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FXUS06 KWBC 171902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT FRI APRIL 17 2015

6-10 DAY OUTLOOK FOR APR 23 - 27 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. SPLIT FLOW IS
FORECAST OVER WESTERN NORTH AMERICA FEATURING A RIDGE IN THE NORTHERN STREAM
OVER WESTERN CANADA WITH TROUGH ENERGY UNDERCUTTING THE RIDGE IN THE SOUTHERN
STREAM NEAR THE WEST COAST. FARTHER TO THE EAST, A CLOSED 500-HPA LOW IS
PREDICTED BY ALL OF TODAY`S MODEL SOLUTIONS OVER NORTHEASTERN NORTH AMERICA.
OVER THE ALASKA SECTOR, MOST MODELS PREDICT A TROUGH OR CLOSED LOW OVER THE
BERING SEA AND THE ALEUTIANS. BELOW NORMAL HEIGHTS ARE EXPECTED ACROSS THE
ALEUTIANS AND MOST OF THE CONUS EXCEPT PARTS OF THE NORTHWEST, NEAR THE GULF
COAST, SOUTHERN FLORIDA, AND ALASKA WHERE NEAR TO ABOVE NORMAL HEIGHTS ARE
ANTICIPATED.

BELOW NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE CENTRAL, EASTERN, AND
SOUTHWESTERN 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 NORTHWESTERN CONUS. ANOMALOUS SOUTHERLY FLOW AHEAD OF A TROUGH
PREDICTED OVER THE BERING SEA LEADS TO ENHANCED PROBABILITIES FOR ABOVE NORMAL
TEMPERATURES FOR ALASKA, THE ALEUTIANS AND THE PANHANDLE.

ABOVE MEDIAN PRECIPITATION IS FAVORED FOR NEW ENGLAND, EAST OF A CLOSED 500-HPA
LOW PREDICTED OVER EASTERN NORTH AMERICA. PROBABILITIES OF BELOW MEDIAN
PRECIPITATION ARE ENHANCED WEST OF THE LOW FOR PARTS OF THE UPPER MISSISSIPPI
VALLEY, AND WESTERN GREAT LAKES. ENHANCED PROBABILITIES OF ABOVE MEDIAN
PRECIPITATION ARE INDICATED FOR MUCH OF THE SOUTHWESTERN CONUS IN ASSOCIATION
WITH A MEAN SOUTHERN STREAM TROUGH PREDICTED NEAR CALIFORNIA. ABOVE MEDIAN
PRECIPITATION IS ALSO FAVORED FOR THE SOUTHEASTERN COUNS CONSISTENT WITH
PRECIPITATION ESTIMATES FROM THE GFS AND ECMWF CALIBRATED REFORECAST TOOLS.
THERE ARE ENHANCED PROBABILITIES OF ABOVE MEDIAN PRECIPITATION FOR PARTS OF
WESTERN ALASKA AND THE ALEUTIANS EAST OF A TROUGH PREDICTED OVER THE BERING
SEA. ANOMALOUS NORTHERLY FLOW ENHANCES PROBABILITIES FOR BELOW MEDIAN
PRECIPITATION FOR EASTERN ALASKA AND THE ALASKA PANHANDLE.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 20% OF TODAY`S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 10% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 20%
OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 20% OF TODAY`S
OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, 10% OF YESTERDAY`S OPERATIONAL 12Z
ECMWF 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 25 - MAY 01, 2015

TODAY`S WEEK TWO ENSEMBLE MEAN SOLUTIONS DEPICT MEAN 500-HPA TROUGHS OVER THE
BERING SEA/ALEUTIANS AND OVER SOUTHEASTERN CANADA, WITH A RIDGE OVER WESTERN
CANADA AND MUCH OF ALASKA. SPLIT FLOW CONTINUES TO BE FORECAST OVER WESTERN
NORTH AMERICA WITH AN ENERGETIC SOUTHERN STREAM AND A TROUGH 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 TEMPERATURE PROBABILITIES ARE FAVORED FOR MUCH OF THE
CENTRAL AND EASTERN CONUS NEAR THE FORECAST TROUGH EXCEPT THE PACIFIC NORTHWEST
AND THE FLORIDA PENINSULA, WHERE ABOVE-NORMAL TEMPERATURES ARE FAVORED RELATED
TO THE POSITIVE 500HPA ANOMALIES PREDICTED.

ABOVE MEDIAN PRECIPITATION IS FAVORED FOR THE SOUTHEASTERN CONUS, EAST OF A
500-HPA TROUGH PREDICTED OVER EASTERN NORTH AMERICA. PROBABILITIES OF BELOW
MEDIAN PRECIPITATION ARE ENHANCED WEST OF THE TROUGH FOR PARTS OF THE NORTHERN
PLAINS, UPPER MISSISSIPPI VALLEY, AND WESTERN GREAT LAKES. ENHANCED
PROBABILITIES OF ABOVE MEDIAN PRECIPITATION ARE INDICATED FOR MUCH OF THE
WESTERN CONUS IN ASSOCIATION WITH A MEAN SOUTHERN STREAM TROUGH PREDICTED NEAR
CALIFORNIA.  BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE SOUTHWESTERN TEXAS
CONSISTENT WITH PRECIPITATION ESTIMATES FROM THE GFS AND ECMWF CALIBRATED
REFORECAST TOOLS. THERE ARE ENHANCED PROBABILITIES OF BELOW MEDIAN
PRECIPITATION FOR ALASKA AND THE ALASKA PANHANDLE IN ASSOCIATION WITH ANOMALOUS
NORTHERLY FLOW.


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:
20070424 - 19930429 - 19770410 - 19690414 - 19520420


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:
20070424 - 19690413 - 19910409 - 19520419 - 19930429


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR APR 23 - 27 2015

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR APR 25 - MAY 01, 2015

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