Prognostic Meteorological Discussion
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000
FXUS06 KWBC 241943
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT MON JULY 24 2017

6-10 DAY OUTLOOK FOR JUL 30 - AUG 03, 2017

TODAY`S MODELS ARE IN FAIRLY GOOD AGREEMENT ON THE PREDICTED 6-10 DAY 500-HPA
CIRCULATION PATTERN ACROSS THE FORECAST DOMAIN. THE OFFICIAL BLENDED HEIGHT
FIELD DEPICTS MEAN TROUGHS OVER NORTHWEST ALASKA, THE GULF OF ALASKA/EASTERN
PACIFIC, AND THE EAST-CENTRAL CONUS, AND MEAN RIDGES OVER NORTHEAST
ALASKA/YUKON, THE ALEUTIANS, AND THE WESTERN INTERIOR CONUS. THERE ARE
RELATIVELY MINOR DIFFERENCES BETWEEN THE DYNAMICAL MODELS IN PREDICTED
AMPLITUDE AND PHASE OF THESE KEY LONG-WAVE FEATURES. AT THE 5820 METER LEVEL,
THE VARIOUS SPAGHETTI DIAGRAMS SHOW LOW TO MODERATE SPREAD AMONG INDIVIDUAL
ENSEMBLE MEMBERS OVER THE CONUS.

ODDS FOR ABOVE NORMAL TEMPERATURES ARE ELEVATED ACROSS ALASKA, MOST AREAS WEST
OF THE CONTINENTAL DIVIDE, THE NORTHERN GREAT PLAINS AND WESTERN NEBRASKA,
NORTHWEST MINNESOTA, THE NORTHEAST, PARTS OF THE MID-ATLANTIC, THE FLORIDA
PENINSULA, AND SOUTHERN PORTIONS OF TEXAS. THIS IS GENERALLY DUE TO THE
PREDICTED PRESENCE OF 500-HPA RIDGES AND ASSOCIATED ABOVE AVERAGE HEIGHTS, OR
APPROACHING 500-HPA TROUGHS. BELOW NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF
THE CENTRAL AND SOUTHERN GREAT PLAINS, MUCH OF THE MISSISSIPPI AND OHIO
VALLEYS, THE TENNESSEE VALLEY, AND MOST OF THE SOUTHEAST (EXCLUDING FLORIDA).
THIS IS DUE TO THE PREDICTED PRESENCE OF A NEARBY 500-HPA TROUGH.

ABOVE MEDIAN PRECIPITATION IS FAVORED IN WESTERN AND NORTHERN PARTS OF ALASKA,
THE ALASKA PANHANDLE, CENTRAL AND SOUTHERN PORTIONS OF BOTH THE INTERMOUNTAIN
REGION AND ROCKIES, MUCH OF THE SOUTHERN PLAINS, PORTIONS OF THE GULF COAST
REGION AND SOUTHERN APPALACHIANS, AND THE SOUTHERN ATLANTIC STATES FROM FLORIDA
TO SOUTHERN VIRGINIA. THIS IS ATTRIBUTED TO THE EXPECTATION OF APPROACHING
500-HPA TROUGHS AND ASSOCIATED WIDESPREAD ASCENT OF AIR, AND IN THE
SOUTHWESTERN CONUS, THE SOUTHWEST SUMMER MONSOON. BELOW MEDIAN PRECIPITATION IS
FAVORED IN SOUTH-CENTRAL AND EAST-CENTRAL ALASKA, AND ACROSS A LARGE PORTION OF
THE NORTHERN CONUS WHICH INCLUDES THE NORTHERN PORTIONS OF BOTH THE
INTERMOUNTAIN REGION AND ROCKIES, NORTHERN AND CENTRAL PORTIONS OF THE GREAT
PLAINS REGION, ALL BUT FAR SOUTHERN SECTIONS OF THE MISSISSIPPI VALLEY, THE
GREAT LAKES REGION AND NORTHEAST, AND MUCH OF THE OHIO AND TENNESSEE VALLEYS.
THESE FAVORED AREAS OF BELOW MEDIAN PRECIPITATION ARE GENERALLY ASSOCIATED WITH
ANTICIPATED 500-HPA RIDGES AND BELOW AVERAGE HEIGHTS, AND/OR SUFFICIENT
DISTANCE FROM STORM TRACKS.

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


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
FAIRLY GOOD MODEL AGREEMENT, AND REASONABLE AGREEMENT AMONG THE VARIOUS
TEMPERATURE AND PRECIPITATION TOOLS.

8-14 DAY OUTLOOK FOR AUG 01 - 07 2017

TODAY`S MODELS ARE IN FAIR AGREEMENT ON THE PREDICTED WEEK-2 500-HPA
CIRCULATION PATTERN ACROSS THE FORECAST DOMAIN. TO A FIRST APPROXIMATION, THE
PREDICTED PATTERN IS SIMILAR TO THAT FOR DAYS 6-10, BUT THERE ARE INCREASING
DIFFERENCES IN THE PREDICTED AMPLITUDES AND PHASES OF THE MAJOR LONG-WAVES. FOR
EXAMPLE, SOME MODELS NO LONGER PREDICT AN UPSTREAM RIDGE OVER THE ALEUTIANS,
WHILE OTHERS DEPICT SIGNIFICANT VARIATIONS IN THE LOCATION AND AMPLITUDE OF THE
TROUGH EXPECTED OVER THE GULF OF ALASKA. ENSEMBLE SPREAD IS MODERATE OVER MUCH
OF THE FORECAST DOMAIN. THE PREDICTED TEMPERATURE PATTERN IS SIMILAR TO THAT
ANTICIPATED DURING THE 6-10 DAY PERIOD, THOUGH WITH REDUCED PROBABILITIES IN
SOME AREAS. THE EXPECTED PRECIPITATION PATTERN ALSO BEARS REASONABLE
RESEMBLANCE TO THAT ANTICIPATED DURING THE 6-10 DAY PERIOD, THOUGH WITH VERY
MODEST PROBABILITIES OVER MOST OF THE CONUS AND ALASKA, RELATED IN LARGE PART
TO THE WEAK HEIGHT ANOMALY PATTERN THAT IS FORECAST AT 500-HPA DURING WEEK-2.

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, 10% OF TODAY`S OPERATIONAL 0Z GFS CENTERED ON DAY 11, 10% OF TODAY`S
OPERATIONAL 6Z GFS CENTERED ON DAY 11, 20% 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: BELOW AVERAGE, 2 OUT OF 5, DUE
TO FAIR MODEL AGREEMENT, OFFSET BY THE PREDICTION OF VERY MODEST 500-HPA HEIGHT
ANOMALIES AND SURFACE PRECIPITATION ANOMALIES.

FORECASTER: ANTHONY A

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
AUGUST 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:
19800725 - 19880715 - 19590725 - 19620726 - 19840806


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:
19620725 - 19600707 - 19560713 - 19800724 - 19840806


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 30 - AUG 03, 2017

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 01 - 07 2017

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