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FXUS06 KWBC 281902
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 28 2017

6-10 DAY OUTLOOK FOR MAY 04 - 08 2017

TODAY`S DYNAMICAL MODEL SOLUTIONS FOR THE 6-10 DAY PERIOD ARE IN GOOD AGREEMENT
ON THE EXPECTED 500-HPA CIRCULATION PATTERN OVER MOST OF NORTH AMERICA. TROUGHS
ARE PREDICTED OVER THE EASTERN AND SOUTHWESTERN CONUS AND THE BERING
SEA/ALEUTIANS, WHILE RIDGES ARE ANTICIPATED OVER THE WEST-CENTRAL ATLANTIC, THE
WEST-CENTRAL CONUS, AND WESTERN CANADA AND ALASKA. ENSEMBLE SPREAD IS MODERATE
TO HIGH OVER THE MAJORITY OF THE FORECAST DOMAIN. TODAY`S OFFICIAL 500-HPA
MANUAL HEIGHT BLEND INDICATES NEAR TO ABOVE NORMAL HEIGHTS OVER THE WESTERN
CONUS, WHILE NEAR TO BELOW NORMAL HEIGHTS ARE EXPECTED OVER THE EASTERN CONUS,
PARTS OF THE SOUTHERN PLAINS, AND ALASKA.

ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES FOR NEAR TO ABOVE NORMAL
TEMPERATURES FOR MOST OF THE WESTERN CONUS, WHILE BELOW NORMAL HEIGHTS FAVOR
NEAR TO BELOW NORMAL TEMPERATURES FOR MOST OF THE EAST-CENTRAL AND EASTERN
CONUS AND SOUTHERN PLAINS. ANOMALOUS EASTERLY FLOW AND ABOVE NORMAL SEA SURFACE
TEMPERATURES ENHANCE PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR WESTERN
AND SOUTHERN ALASKA.

THE TROUGH FORECAST OVER THE EASTERN CONUS FAVORS ABOVE MEDIAN PRECIPITATION
FOR MUCH OF THE EASTERN U.S. ANOMALOUS NORTH/NORTHWESTERLY FLOW TILTS THE ODDS
TO BELOW MEDIAN PRECIPITATION FOR PARTS OF THE CENTRAL CONUS. THE TROUGH
PREDICTED OVER THE SOUTHWESTERN CONUS ENHANCES PROBABILITIES FOR ABOVE MEDIAN
PRECIPITATION FOR PARTS OF THE INTERIOR WESTERN U.S. ABOVE NORMAL HEIGHTS
FAVORS BELOW MEDIAN PRECIPITATION FOR PARTS OF NORTHERN CALIFORNIA, WESTERN
OREGON AND SOUTHWESTERN WASHINGTON. BELOW NORMAL HEIGHTS AND THE TROUGH
FORECAST OVER THE BERING SEA ENHANCE PROBABILITIES OF ABOVE MEDIAN
PRECIPITATION FOR THE ALASKA PANHANDLE, SOUTH COASTAL ALASKA AND THE ALEUTIANS,
WHILE RIDGING FAVORS BELOW MEDIAN PRECIPITATION FOR PARTS OF NORTHWESTERN
ALASKA.

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


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO
GOOD AGREEMENT ON A MODERATELY AMPLIFIED PATTERN FOR MUCH OF THE FORECAST
DOMAIN AND FAIRLY GOOD AGREEMENT AMONG THE FORECAST TOOLS, OFFSET BY MODERATE
TO HIGH SPREAD AMONG THE ENSEMBLE MEMBERS AND THE EXPECTATION OF A PROGRESSIVE
FLOW PATTERN.

8-14 DAY OUTLOOK FOR MAY 06 - 12 2017

COMPARED TO THE 6-10 DAY PERIOD, THE OVERALL CIRCULATION PATTERN IS EXPECTED TO
BE PROGRESSIVE DURING WEEK-2. TROUGHS ARE FORECAST OVER THE NORTHEASTERN AND
WESTERN CONUS AND THE ALEUTIANS/ALASKA PENINSULA, WHILE RIDGES ARE ANTICIPATED
OVER THE CENTRAL CONUS AND ALASKA. THE ENSEMBLE SPAGHETTI CHARTS INDICATE
RELATIVELY HIGH SPREAD ACROSS MOST OF THE FORECAST DOMAIN WITH LARGE
DIFFERENCES NOTED IN BOTH AMPLITUDE AND PHASE OF INDIVIDUAL SHORTWAVE FEATURES.
TODAY`S WEEK-2 BLENDED 500-HPA HEIGHT CHART INDICATES A RELATIVELY WEAK HEIGHT
ANOMALY PATTERN, DUE TO THE HIGH SPREAD AMONG ENSEMBLE MEMBERS. NEAR TO BELOW
NORMAL HEIGHTS ARE PREDICTED OVER THE EASTERN AND SOUTHERN CONUS, SOUTHWESTERN
ALASKA, AND THE ALEUTIANS, WHILE NEAR TO ABOVE NORMAL HEIGHTS ARE ANTICIPATED
OVER THE MUCH OF THE NORTHWESTERN AND NORTH-CENTRAL CONUS AND NORTHERN AND
EASTERN ALASKA AND THE ALASKA PANHANDLE.

BELOW NORMAL HEIGHTS ENHANCE PROBABILITIES FOR BELOW NORMAL TEMPERATURES FOR
MUCH OF THE EASTERN THIRD OF THE CONUS, LOWER MISSISSIPPI VALLEY, AND PARTS OF
THE SOUTHERN PLAINS. NEAR TO ABOVE NORMAL HEIGHTS FAVOR NEAR TO ABOVE NORMAL
TEMPERATURES FOR MOST OF THE WESTERN TWO-THIRDS OF THE CONUS. ANOMALOUS
SOUTH/SOUTHEASTERLY FLOW ENHANCES PROBABILITIES FOR ABOVE NORMAL TEMPERATURES
FOR SOUTHERN AND CENTRAL ALASKA.

ANOMALOUS NORTH/NORTHEASTERLY FLOW FAVORS NEAR TO BELOW MEDIAN PRECIPITATION
FOR THE EASTERN HALF OF THE CONUS. THE TROUGH OVER THE WESTERN U.S. TILTS THE
ODDS TO ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE INTERIOR WESTERN CONUS.
ABOVE NORMAL HEIGHTS FAVORS BELOW MEDIAN PRECIPITATION FOR NORTHERN CALIFORNIA
AND MUCH OF THE PACIFIC NORTHWEST. THE TROUGH NEAR THE ALEUTIANS FAVORS ABOVE
MEDIAN PRECIPITATION FOR THE ALASKA PENINSULA, SOUTH COASTAL ALASKA, AND THE
ALASKA PANHANDLE. RIDGING ENHANCES PROBABILITIES FOR BELOW MEDIAN PRECIPITATION
FOR PARTS OF CENTRAL AND NORTHWESTERN ALASKA.

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


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: MUCH BELOW AVERAGE, 1 OUT OF 5,
DUE TO FAIRLY GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS OFFSET BY LARGE
SPREAD AMONG INDIVIDUAL ENSEMBLE MEMBERS, DISAGREEMENT AMONG MANY OF THE
FORECAST TOOLS, AND RELATIVELY WEAK HEIGHT ANOMALIES.

FORECASTER: RANDY S

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
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:
19930428 - 19730415 - 19680423 - 20040421 - 19910408


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:
19930430 - 19730416 - 19680423 - 19640410 - 19930408


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 04 - 08 2017

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 06 - 12 2017

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