Prognostic Meteorological Discussion
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FXUS06 KWBC 201916
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT MON APRIL 20 2015

6-10 DAY OUTLOOK FOR APR 26 - 30 2015

TODAY`S ENSEMBLE MODEL SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT ON THE 500-HPA
FLOW PATTERN EXPECTED OVER MUCH OF NORTH AMERICA AND VICINITY. ALL MODELS ARE
FORECASTING A TROUGH OVER THE GULF OF ALASKA, AND A RIDGE OVER THE WESTERN AND
CENTRAL CONUS. FARTHER TO THE EAST, A CLOSED 500-HPA LOW IS PREDICTED BY ALL OF
TODAY`S MODEL SOLUTIONS OVER NORTHEASTERN NORTH AMERICA WITH NEGATIVE 500-HPA
HEIGHT ANOMALIES FORECAST OVER THE EASTERN CONUS.

BELOW NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE GREAT LAKES AND EASTERN
CONUS IN ASSOCIATION WITH BELOW NORMAL 500-HPA HEIGHTS. ABOVE NORMAL
TEMPERATURES ARE FAVORED FOR THE FLORIDA PENINSULA AND ALONG THE GULF COAST
CONSISTENT WITH BIAS CORRECTED TEMPERATURES FROM THE ECMWF, GFS, AND CANADIAN
ENSEMBLES, AND WITH GEFS REFORECAST GUIDANCE. RIDGING OVER NORTHWESTERN NORTH
AMERICA INCREASES THE CHANCES FOR ABOVE NORMAL TEMPERATURES FOR THE CENTRAL
CONUS. ANOMALOUS SOUTHEASTERLY FLOW FROM A LOW PRESSURE PREDICTED OVER THE GULF
OF ALASKA LEADS TO ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR
EASTERN AND CENTRAL ALASKA, THE ALEUTIANS AND THE ALASKA PANHANDLE.

BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE GREAT LAKES WEST OF A CLOSED
500-HPA LOW PREDICTED OVER EASTERN NORTH AMERICA. PROBABILITIES OF BELOW MEDIAN
PRECIPITATION ARE ENHANCED NEAR THE RIDGE POSITION OVER THE SOUTHERN CONUS.
ENHANCED PROBABILITIES OF ABOVE MEDIAN PRECIPITATION ARE INDICATED FOR MUCH OF
THE NORTHWESTERN CONUS IN ASSOCIATION WITH A MEAN TROUGH PREDICTED OFF THE WEST
COAST. ABOVE MEDIAN PRECIPITATION IS ALSO FAVORED FOR THE SOUTHEASTERN COUNS
CONSISTENT WITH PRECIPITATION ESTIMATES FROM THE GFS AND ECMWF CALIBRATED
REFORECAST TOOLS. EXCEPT FOR THE ALASKA PANHANDLE, THERE ARE ENHANCED CHANCE OF
BELOW MEDIAN PRECIPITATION FOR ALASKA AND THE ALEUTIANS  WEST OF A TROUGH
PREDICTED OVER THE GULF OF ALASKA.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 10% OF TODAY`S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 20% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 20%
OF YESTERDAY`S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 7, 20% OF TODAY`S 0Z
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 10% OF YESTERDAY`S 12Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 7, AND 20% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN
CENTERED ON DAY 8


MODEL OF THE DAY: NO PREFERENCE

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO FAIRLY
GOOD ENSEMBLE MEAN AGREEMENT OFFSET BY LARGE SPREAD AMONG ENSEMBLE MEMBERS OVER
THE NORTHERN CONUS

8-14 DAY OUTLOOK FOR APR 28 - MAY 04, 2015

TODAY`S WEEK TWO ENSEMBLE MEAN SOLUTIONS DEPICT MEAN 500-HPA TROUGHS OVER THE
GULF OF ALASKA AND OVER SOUTHEASTERN CANADA, WITH A RIDGE OVER WESTERN CANADA
AND MUCH OF CENTRAL CONUS. A TROUGH IS FORECAST OFF THE WEST COAST OF THE NORTH
AMERICA WITH AN ENERGETIC SHORT WAVE NEAR THE SOUTHWESTERN CONUS. MODEL SPREAD
IS FAIRLY HIGH OVER MUCH OF NORTH AMERICA DURING THE OUTLOOK PERIOD, ESPECIALLY
IN THE NORTHERN STREAM. AS A RESULT OF THIS UNCERTAINTY, TODAY`S WEEK TWO
500-HPA MANUAL HEIGHT BLEND IS BASED PRIMARILY ON THE ENSEMBLE MEAN SOLUTIONS.

ABOVE-NORMAL TEMPERATURE PROBABILITIES ARE ENHANCED FOR ALASKA, THE ALEUTIANS
AND THE ALASKA PANHANDLE IN ASSOCIATION WITH THE POSITIVE 500-HPA HEIGHT
ANOMALIES. BELOW-NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF EASTERN CONUS AND
THE GULF COAST NEAR THE FORECAST TROUGH EXCEPT THE FLORIDA PENINSULA.
ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE SOUTHERN PLATEAU, THE
CENTRAL AND SOUTHERN HIGH PLAINS RELATED TO THE POSITIVE 500-HPA ANOMALIES
PREDICTED.

PROBABILITIES OF BELOW MEDIAN PRECIPITATION ARE ENHANCED WEST OF THE PREDICTED
TROUGH FOR PARTS OF THE CENTRAL PLAINS, UPPER MISSISSIPPI VALLEY, AND THE GREAT
LAKES. ENHANCED PROBABILITIES OF BELOW MEDIAN PRECIPITATION ARE INDICATED FOR
MUCH OF THE WESTERN CONUS IN ASSOCIATION WITH A MEAN RIDGE PREDICTED.  ABOVE
MEDIAN PRECIPITATION IS FAVORED FOR THE WESTERN TEXAS, NORTHWESTERN AND
SOUTHEAST COAST CONSISTENT WITH PRECIPITATION ESTIMATES FROM THE GFS AND ECMWF
CALIBRATED REFORECAST TOOLS. THERE ARE ENHANCED PROBABILITIES OF BELOW MEDIAN
PRECIPITATION FOR ALASKA AND THE ALEUTIANS WEST OF THE TROUGH FORECAST OVER THE
GULF OF ALASKA.


THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 20% OF TODAY`S 6Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 20% OF YESTERDAY`S GFS SUPERENSEMBLE MEAN CENTERED ON
DAY 10, 20% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 20% OF
YESTERDAY`S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10, AND 20% OF TODAY`S
0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: AVERAGE, 3 OUT OF 5, DUE TO
RELATIVELY GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS OFFSET BY LARGE
SPREAD AMONG THE COMPONENT ENSEMBLE MEMBERS OVER MUCH OF NORTH AMERICA

FORECASTER: QIN GINGER ZHANG

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 MAY
21

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:
19690414 - 19640407 - 19740412 - 19800331 - 20070424


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:
19800331 - 19940503 - 19690412 - 19640406 - 19620401


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR APR 26 - 30 2015

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR APR 28 - MAY 04, 2015

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

                           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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