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FXUS06 KWBC 241902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT WED AUGUST 24 2016

6-10 DAY OUTLOOK FOR AUG 30 - SEP 03, 2016

TODAY`S 500-HPA HEIGHT MANUAL BLEND CONTINUES TO REVEAL AN AMPLIFIED FORECAST
PATTERN OVER THE NORTH PACIFIC WITH ANOMALOUS TROUGHING SOUTH OF THE ALEUTIANS
AND OVER THE PACIFIC NORTHWEST, AND ANOMALOUS RIDGING OVER THE GULF OF ALASKA
EXTENDING TO CENTRAL AND WESTERN PARTS OF ITS NAMESAKE STATE. WEAK DOWNSTREAM
RIDGING IS FORECAST OVER SOUTH-CENTRAL CANADA AND THE GREAT LAKES, THOUGH THE
AMPLITUDE OF FORECAST HEIGHT ANOMALIES OVER MUCH OF THE CONUS REMAINS RATHER
LOW. THE VARIOUS PRODUCTS DERIVED FROM THE GFS AND ECMWF SYSTEMS ARE GIVEN
FAIRLY EQUAL WEIGHTING, WHILE THE CANADIAN IS ALSO INCLUDED IN TODAY`S MANUAL
BLEND AT A MODEST WEIGHTING. THERE IS SLIGHTLY MORE DISAGREEMENT BETWEEN
VARIOUS ENSEMBLE MEANS COMPARED TO YESTERDAY, THOUGH THIS DIVERGENCE IS MORE
APPARENT DURING THE WEEK-2 PERIOD.

ABOVE-NORMAL TEMPERATURES ARE FAVORED OVER MUCH OF THE CENTRAL AND EASTERN
CONUS, WITH THE HIGHEST PROBABILITIES INDICATED NEAR THE ANOMALOUS RIDGE AXIS
FROM THE GREAT LAKES TO THE SOUTHEAST. DYNAMICAL AND STATISTICAL TOOLS ARE IN
GOOD AGREEMENT ON A TREND TOWARD COOLER CONDITIONS OVER MUCH OF THE
NORTHWESTERN PORTION OF THE CONUS, WHERE ANOMALOUS TROUGHING IS FORECAST. AS
THE FORECAST PATTERN AMPLIFIES SOMEWHAT OVER THE WESTERN U.S. COMPARED TO
YESTERDAY`S OUTLOOK, THE FORECAST TEMPERATURE GRADIENT TIGHTENS AS WELL, WITH
ENHANCED ODDS OF ABOVE-NORMAL TEMPERATURES INDICATED OVER THE NORTHERN AND
CENTRAL PLAINS, EXTENDING TO THE SOUTHWEST.

THE PRECIPITATION OUTLOOK IS DERIVED MAINLY FROM THE REFORECAST-CALIBRATED GEFS
AND ECMWF SYSTEMS. ABOVE-MEDIAN PRECIPITATION IS FAVORED OVER THE
NORTHWESTERN-MOST CONUS NEAR THE FORECAST TROUGH AXIS, EXTENDING EASTWARD ACROS
THE NORTHERN PLAINS. ABOVE-MEDIAN PRECIPITATION IS ALSO MORE LIKELY ACROSS THE
MIDWEST, GREAT LAKES, AND NORTHEAST, WITH AN EXTENSION SOUTHWARD TO THE
SOUTHEAST COAST THROUGH THE OHIO AND TENNESSEE VALLEYS TO THE GULF COAST. A KEY
UNCERTAINTY OVER THE SOUTHEAST IS THE PATH OF A TROPICAL DISTURBANCE OVER THE
ATLANTIC BASIN. FORECAST MODELS SUGGEST THAT THIS COULD IMPACT THE GULF COAST
AND PARTS OF THE INTERIOR SOUTHEAST DURING THE PERIOD. BELOW-MEDIAN RAINFALL IS
LIKELY CENTERED ON THE MONSOON REGION OF THE SOUTHWEST, WHERE THE FORECAST
CIRCULATION IS NOT CONDUCIVE TO MONSOON RAINFALL.

WITH AN ANOMALOUS RIDGE AXIS FORECAST OVER ALASKA, ABOVE-NORMAL TEMPERATURES
ARE FAVORED, WHILE ABOVE-(BELOW-)MEDIAN PRECIPITATION IS FAVORED WEST (EAST) OF
THE RIDGE AXIS.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 10% OF TODAY`S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 10% 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, 30% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY
8, 10% OF TODAY`S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, AND 20% 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
FAIRLY GOOD AGREEMENT AMONG THE MODELS AND VARIOUS TOOLS, OFFSET SOMEWHAT BY
UNCERTAINTY IN THE PRECIPITATION OUTLOOK OVER THE SOUTHEAST AS WELL AS
INCREASED MODEL UNCERTAINTY.


8-14 DAY OUTLOOK FOR SEP 01 - 07 2016

THE 500-HPA HEIGHT MANUAL BLEND FOR WEEK-2 IS SLIGHTLY DEAMPLIFIED WITH RESPECT
TO THE 6-10 DAY PERIOD, BUT THE MAJOR FEATURES REMAIN LARGELY UNCHANGED. THE
VARIOUS ENSEMBLE MEAN SOLUTIONS DIVERGE SIGNIFICANTLY, HOWEVER, WITH THE ECMWF
FAVORING A MORE PROGRESSIVE SOLUTION ACROSS THE WESTERN CONUS COMPARED TO THE
GEFS. TELECONNECTIONS UPON THE FORECAST POSITIVE HEIGHT ANOMALY OVER THE
NORTHEAST PACIFIC SEEM TO SUPPORT THE ECMWF SOLUTION. THIS, ALONG WITH SLIGHTLY
BETTER 500-HPA SKILL SCORES, LEADS TO THE MANUAL BLEND BEING TILTED HEAVILY
TOWARD THE ECMWF, WITH ANOMALOUS TROUGHING FAVORED OVER MUCH OF THE WESTERN
CONUS.

ABOVE-NORMAL TEMPERATURES ARE AGAIN FAVORED ACROSS THE CENTRAL AND EASTERN
CONUS UNDER WEAKLY POSITIVE 500-HPA HEIGHT ANOMALIES. BELOW-NORMAL TEMPERATURES
ARE FAVORED OVER A LARGE REGION OF THE WESTERN CONUS, AS THE VARIOUS TOOLS
REMAIN IN DECENT AGREEMENT DESPITE THE CIRCULATION DIFFERENCE DISCUSSED ABOVE.
AS IN THE 6-10 DAY PERIOD, A SLIGHT WEAKNESS IN ABOVE-NORMAL PROBABILITIES IS
INDICATED FROM THE NORTHERN PLAINS SOUTHWARD THROUGH THE CENTRAL U.S.,
HIGHLIGHTING UNCERTAINTY WITH RESPECT TO POTENTIAL INCURSIONS OF CANADIAN AIR
MASSES. THE DAILY PROGRESSION OF FORECAST HEIGHT ANOMALIES THROUGH THE PERIOD
SUGGESTS THAT BELOW-NORMAL TEMPERATURES WILL BUILD SOUTHEASTWARD THROUGH THE
PERIOD. AREAS FAVORING NEAR-NORMAL TEMPERATURES ARE WHERE THE TRANSITION IS
EXPECTED TO BE CENTERED ON THE MIDDLE OF THE PERIOD.

THE PRECIPITATION OUTLOOK IS UNCERTAIN, A NOT-UNCOMMON FEATURE OF EXTENDED
RANGE OUTLOOKS DURING LATE SUMMER AND EARLY AUTUMN. THE TROPICAL CYCLONE THREAT
IS EXPECTED TO TIME OUT BEFORE THE START OF THE PERIOD OVER THE SOUTHEAST,
THOUGH UNCERTAINTY LINGERS FARTHER NORTH DUE TO THE POTENTIAL EXTRATROPICAL
TRANSITION OF THE TROPICAL CYCLONE REMNANTS. THE FORECAST SOUTHWEST TO
NORTHEAST DIPOLE OF FORECAST PROBABILITIES OVER THE CENTRAL CONUS HINTS AT
ANOMALOUS NORTHWARD MOISTURE TRANSPORT AHEAD OF A MIDLATITUDE SHORTWAVE.
ANOMALOUS TROUGHING ACROSS THE PACIFIC NORTHWEST FAVORS ABOVE-MEDIAN
PRECIPITATION OVER THAT REGION.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 10% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 10% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY
11, 10% OF YESTERDAY`S 18Z GFS ENSEMBLE MEAN CENTERED ON DAY 10, AND 70% OF
TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: BELOW AVERAGE, 2 OUT OF 5, DUE
TO FAIR AGREEMENTS AMONG FORECAST TOOLS OFFSET BY MODEL DISAGREEMENT AT 500-HPA
AND UNCERTAINTY RELATED TO REMNANT TROPICAL CYCLONE IMPACTS OVER THE CENTRAL
AND EASTERN CONUS.


FORECASTER: STEPHEN BAXTER

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 15

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:
19530902 - 19510901 - 19580822 - 20080905 - 19660820


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:
19660820 - 19520804 - 19580821 - 19510901 - 19890903


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 30 - SEP 03, 2016

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 01 - 07 2016

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

                           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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