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FXUS06 KWBC 221920
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT WED OCTOBER 22 2014

6-10 DAY OUTLOOK FOR OCT 28 - NOV 01, 2014

SIGNIFICANT UNCERTAINTY IS EVIDENT IN THE MODEL FORECASTS OVER ALASKA AND THE
NORTH PACIFIC EVEN AT RELATIVELY EARLY LEAD TIMES. BY THE 6-10 DAY PERIOD,
THERE IS RELATIVELY POOR AGREEMENT AMONG MODEL ENSEMBLES AND POOR RUN TO RUN
CONSISTENCY OVER MOST MUCH OF THE WESTERN PART OF NORTH AMERICA AND THE NORTH
PACIFIC. AGREEMENT AMONG THE ENSEMBLE MEANS OF THE GFS, ECMWF, AND CANADIAN
MODELS IS FAIR OVER EASTERN NORTH AMERICA. DIFFERENCES IN 500-HPA HEIGHTS OVER
ALASKA WERE SO GREAT THAT AN EVEN BLEND OF GFS AND ECMWF MODEL ENSEMBLES WOULD
RESULT IN NEAR AVERAGE HEIGHTS, WHICH NEITHER MODEL PREDICTS. THE CANADIAN
MODEL SOLUTION AGREES WITH THE ECMWF, AND THOSE TWO MODELS SHOW BETTER
CONSISTENCY IN THE LAST FEW RUNS, SO THEY WERE WEIGHTED QUITE HEAVILY IN
TODAY`S BLEND. THE MANUAL BLEND SHOWS A 500-HPA RIDGE OVER ALASKA, WITH A WEAK
TROUGH OVER THE WEST COAST OF THE CONUS, PUSHING THE PACIFIC JET SOUTH OF ITS
NORMAL POSITION FOR THIS TIME OF YEAR. THE CIRCULATION OVER THE REMAINDER OF
THE CONUS IS MOSTLY ZONAL EXCEPT FOR A WEAK RIDGE OVER THE NORTHEASTERN CONUS.

THE MOSTLY ZONAL UPPER LEVEL FLOW OVER THE CONUS LEADS TO ELEVATED CHANCES FOR
ABOVE-NORMAL TEMPERATURES FOR MUCH OF THE NATION. THE 500-HPA TROUGH EXPECTED
OVER THE WEST COAST INCREASE THE CHANCES FOR NEAR- TO BELOW-NORMAL TEMPERATURES
FROM THE PACIFIC NORTHWEST TO THE NORTHERN ROCKIES, EXTENDING TO PARTS OF THE
NORTHERN GREAT PLAINS. MOST OF ALASKA IS EXPECTED TO BE UNDERNEATH 500-HPA
RIDGE, FAVORING ABOVE-NORMAL TEMPERATURES EXCEPT FOR NEAR THE ALASKA PANHANDLE,
WHERE NORTHERLY UPPER LEVEL FLOW ALLOWS COOLER AIR FROM THE NORTH INTO THE
REGION.

SOUTHWEST 500-HPA FLOW OVER WESTERN ALASKA FAVORS ABOVE-MEDIAN PRECIPITATION
FOR CENTRAL AND WESTERN PARTS OF THE STATE, WHILE BELOW-MEDIAN PRECIPITATION IS
FAVORED IN SOUTHEASTERN ALASKA UNDER NORTHERLY FLOW AHEAD OF THE MEAN RIDGE
POSITION. TROUGHING NEAR THE PACIFIC NORTHWEST WITH AN ENHANCED PACIFIC JET
FAVORS ABOVE-MEDIAN PRECIPITATION FROM THE PACIFIC NORTHWEST TO THE UPPER GREAT
LAKES. THE SOUTHERN EXTENT OF ENHANCED PRECIPITATION CHANCES IS QUITE
UNCERTAIN, WITH TODAY`S MODELS INCREASING THE RISK FOR ABOVE-MEDIAN
PRECIPITATION INTO CENTRAL CALIFORNIA. BELOW-MEDIAN PRECIPITATION IS LIKELY
ACROSS THE SOUTHWEST DUE TO THE INFLUENCE OF LOW-LEVEL HIGH PRESSURE, AND FROM
THE GULF COAST TO NEW ENGLAND DUE TO A NORTHWARD DISPLACEMENT OF THE MEAN STORM
TRACK OVER THE EASTERN CONUS. THE POSSIBLE DEVELOPMENT OF A TROPICAL DEPRESSION
CURRENTLY WEST OF THE YUCATAN MAY ENHANCE MOISTURE OVER THE GULF OF MEXICO,
INCREASING THE CHANCES FOR ABOVE-MEDIAN RAINFALL FOR PARTS OF THE FLORIDA
PENINSULA, HOWEVER THE DEVELOPMENT AND PATH OF THIS SYSTEM IS VERY UNCERTAIN AT
THIS TIME.

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


MODEL OF THE DAY: TODAY`S 0Z EUROPEAN ENSEMBLE MEAN

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 2 OUT OF 5, DUE TO POOR
AGREEMENT BETWEEN CANADIAN AND ECMWF ENSEMBLE MEANS, AND THE GFS ENSEMBLES.

8-14 DAY OUTLOOK FOR OCT 30 - NOV 05, 2014

THE ENSEMBLE MEANS FOR THE 8-14 DAY PERIOD CONTINUE TO DISAGREE SUBSTANTIALLY
OVER ALASKA AND ADJACENT OCEAN AREAS, BUT ARE FAIRLY CLOSE IN THE PREDICTED
CIRCULATION OVER THE CONUS. THE ENSEMBLE SPREAD, HOWEVER IS QUITE LARGE,
LEADING TO RELATIVE WEAK FORECAST ANOMALIES IN 500-HPA HEIGHTS, AND A RELATIVE
UNCERTAIN FORECAST. AS IN THE 6-10 DAY FORECAST, THE ECMWF AND CANADIAN
ENSEMBLE MEAN SOLUTIONS WERE EMPHASIZED IN THE BLEND.

THE LARGELY ZONAL 500-HPA FLOW OVER MOST OF THE CONUS FAVOR ABOVE-NORMAL
TEMPERATURES, EXCEPT FOR THE PARTS OF THE PACIFIC NORTHWEST, NORTHERN ROCKIES,
NORTHERN GREAT PLAINS, AND UPPER GREAT LAKES NEAR THE PREDICTED STORM TRACK.
SOUTHWEST FLOW AND ABOVE-NORMAL HEIGHTS FAVOR ABOVE-NORMAL TEMPERATURES OVER
ALASKA, EXCEPT FOR THE PANHANDLE.

SOUTHWEST UPPER LEVEL FLOW FAVORS ABOVE-MEDIAN PRECIPITATION FOR MUCH OF
ALASKA, WHILE LOW-LEVEL RIDGING SUPPORTS BELOW-MEDIAN PRECIPITATION ACROSS THE
ALASKA PANHANDLE. AN ACTIVE STORM TRACK IS FORECAST FOR THE NORTHERN ROCKIES
AND NORTHERN GREAT PLAINS, FAVORING ABOVE-MEDIAN PRECIPITATION FOR THOSE
REGIONS. LOW-LEVEL RIDGING IS FORECAST OVER THE SOUTHEAST, FAVORING
BELOW-MEDIAN PRECIPITATION FOR THE GULF COAST BUT SUPPORTING ABOVE-MEDIAN RAINS
FOR MUCH OF FLORIDA.  MEAN SURFACE PRESSURE FEATURES FROM THE MODELS SUGGEST
RETURN FLOW OVER THE PARTS OF CENTRAL GREAT PLAINS INCREASES THE ODDS FOR
ABOVE-MEDIANS PRECIPITATION IN THAT REGION.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 10% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 10% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY
11, 50% 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 LARGE SPREAD AMONG INDIVIDUAL ENSEMBLE MEMBERS OF EACH MODEL, AND
DISAGREEMENTS BETWEEN THE CANADIAN AND ECMWF ENSEMBLE MEANS AND THE GFS
ENSEMBLE MEANS OVER ALASKA AND ADJACENT AREAS OVER THE NORTH PACIFIC.


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
NOVEMBER 20

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:
19541019 - 19841008 - 20051027 - 19831102 - 19531012


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:
19841008 - 19831101 - 19531011 - 19541019 - 19631012


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 28 - NOV 01, 2014

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 30 - NOV 05, 2014

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

                           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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