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FXUS06 KWBC 291901
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT WED JULY 29 2015

6-10 DAY OUTLOOK FOR AUG 04 - 08 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 IS NOT AS AMPLIFIED AS WAS YESTERDAY`S FORECAST,
WITH MORE MODEL UNCERTAINTY OVER THE WESTERN CONUS. NEGATIVE HEIGHT ANOMALIES
CONTINUE TO BE FORECAST OVER THE NORTHERN CONUS, NOW EXTENDING WESTWARD ACROSS
THE NORTHERN TIER OF THE U.S. RECENT DETERMINISTIC RUNS OF THE GFS AND ECMWF
ARE IN GOOD AGREEMENT WITH THEIR RESPECTIVE ENSEMBLE MEANS, AND SO A HEALTHY
DOSE OF THE DETERMINISTIC SOLUTIONS IS INCLUDED IN TODAY`S OFFICIAL 500-HPA
HEIGHT MANUAL BLEND.

BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE NORTH-CENTRAL CONUS AND THE GREAT
LAKES REGION DUE TO THE TROUGH PREDICTED OVER EASTERN NORTH AMERICA. THE GEFS
REFORECAST TOOL IS THE PREFERRED SOLUTION GIVEN THAT IT IS MORE WITH VARIOUS
STATISTICAL TOOLS. TODAY`S OBJECTIVE FIRST GUESS WAS THEREFORE TWEAKED COLDER
OVER PARTS OF THE CENTRAL AND EASTERN U.S. TO ALIGN MORE CLOSELY WITH THE
GEFS-DERIVED SOLUTION. ALL TOOLS ARE IN BETTER AGREEMENT ON THE FORECAST
ABOVE-NORMAL TEMPERATURES OVER THE SOUTHERN TIER OF THE CONUS, CENTERED IN THE
SOUTHEAST.

THE PRECIPITATION OUTLOOK DEPICTS ABOVE-MEDIAN RAINFALL FAVORED FROM NEAR THE
ROCKY MOUNTAINS EASTWARD TO PARTS OF THE MIDWEST AND NORTHEAST. THE ENHANCED
RAINFALL FAVORED OVER PARTS OF THE SOUTHWEST IS CONSISTENT WITH ABOVE-NORMAL
HEIGHTS AND ENHANCED MONSOONAL FLOW. FARTHER NORTH, THE REGION FAVORING
WETTER-THAN-NORMAL CONDITIONS ALIGNS WITH THE FORECAST ANOMALOUS TEMPERATURE
GRADIENT, WITH THE MEAN FRONTAL BOUNDARY SERVING AS THE MAIN FORCING MECHANISM.
TO THE SOUTH OF THE FRONTAL ZONE, MUCH OF THE SOUTHEAST IS FORECAST TO RECEIVE
BELOW-MEDIAN RAINFALL. FORECAST ANOMALOUS NORTHERLY FLOW ALOFT IS EXPECTED TO
LEAD TO BELOW-MEDIAN RAINFALL OVER MUCH OF CENTRAL AND WESTERN ALASKA.

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, 15% OF TODAY`S OPERATIONAL 6Z
GFS CENTERED ON DAY 8, 15% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY
8, AND 30% OF TODAY`S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO
GOOD AGREEMENT ON THE FORECAST CIRCULATION, OFFSET BY FAIRLY LARGE DISAGREEMENT
AMONG SURFACE CLIMATE TOOLS.

8-14 DAY OUTLOOK FOR AUG 06 - 12 2015

THE FORECAST CIRCULATION FOR WEEK-2 EXHIBITS A SLIGHT EASTWARD PROGRESSION
ACROSS THE CONUS, BUT WITH A NOTABLE DEAMPLIFICATION OF THE PATTERN BOTH OVER
NORTH AMERICA AS WELL AS UPSTREAM OVER THE NORTH PACIFIC. INSPECTION OF THE
SPAGHETTI DIAGRAMS REVEAL A LARGE AMOUNT OF ENSEMBLE SPREAD FROM THE ECMWF
SYSTEM, INDICATIVE OF A LOWER-CONFIDENCE FORECAST.

DUE TO THE FAIRLY POOR MODEL SKILL SCORES AT THIS LEAD AND TIME OF YEAR,
INCREASED ATTENTION IS PAID TO THE LOW-FREQUENCY CLIMATE BACKGROUND, WHICH IS
HIGHLIGHTED BY THE ONGOING STRONG WARM ENSO EVENT. REGRESSIONS OF THE MONTHLY
NINO 3.4 SSTS WITH AUGUST 500-HPA HEIGHT, SURFACE TEMPERATURE, AND
PRECIPITATION, SERVE AS A BASELINE AGAINST WHICH TO COMPARE MODEL FORECASTS.
THE FORECAST CIRCULATION OVER THE NORTH PACIFIC DURING WEEK-2 (AND THE 6-10 DAY
PERIOD, FOR THAT MATTER) IS REMARKABLY CONSISTENT WITH THE PROMINENT FEATURES
OBSERVED IN THE WARM ENSO FOOTPRINT. THE GEFS-DERIVED SURFACE CLIMATE TOOLS ARE
MORE CLOSELY ALIGNED WITH THE SURFACE TEMPERATURE AND PRECIPITATION REGRESSION
PATTERNS, SO AGAIN THE FIRST GUESS BLEND IS ALTERED TO RELY MORE HEAVILY UPON
THE GEFS-BASED TOOLS.

THE USE OF THE LOW-FREQUENCY STATE SHOULD YIELD INTERESTING RESULTS AS WE HEAD
TOWARD A TIME OF YEAR WITH HISTORICALLY LOW FORECAST SKILL. IT IS IMPORTANT TO
NOTE THAT THE MODELS DO NOT ALWAYS GENERATE EXTRATROPICAL TELECONNECTIONS MOST
CONSISTENT WITH ENSO. TODAY`S COMPOSITE ANALOG PACKAGE OFF THE MANUAL BLEND IS
ONLY WEAKLY TILTED TOWARD EL NINO EVENTS, SO THE ALIGNMENT OF THE MODELS`
SURFACE FORECASTS WITH THE ENSO FOOTPRINT COULD BE SOMEWHAT COINCIDENTAL.
NONETHELESS, OVER WEEK-LONG AVERAGED PERIODS, A STRONG ENSO EVENT COULD BE
LEVERAGED STATISTICALLY TO ADD VALUE TO LOW-SKILL MODEL FORECASTS IN LATE
SUMMER AND AUTUMN.

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, 10% OF TODAY`S OPERATIONAL 0Z GFS CENTERED ON DAY 11, 10% OF TODAY`S
OPERATIONAL 6Z GFS CENTERED ON DAY 11, 35% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 10% 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 - 19540723 - 19750801 - 19570721 - 19960805


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 - 19570721 - 19750731 - 20080720 - 19960804


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 04 - 08 2015

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 06 - 12 2015

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    B     OREGON      A    B     NRN CALIF   A    B
SRN CALIF   A    B     IDAHO       N    N     NEVADA      N    B
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      N    A     OKLAHOMA    A    N
N TEXAS     A    B     S TEXAS     A    B     W TEXAS     A    N
MINNESOTA   B    A     IOWA        B    A     MISSOURI    N    A
ARKANSAS    A    B     LOUISIANA   A    B     WISCONSIN   B    N
ILLINOIS    B    A     MISSISSIPPI A    B     MICHIGAN    B    N
INDIANA     B    A     OHIO        B    A     KENTUCKY    A    N
TENNESSEE   A    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  N    N
MARYLAND    N    N     DELAWARE    N    N     VIRGINIA    N    N
N CAROLINA  A    N     S CAROLINA  A    N     GEORGIA     A    B
FL PNHDL    A    B     FL PENIN    A    B     AK N SLOPE  N    N
AK ALEUTIAN A    B     AK WESTERN  A    B     AK INT BSN  A    N
AK S INT    A    B     AK SO COAST A    B     AK PNHDL    A    B

                           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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