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FXUS06 KWBC 231923
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE AUGUST 23 2016

6-10 DAY OUTLOOK FOR AUG 29 - SEP 02, 2016

TODAY`S 500-HPA HEIGHT MANUAL BLEND REVEALS 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 IS RATHER LOW (GENERALLY LESS
THAN 40 METERS). THE VARIOUS PRODUCTS DERIVED FROM THE GFS AND ECMWF SYSTEMS
ARE GIVEN FAIRLY EQUAL WEIGHTING, THOUGH THE CANADIAN IS DISCOUNTED DUE TO ITS
TRENDING TOWARD THE OTHER MODEL GUIDANCE OVER THE PAST COUPLE OF DAYS. IN ANY
CASE, ENSEMBLE MEAN SOLUTIONS ARE VERY SIMILAR, AND SPAGHETTI CHARTS INDICATE
THAT ENSEMBLE SPREAD IS NOT EXCESSIVE, INCREASING CONFIDENCE IN THE OUTLOOK.

ABOVE-NORMAL TEMPERATURES ARE FAVORED OVER MUCH OF THE CENTRAL AND EASTERN
CONUS, WITH THE HIGHEST PROBABILITIES INDICATED NEAR THE ANOMALOUS RIDGE AXIS.
SOME TILT TOWARD BELOW-NORMAL TEMPERATURES IS FORECAST OVER NORTHERN CALIFORNIA
AT THE FORECAST TROUGH AXIS. NEAR-NORMAL TEMPERATURES AND ABOVE-NORMAL
TEMPERATURES ARE SLIGHTLY FAVORED OVER PARTS OF THE NORTHERN ROCKIES EXTENDING
SOUTHWARD THROUGH THE SOUTHERN HIGH PLAINS AND TEXAS. UNCERTAINTY IS SOMEWHAT
HIGHER OVER THIS REGION DUE TO THE TIMING OF INDIVIDUAL FRONTAL SYSTEMS AND
MODIFICATION OF A RELATIVE COOL AIR MASS IN PLACE AT THE START OF THE PERIOD.

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. ABOVE-MEDIAN
PRECIPITATION IS ALSO MORE LIKELY ACROSS THE MIDWEST, GREAT LAKES, AND
NORTHEAST, WITH AN EXTENSION SOUTHWARD TO THE SOUTHEAST 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 FLORIDA
PENINSULA OR NEARBY COASTAL REGIONS 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, 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, 35% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY
8, AND 20% OF TODAY`S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 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.


8-14 DAY OUTLOOK FOR AUG 31 - SEP 06, 2016

THE 500-HPA HEIGHT MANUAL BLEND FOR WEEK-2 IS DEAMPLIFIED WITH RESPECT TO THE
6-10 DAY PERIOD, BUT THE MAJOR FEATURES REMAIN LARGELY UNCHANGED. THE FORECAST
ANOMALIES OVER THE CONUS ARE OF EXCEEDINGLY LOW AMPLITUDE, SUGGESTING A FAIR
AMOUNT OF UNCERTAINTY WITH RESPECT TO THE EVOLUTION OF VARIOUS SYNOPTIC-SCALE
WEATHER SYSTEMS. THIS IS CONFIRMED BY THE SPAGHETTI CHARTS, WHICH INDEED SHOW A
FAIRLY LARGE AMOUNT OF ENSEMBLE SPREAD FROM THE VARIOUS MODELS.

ABOVE-NORMAL TEMPERATURES ARE AGAIN FAVORED ACROSS THE CENTRAL AND EASTERN
CONUS UNDER WEAKLY POSITIVE 500-HPA HEIGHT ANOMALIES. BELOW-NORMAL TEMPERATURES
ARE FAVORED FROM NORTHERN CALIFORNIA TO THE NORTHERN INTERMOUNTAIN REGION AND
NORTHERN ROCKIES. AS IN THE 6-10 DAY PERIOD, A 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 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,
WHILE 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: 15% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 25% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY
11, AND 60% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOUT AVERAGE, 3 OUT OF 5, DUE
TO FAIR AGREEMENTS AMONG THE MODELS AND THE TOOLS.


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:
19770804 - 19530903 - 19720903 - 19660818 - 19800807


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:
19770804 - 19530903 - 19800806 - 19720903 - 19520802


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 29 - SEP 02, 2016

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  N    A     OREGON      N    N     NRN CALIF   B    N
SRN CALIF   A    N     IDAHO       N    B     NEVADA      N    B
W MONTANA   N    N     E MONTANA   A    N     WYOMING     N    B
UTAH        A    B     ARIZONA     A    B     COLORADO    A    B
NEW MEXICO  A    B     N DAKOTA    A    N     S DAKOTA    A    B
NEBRASKA    A    B     KANSAS      A    B     OKLAHOMA    A    B
N TEXAS     A    B     S TEXAS     A    N     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    A
TENNESSEE   A    N     ALABAMA     A    N     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    A     AK N SLOPE  A    A
AK ALEUTIAN A    N     AK WESTERN  A    A     AK INT BSN  A    N
AK S INT    A    B     AK SO COAST A    B     AK PNHDL    A    B



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 31 - SEP 06, 2016

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