Prognostic Meteorological Discussion
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FXUS06 KWBC 211901
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 21 2017

6-10 DAY OUTLOOK FOR JUL 27 - 31 2017

TODAY`S MODELS ARE IN FAIRLY GOOD AGREEMENT ON THE PREDICTED 500-HPA HEIGHT
PATTERN ACROSS THE U.S. TROUGHS ARE PREDICTED OVER THE GULF OF ALASKA AND THE
EASTERN U.S., WHILE RIDGES ARE FORECAST OVER THE ALEUTIANS AND THE WESTERN U.S.
THE ENSEMBLE SPAGHETTI CHARTS INDICATE LOW TO MODERATE SPREAD OVER MOST OF THE
CONUS, AND MODERATE TO LARGE SPREAD OVER THE EASTERN PACIFIC. MOST OF THE
SPREAD OVER THE CONUS SEEMS TO BE RELATED TO AMPLITUDE DIFFERENCES, WHILE THE
OVERALL POSITION OF THE TROUGH AND RIDGE AXES SHOW RELATIVELY GOOD AGREEMENT.
TODAY`S 500-HPA BLEND CHART DEPICTS NEAR TO BELOW NORMAL HEIGHTS OVER THE
EASTERN THIRD OF THE U.S. AND NORTHERN ALASKA,  WHILE NEAR TO ABOVE NORMAL
HEIGHTS ARE ANTICIPATED OVER THE REMAINDER OF THE CONUS AND ALASKA. EXPECTED
HEIGHT ANOMALIES OVER THE CONUS ARE MOSTLY LESS THAN 30 METERS, WHILE POSITIVE
HEIGHT ANOMALIES FORECAST NEAR THE ALEUTIANS APPROACH 200 METERS.

NEAR TO ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES FOR ABOVE NORMAL
TEMPERATURES FOR MUCH OF THE CONUS. THE EXCEPTIONS ARE OVER PARTS OF THE
SOUTHWEST WHERE CLOUDS AND PRECIPITATION ASSOCIATED WITH MONSOONAL FLOW TILT
THE ODDS TO NEAR NORMAL TEMPERATURES, AND OVER PARTS OF THE NORTHEASTERN CONUS
WHERE NEAR TO BELOW NORMAL HEIGHTS FAVOR NEAR TO BELOW NORMAL TEMPERATURES.
ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES FOR NEAR TO ABOVE NORMAL
TEMPERATURES FOR MUCH OF ALASKA.

THE TROUGH PREDICTED OVER THE EASTERN U.S. FAVORS NEAR TO ABOVE MEDIAN
PRECIPITATION FOR MUCH OF THE REGION. MONSOONAL FLOW ENHANCES PROBABILITIES FOR
ABOVE MEDIAN PRECIPITATION FOR PARTS OF THE SOUTHWEST U.S., CENTRAL GREAT
BASIN, AND CENTRAL ROCKIES. RIDGING OVER THE WEST-CENTRAL U.S. TILTS THE ODDS
TO BELOW MEDIAN PRECIPITATION FOR PARTS OF THE CENTRAL AND SOUTHERN GREAT
PLAINS AND MIDDLE AND LOWER MISSISSIPPI VALLEYS. WITH THE MAIN STORM TRACK
EXPECTED OVER SOUTHERN CANADA, BELOW MEDIAN PRECIPITATION IS ANTICIPATED FOR
PARTS OF THE NORTHWEST AND NORTH-CENTRAL CONUS. THE AMPLIFIED RIDGE FORECAST
OVER THE ALEUTIANS ENHANCES PROBABILITIES FOR BELOW MEDIAN PRECIPITATION FOR
THE REGION, WHILE A DEEP TROUGH NORTH OF ALASKA FAVORS ABOVE MEDIAN
PRECIPITATION FOR MUCH OF CENTRAL AND NORTHERN ALASKA.

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


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, DUE TO
FAIRLY GOOD MODEL AGREEMENT, BUT WEAK LARGE-SCALE ANOMALIES AND SOME
DIFFERENCES AMONG THE TEMPERATURE AND PRECIPITATION TOOLS.

8-14 DAY OUTLOOK FOR JUL 29 - AUG 04, 2017

THE PATTERN FORECAST DURING THE WEEK-2 PERIOD IS VERY SIMILAR TO THE 6-10 DAY
PERIOD, EXCEPT SHIFTED WESTWARD A BIT. ENSEMBLE SPREAD CONTINUES TO BE LOW TO
MODERATE ACROSS MOST OF THE CONUS, AND MODERATE TO LARGE OVER THE EASTERN
PACIFIC AND GULF OF ALASKA. THE BLENDED 500-HPA HEIGHT CHART INDICATES NEAR TO
BELOW NORMAL HEIGHTS OVER THE EASTERN U.S., AND EXTREME NORTHERN ALASKA, AND
NEAR TO ABOVE NORMAL HEIGHTS OVER THE CENTRAL AND WESTERN CONUS, AND THE
REMAINDER OF ALASKA. PARTS OF THE WESTERN CONUS ARE ANTICIPATED TO HAVE
POSITIVE HEIGHT ANOMALIES IN EXCESS OF 30 METERS.

THE EXPECTED TEMPERATURE ANOMALY PATTERN FOR WEEK-2 IS QUITE SIMILAR TO THAT
FORECAST FOR THE 6-10 DAY PERIOD, ALTHOUGH AS THE TROUGH OVER THE EAST
RETROGRADES SLIGHTLY, A WARMER PATTERN IS ANTICIPATED OVER PARTS OF THE
NORTHEAST, WHILE A SLIGHTLY COOLER PATTERN IS FORECAST FOR PARTS OF THE MIDDLE
MISSISSIPPI AND TENNESSEE VALLEYS.

THE TROUGH FORECAST FOR THE EASTERN CONUS ENHANCES PROBABILITIES FOR ABOVE
MEDIAN PRECIPITATION FOR PARTS OF THE SOUTHEAST. AS THE RIDGE OVER THE WEST
SHIFTS A BIT WESTWARD DURING WEEK-2, MONSOONAL FLOW IS EXPECTED TO BE ORIENTED
ALONG A NORTHWEST TO SOUTHEAST AXIS, TILTING THE ODDS TO ABOVE MEDIAN
PRECIPITATION FOR PARTS OF SOUTHWESTERN TEXAS, SOUTHERN NEW MEXICO, AND MUCH OF
ARIZONA. THE POSITION OF THE WESTERN RIDGE ENHANCES PROBABILITIES FOR BELOW
MEDIAN PRECIPITATION FOR THE NORTHERN U.S. FROM THE PACIFIC NORTHWEST EASTWARD
TO THE NORTHERN PLAINS, THEN SOUTHWARD ACROSS PARTS OF THE CENTRAL AND SOUTHERN
PLAINS TO THE MIDDLE MISSISSIPPI AND TENNESSEE VALLEYS. THE EXPECTATION OF
MESOSCALE CONVECTIVE SYSTEMS RIDING ACROSS THE TOP OF THE WESTERN RIDGE FAVORS
ABOVE MEDIAN PRECIPITATION FOR PARTS OF THE UPPER MISSISSIPPI VALLEY, GREAT
LAKES, AND OHIO VALLEY. A TROUGH NORTH OF ALASKA FAVORS ABOVE MEDIAN
PRECIPITATION FOR THE NORTHERN PART OF THE STATE, WHILE THE AMPLIFIED RIDGE
NEAR THE ALEUTIANS ENHANCES PROBABILITIES FOR BELOW MEDIAN PRECIPITATION FOR
THAT REGION AND SOUTHWESTERN MAINLAND ALASKA.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 10% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 15% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY
11, 15% OF TODAY`S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11, 25% OF TODAY`S 0Z
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 15% OF YESTERDAY`S 12Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 10, 5% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 15% OF YESTERDAY`S 12Z CANADIAN ENSEMBLE MEAN CENTERED
ON DAY 10


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: MUCH BELOW AVERAGE, 1 OUT OF 5,
DUE TO FAIRLY GOOD MODEL AGREEMENT, BUT WEAK LARGE-SCALE ANOMALIES AND SOME
LARGE DIFFERENCES AMONG THE TEMPERATURE AND PRECIPITATION TOOLS.

FORECASTER: RANDY S

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:
19790804 - 20050701 - 19780725 - 19790728 - 20040719


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:
19790803 - 19780725 - 20050701 - 19790729 - 20040721


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 27 - 31 2017

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 29 - AUG 04, 2017

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