Prognostic Meteorological Discussion
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FXUS06 KWBC 221902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT FRI MAY 22 2015

6-10 DAY OUTLOOK FOR MAY 28 - JUN 01, 2015

TODAY`S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE 500-HPA CIRCULATION
PATTERN OVER NORTH AMERICA. SPLIT-FLOW IS PREDICTED OVER THE WEST COAST OF
NORTH AMERICA WITH A RIDGE IN THE NORTHERN STREAM OVER WESTERN CANADA AND A
TROUGH IN THE SOUTHERN STREAM OVER CALIFORNIA AND THE U.S. SOUTHWEST. A TROUGH
IS PREDICTED OVER CENTRAL AND EASTERN CANADA WHILE ABOVE-NORMAL HEIGHTS ARE
PREDICTED OVER THE EASTERN U.S. ENSEMBLE SPREAD IS HIGHER OVER THE WEST IN THE
MODELS WITH UNCERTAINTY IN THE SPLIT FLOW PATTERN. THERE IS CONSENSUS AMONG
ENSEMBLE MEMBERS IN PREDICTING ABOVE-NORMAL HEIGHTS OVER THE EAST.

BELOW NORMAL TEMPERATURES ARE MOST LIKELY IN A SMALL AREA OF WESTERN TEXAS,
WHILE NEAR NORMAL TEMPERATURES ARE MOST LIKELY FOR MOST OF THE SOUTHERN PLAINS,
ASSOCIATED WITH THE SOUTHERN STREAM TROUGH AND PRECIPITATION. THERE ARE
ENHANCED PROBABILITIES OF ABOVE NORMAL TEMPERATURES FOR THE EASTERN U.S.,
CONSISTENT WITH PREDICTED ABOVE NORMAL HEIGHTS. RIDGING OVER WESTERN NORTH
AMERICA LEADS TO INCREASED PROBABILITIES OF ABOVE NORMAL TEMPERATURES FOR THE
WEST AND ALASKA.

THE TROUGH PREDICTED OVER THE SOUTHWEST AND CONVERGENT FLOW TO THE EAST LEADS
TO ENHANCED PROBABILITIES OF ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE CONUS,
WITH THE GREATEST PROBABILITIES FOR THE LOWER MISSISSIPPI VALLEY. BELOW MEDIAN
PRECIPITATION IS MORE LIKELY IN COASTAL REGIONS OF THE PACIFIC NORTHWEST AND
ALONG THE U.S.-CANADIAN BORDER FROM NORTH DAKOTA TO LAKE SUPERIOR, AS WELL AS
FOR THE ATLANTIC COAST IN THE SOUTHEAST, AS INDICATED BY REFORECAST CALIBRATED
PROBABILITIES FROM THE NCEP GEFS AND THE ECMWF ENSEMBLES.

THE PROBABILITY OF ABOVE MEDIAN PRECIPITATION IS ENHANCED FOR THE WEST COAST OF
ALASKA AND THE ALEUTIAN ISLANDS UNDER A PREDICTED TROUGH, WHILE BELOW MEDIAN
PRECIPITATION IS MOST LIKELY FOR SOUTHEAST ALASKA INCLUDING THE PANHANDLE,
UNDER A PREDICTED RIDGE.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 35% OF TODAY`S 6Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 30% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8,
AND 35% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8


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

8-14 DAY OUTLOOK FOR MAY 30 - JUN 05, 2015

DURING THE WEEK TWO PERIOD, MODELS SOMEWHAT PERSIST THE CIRCULATION PATTERN OF
THE 6-10 DAY PERIOD FORECAST, WITH INCREASED UNCERTAINTY AND LARGER ENSEMBLE
SPREAD IN THE TROUGH AND RIDGE OVER ALASKA. MODELS CONTINUE TO PREDICT TROUGHS
OVER THE ALEUTIAN ISLANDS, EASTERN CANADA, AND THE U.S. SOUTHWEST, AND RIDGES
OVER EASTERN ALASKA AND WESTERN CANADA. THE EASTERN HALF OF THE U.S. IS
FORECAST TO BE UNDER ABOVE NORMAL HEIGHTS.

ABOVE NORMAL TEMPERATURES ARE MOST LIKELY FOR THE U.S. WEST, AS WELL AS FOR
MUCH OF THE EASTERN CONUS, UNDER ABOVE-NORMAL ATMOSPHERIC HEIGHTS.
PROBABILITIES OF BELOW NORMAL TEMPERATURES ARE ENHANCED FOR WEST TEXAS,
ASSOCIATED WITH THE PREDICTED SOUTHERN STREAM TROUGH, AND FOR PARTS OF NORTH
DAKOTA AND THE WESTERN GREAT LAKES REGION. ABOVE NORMAL TEMPERATURES ARE MOST
LIKELY FOR ALASKA WITH RIDGING PREDICTED OVER WESTERN NORTH AMERICA.

ABOVE MEDIAN PRECIPITATION IS MOST LIKELY OVER MUCH OF THE CONUS ASSOCIATED
WITH THE SOUTHERN STREAM TROUGH AND CONVERGENCE AHEAD OF THE SPLIT STREAM.
BELOW MEDIAN PRECIPITATION IS MOST LIKELY FOR SOUTHEASTERN ALASKA, AND COASTAL
AREAS OF THE PACIFIC NORTHWEST, UNDER THE RIDGE OVER THE WEST COAST OF NORTH
AMERICA. ABOVE MEDIAN PRECIPITATION IS MOST LIKELY FOR THE WEST COAST OF ALASKA
ASSOCIATED WITH THE TROUGH OVER THE ALEUTIAN ISLANDS.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 35% OF TODAY`S 6Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 30% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON
DAY 11, AND 35% 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 GOOD AGREEMENT AMONG MODELS AND TOOLS.

FORECASTER: DAN COLLINS

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 18

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:
20080526 - 19720506 - 19710605 - 19890602 - 19630520


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:
20080526 - 19720505 - 19890602 - 20090604 - 19950502


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 28 - JUN 01, 2015

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    B     OREGON      A    A     NRN CALIF   A    N
SRN CALIF   A    N     IDAHO       A    A     NEVADA      A    A
W MONTANA   A    A     E MONTANA   A    A     WYOMING     A    A
UTAH        A    A     ARIZONA     A    N     COLORADO    N    A
NEW MEXICO  N    A     N DAKOTA    N    N     S DAKOTA    N    A
NEBRASKA    A    A     KANSAS      A    A     OKLAHOMA    N    A
N TEXAS     N    A     S TEXAS     N    A     W TEXAS     B    A
MINNESOTA   A    A     IOWA        A    A     MISSOURI    A    A
ARKANSAS    A    A     LOUISIANA   A    A     WISCONSIN   A    A
ILLINOIS    A    A     MISSISSIPPI A    A     MICHIGAN    A    A
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    A
TENNESSEE   A    A     ALABAMA     A    A     NEW YORK    A    A
VERMONT     A    A     NEW HAMP    A    A     MAINE       A    A
MASS        A    A     CONN        A    A     RHODE IS    A    N
PENN        A    A     NEW JERSEY  A    A     W VIRGINIA  A    A
MARYLAND    A    A     DELAWARE    A    N     VIRGINIA    A    A
N CAROLINA  A    B     S CAROLINA  A    N     GEORGIA     A    N
FL PNHDL    A    N     FL PENIN    A    B     AK N SLOPE  A    N
AK ALEUTIAN A    A     AK WESTERN  A    N     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 MAY 30 - JUN 05, 2015

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