Prognostic Meteorological Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2
000
FXUS06 KWBC 172016
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 17 2017

6-10 DAY OUTLOOK FOR JAN 23 - 27 2017

TODAY`S DYNAMICAL MODEL SOLUTIONS ARE IN VERY GOOD AGREEMENT ON THE 500-HPA
CIRCULATION PATTERN PREDICTED OVER NORTH AMERICA. TROUGHS ARE PREDICTED OVER
THE ALEUTIANS , AND THE CENTRAL CONUS, WHILE RIDGES ARE ANTICIPATED OVER THE
NORTHEAST AND NORTHWEST CONUS. A ZONAL FLOW PATTERN IS EXPECTED ACROSS THE
SOUTHERN CONUS. TODAY`S BLENDED 500-HPA CHART INDICATES NEAR TO ABOVE NORMAL
HEIGHTS OVER THE NORTHEAST CONUS, THE NORTHERN MID-ATLANTIC, THE GREAT LAKES,
THE UPPER MISSISSIPPI VALLEY, NORTH DAKOTA, AND THE ALASKA PANHANDLE, WHILE
NEAR TO BELOW NORMAL HEIGHTS ARE ANTICIPATED OVER THE REMAINDER OF THE CONUS
AND ALASKA.

THE ENSEMBLE SPAGHETTI CHARTS INDICATE MODERATE TO LARGE SPREAD IN THE NORTHERN
JET STREAM, AND LOW TO MODERATE SPREAD IN THE SOUTHERN JET STREAM. THE AO INDEX
WHICH RECENTLY HAS BEEN CLOSE TO ZERO IS FORECAST TO REMAIN WEAKLY
POSITIVE/CLOSE TO ZERO THROUGH DAY 14, ALTHOUGH THERE IS RELATIVELY LARGE
SPREAD AMONG ENSEMBLE MEMBERS REGARDING THE SIGN AND MAGNITUDE OF THE INDEX.
THE PNA INDEX WHICH RECENTLY HAS BEEN STRONGLY POSITIVE IS FORECAST TO BECOME
WEAKLY NEGATIVE BY DAY 7, BE CLOSE TO ZERO AT DAY 10, AND REMAIN NEAR ZERO
THROUGH DAY 14.

ABOVE NORMAL HEIGHTS AND/OR THE EXPECTATION OF AIR MASSES OF PACIFIC ORIGIN
LEAD TO ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR MOST OF THE
EASTERN TWO THIRDS OF THE CONUS. BELOW NORMAL HEIGHTS FAVOR NEAR TO BELOW
NORMAL TEMPERATURES FOR NORTHERN ALASKA AND THE WESTERN THIRD OF THE CONUS,
WHILE ANOMALOUS SOUTHERLY FLOW TILTS THE ODDS TO ABOVE NORMAL TEMPERATURES FOR
SOUTHEASTERN ALASKA AND THE ALASKA PANHANDLE.

A SOUTHERN JET STREAM AND THE TROUGH PREDICTED OVER THE CENTRAL CONUS ENHANCE
PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE CONUS. EXCEPTIONS
ARE OVER MAINE WHERE A RIDGE FORECAST TO LIFT OUT TO THE NORTHEAST TILTS THE
ODDS TO NEAR NORMAL PRECIPITATION, AND OVER PARTS OF THE SOUTHERN PLAINS WHERE
ANOMALOUS WEST-NORTHWESTERLY FLOW FAVORS BELOW MEDIAN PRECIPITATION. SUBSIDENCE
ON THE REAR SIDE OF THE CENTRAL U.S. TROUGH TILT THE ODDS TO BELOW MEDIAN
PRECIPITATION FOR A SMALL PORTION OF THE NORTHERN ROCKIES/NORTHERN PLAINS. THE
TROUGH EXPECTED OVER THE ALEUTIANS ENHANCE PROBABILITIES FOR ABOVE MEDIAN
PRECIPITATIONS FOR THAT REGION AND WESTERN ALASKA, WHILE A WEAK RIDGE TILT THE
ODDS TO BELOW MEDIAN PRECIPITATION FOR THE NORTHEASTERN PORTION OF THE STATE.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 25% 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, 20% OF TODAY`S 0Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 8, 10% OF YESTERDAY`S 12Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 7, 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


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
VERY GOOD AGREEMENT AMONG THE MODEL SOLUTIONS AND THE VARIOUS FORECAST TOOLS,
PARTIALLY OFFSET BY RELATIVELY LARGE SPREAD AMONG THE ENSEMBLE MEMBERS IN THE
NORTHERN STREAM

8-14 DAY OUTLOOK FOR JAN 25 - 31 2017

TODAY`S ENSEMBLE MEAN DYNAMICAL MODEL FORECASTS ARE IN FAIRLY GOOD AGREEMENT ON
THE PREDICTED 500-HPA CIRCULATION PATTERN OVER NORTH AMERICA FOR THE WEEK-2
PERIOD. COMPARED TO THE 6-10 DAY PERIOD, A PATTERN CHANGE DURING WEEK-2 IS
EXPECTED, WITH A RIDGE DEVELOPING NEAR THE WEST COAST AS HEIGHTS FALL OVER THE
EAST-CENTRAL AND NORTHEASTERN CONUS. TROUGHS ARE PREDICTED OVER THE ALEUTIANS,
AND THE GREAT LAKES EXTENDING SOUTHWESTWARD TO OVER THE SOUTHERN
PLAINS/SOUTHERN ROCKIES, WHILE A RIDGE IS FORECAST OVER ALASKA EXTENDING
SOUTHEASTWARD TO ALONG THE WEST COAST OF THE CONUS. THE ENSEMBLE SPAGHETTI
DIAGRAMS INDICATE LOW TO MODERATE SPREAD ACROSS MOST OF THE FORECAST DOMAIN,
WITH LARGE SPREAD INDICATED OVER THE EAST PACIFIC. TODAY`S 500-HPA HEIGHT BLEND
GENERALLY INDICATES ABOVE NORMAL HEIGHTS OVER THE NORTHEAST AND WESTERN CONUS
AND ALASKA, AND BELOW NORMAL HEIGHTS OVER THE REMAINDER OF THE CONUS AND THE
ALEUTIANS.

ABOVE NORMAL HEIGHTS AND AIR MASSES OF MOSTLY PACIFIC ORIGIN TILT THE ODDS TO
ABOVE NORMAL TEMPERATURES FOR MUCH OF THE NORTHEASTERN AND NORTH-CENTRAL CONUS.
BELOW NORMAL HEIGHTS ENHANCE PROBABILITIES FOR BELOW NORMAL TEMPERATURES FOR
THE SOUTHERN TIER OF THE CONUS. ANOMALOUS NORTHEASTERLY FLOW FAVORS BELOW
NORMAL TEMPERATURES FOR THE WESTERN THIRD OF THE U.S. ABOVE NORMAL HEIGHTS AND
ANOMALOUS SOUTHERLY FLOW ENHANCE PROBABILITIES FOR ABOVE NORMAL TEMPERATURES
FOR MUCH OF SOUTHERN AND CENTRAL ALASKA AND THE ALASKA PANHANDLE. ABOVE NORMAL
SST`S ENHANCE PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR THE ALEUTIANS.

ANOMALOUS WESTERLY FLOW ENHANCES PROBABILITIES FOR BELOW MEDIAN PRECIPITATION
FOR THE SOUTHERN PORTION OF THE CONUS FROM THE SOUTHERN PLAINS TO THE
MID-ATLANTIC COAST. THE TROUGH OVER THE GREAT LAKES FAVORS ABOVE MEDIAN
PRECIPITATION FROM THE CENTRAL PLAINS NORTHEASTWARD TO THE GREAT LAKES AND
NORTHEAST CONUS. THE RIDGE BUILDING OVER THE WESTERN CONUS INDICATES A CHANGE
TO THE VERY WET PATTERN SEEN THERE IN RECENT WEEKS AND ENHANCES PROBABILITIES
FOR BELOW MEDIAN PRECIPITATION FOR MOST OF THE WESTERN QUARTER OF THE CONUS.
ANOMALOUS SOUTHERLY FLOW TILT THE ODDS TO ABOVE MEDIAN PRECIPITATION FOR
WESTERN, CENTRAL AND SOUTHEASTERN ALASKA, AND THE ALASKA PANHANDLE. ANOMALOUS
NORTHERLY FLOW FAVORS BELOW MEDIAN PRECIPITATION FOR THE WESTERN ALEUTIANS.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 10% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 20% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY
11, 20% OF TODAY`S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11, 35% OF TODAY`S 0Z
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 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: BELOW AVERAGE, 2 OUT OF 5, DUE
TO FAIRLY GOOD AGREEMENT AMONG THE MODEL SOLUTIONS AND THE VARIOUS SURFACE
TOOLS, OFFSET BY UNCERTAINTY SURROUNDING THE EXPECTED TRANSITION OF THE
LONGWAVE PATTERN DURING THE PERIOD

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
JANUARY 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:
19890125 - 20070101 - 19741230 - 20070119 - 19910112


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:
19890125 - 20061231 - 20070119 - 19910113 - 19741228


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 23 - 27 2017

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 25 - 31 2017

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