Prognostic Meteorological Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2
000
FXUS06 KWBC 272006
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST TUE JANUARY 27 2015

6-10 DAY OUTLOOK FOR FEB 02 - 06 2015

TODAY`S MODELS ARE IN GOOD AGREEMENT ON THE 500-HPA CIRCULATION PATTERN
FORECAST OVER NORTH AMERICA. TROUGHS ARE ANTICIPATED OVER THE EASTERN
TWO-THIRDS OF THE CONUS, AND SOUTH OF THE ALEUTIANS, WHILE A RIDGE IS FORECAST
OVER THE WESTERN THIRD OF CONUS EXTENDING NORTHWARD TOWARDS ALASKA. YESTERDAY`S
12Z ECMWF ENSEMBLE MEAN IS MORE PROGRESSIVE WITH THE TROUGH NEAR THE ALEUTIANS
AND DEPICTS IT OVER THE GULF OF ALASKA. RECENT HIGH RESOLUTION RUNS FROM THE
GFS AND ECMWF DEPICT MORE TROUGH ENERGY BEING HELD BACK NEAR THE SOUTHWEST
CONUS/NORTHWESTERN MEXICO.

THE ENSEMBLE SPAGHETTI CHARTS GENERALLY INDICATE VERY LOW SPREAD OVER THE
EASTERN CONUS, AND MODERATE TO LARGE SPREAD OVER THE WESTERN CONUS. THE PNA
INDEX WHICH RECENTLY HAS BEEN WEAKLY POSITIVE IS FORECAST TO BE CLOSE TO ZERO
BY DAY 7, BE POSITIVE BY DAY 10, AND REMAIN POSITIVE THROUGH DAY 14. THE NAO
INDEX WHICH RECENTLY HAS BEEN POSITIVE IS FORECAST TO BE NEAR ZERO BY DAY 7, BE
POSITIVE BY DAY 10, AND REMAIN POSITIVE THROUGH DAY 14. TODAY`S BLENDED 500-HPA
HEIGHT CHART INDICATES NEAR TO BELOW NORMAL HEIGHTS OVER MUCH OF THE EASTERN
TWO-THIRDS OF THE CONUS (EXCEPT FLORIDA), AND NEAR TO ABOVE NORMAL HEIGHTS OVER
MOST OF THE WESTERN THIRD OF THE CONUS, FLORIDA, AND ALASKA.

FOR THE CONUS, AREAS EXPECTED TO HAVE NEAR TO BELOW (ABOVE) NORMAL HEIGHTS
ROUGHLY CORRESPOND TO AREAS FORECAST TO HAVE NEAR TO BELOW (ABOVE) NORMAL
TEMPERATURES. SINCE THE NORTHERN PLAINS HAVE LOWER HEIGHTS FORECAST TODAY
COMPARED TO YESTERDAY, A TWO CATEGORY CHANGE (FROM ABOVE NORMAL TO BELOW NORMAL
TEMPERATURES) IS APPARENT FOR THE REGION. WARMER THAN NORMAL SEA SURFACE
TEMPERATURES ENHANCE PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR PARTS OF
THE ALEUTIANS, THE SOUTH COAST OF ALASKA, AND THE ALASKAN PANHANDLE. COLD
SURFACE HIGH PRESSURE BUILDING NORTHWEST OF ALASKA TILT THE ODDS TO BELOW
NORMAL TEMPERATURES FOR PARTS OF NORTHWESTERN ALASKA.

THE TROUGH OVER EASTERN NORTH AMERICA ENHANCES PROBABILITIES FOR ABOVE MEDIAN
PRECIPITATION FOR THE EASTERN CONUS. THE EXPECTATION OF UPSLOPE FLOW FAVORS
ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE ROCKIES. SUBSIDENCE ON THE REAR SIDE
OF THE TROUGH FORECAST OVER THE EAST ENHANCES PROBABILITIES FOR BELOW MEDIAN
PRECIPITATION FOR MUCH OF THE CENTRAL CONUS. ABOVE NORMAL HEIGHTS TILT THE ODDS
TO FAVORING BELOW MEDIAN PRECIPITATION FOR THE SOUTHWEST CONUS. A TROUGH
FORECAST NEAR THE ALEUTIANS ENHANCES PROBABILITIES FOR ABOVE MEDIAN
PRECIPITATION FOR THE SOUTH COAST OF ALASKA AND THE ALASKA PANANDLE. HIGH
PRESSURE BUILDING NORTHWEST OF ALASKA TILT THE ODDS TO BELOW MEDIAN
PRECIPITATION FOR MUCH OF NORTHERN ALASKA.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 20% OF TODAY`S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 20% 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, 5% OF TODAY`S OPERATIONAL 0Z ECMWF CENTERED ON
DAY 8, 10% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 10% OF
YESTERDAY`S 12Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 7


MODEL OF THE DAY: 0Z ECMWF ENSEMBLE.

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG THE MODELS AND TOOLS, AND A PERSISTENT, HIGHLY AMPLIFIED
PATTERN.

8-14 DAY OUTLOOK FOR FEB 04 - 10 2015

DURING THE WEEK-2 PERIOD, THE ENSEMBLE MEAN SOLUTIONS GENERALLY INDICATE A
PROGRESSION OF THE CIRCULATION PATTERN FROM THAT FORECAST FOR THE 6-10 DAY
PERIOD AS HEIGHTS RISE OVER THE CENTRAL CONUS. A TROUGH IS ANTICIPATED OVER THE
EASTERN CONUS WHILE A RIDGE BUILDS OVER THE WEST. A TROUGH IS FORECAST OVER
WESTERN ALASKA WHILE A RIDGE IS EXPECTED OVER THE EASTERN PART OF THE STATE.
THE HIGH RESOLUTION GFS FORECASTS SHOW ONLY FAIR RUN TO RUN CONSISTENCY AND
WERE MOSTLY DISCOUNTED. THE ENSEMBLE SPAGHETTI CHARTS INDICATE LOW TO MODERATE
SPREAD OVER THE EASTERN CONUS AND MODERATE TO LARGE SPREAD OVER THE WEST.

TODAY`S WEEK 2 BLEND CHART INDICATES NEAR TO BELOW NORMAL HEIGHTS OVER THE
EASTERN QUARTER OF THE CONUS AND MOST OF ALASKA, WHILE NEAR TO ABOVE NORMAL
HEIGHTS ARE ANTICIPATED OVER THE WESTERN THREE QUARTERS OF THE CONUS AND THE
WESTERN ALEUTIANS.

THE EXPECTED TEMPERATURE AND PRECIPITATION ANOMALY PATTERNS FOR WEEK 2 ARE
MOSTLY SIMILAR TO THOSE EXPECTED DURING THE 6-10 DAY PERIOD. ALTHOUGH, AS
HEIGHTS RISE OVER THE EAST-CENTRAL CONUS, THE AREA OF EXPECTED BELOW NORMAL
TEMPERATURES OVER THE CENTRAL CONUS DEPICTED FOR THE 6-10 DAY PERIOD SHRINKS A
BIT AS THE AREA OF ABOVE NORMAL TEMPERATURES EXPANDS EASTWARD. IN ADDITION, AS
THE TROUGH OVER THE EASTERN U.S. SHIFTS EASTWARD, THE AREA OF EXPECTED ABOVE
MEDIAN PRECIPITATION IS SUPPRESSED SOUTHEASTWARD.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 20% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 15% 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, 10% OF YESTERDAY`S 12Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 10, 10% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 5% OF YESTERDAY`S 12Z CANADIAN ENSEMBLE MEAN CENTERED
ON DAY 10


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOUT AVERAGE, 3 OUT OF 5, DUE
TO GOOD AGREEMENT AMONG THE MODELS AND TOOLS, OFFSET BY THE DIFFICULTIES IN
TIMING ASSOCIATED WITH A PROGRESSIVE CIRCULATION PATTERN.

FORECASTER: RANDY SCHECHTER

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
FEBRUARY 19

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:
19540207 - 19620201 - 19540201 - 19760119 - 19840201


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:
19760119 - 19620131 - 19540206 - 19840131 - 19840106


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR FEB 02 - 06 2015

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR FEB 04 - 10 2015

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

                           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.