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FXUS06 KWBC 051902
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 05 2015

6-10 DAY OUTLOOK FOR MAY 11 - 15 2015

THE AVAILABLE MODELS EXHIBIT GOOD AGREEMENT ON THE 500-HPA HEIGHT FIELD OVER
NORTH AMERICA. MOST MODELS DEPICT A TROUGH NEAR THE WEST COAST OF NORTH AMERICA
THAT EXTENDS OVER THE SOUTHWEST, RIDGING OVER THE CENTRAL PORTIONS OF THE
CONUS, AND A DEEP TROUGH OVER NORTHEAST CANADA. THAT RESULTS IN A MEAN
SOUTHERLY COMPONENT TO THE UPPER-LEVEL FLOW OVER THE CONUS. THE MOST APPARENT
DIFFERENCES IN THE MODEL SOLUTIONS ARE OVER THE GREAT PLAINS WHERE THE
ECMWF-BASED SOLUTIONS HAVE A SHARPER RIDGE INTO CANADA AND SOME TROUGHING BACK
OVER THE GREAT LAKES. THE GFS AND ENVIRONMENT CANADA MODELS HAVE INDICATIONS OF
SHORTWAVE ACTIVITY, BUT ARE HAVE A MORE PROGRESSIVE FLOW.

THE AVERAGE ANALOG CORRELATION FOR THE GFS-BASED SOLUTIONS IS SLIGHTLY HIGHER,
SO THE 500-HPA MANUAL HEIGHT BLEND IS WEIGHTED SLIGHTLY IN FAVOR OF THE
GFS-BASED SOLUTIONS. THE MOST WEIGHT IS GIVEN TO THE 0Z GFS ENSEMBLE MEAN AS
THAT MODEL HAS THE HIGHEST COMBINED ANALOG CORRELATION AND ANOMALY CORRELATION
SCORE.

THE RESULTANT UPPER-LEVEL PATTERN SUPPORTS ABOVE NORMAL TEMPERATURES OVER
ALASKA DUE TO MEAN SOUTHERLY FLOW IN THE LOW-LEVELS AND ABOVE NORMAL HEIGHTS
ALOFT. MEAN SOUTHWESTERLY FLOW EAST OF THE TROUGH NEAR THE WEST COAST, FAVORS
ABOVE NORMAL TEMPERATURES FOR THE NORTHERN ROCKIES, GREAT BASIN, AND
CALIFORNIA, EXCEPT ALONG THE IMMEDIATE COAST. BELOW NORMAL TEMPERATURES ARE
FAVORED OVER THE GREAT PLAINS, SUPPORTED BY THE ENHANCED ODDS OF ABOVE MEDIAN
PRECIPITATION ACROSS MUCH OF THE SOUTHERN AND CENTRAL GREAT PLAINS AND THE
POTENTIAL FOR HIGH PRESSURE TO EXTEND SOUTHWARD OUT OF CANADA. MEAN RIDGING
FAVORS ABOVE NORMAL TEMPERATURES FOR THE EASTERN THIRD OF THE CONUS.

MEAN SOUTHWESTERLY FLOW ALOFT AND EASTERLY FLOW AT LOWER LEVELS, GENERALLY
FAVORS ABOVE MEDIAN PRECIPITATION FOR MOST OF THE SOUTHERN CONUS. THE POTENTIAL
FOR HIGH PRESSURE TO EXTEND SOUTHWARD FROM CANADA ENHANCES THE ODDS FOR BELOW
MEDIAN PRECIPITATION OVER THE NORTHERN GREAT PLAINS. OFFSHORE FLOW INCREASES
THE ODDS OF BELOW MEDIAN PRECIPITATION FOR THE COASTS OF OREGON AND NORTHERN
CALIFORNIA.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 35% OF TODAY`S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 15% OF TODAY`S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 8, 10%
OF TODAY`S OPERATIONAL 0Z GFS CENTERED ON DAY 8, 20% OF YESTERDAY`S 12Z
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 7, AND 20% OF TODAY`S 0Z CANADIAN
ENSEMBLE MEAN CENTERED ON DAY 8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO GOOD
AGREEMENT AMONG THE MODEL SOLUTIONS, TEMPERED BY DISAGREEMENT AMONG THE SURFACE
TEMPERATURE AND PRECIPITATION TOOLS.

8-14 DAY OUTLOOK FOR MAY 13 - 19 2015

MODEL SOLUTIONS FOR THE WEEK-2 PERIOD EXHIBIT VERY GOOD AGREEMENT. MOST MODELS
PREDICT A TROUGH NEAR THE ALEUTIANS, SPLIT FLOW OVER WESTERN NORTH AMERICA WITH
A TROUGH OVER THE SOUTHWEST, AND GENERALLY ABOVE NORMAL 500-HPA HEIGHTS OVER
THE EASTERN THIRD OF THE CONUS. OVERALL, THE GFS-BASED SOLUTIONS GENERALLY
DEPICT HIGHER HEIGHTS OVER THE NORTHERN TIER OF THE CONUS THAN THE ECWMF AND
ENVIRONMENT CANADA MODEL SOLUTION.

DUE TO THE ABOVE AVERAGE LEVEL OF AGREEMENT, THE 500-HPA MANUAL BLEND IS A
50/50 WEIGHTING OF GFS-BASED MODELS AND NON GFS-BASED MODELS. THE 6Z GFS
ENSEMBLE MEAN AND YESTERDAY`S 12Z ECMWF ENSEMBLE MEAN RECEIVE THE MOST WEIGHT
IN THE MANUAL BLEND, WITH THE 0Z GFS AND CANDIAN ENSEMBLE MEANS FILLING OUT THE
REMAINDER.

THE RESULTANT UPPER-LEVEL PATTERN FAVORS ABOVE NORMAL TEMPERATURES OVER ALL OF
ALASKA AND MOST OF THE CONUS, EXCEPT FOR AN AREA CENTERED ON THE SOUTHWEST.
ABOVE NORMAL 500-HPA HEIGHTS AND LOW LEVEL RIDGING SUPPORT ABOVE NORMAL
TEMPERATURES EAST OF THE MISSISSIPPI RIVER. NEAR OR BELOW NORMAL TEMPERATURES
ARE FAVORED FROM CALIFORNIA TO TEXAS, AS FAR NORTH AS CENTRAL UTAH AND COLORADO
DUE TO A PREDICTED TROUGH OVER THAT REGION.

LOW-LEVEL SOUTHWESTERLY FLOW INCREASES THE ODDS FOR ABOVE MEDIAN PRECIPITATION
OVER SOUTHWEST ALASKA, WITH BELOW MEDIAN PRECIPITATION OVER THE INTERIOR BASIN
OF ALASKA. UPPER-LEVEL AND SURFACE RIDGING FAVORS BELOW MEDIAN PRECIPITATION
FROM THE PACIFIC NORTHWEST TO NORTHERN CALIFORNIA. MEAN SOUTHERLY LOW-LEVEL
FLOW AND AN UPPER-LEVEL TROUGH FAVOR ABOVE MEDIAN PRECIPITATION FROM THE
ROCKIES TO THE SOUTHERN GREAT PLAINS AND ACROSS TO THE SOUTHEAST. SURFACE
RIDGING AND A PROGRESSIVE UPPER-LEVEL FLOW FAVOR BELOW MEDIAN PRECIPITATION
FROM MISSOURI TO THE GREAT LAKES AND PORTIONS OF THE MID-ATLANTIC.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 20% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 30% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY
11, 30% 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: ABOVE AVERAGE, 4 OUT OF 5, DUE
TO VERY GOOD AGREEMENT AMONG THE MODELS BUT TEMPERED BY SMALL DISAGREEMENTS
AMONG THE TOOLS

FORECASTER: MATT ROSENCRANS

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:
20040415 - 20090423 - 20040504 - 19540424 - 20000417


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:
20040414 - 20000416 - 20090423 - 19810416 - 20040504


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 11 - 15 2015

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 13 - 19 2015

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