Prognostic Meteorological Discussion
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FXUS06 KWBC 301901
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU JULY 30 2015

6-10 DAY OUTLOOK FOR AUG 05 - 09 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.
THE FORECAST HEIGHT PATTERN CONTINUES TO DEPICT AN ANOMALOUS TROUGH OVER THE
NORTHEAST CONUS, WITH NEAR TO SLIGHTLY BELOW NORMAL HEIGHTS OVER MUCH OF THE
REMAINING PARTS OF THE CONUS. THE CANADIAN ENSEMBLE MEAN EXHIBITS GOOD
RUN-TO-RUN CONTINUITY, AND IS THEREFORE WEIGHTED MORE IN TODAY`S MANUAL BLEND
THAN WAS THE CASE YESTERDAY. OVER THE NORTH PACIFIC, AN OMEGA-TYPE BLOCKING
PATTERN IS EVIDENT IN THE 500-HPA HEIGHT MANUAL BLEND, WITH RIDGING CENTERED
NEAR THE BERING STRAIT. THE DOWNSTREAM TROUGHING NEAR THE PACIFIC NORTHWEST IS
DEEPER THAN IN YESTERDAY`S MODEL SUITE. ELSEWHERE, THERE IS ONLY SOME EASTWARD
PROGRESSION RELATIVE TO YESTERDAY`S 500-HPA HEIGHT OUTLOOK.

BELOW-NORMAL TEMPERATURES ARE FAVORED FOR THE NORTHEASTERN CONUS EXTENDING
WESTWARD ACROSS THE NORTHERN TIER OF STATES. THE ECMWF AND GEFS TEMPERATURE
TOOLS ARE IN BETTER AGREEMENT TODAY, TRENDING TOWARD YESTERDAY`S PREFERRED GEFS
SOLUTION. ALL TOOLS REMAIN IN GOOD AGREEMENT ON THE FORECAST ABOVE-NORMAL
TEMPERATURES OVER THE SOUTHERN TIER OF THE CONUS, CENTERED IN THE SOUTHEAST.
FORECAST UNCERTAINTY IS HIGHEST OVER THE WESTERN U.S., WHERE THE GEFS-DERIVED
TOOLS HAVE HIGH PROBABILITIES OF BELOW-NORMAL TEMPERATURES WEST OF THE ROCKIES.
THIS IS A FAIRLY SIGNIFICANT CHANGE FROM YESTERDAY, AND ABSENT BETTER AGREEMENT
WITH OTHER GUIDANCE, TODAY`S OUTLOOK WAS CONSTRUCTED TO AVOID LARGE
TWO-CATEGORY CHANGES FROM YESTERDAY.

THE PRECIPITATION OUTLOOK IS SIMILAR TO YESTERDAY`S WITH THE LARGEST CHANGES
OVER THE WEST COAST, WHERE ANOMALOUS TROUGHING FAVORS ABOVE-MEDIAN
PRECIPITATION ACROSS THE PACIFIC NORTHWEST. FARTHER EAST, ABOVE-MEDIAN
PRECIPITATION REMAINS MORE LIKELY NEAR THE MEAN FRONTAL ZONE INFERRED FROM THE
TEMPERATURE OUTLOOK. SURFACE HIGH PRESSURE IS EXPECTED TO DOMINATE MUCH OF THE
PERIOD ACROSS THE GREAT LAKES AND INTERIOR NORTHEAST, REDUCING FORECAST
PRECIPITATION AMOUNTS.

THE AFOREMENTIONED BLOCKING PATTERN OVER WESTERN ALASKA FAVORS CONFIDENT
PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES AND BELOW-MEDIAN PRECIPITATION FOR
MUCH OF THE STATE.

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 6Z GFS CENTERED ON DAY 8, 25% OF TODAY`S 0Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 8, 20% 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: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG VARIOUS TOOLS, OFFSET BY INCREASED UNCERTAINTY OVER THE
WESTERN CONUS.

8-14 DAY OUTLOOK FOR AUG 07 - 13 2015

THE FORECAST CIRCULATION FOR WEEK-2 IS NEARLY STATIONARY COMPARED TO THAT FOR
THE 6-10 DAY PERIOD, THOUGH WITH SOME DEAMPLIFICATION RESULTING IN
LOW-AMPLITUDE HEIGHT ANOMALIES OVER MOST OF THE CONUS. IN FACT, COMPARED TO
YESTERDAY`S MANUAL BLEND THERE IS SOME RETROGRESSION EVIDENT. THE STATIONARY
BLOCKING FEATURE OVER THE NORTH PACIFIC IS A MAJOR REASON FOR THIS SLOW-MOVING
PATTERN, THOUGH ITS FAR-FIELD IMPACTS OVER MUCH OF THE CONUS ARE UNCLEAR.

THERE ARE SOME SIGNIFICANT CHANGES FROM YESTERDAY, MAINLY IN THE PRECIPITATION
OUTLOOK. THOUGH THE LONG WAVE PATTERN IS FORECAST TO BE FAIRLY STATIONARY,
EASTWARD PROGRESSION OF MULTIPLE COLD FRONTS IS EXPECTED TO USHER IN CANADIAN
HIGH PRESSURE CENTERED NEAR THE GREAT LAKES. THIS LEADS TO INCREASED ODDS OF
BELOW-MEDIAN RAINFALL IN THAT REGION, EXTENDING SOUTHEASTWARD UNDER ANOMALOUS
NORTHERLY FLOW ALOFT.

ANALOGS BASED ON TODAY`S 500-HPA HEIGHT BLEND FAVOR A WARM ENSO STATE,
HIGHLIGHTING THE CONSISTENCY OF THE FORECAST WITH THE ONGOING LOW-FREQUENCY
STATE. SEE YESTERDAY`S DISCUSSION IN THE ARCHIVES FOR A MORE DETAILED
DISCUSSION OF THE USEFULNESS OF ENSO AS A WEEK-2 PREDICTOR OVER THE NEXT FEW
MONTHS.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 15% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 20% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY
11, 40% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 25% OF
TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11


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 A FORECAST
LOW-AMPLITUDE FLOW.

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
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 - 19750801 - 19960805 - 19540723 - 19590804


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:
19810802 - 19960808 - 19750801 - 19840711 - 19570721


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 05 - 09 2015

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  N    A     OREGON      N    N     NRN CALIF   A    N
SRN CALIF   A    N     IDAHO       N    A     NEVADA      N    N
W MONTANA   N    A     E MONTANA   B    A     WYOMING     N    A
UTAH        N    N     ARIZONA     A    N     COLORADO    A    A
NEW MEXICO  A    N     N DAKOTA    B    A     S DAKOTA    B    A
NEBRASKA    N    A     KANSAS      A    A     OKLAHOMA    A    B
N TEXAS     A    B     S TEXAS     A    B     W TEXAS     A    N
MINNESOTA   B    N     IOWA        B    A     MISSOURI    N    A
ARKANSAS    A    B     LOUISIANA   A    B     WISCONSIN   B    N
ILLINOIS    B    A     MISSISSIPPI A    B     MICHIGAN    B    B
INDIANA     B    A     OHIO        B    A     KENTUCKY    N    N
TENNESSEE   N    N     ALABAMA     A    B     NEW YORK    B    N
VERMONT     B    N     NEW HAMP    B    N     MAINE       B    N
MASS        B    N     CONN        B    N     RHODE IS    B    N
PENN        B    N     NEW JERSEY  B    N     W VIRGINIA  B    A
MARYLAND    N    N     DELAWARE    N    N     VIRGINIA    N    N
N CAROLINA  A    N     S CAROLINA  A    N     GEORGIA     A    B
FL PNHDL    A    N     FL PENIN    A    N     AK N SLOPE  N    B
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 07 - 13 2015

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

$$



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