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FXUS06 KWBC 272016
PMDMRD
PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300 PM EDT WED AUG 27 2008
6-10 DAY OUTLOOK VALID FOR SEP 02 - 06 2008
THE ENSEMBLE MEAN SOLUTIONS CONTINUE TO BE IN REASONABLY GOOD AGREEMENT FOR THE
EXPECTED 500-HPA FLOW PATTERN OVER THE FORECAST DOMAIN. THE CANADIAN ENSEMBLE
MEAN IS IN BETTER AGREEMENT WITH THE OTHER MODEL SOLUTIONS TODAY THAN IN
PREVIOUS DAYS. THE PRIMARY CHANGES TODAY COMPARED TO YESTERDAY ARE THE
CONSIDERABLE DIFFERENCES IN THE 00Z AND 06Z OPERATIONAL RUNS. THESE MODEL
SOLUTIONS VARY CONSIDERABLY FROM THEIR ENSEMBLE MEAN SOLUTIONS. THERE IS SOME
RUN TO RUN CONSISTENCY IN THESE SOLUTIONS BUT AT THE CURRENT TIME THESE
SOLUTIONS DID NOT RECEIVE SIGNIFICANT WEIGHT IN THE OFFICIAL BLEND FORECAST
WHICH INCLUDES MAINLY CONTRIBUTIONS FROM THE GFS SUPERENSEMBLE AND THE 00Z AND
06Z GFS ENSEMBLE MEANS. BASED ON THE ABOVE APPROACH, A TROUGH IS EXPECTED TO
SITUATE ITSELF ALONG THE US WEST COAST WITH A RIDGE ACROSS THE EASTERN
TWO-THIRDS OF THE COUNTRY. A CUTOFF LOW IS NOW EVIDENT IN THE OFFICAL BLEND AS
THE GFS ENSEMBLE MEAN FORECASTS ARE IN CLOSER AGREEMENT TO THAT OF YESTERDA'S
EUROPEAN. AS A RESULT OF THIS FORECAST PATTERN, ABOVE-AVERAGE TEMPERATURES AND
BELOW-MEDIAN PRECIPITATION ARE EXPECTED TO PREVAIL ACROSS PARTS OF THE
NORTH-CENTRAL US AND GREAT LAKES DUE TO THE RIDGE AND ABOVE-AVERAGE HEIGHTS IN
THIS AREA. DUE TO INCREASING UNCERTAINTY, THE SPATIAL EXTENT AND PROBABILITIES
FOR THESE AREAS OF ANOMALOUS TEMPERATURES AND PRECIPITATION HAVE BEEN
DECREASED. FAVORABLE ORIENTATION OF SUB-TROPICAL RIDGING ACROSS THE ATLANTIC
BASIN WILL ALLOW NUMEROUS TROPICAL DISTURBANCES AND CONTINUED AMPLE MOISTURE
FLOW TO IMPACT THE GULF COAST WITH ABOVE-MEDIAN PRECIPITATION DURING THE
PERIOD. ALSO, THE TROUGH ALONG THE WEST COAST AND FLOW AROUND THE WESTERN
PERIPHERY OF THE RIDGE LIKELY WILL LEAD TO AN INCREASING FLOW OF MOISTURE INTO
THE PLAINS. MOREOVER, THE MEAN TROUGH ALONG THE WEST COAST SHOULD LEAD TO
COOLER THAN AVERAGE TEMPERATURES ACROSS PARTS OF THE PACIFIC NORTHWEST AND THIS
IS SUPPORTED BY MULTIPLE TOOLS.
TODAYS OFFICIAL 500-HPA BLEND CONSISTS OF 10 PERCENT OF TODAY'S OPERATIONAL 0Z
GFS CENTERED ON DAY 8...10 PERCENT OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON
DAY 8...20 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...AND 40 PERCENT OF
TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 8.
MODEL(S) OF THE DAY: GFS SUPERENSEMBLE
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD IS NEAR-AVERAGE, 3 ON A SCALE OF 1
TO 5 DUE TO GENERALLY GOOD ENSEMNBLE MEAN AGREEMENT OFFSET BY CONSIDERABLE
DIFFERENCES IN OPERATIONAL MODEL RUNS. THE EVOLUTION OF TROPICAL SYSTEMS ACROSS
THE SOUTHERN TIER INCREASES THE UNCERTAINTY IN THIS REGION DURING THE PERIOD.
THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS
FROM THE OFFICIAL BLEND, THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS)
TEMPERATURE PROBABILITY FORECASTS, THE KLEIN PROBABILITIES FROM THE VARIOUS
ENSEMBLES INCLUDING THE SUPERENSEMBLE, AND UNCALIBRATED AND CALIBRATED
TEMPERATURES FROM THE GFS ENSEMBLE MEAN.
THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE ANALOG AND NEURAL NET
SPECIFICATIONS FROM THE OFFICIAL BLEND, THE AUTO PRECIPITATION FORECAST, THE
NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS) PRECIPITATION PROBABILITY
FORECASTS, AND NEURAL NET PROBABILITIES FROM THE VARIOUS ENSEMBLES.
8-14 DAY OUTLOOK FOR SEP 04 - 10 2008:
FOR WEEK 2, THERE IS REASONABLY GOOD AGREEMENT AMONG THE ENSEMBLE MEAN
SOLUTIONS WHICH GENERALLY REFLECT A DEAMPLIFIED 500-HPA PATTERN COMPARED TO
THAT SHOWN FOR THE 6-10 DAY PERIOD. THE MAIN CIRCULATION FEATURES DURING THE
6-10 DAY PERIOD ARE ALSO EXPECTED TO BE IN PLACE DURING THIS FORECAST PERIOD.
THERE WILL CONTINUE TO BE A TROUGH ALONG THE US WEST COAST WITH A RIDGE ACROSS
THE EASTERN TWO-THIRDS OF THE COUNTRY. THE MAIN DIFFERENCE DURING THIS PERIOD
FROM THE 6-10 DAY PERIOD IS SUBSTANTIALLY DECREASED AGREEMENT IN THE FORECAST
TOOLS ESPECIALLY FOR PRECIPITATION. THEREFORE CONFIDENCE IS LOWER FOR THE WEEK
2 PERIOD. THE OFFICIAL BLEND IS BASED ON THE GFS SUPERENSEMBLE AND 00Z AND 06Z
GFS ENSEMBLE MEAN SOLUTIONS. ABOVE-AVERAGE TEMPERATURES ARE EXPECTED TO
CONTINUE ACROSS MUCH OF THE NORTH-CENTRAL US, GREAT LAKES AND NORTHEAST US DUE
TO THE CONTINUATION OF THE RIDGE IN THIS AREA BUT DUE TO GREATER VARIABILITY IN
THE FORECAST TOOLS, PROBABILITIES ARE SOMEWHAT LOWER. BELOW-AVERAGE
TEMPERATURES ARE EXPECTED ACROSS PARTS OF THE SOUTHWEST US, AND ALONG THE GULF
COAST ASSOCIATED WITH INCREASED CLOUD COVER AND MOISTURE FROM POSSIBLE TROPICAL
CYCLONE ACTIVITY AND SLIGHTLY BELOW NORMAL HEIGHTS. ABOVE-MEDIAN PRECIPITATION
IS EXPECTED TO CONTINUE DURING THIS PERIOD ACROSS THE GULF COAST AND ALSO
INCLUDE PARTS OF THE SOUTHWEST US. THE AREA OF ABOVE-MEDIAN PRECIPITATION IS
LIKELY TO BE ORIENTED SLIGHTLY NORTHWARD AND EASTWARD DURING THIS PERIOD
COMPARED TO THE 6-10 DAY PERIOD AS THE UPPER-LEVEL TROUGH AND WESTERN EDGE OF
THE SUBTROPICAL RIDGE SHOULD ALLOW SUBSTANTIAL MOISTURE TRANSPORT INTO THE
CENTRAL PART OF THE COUNTRY. CONSIDERABLE DIFFERENCES EXIST IN THE FORECAST
TOOLS ACROSS THE WESTERN AND NORTHEAST US.
THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 25 PERCENT OF YESTERDAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 10...25 PERCENT OF YESTERDAY'S 6Z GFS ENSEMBLE
MEAN CENTERED ON DAY 10...AND 50 PERCENT OF YESTERDAY'S GFS SUPERENSEMBLE MEAN
CENTERED ON DAY 10.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS BELOW AVERAGE, 2 ON A SCALE OF 1
TO 5 DUE TO GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS OFFSET BY
RELATIVELY POOR AGREEMENT AMONG THE FORECAST TOOLS AND LARGE UNCERTAINTY FOR
FUTURE DEVELOPMENTS IN THE TROPICS.
THE 8-14 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS
FROM THE OFFICIAL BLEND, THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS)
TEMPERATURE PROBABILITY FORECASTS, AND THE KLEIN PROBABILITIES FROM THE GFS
ENSEMBLES MEAN FORECASTS INCLUDING THE SUPERENSEMBLE.
THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE NEURAL NET SPECIFICATION FROM
THE OFFICIAL BLEND AND VARIOUS ENSEMBLE MEAN FORECASTS, NORTH AMERICAN ENSEMBLE
FORECAST SYSTEM (NAEFS) PRECIPITATION PROBABILITY FORECASTS, THE AUTO BLEND
PRECIPITATION FORECAST, AND THE CDC PRECIPITATION FORECAST.
FORECASTER: GOTTSCHALCK
NOTES:
OPERATIONAL CHANGE: AS OF JULY 5 2005 SHADED MAPS HAVE REPLACED THE
CONTOUR-ONLY MAPS ON THE CPC WEB SITE. THE CONTOURED MAPS ARE
STILL AVAILABLE AT THEIR CURRENT FILE NAMES - SO DIRECT-LINKED USERS
ARE NOT AFFECTED. AWIPS GRAPHICS ARE ALSO NOT AFFECTED BY THIS
CHANGE.
AUTOMATED FORECASTS ARE ISSUED ON SATURDAY AND SUNDAY. OTHERWISE -
FORECASTS INCORPORATE FORECASTER INPUT.
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
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 NARRATIVE DESCRIPTION OF THE FORECAST PATTERNS FOR TEMPERATURE
AND PRECIPITATION FOR BOTH THE 6-10 OR 8-14 DAY PERIODS HAS BEEN
DISCONTINUED. THE STATE TABLES FOR BOTH THE 6-10 AND 8-14 DAY
PERIODS ARE NOW CONTAINED IN THIS MESSAGE...AVAILABLE AS PMDMRD ON
AWIPS.
THE CLIMATE PREDICTION CENTER USES 1971-2000 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
SEPTEMBER 18
NEW NOTE EFFECTIVE MAR 16 2004:
THE GLOSSARY FORMERLY FOUND AT THIS LOCATION WILL NO LONGER BE
TRANSMITTED AS PART OF THIS MESSAGE. IF YOU WISH TO SEE THE
DEFINITIONS OF TERMS USED IN THESE MESSAGES... PLEASE GO TO THE
CPC WEB PAGE AT (USE LOWER CASE) HTTP://WWW.CPC.NCEP.NOAA.GOV
AND FOLLOW THE APPROPRIATE LINKS.
6 TO 10 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 02 - 06, 2008
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B N OREGON B N NRN CALIF N N
SRN CALIF N N IDAHO B N NEVADA B N
W MONTANA B N E MONTANA N N WYOMING B N
UTAH B N ARIZONA B N COLORADO B N
NEW MEXICO B N N DAKOTA N N S DAKOTA N A
NEBRASKA N A KANSAS N A OKLAHOMA N A
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA A N IOWA A N MISSOURI N A
ARKANSAS N A LOUISIANA B A WISCONSIN A B
ILLINOIS A N MISSISSIPPI B A MICHIGAN A B
INDIANA A B OHIO A B KENTUCKY N N
TENNESSEE N N ALABAMA B A NEW YORK N B
VERMONT N N NEW HAMP N N MAINE N N
MASS N N CONN N N RHODE IS N N
PENN N B NEW JERSEY N N W VIRGINIA N B
MARYLAND N N DELAWARE N N VIRGINIA N N
N CAROLINA N N S CAROLINA B A GEORGIA B A
FL PNHDL B A FL PENIN B A AK N SLOPE N N
AK ALEUTIAN N A AK WESTERN N A AK INT BSN N N
AK S INT N A AK SO COAST N A AK PNHDL N N
8 TO 14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 04 - 10, 2008
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B N OREGON B N NRN CALIF N N
SRN CALIF N N IDAHO B N NEVADA B N
W MONTANA B N E MONTANA N N WYOMING B N
UTAH B N ARIZONA B A COLORADO B A
NEW MEXICO B A N DAKOTA N N S DAKOTA N A
NEBRASKA N A KANSAS N A OKLAHOMA N A
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA A N IOWA A A MISSOURI N A
ARKANSAS N A LOUISIANA B A WISCONSIN A N
ILLINOIS A A MISSISSIPPI B A MICHIGAN A N
INDIANA A N OHIO A N KENTUCKY N N
TENNESSEE N N ALABAMA B A NEW YORK A N
VERMONT N N NEW HAMP N N MAINE N N
MASS N N CONN N N RHODE IS N N
PENN A N NEW JERSEY N N W VIRGINIA A N
MARYLAND N N DELAWARE N N VIRGINIA N N
N CAROLINA N N S CAROLINA N N GEORGIA B A
FL PNHDL B A FL PENIN B A AK N SLOPE N N
AK ALEUTIAN B A AK WESTERN B A AK INT BSN N N
AK S INT B A AK SO COAST B A AK PNHDL N 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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