Prognostic Meteorological Discussion
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FXUS06 KWBC 011901
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT WED OCTOBER 01 2014

6-10 DAY OUTLOOK FOR OCT 07 - 11 2014

TODAY`S MODELS ARE IN FAIR AGREEMENT ON THE FORECAST CIRCULATION FOR THE 6-10
DAY PERIOD OVER NORTH AMERICA AND ADJACENT OCEAN AREAS. THE LATEST TWO RUNS OF
THE GFS ENSEMBLE MEAN AND DETERMINISTIC SOLUTIONS PREDICT A DEEP TROUGH OVER
THE CENTRAL NORTH PACIFIC, AN AMPLIFIED RIDGE NEAR THE WEST COAST OF NORTH
AMERICA, AND ANOTHER DEEP TROUGH OVER THE EASTERN CONUS. THE 00Z CANADIAN
ENSEMBLE MEAN FORECASTS A SIMILAR LONG-WAVE SETUP, THOUGH THE TROUGH OVER THE
EASTERN CONUS IS FORECAST TO BE VERY BROAD, AND CENTERED FARTHER WEST, OVER THE
NORTH-CENTRAL STATES. THE 00Z ECMWF ENSEMBLE MEAN SOLUTION IS SOMEWHAT
DIFFERENT COMPARED TO THE GFS AND CANADIAN SOLUTIONS. IT PREDICTS A WEAK TROUGH
CENTERED OVER EASTERN ALASKA, WHERE THE SOLUTIONS NOTED EARLIER HAD RIDGING.
THIS FEATURE, ALONG WITH THE TROUGHS PREDICTED OVER THE CENTRAL NORTH PACIFIC
AND EASTERN CONUS, RESULTS IN A BROAD REGION OF WESTERLY FLOW ALOFT ACROSS THE
MID-LATITUDES OF THE PACIFIC AND THE CONTIGUOUS UNITED STATES. INTERESTINGLY,
DESPITE THESE DIFFERENCES, NEARLY ALL MODEL RUNS FORECAST A WEAK TROUGH IN THE
GENERAL VICINITY OF CALIFORNIA. IN GENERAL, THE ECMWF ENSEMBLE MEAN IS LESS
AMPLIFIED WITH THE PREDICTED LONG-WAVE FEATURES COMPARED TO BOTH THE GFS-BASED
RUNS AND CANADIAN ENSEMBLE MEAN.

THE SPREAD/DISPERSION AMONG THE INDIVIDUAL MEMBERS OF THE 00Z AND 06Z GFS (5760
M) IS LOW, LOW TO MODERATE FOR THE 00Z CANADIAN MODEL, AND MODERATE TO HIGH FOR
THE 00Z ECMWF. THE GREATEST UNCERTAINTY (SPREAD) IS DEPICTED OVER THE EASTERN
PACIFIC AND WESTERN CONUS.

ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR MOST OF THE WESTERN HALF OF THE CONUS
UNDER AN ANTICIPATED BROAD RIDGE, AND FOR THE NORTHEAST IN ADVANCE OF THE
EXPECTED TROUGH OVER THE EAST-CENTRAL CONUS. ABOVE-NORMAL TEMPERATURES ARE ALSO
FAVORED OVER FAR NORTHERN AND WESTERN ALASKA, ASSOCIATED WITH UPPER-AIR RIDGING
AND RELATIVELY WARM SEA SURFACE TEMPERATURES. BELOW-NORMAL TEMPERATURES ARE
FAVORED FROM THE DAKOTAS TO MICHIGAN AND OHIO, ASSOCIATED WITH THE EXPECTED
TROUGH. BELOW-NORMAL TEMPERATURES ARE ALSO FAVORED OVER THE SOUTHEAST MAINLAND
OF ALASKA DUE TO THE EXPECTATION OF A WEAK TROUGH IN THAT REGION.

BELOW-MEDIAN PRECIPITATION AMOUNTS ARE FAVORED OVER APPROXIMATELY THE WESTERN
THIRD OF THE CONUS, MUCH OF THE SOUTHEAST, AND MOST OF NORTHERN AND CENTRAL
ALASKA. THIS IS GENERALLY ATTRIBUTED TO UPPER-AIR RIDGING, AND NEAR TO
ABOVE-NORMAL 500-HPA HEIGHTS. ABOVE-MEDIAN PRECIPITATION AMOUNTS ARE FAVORED
FROM THE EASTERN PLAINS AND MISSISSIPPI VALLEY EASTWARD ACROSS THE GREAT LAKES,
MUCH OF THE OHIO VALLEY, AND NORTHEAST, AND ALSO OVER SOUTHWESTERN AND SOUTHERN
COASTAL SECTIONS OF ALASKA. THIS IS GENERALLY DUE TO THE EXPECTATION OF
UPPER-AIR TROUGHS AND ASSOCIATED STORM TRACKS.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 30% OF TODAY`S 6Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 10% OF TODAY`S OPERATIONAL 0Z GFS CENTERED ON DAY 8, 10% OF
TODAY`S OPERATIONAL 6Z GFS CENTERED ON DAY 8, 30% OF TODAY`S 0Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 8, AND 20% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN
CENTERED ON DAY 8


MODEL OF THE DAY: 6Z GFS ENSEMBLE MEAN AND 0Z ECMWF ENSEMBLE MEAN (TIED)

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: NEAR AVERAGE, 3 OUT OF 5, DUE TO
REASONS NOTED ABOVE.

8-14 DAY OUTLOOK FOR OCT 09 - 15 2014

TODAY`S MODEL RUNS OF THE PREDICTED 8-14 DAY MEAN HEIGHT FIELD OVER NORTH
AMERICA AND ADJACENT OCEAN AREAS DEPICT CLEAR CONVERGENCE OF EXPECTED OUTCOMES,
COMPARED TO THE MORE UNCERTAIN 6-10 DAY PERIOD. FOR WEEK 2, ALL RUNS PREDICT A
DEEP TROUGH OVER THE CENTRAL NORTH PACIFIC, AN AMPLIFIED RIDGE NEAR THE WEST
COAST OF NORTH AMERICA, AND A DEEP TROUGH CENTERED OVER THE EAST-CENTRAL CONUS.
THE DETERMINISTIC 00Z AND 06Z GFS RUNS ARE THE MOST AMPLIFIED OF ALL SOLUTIONS.
THE SPREAD AMONG THE INDIVIDUAL MEMBERS OF THE 00Z AND 06Z GFS AND 00Z CANADIAN
RUN (5760 M CONTOURS) DEPICT MODERATE SPREAD, WITH A TIGHTENING UP OF SOLUTIONS
(LESS DISPERSIVE) OF THE MOST RECENT 06Z GFS. THE 00Z ECMWF HOWEVER, CONTINUES
TO EXHIBIT LARGE SPREAD ACROSS THE EASTERN PACIFIC AND THE CONUS.

THE WEEK 2 SURFACE TEMPERATURE AND PRECIPITATION PATTERNS ARE SIMILAR TO THOSE
ANTICIPATED FOR THE 6-10 DAY PERIOD. THE MAIN ISSUE DURING WEEK 2 IS THE
PREDICTED SOUTHWARD PUSH OF ANOMALOUSLY COLD AIR PRIMARILY BETWEEN THE ROCKIES
AND THE APPALACHIANS. TELECONNECTIONS USING A NEGATIVE 500-HPA HEIGHT ANOMALY
CENTER IN THE CENTRAL NORTH PACIFIC NEAR 40N/180W SUGGESTS ANOMALOUSLY COLD AIR
COULD OVERSPREAD MOST OF THE CONUS, BUT THIS MAY BE OVERDONE. MOST TOOLS
INDICATE THE COLD AIR WILL REMAIN EAST OF THE CONTINENTAL DIVIDE. THERE IS
CONSIDERABLE UNCERTAINTY EAST OF THE APPALACHIANS THOUGH, AS TO HOW MUCH
RESIDUAL WARMTH MAY LINGER IN ADVANCE OF THE ANTICIPATED TROUGH.

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


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOVE AVERAGE, 4 OUT OF 5, DUE
TO THE CONVERGENCE OF MODELS TOWARDS A SINGLE, AMPLIFIED CIRCULATION PATTERN.

FORECASTER: ANTHONY ARTUSA

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
OCTOBER 16

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:
19511013 - 20080921 - 19820929 - 19520911 - 19971010


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:
19511013 - 19820928 - 19571004 - 19971009 - 19571010


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 07 - 11 2014

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



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 09 - 15 2014

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

$$



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