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FXUS06 KWBC 251901
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE APRIL 25 2017

6-10 DAY OUTLOOK FOR MAY 01 - 05 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 EAST-CENTRAL CONUS AND THE BERING SEA, WHILE RIDGES ARE
ANTICIPATED OVER THE WESTERN ATLANTIC AND THE NORTHWESTERN CONUS EXTENDING
NORTH/NORTHWESTWARD TO WESTERN CANADA AND ALASKA. ENSEMBLE SPREAD IS MODERATE
TO HIGH OVER MOST OF THE FORECAST DOMAIN. TODAY`S OFFICIAL 500-HPA MANUAL
HEIGHT BLEND INDICATES NEAR TO ABOVE NORMAL HEIGHTS OVER THE EXTREME EASTERN
CONUS, THE WESTERN QUARTER OF THE CONUS, EASTERN AND NORTHERN ALASKA, AND THE
ALASKA PANHANDLE, WHILE NEAR TO BELOW NORMAL HEIGHTS ARE EXPECTED OVER THE
CENTRAL AND EAST-CENTRAL CONUS, SOUTHWESTERN ALASKA, THE ALASKA PENINSULA, AND
THE ALEUTIANS.

ABOVE NORMAL HEIGHTS TILT THE ODDS TO ABOVE NORMAL TEMPERATURES FOR MUCH OF THE
EAST COAST AND PARTS OF THE WESTERN CONUS. BELOW NORMAL HEIGHTS AND/OR
ANOMALOUS NORTHERLY FLOW FAVOR BELOW NORMAL TEMPERATURES FOR MUCH OF THE
CENTRAL CONUS. ANOMALOUS SOUTHEASTERLY FLOW, ABOVE NORMAL HEIGHTS OVER EASTERN
AND NORTHERN ALASKA, AND ABOVE NORMAL SEA SURFACE TEMPERATURES ENHANCE
PROBABILITIES FOR NEAR TO ABOVE NORMAL TEMPERATURES FOR ALASKA.

THE TROUGH FORECAST OVER THE EAST-CENTRAL CONUS FAVORS ABOVE MEDIAN
PRECIPITATION FOR MUCH OF THE EASTERN CONUS. ANOMALOUS NORTH/NORTHWESTERLY FLOW
TILTS THE ODDS TO BELOW MEDIAN PRECIPITATION FOR PARTS OF THE SOUTHERN AND
CENTRAL PLAINS. SHORTWAVE ENERGY RIDING OVER THE TOP OF THE RIDGE FORECAST OVER
THE PACIFIC NORTHWEST ENHANCE PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR
PARTS OF THE NORTHERN AND CENTRAL ROCKIES AND NORTHERN PLAINS. BELOW NORMAL
HEIGHTS AND THE TROUGH FORECAST OVER THE BERING SEA ENHANCE PROBABILITIES OF
ABOVE MEDIAN PRECIPITATION FOR THE ALEUTIANS AND MUCH OF SOUTHWESTERN ALASKA,
WHILE RIDGING FAVORS BELOW MEDIAN PRECIPITATION FOR PARTS OF NORTHERN ALASKA.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 30% OF TODAY`S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 20% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8,
20% OF YESTERDAY`S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 7, 10% OF
YESTERDAY`S OPERATIONAL 12Z ECMWF CENTERED ON DAY 7, AND 20% OF YESTERDAY`S 12Z
CANADIAN ENSEMBLE MEAN CENTERED ON DAY 7


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 RELATIVELY
LARGE SPREAD AMONG THE ENSEMBLE MEMBERS AND THE EXPECTATION OF A PROGRESSIVE
FLOW PATTERN.

8-14 DAY OUTLOOK FOR MAY 03 - 09 2017

COMPARED TO THE 6-10 DAY PERIOD, THE OVERALL CIRCULATION PATTERN IS EXPECTED TO
BE PROGRESSIVE AND DEAMPLIFIED DURING WEEK-2. TROUGHS ARE FORECAST OVER THE
NORTHEASTERN CONUS AND THE BERING SEA/ALEUTIANS, WHILE A RIDGE IS ANTICIPATED
OVER THE PACIFIC NORTHWEST, EXTENDING NORTH-NORTHWESTWARD OVER WESTERN CANADA
AND ALASKA. TROUGH ENERGY IS EXPECTED OVER THE SOUTHWEST CONUS UNDERCUTTING THE
RIDGE FORECAST OVER THE PACIFIC NORTHWEST. 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 HALF OF THE CONUS AND
SOUTHWESTERN ALASKA, AND NEAR TO ABOVE NORMAL HEIGHTS OVER THE WESTERN HALF OF
THE CONUS AND NORTHERN AND EASTERN ALASKA.

DUE TO THE ANTICIPATION OF A PROGRESSIVE CIRCULATION PATTERN, THE EXPECTED
AREAS OF TEMPERATURE ANOMALIES FOR WEEK-2 ARE QUITE SIMILAR TO THOSE FORECAST
FOR THE 6-10 DAY PERIOD EXCEPT DISPLACED EASTWARD. THE TROUGH FORECAST OVER THE
NORTHEAST CONUS ENHANCES PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR THE
EAST-CENTRAL AND NORTHEASTERN CONUS. THE EXPECTATION OF SURFACE HIGH PRESSURE
TILTS THE ODDS TO BELOW MEDIAN PRECIPITATION FOR PARTS OF THE MID-ATLANTIC AND
SOUTHEAST. SHORTWAVE ENERGY RIDING OVER THE TOP OF THE RIDGE FORECAST OVER THE
PACIFIC NORTHWEST ENHANCES PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR
PARTS OF THE INTERIOR WEST. ABOVE NORMAL HEIGHTS FAVORS BELOW MEDIAN
PRECIPITATION FOR MUCH OF THE NORTHWESTERN CONUS. A TROUGH OVER THE BERING
SEA/ALEUTIANS ENHANCE PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR SOUTH
COASTAL ALASKA AND THE ALASKA PANHANDLE. THE RIDGE OVER ALASKA FAVORS BELOW
MEDIAN PRECIPITATION FOR PARTS OF NORTH-CENTRAL ALASKA.


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, 25% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 25% OF
YESTERDAY`S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10, AND 10% OF
YESTERDAY`S 12Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 10


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: BELOW AVERAGE, 2 OUT OF 5, DUE
TO FAIRLY GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS OFFSET BY LARGE
SPREAD AMONG INDIVIDUAL ENSEMBLE MEMBERS 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:
19930426 - 20090502 - 19740430 - 19940405 - 20040421


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:
19930426 - 19940405 - 19510423 - 20090502 - 19740429


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 01 - 05 2017

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 03 - 09 2017

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