Prognostic Meteorological Discussion
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FXUS06 KWBC 011949
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT MON SEPTEMBER 01 2014

6-10 DAY OUTLOOK FOR SEP 07 - 11 2014

TODAY`S MODEL SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT ON THE PREDICTED 500-HPA
MEAN CIRCULATION PATTERN OVER NORTH AMERICA AND ADJACENT OCEANIC AREAS FOR THE
6-10 DAY PERIOD. THE GENERAL PATTERN FEATURES 500-HPA RIDGES OVER THE FAR
WESTERN PACIFIC, FAR EASTERN PACIFIC, AND SOUTHEAST CONUS, AND 500-HPA TROUGHS
OVER THE CENTRAL PACIFIC AND FROM THE WESTERN CONUS INTO THE GREAT LAKES
REGION, WITH RELATIVELY MINOR PHASE DIFFERENCES. THOUGH THE 500-HPA HEIGHT
DEPARTURES RANGE FROM ABOUT 60-150 METERS ABOVE OR BELOW THE 1981-2010 NORMALS
ACROSS THE PACIFIC BASIN AND PORTIONS OF CANADA, THE ANTICIPATED DEPARTURES
OVER THE CONUS ARE MUCH LESS, RANGING FROM NEAR ZERO TO ABOUT 45 METERS (PLUS
OR MINUS) IN MOST CASES. THE ENSEMBLE SPAGHETTI DIAGRAMS (06Z GFS, 00Z ECMWF,
AND 00Z CANADIAN RUNS, 5820 METER CONTOURS) INDICATE LOW DISPERSION/SPREAD OVER
MUCH OF THE NORTHERN HEMISPHERE, AND MODERATE DISPERSION ASSOCIATED WITH THE
PREDICTED TROUGH OVER THE WESTERN CONUS AND ADJACENT FAR EASTERN PACIFIC.

BELOW-NORMAL TEMPERATURE PROBABILITIES ARE ENHANCED FOR NORTHEASTERN ALASKA,
THE CENTRAL ROCKIES AND ENVIRONS, AND MOST OF THE NORTHEAST CONUS DUE TO
VARIOUS FACTORS SUCH AS 500-HPA TROUGHS, NEGATIVE HEIGHT ANOMALIES, AND WEAK
DISTURBANCES ALOFT. ABOVE-NORMAL TEMPERATURE PROBABILITIES ARE FAVORED FOR MUCH
OF THE REMAINDER OF ALASKA, THE WEST COAST STATES INCLUDING WESTERN NEVADA, AND
FROM THE SOUTHERN GREAT PLAINS EAST-NORTHEAST TO THE ATLANTIC COAST FROM
DELAWARE SOUTHWARD THROUGH FLORIDA. THIS IS BASED ON 500-HPA RIDGING AND/OR
ASSOCIATED POSITIVE HEIGHT ANOMALIES. THIS TEMPERATURE OUTLOOK IS GENERALLY
CONSISTENT WITH NAEFS AND REFORECAST TOOL TEMPERATURE GUIDANCE, AND THE
AUTOMATIC BLENDED TEMPERATURE PROG.

CHANCES FOR ABOVE-MEDIAN PRECIPITATION AMOUNTS ARE ELEVATED OVER NORTHERN AND
EASTERN ALASKA, MUCH OF THE SOUTHWEST AND PLAINS, AND NEARLY ALL AREAS FROM THE
MISSISSIPPI VALLEY TO THE ATLANTIC COAST. THESE AREAS ARE GENERALLY ATTRIBUTED
TO THE EXPECTATION OF APPROACHING 500-HPA TROUGHS AND/OR MONSOON MOISTURE.
CHANCES FOR BELOW-MEDIAN PRECIPITATION AMOUNTS ARE ELEVATED OVER SOUTHWEST
ALASKA, MOST OF THE PACIFIC NORTHWEST AND NORTHERN ROCKIES, MOST OF NORTHERN
UTAH, AND MOST OF NEVADA AND CALIFORNIA, AS WELL AS SOUTH TEXAS. THIS IS
GENERALLY DUE TO THE ANTICIPATION OF 500-HPA RIDGES AND/OR POSITIVE HEIGHT
ANOMALIES. THIS PRECIPITATION OUTLOOK IS GENERALLY CONSISTENT WITH NAEFS, THE
REFORECAST TOOL, AND THE AUTOMATIC BLENDED PRECIPITATION PROG.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 15% OF TODAY`S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 15% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 10%
OF TODAY`S OPERATIONAL 0Z GFS CENTERED ON DAY 8, 10% OF TODAY`S OPERATIONAL 6Z
GFS CENTERED ON DAY 8, 25% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY
8, 10% OF TODAY`S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, AND 15% OF TODAY`S 0Z
CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8


MODEL OF THE DAY: TODAY`S 00Z ECMWF ENSEMBLE MEAN

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
FAIRLY GOOD AGREEMENT AMONG THE MODELS AND TOOLS

8-14 DAY OUTLOOK FOR SEP 09 - 15 2014

THE ENSEMBLE MEAN PREDICTIONS OF THE 500-HPA HEIGHT PATTERN FOR THE WEEK-2
PERIOD ARE IN FAIR AGREEMENT ACROSS NORTH AMERICA. A SLIGHT FLATTENING OF THE
FLOW PATTERN IS FORECAST BY MOST SOLUTIONS, AND THE OPERATIONAL 00Z AND 06Z GFS
RUNS ANTICIPATE A NOTICEABLE EASTWARD SHIFT (ABOUT 10 DEGREES OF LONGITUDE) IN
THE PRIMARY LONG-WAVES FROM THE 6-10 DAY PERIOD. A SLIGHT COOL DOWN IS FORECAST
OVER SOUTHERN PORTIONS OF MAINLAND ALASKA, IN ASSOCIATION WITH A DEEPENING
TROUGH. THE ENSEMBLE SPAGHETTI MAPS (5820 METER CONTOURS FOR MODELS NOTED IN
THE 6-10 DAY PERIOD) INDICATE MODERATE SPREAD ACROSS MUCH OF THE NORTHERN
HEMISPHERE, AND MODERATE TO HIGH SPREAD ASSOCIATED WITH THE PREDICTED MEAN
TROUGH OVER THE WESTERN CONUS.

THERE ARE ENHANCED PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES IN SOUTHWEST
ALASKA AND THE SOUTHERN ALASKA PANHANDLE (RESIDUAL RIDGING), THE WEST COAST
STATES INCLUDING MUCH OF NEVADA (RIDGING AND ASSOCIATED 500-HPA POSITIVE HEIGHT
ANOMALIES), AND FROM THE SOUTHERN PLAINS EAST-NORTHEAST TO THE ATLANTIC COAST
FROM FLORIDA NORTHWARD TO NEW JERSEY, CAPE COD AND MUCH OF MAINE (SUBTROPICAL
RIDGING IN THE SOUTH, WEAK RIDGING IN THE NORTH). THERE ARE ELEVATED ODDS FOR
BELOW-NORMAL TEMPERATURES ACROSS MOST OF MAINLAND ALASKA (500-HPA TROUGH AND
ASSOCIATED NEGATIVE HEIGHT ANOMALIES), AND FROM THE FOUR CORNERS REGION
NORTH-NORTHEAST INTO THE NORTHERN GREAT PLAINS (EXPECTATION OF MONSOONAL
MOISTURE IN THE SOUTH AND A TROUGH IN THE NORTH).

ABOVE-MEDIAN PRECIPITATION IS FAVORED FOR NORTHERN AND EASTERN ALASKA, MUCH OF
THE SOUTHWEST AND PLAINS, AND NEARLY ALL AREAS FROM THE MISSISSIPPI VALLEY TO
THE ATLANTIC COAST. THESE AREAS ARE GENERALLY ATTRIBUTED TO THE EXPECTATION OF
APPROACHING 500-HPA TROUGHS AND/OR MONSOON MOISTURE. CHANCES FOR BELOW-MEDIAN
PRECIPITATION AMOUNTS ARE ELEVATED OVER EXTREME SOUTHWEST ALASKA, AND FROM MOST
OF CALIFORNIA AND OREGON GENERALLY EASTWARD THROUGH WYOMING. THIS IS DUE TO THE
ANTICIPATION OF 500-HPA RIDGES AND/OR POSITIVE HEIGHT ANOMALIES. THIS OUTLOOK
IS GENERALLY CONSISTENT WITH NAEFS, THE REFORECAST TOOL, AND THE AUTOMATIC
BLENDED PRECIPITATION PROG.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 20% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 20% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY
11, 5% OF TODAY`S OPERATIONAL 0Z GFS CENTERED ON DAY 11, 10% OF TODAY`S
OPERATIONAL 6Z GFS CENTERED ON DAY 11, 25% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 20% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: NEAR AVERAGE, 3 OUT OF 5, DUE
TO REASONABLE AGREEMENT AMONG MODEL SOLUTIONS AND TOOLS, OFFSET BY AN EXPECTED
LOWER-AMPLITUDE FORECAST PATTERN

FORECASTER: ANTHONY ARTUSA

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 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:
19830904 - 19920908 - 20010905 - 20000909 - 19800901


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:
19920908 - 20000909 - 19830906 - 19580901 - 19800831


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 07 - 11 2014

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 09 - 15 2014

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