Prognostic Meteorological Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2
000
FXUS06 KWBC 031909
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT FRI JULY 03 2015

6-10 DAY OUTLOOK FOR JUL 09 - 13 2015

TODAY`S ENSEMBLE MEAN AND DETERMINISTIC SOLUTIONS ARE IN GOOD AGREEMENT ON
THE 500-HPA MEAN CIRCULATION PATTERN FORECAST OVER MOST OF THE NORTH AMERICA
DOMAIN FOR THE 6-10 DAY PERIOD. TROUGHS ARE PREDICTED OVER THE WESTERN
ALEUTIANS AND ALONG THE WEST COAST OF THE CONTINENT, WHILE A WEAK RIDGE IS
EXPECTED OVER THE SOUTHERN CONUS. TODAY`S MANUAL BLEND CHART INDICATES NEAR TO
BELOW-NORMAL HEIGHTS FOR MUCH OF THE WESTERN HALF OF THE CONUS, AND NEAR TO
ABOVE-NORMAL HEIGHTS OVER THE REMAINDER OF THE CONUS. TODAY`S MANUAL 500-HPA
HEIGHT BLEND IS COMPOSED PRIMARILY OF THE ENSEMBLE MEAN SOLUTIONS AND BASED
LARGELY ON CONSIDERATIONS OF RECENT SKILL AND ON ANALOG CORRELATIONS, WHICH
MEASURE HOW CLOSELY THE MODEL SOLUTIONS RESEMBLE CASES THAT HAVE OCCURRED IN
THE PAST. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE MODERATE SPREAD ACROSS THE
MAJORITY OF THE FORECAST DOMAIN.

BELOW-NORMAL 500-HPA HEIGHTS INCREASE THE CHANCES FOR BELOW-NORMAL TEMPERATURES
FOR CALIFORNIA, THE CENTRAL GREAT BASIN AND THE SOUTHWEST. NEAR TO ABOVE-NORMAL
MEAN TEMPERATURES ARE FORECAST OVER THE EASTERN CONUS AND THE PACIFIC
NORTHWEST, CONSISTENT WITH GEFS REFORECAST GUIDANCE. MEAN SOUTHERLY LOW-LEVEL
FLOW AND TROUGHING TO THE WEST FAVOR ABOVE NORMAL TEMPERATURES FOR ALASKA.

THE ACTIVE STORM TRACK ASSOCIATED WITH MULTIPLE SHORTWAVE TROUGHS, FAVORS ABOVE
MEDIAN PRECIPITATION FROM THE GREAT BASIN TO THE NORTHERN ROCKIES AND EASTWARD
TO THE GREAT LAKES AND NORTHEAST. SUBTROPICAL RIDGING FAVORS BELOW MEDIAN
PRECIPITATION FOR PARTS OF TEXAS AND THE LOWER MISSISSIPPI VALLEY. TROUGHING
AND SOUTHERLY LOW-LEVEL FLOW FAVOR ABOVE MEDIAN PRECIPITATION FOR MUCH OF
ALASKA. THERE ARE ENHANCED CHANCES OF BELOW MEDIAN PRECIPITATION FOR THE ALASKA
PANHANDLE, PARTS OF ARIZONA AND UTAH IN CONSISTENT WITH PRECIPITATION ESTIMATES
FROM THE GEFS AND ECMWF ENSEMBLE MEMBERS. ALSO WESTERLY FLOW ALOFT FAVORS
BELOW-MEDIAN PRECIPITATION ACROSS THE DESERT SOUTHWEST.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 10% OF TODAY`S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 20% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 20%
OF TODAY`S GFS SUPERENSEMBLE MEAN 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, 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
GOOD AGREEMENT AMONG THE MODELS OFFSET BY FAIR AGREEMENT AMONG TEMPERATURE AND
PRECIPITATION TOOLS.

8-14 DAY OUTLOOK FOR JUL 11 - 17 2015

TODAY`S ENSEMBLE MEAN AND DETERMINISTIC SOLUTIONS ARE IN GOOD AGREEMENT ON THE
500-HPA MEAN CIRCULATION PATTERN FORECAST OVER MOST OF NORTH AMERICA FOR THE
WEEK-2 PERIOD. THE PREDICTED CIRCULATION PATTERN IS SIMILAR TO THAT EXPECTED
FOR THE 6-10 DAY PERIOD. TROUGHS ARE PREDICTED OVER THE ALEUTIANS AND NEAR THE
PACIFIC NORTHWEST, WITH WEAK RIDGING OVER THE SOUTHERN CONUS.

ABOVE-NORMAL 500-HPA HEIGHTS AND A SUBTROPICAL RIDGE OVER THE SOUTH-CENTRAL
CONUS, FAVORS ABOVE AVERAGE TEMPERATURES OVER MOST OF THE EASTERN AND CENTRAL
CONUS. MEAN SOUTHERLY FLOW INCREASE THE CHANCES FOR ABOVE-NORMAL TEMPERATURES
FOR ALASKA. NEAR-NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE WESTERN CONUS
DUE TO SMALL 500-HPA HEIGHT ANOMALIES. THE OUTLOOK IS FAIRLY UNCERTAIN, DUE TO
SMALL ANOMALIES.

THE UNCERTAINTY CARRIES OVER TO THE PRECIPITATION OUTLOOK, WHERE THE
PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FROM THE NORTHERN ROCKIES TO THE
GREAT LAKES AND NORTHEAST ARE QUITE LOW. THOSE AREAS ARE WHERE THE MEAN
BAROCLINICITY IS EXPECTED TO BE HIGHEST, WHILE SUBTROPICAL RIDGING FAVORS BELOW
MEDIAN PRECIPITATION OVER THE SOUTHERN PLAINS AND THE LOWER MISSISSIPPI VALLEY.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 20% OF TODAY`S 6Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 20% OF TODAY`S GFS SUPERENSEMBLE MEAN CENTERED ON DAY
11, 20% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 20% OF
YESTERDAY`S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10, 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 GOOD AGREEMENT AMONG THE MODELS OFFSET BY SMALL ANOMALIES, FAIR AGREEMENT
AMONG TEMPERATURE AND PRECIPITATION TOOLS.

FORECASTER: LUKE HE

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
JULY 16

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:
19790717 - 19560709 - 20060624 - 19990711 - 19720702


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:
19790716 - 19720701 - 20070708 - 20060623 - 19560709


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

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



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

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

                           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.

$$



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.