASE BY THE WEEK-2
PERIOD, NEAR NORMAL TEMPERATURES ARE NOW FAVORED FOR WEEK-2 IN ALASKA. WITH THE
POSSIBILITY OF LOW-LEVEL SOUTHERLY FLOW INCREASING OVER THE SOUTH CENTRAL
PLAINS, NEAR NORMAL TEMPERATURES ARE NOW FAVORED THERE.

THE PRECIPITATION PROBABILITY FORECAST IS SIMILAR IN WEEK-2 TO THE 6-10 DAY
PERIOD, WITH A FEW EXCEPTIONS. STORM SYSTEM ACTIVITY IS FORECAST TO DIMINISH
OVER THE NORTHERN PLAINS IN THE WEEK-2 PERIOD, FAVORING NEAR MEDIAN
PRECIPITATION INSTEAD OF ABOVE MEDIAN PRECIPITATION. HIGH UNCERTAINTY IN THE
POTENTIAL STORM ACTIVITY IN THE EASTERN U.S. FAVORS NEAR MEDIAN PRECIPITATION
THERE.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 40% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, AND 60% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED
ON DAY 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: WELL BELOW AVERAGE, 1 OUT OF 5,
DUE TO FAIRLY POOR AGREEMENT AMONG THE MODELS, AS WELL AS WEAKER ANOMALIES, AND
FAIRLY POOR AGREEMENT AMONG THE TOOLS.

FORECASTER: MIKE CHARLES

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:
20001119 - 19511031 - 19761129 - 19921114 - 20021102


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:
20001118 - 19511103 - 20021103 - 19921115 - 19761128


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 26 - 30 2014

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 28 - DEC 04, 2014

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