Prognostic Meteorological Discussion
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FXUS06 KWBC 271902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT MON APRIL 27 2015

6-10 DAY OUTLOOK FOR MAY 03 - 07 2015

TODAY`S ENSEMBLE MEAN AND DETERMINISTIC SOLUTIONS ARE IN GOOD AGREEMENT ON
THE 500-HPA MEAN CIRCULATION PATTERN FORECAST OVER MOST OF THE NORTH AMERICA
DOMAIN FOR THE 6-10 DAY PERIOD. A TROUGH IS EXPECTED OVER THE BERING SEA.
A SPLIT FLOW PATTERN IS FORECAST OVER THE NORTH PACIFIC OCEAN NEAR THE WEST
COAST OF THE CONUS, WITH A RIDGE OVER ALASKA AND A TROUGH DIRECTLY SOUTH OF IT
OVER CALIFORNIA. A SOUTHWESTLY FLOW IS FORECAST ACROSS MOST OF THE CENTRAL AND
EASTERN CONUS WHILE A TROUGH IS OVER KEY WEST AND CUBA. TODAY`S MANUAL 500-HPA
HEIGHT BLEND IS COMPOSED PRIMARILY OF THE ENSEMBLE MEAN SOLUTIONS AND BASED
LARGELY ON CONSIDERATIONS OF RECENT SKILL AND ON ANALOG CORRELATIONS, WHICH
MEASURE HOW CLOSELY THE MODEL SOLUTIONS RESEMBLE CASES THAT HAVE OCCURRED IN
THE PAST. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE MODERATE SPREAD ACROSS THE
MAJORITY OF THE FORECAST DOMAIN.

THERE ARE ENHANCED ODDS FOR ABOVE-NORMAL MEAN TEMPERATURES OVER MOST OF THE
NORTHERN CONUS, DUE TO ABOVE-NORMAL 500-HPA HEIGHTS, AND SOUTHWESTLY ANOMALOUS
FLOW. RIDGING OVER ALASKA ALSO INCREASES THE CHANCES FOR NEAR TO ABOVE NORMAL
TEMPERATURES FOR ALASKA.

NEAR TO ABOVE-MEDIAN PRECIPITATION IS LIKELY FOR MOST OF ALASKA AHEAD OF A
TROUGH PREDICTED OVER THE BERING SEA. ABOVE-MEDIAN PRECIPITATION IS ALSO
FAVORED FOR MUCH OF THE ROCKIES, THE PLAINS AND THE MISSISSIPPI VALLEY IN
ASSOCIATION WITH A TROUGH PREDICTED NEAR THE WESTERN COAST OF THE CONUS. THERE
ARE ENHANCED CHANCES OF ABOVE MEDIAN PRECIPITATION FOR FLORIDA NEAR A TROUGH
PREDICTED OVER KEY WEST. THERE ARE ENHANCED CHANCES OF BELOW-MEDIAN
PRECIPITATION FOR BOTH WEST AND EAST COAST OF THE CONUS IN CONSISTENT WITH
PRECIPITATION ESTIMATES FROM THE GEFS AND ECMWF ENSEMBLE MEMBERS.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 10% OF TODAY`S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 20% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 20%
OF TODAY`S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 8, 20% OF TODAY`S 0Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 8, 10% 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: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG THE MODELS.

8-14 DAY OUTLOOK FOR MAY 05 - 11 2015

TODAY`S ENSEMBLE MEAN AND DETERMINISTIC SOLUTIONS ARE IN GOOD AGREEMENT ON THE
500-HPA MEAN CIRCULATION PATTERN FORECAST OVER MOST OF NORTH AMERICA FOR THE
WEEK-2 PERIOD. THE PREDICTED CIRCULATION PATTERN IS SIMILAR TO THAT EXPECTED
FOR THE 6-10 DAY PERIOD. A RIDGE IS FORECAST OVER ALASKA AND A TROUGH ACROSS
THE WESTERN CONUS. A SOUTHWESTLY FLOW IS FORECAST ACROSS MOST OF THE CENTRAL
AND EASTERN CONUS. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE MODERATE SPREAD
ACROSS THE MAJORITY OF THE FORECAST DOMAIN.

ABOVE NORMAL TEMPERATURE PROBABILITIES ARE ENHANCED FOR ALASKA, AND MUCH OF THE
NORTHERN, EAST AND WEST COAST OF THE CONUS IN ASSOCIATION WITH SOUTHWESTLY
ANOMALOUS FLOW AND POSITIVE 500-HPA HEIGHT ANOMALIES. THERE ARE ENHANCED ODDS
FOR BELOW-NORMAL MEAN TEMPERATURES OVER PARTS OF THE SOUTHWEST, THE SOUTHERN
AND CENTRAL ROCKIES, AND THE SOUTHERN PLAINS, CONSISTENT WITH GEFS REFORECAST
GUIDANCE.

NEAR TO ABOVE-MEDIAN PRECIPITATION IS LIKELY FOR MOST OF ALASKA AHEAD OF A
TROUGH PREDICTED OVER THE BERING SEA. ABOVE-MEDIAN PRECIPITATION IS ALSO
FAVORED FOR MUCH OF THE CENTRAL AND EASTERN CONUS ASSOCIATION WITH A TROUGH
PREDICTED NEAR THE WESTERN COAST OF THE CONUS. THERE ARE ENHANCED CHANCE OF
BELOW-MEDIAN PRECIPITATION FOR WEST COAST OF THE CONUS IN CONSISTENT WITH
PRECIPITATION ESTIMATES FROM THE GEFS AND ECMWF ENSEMBLE MEMBERS.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 20% OF TODAY`S 6Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 20% OF TODAY`S GFS SUPERENSEMBLE MEAN CENTERED ON DAY
11, 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
GOOD AGREEMENT AMONG THE MODELS OFFSET BY FAIR AGREEMENT AMONG 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 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:
19990413 - 19750429 - 19790409 - 19630409 - 19560416


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:
19790410 - 19990412 - 19790415 - 19710421 - 19750429


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 03 - 07 2015

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 05 - 11 2015

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    B     OREGON      A    B     NRN CALIF   A    B
SRN CALIF   N    N     IDAHO       A    N     NEVADA      A    N
W MONTANA   A    N     E MONTANA   A    A     WYOMING     A    A
UTAH        N    A     ARIZONA     B    N     COLORADO    B    A
NEW MEXICO  B    N     N DAKOTA    A    A     S DAKOTA    A    A
NEBRASKA    A    A     KANSAS      N    A     OKLAHOMA    N    A
N TEXAS     N    A     S TEXAS     N    A     W TEXAS     B    A
MINNESOTA   A    A     IOWA        A    A     MISSOURI    N    A
ARKANSAS    N    A     LOUISIANA   N    A     WISCONSIN   A    A
ILLINOIS    N    A     MISSISSIPPI N    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    N     MAINE       A    N
MASS        A    N     CONN        A    A     RHODE IS    A    N
PENN        A    A     NEW JERSEY  A    A     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    A     AK INT BSN  A    A
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    A    A

                           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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