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FXUS06 KWBC 151932
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE OCTOBER 15 2013
6-10 DAY OUTLOOK FOR OCT 21 - 25 2013
TODAY'S MODEL SOLUTIONS ARE IN GOOD AGREEMENT IN FORECASTING AN AMPLIFIED
PATTERN OVER THE FORECAST DOMAIN. MID-LEVEL TROUGHS ARE FORECAST OVER THE
BERING SEA AND OVER THE GREAT LAKES REGION WHILE A RIDGE IS PREDICTED FOR
WESTERN NORTH AMERICA. ENSEMBLE SPREAD IS HIGHEST OVER THE WEST COAST OF THE
CONUS DUE TO UNCERTAINTIES REGARDING THE POTENTIAL FOR A SOUTHERN STREAM TROUGH
TO UNDERCUT THE RIDGE OVER WESTERN NORTH AMERICA. THE DETERMINISTIC 00Z ECMWF
AND 12Z GFS BOTH FORECAST THIS SOUTHERN STREAM TROUGH NEAR THE SOUTHWESTERN
CONUS AND MAINTAIN A STRONG RIDGE FURTHER TO THE NORTH, OVER THE PACIFIC
NORTHWEST. TODAY'S MANUAL 500-HPA HEIGHT BLEND CONSISTS PRIMARILY OF THE
ENSEMBLE MEANS WITH FAIRLY EVEN WEIGHTING GIVEN TO THE ECWMF- AND GFS-BASED
SOLUTIONS.
ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR ALASKA AND PARTS OF THE NORTHWESTERN
CONUS IN ASSOCIATION WITH A RIDGE PREDICTED OVER WESTERN NORTH AMERICA.
CONVERSELY, THERE ARE ENHANCED ODDS OF BELOW NORMAL TEMPERATURES FOR MUCH OF
THE CENTRAL CONUS AND PARTS OF THE EASTERN CONUS DUE TO THE TROUGH PREDICTED
NEAR THE GREAT LAKES REGION. INCREASED ODDS OF ABOVE NORMAL TEMPERATURES ARE
INDICATED FOR FLORIDA CONSISTENT WITH GEFS REFORECAST AND NAEFS GUIDANCE AS
WELL AS FROM CALIBRATED TEMPERATURES FROM THE ECMWF ENSEMBLE MEMBERS.
THERE ARE ENHANCED ODDS OF ABOVE-MEDIAN PRECIPITATION FOR MOST OF ALASKA DUE TO
MOIST FLOW PREDICTED AHEAD OF THE TROUGH FORECAST OVER THE BERING SEA.
BELOW-MEDIAN PRECIPITATION IS FAVORED FOR MUCH OF THE NORTHWESTERN CONUS DUE TO
THE RIDGE PREDICTED OVER WESTERN NORTH AMERICA. THERE ARE ENHANCED ODDS OF
ABOVE MEDIAN PRECIPITATION FOR PARTS OF THE SOUTHEASTERN CONUS IN ASSOCIATION
WITH THE TROUGH PREDICTED OVER THE EASTERN CONUS. SUBSIDENCE BEHIND THE
FORECAST TROUGH AXIS LEADS TO ENHANCED ODDS OF BELOW-MEDIAN PRECIPITATION FOR
PARTS OF THE MIDDLE MISSISSIPPI VALLEY AND CENTRAL PLAINS. ENHANCED ODDS OF
NEAR- TO ABOVE-MEDIAN PRECIPITATION ARE INDICATED ALONG THE NORTHERN TIER OF
THE CONUS FROM THE NORTHERN HIGH PLAINS TO THE GREAT LAKES DUE TO THE POTENTIAL
FOR SHORTWAVE TROUGHS TO AFFECT THESE REGIONS.
TODAY'S OFFICIAL 500-HPA BLEND CONSISTS OF 5 PERCENT OF TODAY'S OPERATIONAL 0Z
GFS CENTERED ON DAY 8...5 PERCENT OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON DAY
8...15 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...20 PERCENT
OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...10 PERCENT OF TODAY'S
OPERATIONAL 0Z ECMWF CENTERED ON DAY 8...20 PERCENT OF TODAY'S 0Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 8...5 PERCENT OF TODAY'S 0Z CANADIAN ENSEMBLE
MEAN CENTERED ON DAY 8...15 PERCENT OF YESTERDAY'S 12Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 7...AND 5 PERCENT OF YESTERDAY'S 12Z CANADIAN ENSEMBLE MEAN
CENTERED ON DAY 7.
MODEL OF THE DAY: 06Z GFS ENSEMBLE MEAN AND TODAY'S 00Z ECMWF ENSEMBLE MEAN
(TIED)
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD MODEL AND TOOL AGREEMENT OVER MOST OF THE FORECAST DOMAIN OFFSET BY HIGH
MODEL SPREAD ALONG THE WEST COAST OF THE CONUS
8-14 DAY OUTLOOK FOR OCT 23 - 29 2013
TODAY'S ENSEMBLE MEAN SOLUTIONS SHOW GOOD AGREEMENT ON THE FORECAST 500-HPA
HEIGHT PATTERN OVER MUCH OF THE FORECAST DOMAIN AND IS SIMILAR TO THAT
PREDICTED FOR THE PRECEDING 6 TO 10 DAY PERIOD. MID-LEVEL TROUGHS CONTINUE TO
BE FORECAST OVER THE BERING SEA AND GREAT LAKES REGION AND RIDGING IS PREDICTED
OVER WESTERN NORTH AMERICA. THERE ARE, HOWEVER, SOME FAIRLY SIGNIFICANT
DIFFERENCES OVER THE SOUTHWESTERN CONUS AMONG THE DETERMINISTIC GFS RUNS
REGARDING A POTENTIAL SOUTHERN STREAM TROUGH NEAR THE SOUTHWESTERN CONUS.
TODAY'S 00Z AND 06Z DETERMINISTIC GFS FORECAST THIS FEATURE TO REMAIN OFF THE
CALIFORNIA COAST WHILE TODAY'S 12Z DETERMINISTIC GFS RUN PUSHES THIS FEATURE
INLAND OVER THE SOUTHWESTERN CONUS. THIS UNCERTAINTY IS REFLECTED IN THE
ENSEMBLE SPREAD, WHICH IS THE HIGHEST OVER THE WESTERN CONUS. DUE TO THE
UNCERTAINTY AMONG THE DETERMINISTIC GFS RUNS OVER THE SOUTHWESTERN CONUS,
TODAY'S WEEK TWO MANUAL 500-HPA HEIGHT BLEND IS COMPOSED PRIMARILY OF THE
ENSEMBLE MEAN SOLUTIONS.
ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR ALASKA AND PARTS OF THE NORTHWESTERN
CONUS DUE TO THE RIDGE PREDICTED OVER WESTERN NORTH AMERICA. THE TROUGH
FORECAST OVER THE EASTERN U.S. LEADS TO ENHANCED ODDS OF BELOW-NORMAL
TEMPERATURES FOR MOST OF THE CENTRAL AND EASTERN CONUS. ENHANCED PROBABILITIES
OF ABOVE-NORMAL TEMPERATURES ARE INDICATED FOR PARTS OF FLORIDA PENINSULA
CONSISTENT WITH GEFS REFORECAST AND NAEFS GUIDANCE AS WELL AS FROM CALIBRATED
TEMPERATURES FROM THE ECMWF ENSEMBLE MEMBERS.
THERE ARE INCREASED ODDS FOR ABOVE-MEDIAN PRECIPITATION FOR PARTS OF THE
SOUTHEASTERN CONUS AND GULF COAST REGIONS NEAR THE BASE OF THE TROUGH PREDICTED
OVER THE EASTERN CONUS. BELOW-MEDIAN PRECIPITATION PROBABILITIES ARE ENHANCED
FOR PARTS OF THE MIDDLE MISSISSIPPI VALLEY AND CENTRAL PLAINS BEHIND THE
PREDICTED TROUGH AXIS. ENHANCED ODDS OF ABOVE-MEDIAN PRECIPITATION ARE
INDICATED FOR PARTS OF THE NORTHERN HIGH PLAINS AND GREAT LAKES CONSISTENT WITH
GEFS REFORECAST AND NAEFS SPECIFICATIONS. CONVERSELY, BELOW-MEDIAN
PRECIPITATION IS FAVORED FOR THE NORTHWESTERN CONUS DUE TO THE RIDGE PREDICTED
OVER WESTERN NORTH AMERICA. MOIST FLOW AHEAD OF THE TROUGH PREDICTED OVER THE
BERING SEA LEADS TO ENHANCED PROBABILITIES OF ABOVE-MEDIAN PRECIPITATION FOR
MOST OF ALASKA.
THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 10 PERCENT OF TODAY'S
OPERATIONAL 0Z GFS CENTERED ON DAY 11...10 PERCENT OF TODAY'S OPERATIONAL 6Z
GFS CENTERED ON DAY 11...20 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON
DAY 11...20 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...20
PERCENT OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11...AND 20
PERCENT OF YESTERDAY'S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: AVERAGE, 3 OUT OF 5, DUE TO
GOOD MODEL AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS OFFSET BY HIGH MODEL
SPREAD OVER THE WEST COAST OF THE CONUS.
FORECASTER: SCOTT HANDEL
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 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:
20081011 - 20061019 - 19830930 - 19701008 - 19711028
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:
20081011 - 20061019 - 19811012 - 19701010 - 19911027
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 21 - 25 2013
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 B NEVADA A B
W MONTANA B N E MONTANA B A WYOMING B N
UTAH N B ARIZONA N B COLORADO B N
NEW MEXICO B N N DAKOTA B A S DAKOTA B N
NEBRASKA B B KANSAS B B OKLAHOMA B B
N TEXAS B B S TEXAS B N W TEXAS B N
MINNESOTA B N IOWA B B MISSOURI B B
ARKANSAS B B LOUISIANA B N WISCONSIN B N
ILLINOIS B B MISSISSIPPI B N MICHIGAN B A
INDIANA B B OHIO B N KENTUCKY B B
TENNESSEE B N ALABAMA N A NEW YORK N A
VERMONT N N NEW HAMP N N MAINE N N
MASS N B CONN N B RHODE IS N B
PENN B N NEW JERSEY N B W VIRGINIA B N
MARYLAND N B DELAWARE N B VIRGINIA N N
N CAROLINA N N S CAROLINA N A GEORGIA N A
FL PNHDL A A FL PENIN A A AK N SLOPE A A
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL A N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 23 - 29 2013
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A B NRN CALIF A B
SRN CALIF N B IDAHO N B NEVADA N B
W MONTANA B N E MONTANA B A WYOMING B N
UTAH N B ARIZONA N B COLORADO B N
NEW MEXICO B N N DAKOTA B N S DAKOTA B N
NEBRASKA B N KANSAS B B OKLAHOMA B B
N TEXAS B N S TEXAS N A W TEXAS B N
MINNESOTA B N IOWA B N MISSOURI B B
ARKANSAS B N LOUISIANA N A WISCONSIN B N
ILLINOIS B B MISSISSIPPI B A MICHIGAN B A
INDIANA B N OHIO B A KENTUCKY B N
TENNESSEE B N ALABAMA B A NEW YORK B A
VERMONT B A NEW HAMP B A MAINE B A
MASS B N CONN B N RHODE IS B N
PENN B A NEW JERSEY B N W VIRGINIA B N
MARYLAND B N DELAWARE B N VIRGINIA B N
N CAROLINA B N S CAROLINA B A GEORGIA N A
FL PNHDL N A FL PENIN A A AK N SLOPE A A
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL A 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.
$$