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FXUS06 KWBC 211912
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE MAY 21 2013

6-10 DAY OUTLOOK FOR MAY 27 - 31 2013

TODAY`S ENSEMBLE MEAN SOLUTIONS EXHIBIT GOOD AGREEMENT ON THE PREDICTED MEAN
500-HPA HEIGHTS FOR THE 6-10 DAY PERIOD OVER NORTH AMERICA. MOST SOLUTIONS
AGREE ON A 500-HPA TROUGH ALONG THE WEST COAST OF THE LOWER 48 STATES WITH A
500-HPA RIDGE OVER THE EAST-CENTRAL CONUS. THE GFS AND ECMWF OPERATIONAL RUNS
ARE IN FAIRLY GOOD AGREEMENT WITH THEIR RESPECTIVE ENSEMBLE MEANS, ALTHOUGH THE
OPERATIONAL SOLUTIONS ARE GENERALLY MORE AMPLIFIED WITH THE MAIN CIRCULATION
FEATURES. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE LOW TO MODERATE SPREAD
ACROSS THE MAJORITY OF THE FORECAST DOMAIN. MORE WEIGHTING WAS GIVEN TO THE 00Z
ECMWF ENSEMBLE MEAN BASED ON ITS SKILL DURING THE PAST 60 DAYS.

TODAYS BLEND CHART INDICATES NEAR TO BELOW NORMAL HEIGHTS FOR THE WESTERN
CONUS, WITH NEAR TO ABOVE NORMAL HEIGHTS EXPECTED OVER MUCH OF THE CENTRAL AND
EASTERN CONUS.

ANOMALOUS UPPER-LEVEL TROUGHING LEADS TO ENHANCED CHANCES FOR BELOW NORMAL
TEMPERATURES OVER THE WEST COAST OF THE LOWER 48 STATES. THERE ARE INCREASED
ODDS OF ABOVE NORMAL TEMPERATURES OVER MOST OF THE CENTRAL AND EASTERN CONUS,
WHICH IS PRIMARILY ATTRIBUTED TO PREDICTED ABOVE-NORMAL 500-HPA HEIGHTS
ACCOMPANYING THE MAIN RIDGE, AND SOUTHERLY OR SOUTHWESTERLY ANOMALOUS FLOW. THE
RIDGING FORECAST AND ASSOCIATED POSITIVE 500-HPA HEIGHT ANOMALIES OVER ALASKA
LEAD TO ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR THIS AREA.

ANOMALOUS UPPER-LEVEL TROUGHING FAVORS ABOVE MEDIAN PRECIPITATION FOR MOST OF
THE NORTHERN TIER OF THE U.S. EXTENDING FROM PACIFIC NORTHWEST EASTWARD THROUGH
THE NORTHERN PLAINS TO THE GREAT LAKES. THERE ARE ENHANCED ODDS FOR
BELOW-MEDIAN PRECIPITATION FROM THE SOUTHWEST ACROSS THE SOUTHERN PLAINS TO THE
SOUTHEAST. THIS IS PRIMARILY ATTRIBUTED TO ABOVE-NORMAL 500-HPA HEIGHTS AND
ASSOCIATED MEAN RIDGES. BELOW MEDIAN PRECIPITATION IS FAVORED FOR ALASKA.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 10 PERCENT OF TODAY`S OPERATIONAL 0Z
GFS CENTERED ON DAY 8...10 PERCENT OF TODAY`S OPERATIONAL 6Z GFS CENTERED ON
DAY 8...10 PERCENT OF TODAY`S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...10
PERCENT OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...20 PERCENT OF
TODAY`S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 8...25 PERCENT OF TODAY`S 0Z
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8...AND 15 PERCENT OF TODAY`S 0Z
CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8.

MODEL OF THE DAY: TODAY`S 00Z ECMWF ENSEMBLE MEAN

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO GOOD
MODEL AGREEMENT OFFSET SOMEWHAT BY DISAGREEMENTS BETWEEN THE VARIOUS SURFACE
TEMPERATURE AND PRECIPITATION TOOLS.

8-14 DAY OUTLOOK FOR MAY 29 - JUN 04, 2013

TODAY`S ENSEMBLE MEAN SOLUTIONS EXHIBIT GOOD AGREEMENT ON THE EXPECTED MEAN
500-HPA CIRCULATION PATTERN OVER NORTH AMERICA AND VICINITY FOR THE 8-14
DAY PERIOD. THE MAIN CIRCULATION FEATURES DEPICTED BY THE ENSEMBLE MEANS
INCLUDE A 500-HPA HEIGHT RIDGE OVER THE EAST-CENTRAL CONUS AND A TROUGH OVER
THE WEST COAST OF THE CONUS. THE GFS OPERATIONAL RUNS ARE IN FAIRLY GOOD
AGREEMENT WITH THEIR RESPECTIVE ENSEMBLE MEANS, ALTHOUGH THE OPERATIONAL
SOLUTIONS ARE GENERALLY MORE AMPLIFIED WITH THE MAIN CIRCULATION FEATURES. THE
ENSEMBLE SPAGHETTI DIAGRAMS INDICATE LOW TO MODERATE SPREAD ACROSS THE MAJORITY
OF THE FORECAST DOMAIN. TODAY`S WEEK 2 UPPER-LEVEL HEIGHT MANUAL BLEND FAVORS
THE 00Z ECMWF ENSEMBLE MEAN SOLUTION.

THE PRECIPITATION AND TEMPERATURE PATTERNS IN THE WEEK 2 PERIOD ARE EXPECTED TO
BE VERY SIMILAR TO THAT FROM THE 6-10 DAY PERIOD, ONLY LOWER PROBABILITIES.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 10 PERCENT OF TODAY`S
OPERATIONAL 0Z GFS CENTERED ON DAY 11...10 PERCENT OF TODAY`S OPERATIONAL 6Z
GFS CENTERED ON DAY 11...10 PERCENT OF TODAY`S 0Z GFS ENSEMBLE MEAN CENTERED ON
DAY 11...10 PERCENT OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...20
PERCENT OF TODAY`S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11...25 PERCENT OF
TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11...AND 15 PERCENT 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
GOOD MODEL AGREEMENT OFFSET SOMEWHAT BY DISAGREEMENTS BETWEEN THE VARIOUS
SURFACE TEMPERATURE AND PRECIPITATION TOOLS.

FORECASTER: LUKE HE

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
JUNE 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:
19620520 - 19910520 - 19990512 - 19890518 - 20070505


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:
19910520 - 19620519 - 19990514 - 19890517 - 19960529


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 27 - 31 2013

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   B    A
SRN CALIF   B    B     IDAHO       B    A     NEVADA      B    N
W MONTANA   N    A     E MONTANA   N    A     WYOMING     N    N
UTAH        N    B     ARIZONA     N    B     COLORADO    A    B
NEW MEXICO  A    B     N DAKOTA    A    A     S DAKOTA    A    A
NEBRASKA    A    N     KANSAS      A    B     OKLAHOMA    A    B
N TEXAS     A    B     S TEXAS     A    B     W TEXAS     A    B
MINNESOTA   A    A     IOWA        A    A     MISSOURI    A    B
ARKANSAS    A    B     LOUISIANA   A    B     WISCONSIN   A    A
ILLINOIS    A    N     MISSISSIPPI A    B     MICHIGAN    A    A
INDIANA     A    N     OHIO        A    N     KENTUCKY    A    N
TENNESSEE   A    N     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    N     S CAROLINA  A    N     GEORGIA     A    B
FL PNHDL    N    B     FL PENIN    N    N     AK N SLOPE  A    B
AK ALEUTIAN N    N     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 MAY 29 - JUN 04, 2013

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