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FXUS06 KWBC 031902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU SEPTEMBER 03 2015

6-10 DAY OUTLOOK FOR SEP 09 - 13 2015

TODAY`S MODEL SOLUTIONS ARE IN FAIR AGREEMENT ON THE PREDICTED 500-HPA FLOW
PATTERN OVER NORTH AMERICA AND VICINITY. THE ENSEMBLE MEAN SOLUTIONS FROM THE
GFS, ECMWF, AND CANADIAN MODELS INDICATE TROUGHS OVER THE BERING SEA OR WESTERN
ALASKA. A LOW AMPLITUDE CIRCULATION PATTERN IS EXPECTED OVER THE NORTHERN CONUS
WITH A BROADLY CYCLONIC FLOW ANTICIPATED OVER THE CENTRAL AND EASTERN PARTS OF
THE NATION. A SUB-TROPICAL RIDGE IS FORECAST TO DOMINATE THE SOUTHERN CONUS
WITH A WEAKNESS IN THE RIDGE PREDICTED FOR THE SOUTHEASTERN U.S. THE ENSEMBLE
SPAGHETTI CHARTS INDICATE MODERATE SPREAD ACROSS MOST OF THE FORECAST DOMAIN
MOSTLY RELATED TO TIMING DIFFERENCES OF SHORT WAVES IN THE LOW AMPLITUDE FLOW
EXPECTED OVER THE NORTHERN U.S. THE SPREAD IS ALSO PARTIALLY DUE TO THE
UNCERTAINTIES ASSOCIATED WITH TROPICAL SYSTEMS IN THE PACIFIC RECURVING AND
ENTERING THE MID-LATITUDES DURING THE PERIOD. TODAY`S HEIGHT BLEND DEPICTS VERY
SMALL HEIGHT ANOMALIES ACROSS MOST OF THE FORECAST DOMAIN. HEIGHTS ARE
ANTICIPATED TO BE SLIGHLY ABOVE NORMAL OVER THE WESTERN THIRD OF THE CONUS, THE
SOUTHERN PLAINS, THE NORTHEASTERN CONUS, FLORIDA, AND NORTHWESTERN ALASKA, AND
SLIGHTLY BELOW NORMAL OVER THE REMAINDER OF THE CONUS AND ALASKA.

BELOW NORMAL TEMPERATURES ARE FAVORED FOR PARTS OF THE NORTH-CENTRAL CONUS IN
ASSOCIATION WITH THE AREA OF NEAR TO BELOW NORMAL HEIGHTS ANTICIPATED OVER THE
REGION. ABOVE NORMAL TEMPERATURES ARE FAVORED OVER MOST OF THE EASTERN AND
SOUTH-CENTRAL CONUS DUE TO WEAK ANOMALOUS SOUTH/SOUTHWESTERLY FLOW AND THE
RIDGE EXPECTED TO BUILD OVER MUCH OF THE SOUTHERN CONUS. A WEAKNESS IN THIS
RIDGE OVER THE SOUTHEAST CREATES HIGH UNCERTAINTY IN THE FORECAST FOR THIS
REGION. ENHANCED PROBABILITIES OF ABOVE NORMAL TEMPERATURES ARE ALSO INDICATED
FOR MUCH OF SOUTHERN ALASKA AHEAD OF THE TROUGH PREDICTED OVER THE BERING SEA
AND WESTERN ALASKA. ANOMALOUS NORTHERLY FLOW TILTS THE ODDS TO BELOW NORMAL
TEMPERATURES FOR THE NORTH SLOPE OF ALASKA. PROBABILITIES OF ABOVE NORMAL
TEMPERATURES ARE ENHANCED ALONG THE WEST COAST OF THE CONUS DUE TO ABOVE NORMAL
HEIGHTS AND ABOVE NORMAL SSTS CURRENTLY OBSERVED IN ADJACENT WATERS.

THERE ARE ENHANCED PROBABILITIES OF ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE
CENTRAL AND EASTERN CONUS DUE TO THE BROADLY CYCLONIC FLOW EXPECCTED OVER THESE
REGIONS. ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES FOR BELOW MEDIAN
PRECIPITATION FOR THE NORTHWESTERN CONUS AND NORTHWESTERN ALASKA. THE
SUB-TROPICAL RIDGE FORECAST OVER THE SOUTHERN CONUS TILT THE ODDS TO BELOW
MEDIAN PRECIPITATION FOR PARTS OF SOUTHERN TEXAS AND SOUTHERN FLORIDA.  THE
TROUGH PREDICTED OVER WESTERN ALASKA TILTS THE ODDS TO ABOVE MEDIAN
PRECIPITATION FOR SOUTHEASTERN ALASKA AND THE ALASKA PANHANDLE.

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


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, DUE TO
FAIR AGREEMENT AMONG THE MODEL SOLUTIONS, SMALL HEIGHT ANOMALIES, AND MODERATE
SPREAD AMONG THE ENSEMBLE MEMBERS.



8-14 DAY OUTLOOK FOR SEP 11 - 17 2015

TODAY`S WEEK-TWO MODEL SOLUTIONS GENERALLY EXHIBIT LARGE SPREAD AND UNCERTAINTY
FOR MUCH OF THE FORECAST DOMAIN, ALTHOUGH THERE IS FAIRLY GOOD AGREEMENT THAT A
TROUGH WILL BE LOCATED OVER THE EAST-CENTRAL CONUS. ELSEWHERE, TIMING
DIFFERENCES AMONG ENEMBLE MEMBERS LEADS TO RELATIVLY LARGE SPREAD. OVERALL THE
EXPECTED FLOW PATTERN FOR WEEK-2 IS NOT SUBSTANTIALLY DIFFERENT FROM THAT
PREDICTED FOR THE 6-10 DAY PERIOD. THE BROAD TROUGH PREDICTED OVER THE CENTRAL
AND EASTERN CONUS IS FORECAST TO SUPPRESS THE SUB-TROPICAL RIDGE TO THE GULF OF
MEXICO. AGREEMENT IS SOMEWHAT BETTER OVER ALASKA, AS MOST MODEL SOLUTIONS AGREE
IN FORECASTING A TROUGH NEAR THE WESTERN PART OF THE STATE AND A RIDGE NEAR THE
PANHANDLE AND SOUTHEASTERN ALASKA. THE BLENDED HEIGHT CHART INDICATES NEAR TO
BELOW NORMAL HEIGHTS OVER THE EASTERN AND CENTRAL CONUS (EXCEPT FOR THE
NOTHEAST AND SOUTHERN FLORIDA) AND ALASKA, WHILE NEAR TO ABOVE NORMAL HEIGHTS
ARE ANTICIPATED ELSEWHERE.

THE EXPECTED TEMPERATURE AND PRECIPITATION ANOMALY PATTERNS FOR WEEK-2 ARE NOT
SUBSTANTIALLY DIFFERENT FROM THOSE FORECAST FOR THE 6-10 DAY PERIOD. THIS IS
NOT SURPRISING GIVEN HOW LITTLE THE OVERALL CIRCULATION PATTERN IS FORECAST TO
CHANGE BETWEEN THE TWO FORECAST PERIODS.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 10% 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, 5% OF TODAY`S
OPERATIONAL 6Z GFS CENTERED ON DAY 11, 20% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, 15% OF YESTERDAY`S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON
DAY 10, 15% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 5% 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 LARGE MODEL SPREAD AND UNCERTAINTY.

FORECASTER: RANDY SCHECHTER

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
SEPTEMBER 17

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:
20040917 - 19950816 - 19600831 - 19970914 - 19520907


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:
19970914 - 20040916 - 19950817 - 19520909 - 19600902


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 09 - 13 2015

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  N    B     OREGON      A    B     NRN CALIF   A    B
SRN CALIF   A    N     IDAHO       N    B     NEVADA      N    B
W MONTANA   N    N     E MONTANA   B    N     WYOMING     B    B
UTAH        N    N     ARIZONA     A    N     COLORADO    N    N
NEW MEXICO  A    A     N DAKOTA    B    N     S DAKOTA    B    N
NEBRASKA    B    N     KANSAS      B    A     OKLAHOMA    N    A
N TEXAS     A    A     S TEXAS     A    N     W TEXAS     A    A
MINNESOTA   B    N     IOWA        B    A     MISSOURI    B    A
ARKANSAS    N    A     LOUISIANA   A    A     WISCONSIN   B    N
ILLINOIS    B    A     MISSISSIPPI A    A     MICHIGAN    N    A
INDIANA     N    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    A
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    N     AK N SLOPE  B    B
AK ALEUTIAN A    N     AK WESTERN  N    B     AK INT BSN  B    N
AK S INT    N    A     AK SO COAST N    A     AK PNHDL    A    A



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 11 - 17 2015

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    B     NEVADA      A    B
W MONTANA   B    B     E MONTANA   B    N     WYOMING     B    B
UTAH        N    B     ARIZONA     A    N     COLORADO    B    B
NEW MEXICO  N    N     N DAKOTA    B    N     S DAKOTA    B    N
NEBRASKA    B    N     KANSAS      B    N     OKLAHOMA    B    A
N TEXAS     A    A     S TEXAS     A    N     W TEXAS     A    A
MINNESOTA   B    A     IOWA        B    N     MISSOURI    B    N
ARKANSAS    N    A     LOUISIANA   A    A     WISCONSIN   B    A
ILLINOIS    N    A     MISSISSIPPI A    A     MICHIGAN    N    A
INDIANA     N    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    A
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    N     AK N SLOPE  B    N
AK ALEUTIAN A    N     AK WESTERN  N    B     AK INT BSN  B    N
AK S INT    N    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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