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FXUS06 KWBC 261901
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT WED APRIL 26 2017

6-10 DAY OUTLOOK FOR MAY 02 - 06 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 CONUS AND THE BERING SEA/ALEUTIANS, WHILE RIDGES
ARE ANTICIPATED OVER THE WEST-CENTRAL 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 WESTERN
CONUS, WHILE NEAR TO BELOW NORMAL HEIGHTS ARE EXPECTED OVER THE CENTRAL AND
EASTERN CONUS AND ALASKA.

ANOMALOUS SOUTHERLY FLOW TILTS THE ODDS TO ABOVE NORMAL TEMPERATURES ALONG MUCH
OF THE EAST COAST. ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES FOR ABOVE NORMAL
TEMPERATURES FOR MOST OF THE SOUTHWESTERN CONUS, WHILE BELOW NORMAL HEIGHTS
FAVOR BELOW NORMAL TEMPERATURES FOR MOST OF THE CENTRAL AND EAST-CENTRAL CONUS.
ANOMALOUS EAST-SOUTHEASTERLY FLOW AND ABOVE NORMAL SEA SURFACE TEMPERATURES
ENHANCE PROBABILITIES FOR NEAR TO ABOVE NORMAL TEMPERATURES FOR ALASKA.

THE TROUGH FORECAST OVER THE EASTERN 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 PLAINS. SHORTWAVE ENERGY
RIDING OVER THE TOP OF THE RIDGE FORECAST OVER THE NORTHWESTERN CONUS ENHANCE
PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR PARTS OF THE NORTHERN AND
CENTRAL ROCKIES. BELOW NORMAL HEIGHTS AND THE TROUGH FORECAST OVER THE BERING
SEA ENHANCE PROBABILITIES OF ABOVE MEDIAN PRECIPITATION FOR THE ALEUTIANS,
ALASKA PANHANDLE, AND MUCH OF SOUTHERN ALASKA, WHILE RIDGING FAVORS BELOW
MEDIAN PRECIPITATION FOR PARTS OF NORTHERN ALASKA.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 35% OF TODAY`S 6Z 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, 5% OF TODAY`S
OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, 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 04 - 10 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 WESTERN CANADA EXTENDING NORTH-NORTHWESTWARD OVER ALASKA. TROUGH ENERGY IS
EXPECTED OVER THE WESTERN CONUS UNDERCUTTING THE RIDGE FORECAST OVER WESTERN
CANADA. 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, AND
NEAR TO ABOVE NORMAL HEIGHTS OVER THE MUCH OF THE NORTHWESTERN CONUS AND
NORTHEASTERN 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 MEAN FRONTAL POSITION
OVER THE EASTERN CONUS IS EXPECTED TO LIE JUST NORTH OF FLORIDA WHICH FAVORS
ABOVE NORMAL TEMPERATURES FOR MUCH OF THE PENINSULA. THE TROUGH FORECAST OVER
THE NORTHEAST CONUS ENHANCES PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR
THE EAST-CENTRAL AND NORTHEASTERN CONUS. SHORTWAVE ENERGY RIDING OVER THE TOP
OF THE RIDGE FORECAST OVER THE WESTERN CANADA ENHANCES PROBABILITIES FOR ABOVE
MEDIAN PRECIPITATION FOR PARTS OF THE NORTHERN AND CENTRAL ROCKIES. ABOVE
NORMAL HEIGHTS FAVORS BELOW MEDIAN PRECIPITATION FOR MUCH OF THE NORTHWESTERN
CONUS AND PARTS OF THE CENTRAL GREAT BASIN. A TROUGH OVER THE BERING
SEA/ALEUTIANS ENHANCE PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR PARTS OF
SOUTHWESTERN ALASKA, THE ALASKA PENINSULA, AND ALEUTIANS. THE RIDGE OVER ALASKA
FAVORS BELOW MEDIAN PRECIPITATION FOR PARTS OF NORTH-CENTRAL ALASKA.


THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 10% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 20% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY
11, 15% OF TODAY`S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11, 5% OF TODAY`S
OPERATIONAL 6Z GFS 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 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:
19930427 - 20040421 - 19800407 - 19960421 - 19740428


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 - 19510424 - 19960421 - 19740429 - 19800406


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 02 - 06 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    N     NEVADA      A    B
W MONTANA   N    A     E MONTANA   N    N     WYOMING     B    A
UTAH        N    N     ARIZONA     A    N     COLORADO    B    A
NEW MEXICO  N    N     N DAKOTA    B    B     S DAKOTA    B    B
NEBRASKA    B    B     KANSAS      B    B     OKLAHOMA    B    B
N TEXAS     B    B     S TEXAS     N    B     W TEXAS     N    B
MINNESOTA   B    N     IOWA        B    N     MISSOURI    B    N
ARKANSAS    B    N     LOUISIANA   B    A     WISCONSIN   B    N
ILLINOIS    B    N     MISSISSIPPI B    A     MICHIGAN    B    N
INDIANA     B    A     OHIO        B    A     KENTUCKY    B    A
TENNESSEE   B    A     ALABAMA     B    A     NEW YORK    B    A
VERMONT     N    A     NEW HAMP    N    A     MAINE       N    A
MASS        A    A     CONN        A    A     RHODE IS    A    A
PENN        B    A     NEW JERSEY  N    A     W VIRGINIA  B    A
MARYLAND    N    A     DELAWARE    A    A     VIRGINIA    N    A
N CAROLINA  A    A     S CAROLINA  N    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 04 - 10 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       A    N     NEVADA      A    B
W MONTANA   A    A     E MONTANA   N    A     WYOMING     N    A
UTAH        A    N     ARIZONA     A    N     COLORADO    N    A
NEW MEXICO  N    N     N DAKOTA    B    N     S DAKOTA    B    N
NEBRASKA    B    N     KANSAS      B    B     OKLAHOMA    B    N
N TEXAS     B    N     S TEXAS     N    N     W TEXAS     N    N
MINNESOTA   B    B     IOWA        B    B     MISSOURI    B    A
ARKANSAS    B    A     LOUISIANA   B    A     WISCONSIN   B    N
ILLINOIS    B    A     MISSISSIPPI B    A     MICHIGAN    B    A
INDIANA     B    A     OHIO        B    A     KENTUCKY    B    A
TENNESSEE   B    A     ALABAMA     N    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    N    A
N CAROLINA  N    A     S CAROLINA  N    N     GEORGIA     N    N
FL PNHDL    N    N     FL PENIN    A    N     AK N SLOPE  N    N
AK ALEUTIAN A    A     AK WESTERN  A    N     AK INT BSN  A    B
AK S INT    A    N     AK SO COAST A    N     AK PNHDL    N    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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