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FXUS06 KWBC 201902
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 20 2018

6-10 DAY OUTLOOK FOR APR 26 - 30 2018

TODAY`S VARIOUS ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT ON THE 6-10 DAY
PATTERN OVER THE FORECAST DOMAIN. TROUGHS ARE PREDICTED OVER THE ALEUTIANS,
NEAR THE CALIFORNIA COAST, AND OVER THE EASTEARN CONUS, WHILE ANOMALOUS RIDGING
IS FORECAST OVER THE WESTERN CONUS. TODAY`S MANUAL 500-HPA BLEND IS BASED
PRIMARILY ON THE ENSEMBLE MEANS FROM THE CANADIAN, EUROPEAN, AND GEFS MODEL
SUITES. ABOVE NORMAL 500-HPA HEIGHTS ARE FORECAST OVER MOST OF THE WESTERN AND
CENTRAL CONUS, WHILE NEGATIVE HEIGHT ANOMALIES ARE FORECAST OVER MUCH OF ALASKA
AND THE EASTERN CONUS.

ABOVE NORMAL TEMPERATURES ARE FAVORED OVER MUCH OF THE WESTERN HALF OF THE
CONUS, WHERE NEAR TO ABOVE NORMAL HEIGHTS ARE PREDICTED. TROUGHING NEAR THE
EAST COAST LEADS TO INCREASED CHANCES FOR NEAR TO BELOW NORMAL TEMPERATURES
ACROSS MUCH OF THE EASTERN CONUS EXCEPT FOR MAINE WHERE ABOVE NORMAL
TEMPERATURES ARE INDICATED. BELOW NORMAL TEMPERATURES ARE FAVORED OVER PARTS OF
SOUTHEASTERN MAINLAND ALASKA AND THE ALASKA PANHANDLE, WHILE ABOVE NORMAL
TEMPERATURES ARE FAVORED OVER MUCH OF WESTERN AND NORTHERN ALASKA, CONSISTENT
WITH REFORECAST-CALIBRATED GEFS AND ECMWF TOOLS.

BELOW NORMAL PRECIPITATION IS FAVORED FOR MOST OF OF THE NORTHERN AND EASTERN
CONUS, CONSISTENT WITH DYNAMICAL MODEL GUIDANCE FROM THE GEFS AND ECMWF
ENSEMBLE MEAN SOLUTIONS. ABOVE NORMAL PRECIPITATION IS FAVORED FOR CALIFORNIA,
ARIZONA, NEW MEXICO, AND WESTERN TEXAS IN ASSOCIATION WITH A MEAN 500-HPA
TROUGH PREDICTED TO PROGRESS TOWARDS THE WEST COAST. A PREDICTED MEAN 500-HPA
TROUGH OVER THE EASTERN COAST ENHANCES PROBABILITIES OF ABOVE NORMAL
PRECIPITATION FOR PARTS OF THE NORTHEAST. SEVERAL PREDICTED STORM SYSTEMS IN
THE GULF OF ALASKA INCREASE THE LIKELIHOOD OF ABOVE NORMAL PRECIPITATION FOR
MUCH OF ALASKA.

THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 15% OF TODAY`S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 15% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED
ON DAY 8, 5% OF TODAY`S OPERATIONAL 0Z GFS CENTERED ON DAY 8, 25% OF TODAY`S 0Z
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF YESTERDAY`S 12Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 7, 10% OF TODAY`S OPERATIONAL 0Z ECMWF CENTERED
ON DAY 8, 20% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 5% OF
YESTERDAY`S 12Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 7


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

8-14 DAY OUTLOOK FOR APR 28 - MAY 04, 2018

TODAY`S ENSEMBLE MEAN DYNAMICAL MODEL FORECASTS ARE IN GOOD AGREEMENT ON THE
PREDICTED 500-HPA CIRCULATION PATTERN OVER NORTH AMERICA FOR THE WEEK-2 PERIOD.
TROUGHS ARE FORECAST ALONG THE WEST COAST AND OVER THE NORTHEAST. ABOVE NORMAL
500-HPA HEIGHTS ARE FORECAST OVER MOST OF THE CONUS EXCEPT FOR PARTS OF MAINE
AND CALIFORNIA WHERE BELOW NORMAL 500-HPA HEIGHTS ARE INDICATED.

ABOVE NORMAL 500-HPA HEIGHTS FAVOR NEAR TO ABOVE NORMAL TEMPERATURES OVER MUCH
OF THE CONUS, EXCEPT FOR PARTS OF THE SOUTHEAST COAST AND THE NORTHEAST WHERE
BELOW NORMAL TEMPERATURES ARE INDICATED. THE TEMPERATURE PROBABILITY FORECAST
FOR ALASKA DURING THE WEEK-2 PERIOD IS GENERALLY SIMILAR TO THE 6-10 DAY PERIOD.

NEAR TO BELOW NORMAL PRECIPITATION IS FORECAST FOR WASHINGTON AND THE EASTERN
CONUS, CONSISTENT WITH DYNAMICAL MODEL GUIDANCE FROM THE ECMWF ENSEMBLE MEAN
SOLUTION. ABOVE NORMAL PRECIPITATION IS FAVORED FOR MOST OF THE SOUTHWESTERN
CONUS IN ASSOCIATION WITH A MEAN 500-HPA TROUGH PREDICTED ALONG THE WEST COAST.
SEVERAL PREDICTED STORM SYSTEMS IN THE GULF OF ALASKA INCREASE THE LIKELIHOOD
OF NEAR TO ABOVE NORMAL PRECIPITATION FOR MUCH OF ALASKA.

THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 20% OF TODAY`S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 15% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED
ON DAY 11, 5% OF TODAY`S OPERATIONAL 6Z GFS CENTERED ON DAY 11, 30% OF TODAY`S
0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 5% OF YESTERDAY`S 12Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 10, 20% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 5% OF YESTERDAY`S 12Z CANADIAN ENSEMBLE MEAN CENTERED
ON DAY 10


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG THE MODELS AND TOOLS.

FORECASTER: LUKE H

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
17.

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:
19990411 - 19750427 - 19790408 - 20090412 - 19910331


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:
19790409 - 19990411 - 20090412 - 19750427 - 20070501


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR APR 26 - 30 2018

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR APR 28 - MAY 04, 2018

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