Prognostic Meteorological Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2
000
FXUS06 KWBC 281902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE JULY 28 2015

6-10 DAY OUTLOOK FOR AUG 03 - 07 2015

TODAY`S ENSEMBLE MEANS ARE IN GOOD AGREEMENT ON THE FORECAST 500-HPA MEAN
CIRCULATION PATTERN OVER NORTH AMERICA AND VICINITY FOR THE 6-10 DAY PERIOD.
THERE IS GOOD CONSENSUS FOR A 500-HPA RIDGE TO BE LOCATED OVER THE WESTERN
CONUS, WITH A DOWNSTREAM TROUGH LOCATED NEAR THE GREAT LAKES. HOWEVER, THE
DETERMINISTIC 0Z ECMWF SOLUTION HAS A MORE ZONALLY ORIENTED SOLUTION ACROSS THE
NORTHERN TIER OF THE CONUS RELATIVE TO ITS ENSEMBLE MEAN. MOST MODEL SOLUTIONS
PREDICT A RIDGE OVER THE BERING SEA AND A TROUGH NEAR THE EASTERN ALEUTIANS.
POSITIVE 500-HPA HEIGHT ANOMALIES ARE GENERALLY FORECAST OVER ALASKA WHILE
BELOW NORMAL HEIGHTS ARE PREDICTED OVER THE GREAT LAKES REGION. TODAY`S
OFFICIAL 500-HPA BLEND FAVORS THE ENSEMBLE MEAN SOLUTIONS AND IS COMPOSED OF
SIGNIFICANT CONTRIBUTIONS FROM THE ECMWF, GFS, AND CANADIAN ENSEMBLE MEANS.

BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE NORTH-CENTRAL CONUS AND THE GREAT
LAKES REGION DUE TO THE TROUGH PREDICTED OVER EASTERN NORTH AMERICA.
CONVERSELY, THERE ARE ENHANCED PROBABILITIES OF ABOVE NORMAL TEMPERATURES FOR
MUCH OF THE WESTERN CONUS AND ALASKA UNDERNEATH PREDICTED ABOVE NORMAL HEIGHTS.
ENHANCED PROBABILITIES OF ABOVE NORMAL TEMPERATURES ARE ALSO INDICATED FOR MUCH
OF THE SOUTHERN TIER OF THE CONUS CONSISTENT WITH BIAS CORRECTED TEMPERATURES
FROM THE ECMWF ENSEMBLES.

GEFS REFORECAST GUIDANCE AND PRECIPITATION ESTIMATES FROM THE ECMWF ENSEMBLES
INDICATE FAVORABLE CONDITIONS FOR ABOVE-MEDIAN PRECIPITATION FOR MUCH OF THE
GREAT BASIN, CENTRAL ROCKIES, CENTRAL PLAINS, AND PARTS OF THE SOUTHWEST AND
NORTHERN HIGH PLAINS. ABOVE MEDIAN PRECIPITATION IS ALSO FAVORED FOR THE
NORTHEASTERN CONUS IN ASSOCIATION WITH THE TROUGH PREDICTED OVER EASTERN NORTH
AMERICA. BELOW MEDIAN PRECIPITATION IS FAVORED BEHIND THE TROUGH AXIS FOR PARTS
OF THE UPPER MISSISSIPPI VALLEY. PROBABILITIES FOR ABOVE-MEDIAN PRECIPITATION
ARE ENHANCED FOR PARTS OF THE SOUTHEASTERN CONUS IN ASSOCIATION WITH A
PREDICTED WEAKNESS IN THE SUBTROPICAL RIDGE OVER THIS REGION. BELOW MEDIAN
PRECIPITATION IS FAVORED FOR PARTS OF THE SOUTHERN PLAINS AND SOUTHERN
MISSISSIPPI VALLEY CONSISTENT WITH GEFS REFORECAST GUIDANCE, NAEFS GUIDANCE,
AND PRECIPITATION ESTIMATES FROM THE ECMWF ENSEMBLE MEMBERS. ENHANCED
PROBABILITIES OF BELOW MEDIAN PRECIPITATION ARE ALSO INDICATED FOR MUCH OF
ALASKA AND THE PACIFIC NORTHWEST UNDERNEATH PREDICTED ABOVE NORMAL 500-HPA
HEIGHTS.

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, 5% OF
TODAY`S OPERATIONAL 6Z GFS CENTERED ON DAY 8, 20% OF TODAY`S 0Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF YESTERDAY`S 12Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 7, 15% OF TODAY`S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, 20%
OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 5% OF YESTERDAY`S
12Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 7


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

8-14 DAY OUTLOOK FOR AUG 05 - 11 2015

TODAY`S MODEL FORECASTS FOR THE 8-14 DAY 500-HPA CIRCULATION ARE SIMILAR TO AND
REFLECT A SLIGHT PROGRESSION OF THE OVERALL PATTERN OF THE 6-10 DAY MEAN. A
MEAN TROUGH IS PREDICTED OVER EASTERN NORTH AMERICA CENTERED NEAR THE EASTERN
GREAT LAKES WHILE A RIDGE CENTERED NEAR THE ROCKIES IS FORECAST OVER THE
WESTERN CONUS. IN ADDITION, POSITIVE HEIGHT ANOMALIES CONTINUE TO BE FORECAST
FOR MOST OF ALASKA ALTHOUGH SPREAD AND UNCERTAINTY IS HIGH FOR THIS REGION. THE
WEEK TWO MANUAL 500-HPA BLEND IS COMPOSED PRIMARILY OF THE ENSEMBLE MEAN
SOLUTIONS AND IS BASED, IN PART, ON CONSIDERATIONS OF RECENT SKILL AND ON
ANALOG CORRELATIONS, WHICH MEASURE HOW CLOSELY THE FORECAST PATTERN MATCHES
CASES THAT HAVE OCCURRED IN THE PAST.

THE PERSISTENT TROUGH OVER THE EASTERN CONUS ELEVATES CHANCES FOR BELOW-NORMAL
TEMPERATURES FOR A LARGE PORTION OF THE NORTH-CENTRAL AND NORTHEASTERN CONUS.
FARTHER TO THE SOUTH, ABOVE NORMAL TEMPERATURES ARE FAVORED FOR THE SOUTHERN
PLAINS AND SOUTHEASTERN CONUS CONSISTENT WITH GEFS REFORECAST GUIDANCE AND BIAS
CORRECTED TEMPERATURES FROM THE ECMWF ENSEMBLE MEMBERS. PROBABILITIES ARE
ENHANCED FOR ABOVE-NORMAL TEMPERATURES IN MUCH OF THE FAR WEST CONSISTENT WITH
BIAS CORRECTED TEMPERATURES FROM THE ECMWF ENSEMBLE MEMBERS. ABOVE NORMAL
TEMPERATURES ARE ALSO FAVORED FOR MUCH OF ALASKA UNDERNEATH PREDICTED ABOVE
NORMAL 500-HPA HEIGHTS.

GEFS REFORECAST GUIDANCE AND PRECIPITATION ESTIMATES FROM THE ECMWF ENSEMBLE
MEMBERS CONTINUE TO FAVOR ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE INTERIOR
WEST EXTENDING TO THE CENTRAL PLAINS. NEAR TO ABOVE MEDIAN PRECIPITATION IS
FAVORED FOR MUCH OF THE EASTERN SEABOARD IN ASSOCIATION WITH THE TROUGH
PREDICTED OVER EASTERN NORTH AMERICA. HOWEVER, FORECAST PROBABILITIES ARE LOW
FOR THIS REGION DUE TO CONFLICTING GUIDANCE BETWEEN THE WETTER NAEFS AND THE
DRIER SOLUTIONS FROM THE GEFS REFORECAST AND ECMWF PRECIPITATION ESTIMATES.
UNCERTAINTY IS ALSO HIGH OVER THE PACIFIC NORTHWEST AS GEFS REFORECAST GUIDANCE
PREDICTS A WETTER SOLUTION THAN ESTIMATES FROM THE ECMWF ENSEMBLE MEMBERS. DUE
TO THIS UNCERTAINTY, ENHANCED PROBABILITIES OF NEAR MEDIAN PRECIPITATION IS
INDICATED FOR THIS REGION. TOOLS ARE IN BETTER AGREEMENT OVER THE SOUTHERN
PLAINS, WHERE BELOW MEDIAN PRECIPITATION IS FAVORED. BELOW MEDIAN PRECIPITATION
IS ALSO FAVORED FOR PARTS OF THE UPPER MISSISSIPPI VALLEY AND WESTERN GREAT
LAKES BEHIND THE TROUGH AXIS PREDICTED OVER EASTERN NORTH AMERICA. TOOLS ARE IN
GOOD AGREEMENT IN FAVORING BELOW MEDIAN PRECIPITATION FOR MUCH OF ALASKA
UNDERNEATH PREDICTED ABOVE NORMAL 500-HPA HEIGHTS.



THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 15% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 15% OF TODAY`S 6Z GFS ENSEMBLE MEAN 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, 10% OF YESTERDAY`S 12Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 10, 20% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 10% OF YESTERDAY`S 12Z CANADIAN ENSEMBLE MEAN CENTERED
ON DAY 10


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: AVERAGE, 3 OUT OF 5, DUE TO
RELATIVELY GOOD AGREEMENT AMONG THE ENSEMBLE MEANS OFFSET BY DISAGREEMENTS
AMONG THE SURFACE TOOLS (PARTICULARLY FOR PRECIPITATION).

FORECASTER: SCOTT HANDEL

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 20

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:
19810802 - 19640801 - 19540722 - 19960719 - 20060811


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:
19810801 - 20010801 - 19630720 - 19540721 - 19960718


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 03 - 07 2015

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    A     NEVADA      A    A
W MONTANA   A    N     E MONTANA   N    A     WYOMING     N    A
UTAH        A    A     ARIZONA     A    A     COLORADO    N    A
NEW MEXICO  A    A     N DAKOTA    B    N     S DAKOTA    B    A
NEBRASKA    N    A     KANSAS      N    A     OKLAHOMA    A    N
N TEXAS     A    B     S TEXAS     A    B     W TEXAS     A    B
MINNESOTA   B    B     IOWA        B    N     MISSOURI    N    N
ARKANSAS    A    B     LOUISIANA   A    B     WISCONSIN   B    N
ILLINOIS    B    N     MISSISSIPPI A    B     MICHIGAN    B    A
INDIANA     B    A     OHIO        B    A     KENTUCKY    N    N
TENNESSEE   A    N     ALABAMA     A    B     NEW YORK    B    A
VERMONT     N    A     NEW HAMP    N    A     MAINE       N    A
MASS        A    A     CONN        A    A     RHODE IS    A    A
PENN        N    A     NEW JERSEY  A    A     W VIRGINIA  N    N
MARYLAND    A    A     DELAWARE    A    A     VIRGINIA    A    N
N CAROLINA  A    N     S CAROLINA  A    N     GEORGIA     A    N
FL PNHDL    A    A     FL PENIN    A    A     AK N SLOPE  A    N
AK ALEUTIAN A    B     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 AUG 05 - 11 2015

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