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6-10 Day outlooks are issued daily between 3pm & 4pm Eastern Time. All forecasts issued on weekends are completely automated while all weekday outlooks are modified by the forecaster.
 
Please refer to the U.S. Prognostic Discussion for an explanation of terms and symbols used on these maps.


 
 
HOME> Outlook Maps> Prognostic Map Discussion
 
Prognostic Discussions
Valid: May 20 - 24, 2008 (6-10 Day Outlook)
Valid: May 22 - 28, 2008 (8-14 Day Outlook)
Issued: May 14, 2008

PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300 PM EDT WED MAY 14 2008
 
6-10 DAY OUTLOOK VALID FOR MAY 20 - 24 2008 

THERE IS NOT STRONG AGREEMENT AMONG THE VARIOUS GROUPS OF FORECAST MODELS FOR
THE 6-10 DAY 500 HPA HEIGHT PATTERN.  THERE SEEM TO BE TWO MAJOR FAMILIES OF
SOLUTIONS.  THE GFS OPERATIONAL AND ENSEMBLE FORECASTS CONSTITUTE THE FIRST
GROUP... WHILE THE ECMWF AND CMC MODELS CONSTITUTE THE OTHER.  THE PRIMARY
DIFFERENCE FOR THE MEAN PATTERN OVER THE 6-10 DAY TIME FRAME IS THE AMOUNT OF
RIDGING IN THE WESTERN CONUS.  THE GFS SOLUTIONS HAVE A FAIR AMOUNT OF RIDGING
WEST OF THE ROCKIES... WITH MODERATE POSITIVE 500 HPA HEIGHT ANOMALIES.  THE
CMC ENSEMBLE MEAN HAS THE RIDGING LESS AMPLIFIED AND FURTHER OFF OF THE PACIFIC
COAST... WHILE THE ECMWF OPERATIONAL AND ENSEMBLE SOLUTION FAVORS A MORE ZONAL
FLOW.  THE OFFICIAL FORECASTS LEANS IN THE DIRECTION OF THE ECMWF/CMC
SOLUTIONS, CONFINING WEAK RIDGING TO THE COAST ITSELF.  ALL OF THE MODELS ARE
IN AGREEMENT ABOUT THE LOCATION OF A STRONG NEGATIVE HEIGHT ANOMALY CENTERED
OVER THE GREAT LAKES... ALTHOUGH THE CMC AND ECMWF MODELS' NEGATIVE HEIGHT
ANOMALIES ARE NOT AS STRONG.  AS A RESULT... BELOW NORMAL TEMPERATURES ARE
FAVORED OVER MUCH OF THE CONUS, EXCEPT FOR NARROW BANDS OF ABOVE NORMAL
TEMPERATURES ALONG THE WEST COAST AND SOUTHERN FLORIDA.  THE ALASKAN PANHANDLE
AND MUCH OF EASTERN ALASKA SHOULD SEE ABOVE NORMAL TEMPERATURES AS WELL...
WHILE THE ALEUTIANS SHOULD EXPERIENCE BELOW NORMAL TEMPERATURES.THE FORECAST
PRECIPITATION PATTERN HAS LOW CONFIDENCE... BUT MOST TOOLS POINT TOWARDS ABOVE
MEDIAN PRECIPITATION IN THE EASTERN CONUS.  ABOVE MEDIAN PRECIPITATION IS ALSO
MORE LIKELY FOR THE CENTRAL PLAINS AND CENTRAL ROCKIES.  BELOW MEDIAN
PRECIPITATION IS FAVORED FOR THE WEST COAST... THE NORTHERN TIER OF THE CONUS
AND THE SOUTHERN TIER OF THE CONUS.  NORTHERN ALASKA IS FORECAST TO RECEIVE
BELOW MEDIAN PRECIPITATION... WHILE SOUTHERN ALASKA IS FAVORED TO RECEIVE ABOVE
MEDIAN PRECIPITATION.

TODAYS 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...5 PERCENT OF TODAY'S OPERATIONAL ECMWF CENTERED ON DAY 7...10 PERCENT OF
TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...15 PERCENT OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8...15 PERCENT OF TODAY'S GFS SUPERENSEMBLE MEAN
CENTERED ON DAY 8...15 PERCENT OF TODAY'S CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 8...AND 30 PERCENT OF TODAY'S EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 7.

MODEL(S) OF THE DAY: ECMWF ENSEMBLE MEAN

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD IS AVERAGE... 3 ON A SCALE OF 1 TO
5 DUE TO FAIRLY GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS OFFSET BY
LARGE ENSEMBLE SPREAD AMONG THE COMPONENT ENSEMBLE MEMBERS... PARTICULARLY FOR
THE WESTERN CONUS.

THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS
FROM THE BLENDED HEIGHT FIELD, THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM
TEMPERATURE FORECAST, THE CDC TEMPERATURE FORECAST, KLEIN PROBABILITIES FROM
THE ECMWF AND CANADIAN ENSEMBLES, THE CPC AUTO BLEND TEMPERATURE FORECAST, AND
TELECONNECTIONS ON A POSITIVE HEIGHT ANOMALY CENTER AT 72N 70W AND ON NEGATIVE
HEIGHT ANOMALY CENTERS AT 43N 77W AND 40N 172W.

THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE NEURAL NET AND ANALOG
SPECIFICATIONS FROM THE OFFICIAL BLEND, NEURAL NET PROBABILITIES FROM THE ECMWF
AND CANADIAN ENSEMBLES, THE CDC PRECIPITATION FORECAST... TELECONNECTIONS ON A
POSITIVE HEIGHT ANOMALY CENTER AT 72N 70W AND ON NEGATIVE HEIGHT ANOMALY
CENTERS AT 43N 77W AND 40N 172W.

8-14 DAY OUTLOOK FOR MAY 22 - 28 2008:

THE 8-14 DAY FORECAST PERIOD DOESN'T FACE AS MANY OF THE SAME ISSUES THAT THE
6-10 DAY PERIOD DOES.  THE ECMWF MODEL IS NOT AVAILABLE THAT FAR OUT... BUT THE
CMC ENSEMBLE FORECAST IS REASONABLY SIMILAR TO THE GFS ENSEMBLES.  BOTH THE CMC
AND THE GFS ENSEMBLES FORECAST A MODERATELY STRONG 500 HPA HEIGHT ANOMALY
CENTERED OVER THE GREAT LAKES.  THE GFS SOLUTIONS GENERALLY ARE STRONGER WITH
THIS FEATURE.  THE WESTERN EXTENT OF THE NEGATIVE ANOMALIES IS WEST OF THE
ROCKIES IN THE CMC AND EAST OF THE ROCKIES IN THE GFS.  BOTH MODELS HAVE A
MODERATE POSITIVE ANOMALY CENTERED OFF OF THE WEST COAST... BUT THE GFS
SOLUTIONS ARE STRONGER AND EXTEND FURTHER INLAND.  THE OPERATIONAL GFS RUNS
FORECAST A STRONGER NEGATIVE ANOMALY AND INCLUDE MORE RIDGING IN THE WESTERN
CONUS.  THE OFFICIAL FORECAST CONTINUES TO LEAN AWAY FROM THE GFS... KEEPING
THE RIDGING CONFINED AGAIN TO THE WEST COAST.  THE RESULTING TEMPERATURE
FORECAST PREDICTS ABOVE NORMAL TEMPERATURES FOR THE WEST COAST... SOUTHERN
FLORIDA AND EASTERN ALASKA.  BELOW NORMAL TEMPERATURES ARE FAVORED FOR MOST OF
THE CONUS. THE PRECIPITATION FORECAST TOOLS HAVE CONSIDERABLE DIFFERENCES
AMONG THEM AND THE RESULTING PRECIPITATION FORECAST DOES NOT HOLD MUCH
CONFIDENCE.  IN GENERAL... MOST TOOLS PREDICTED BELOW MEDIAN PRECIPITATION FOR
THE NORTHERN TIER OF THE CONUS... THE SOUTHERN PLAINS... FLORIDA AND NORTHERN
ALASKA.  ABOVE MEDIAN PRECIPITATION IS FAVORED FOR THE OHIO VALLEY... CENTRAL
PLAINS AND THE NORTHERN HALF OF THE ATLANTIC COAST.

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 GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11...AND 20 PERCENT OF TODAY'S
CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11.

FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS BELOW AVERAGE... 2 ON A SCALE OF
1 TO 5... DUE TO HIGH SPREAD AMONG THE GFS AND CANADIAN ENSEMBLE FORECASTS OVER
THE WESTERN CONUS.

THE 8-14 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS
FROM THE OFFICIAL BLEND, THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM
TEMPERATURES, THE KLEIN PROBABILITIES FROM THE CANADIAN ENSEMBLE, THE CDC
TEMPERATURE FORECAST, AND TELECONNECTIONS ON A NEGATIVE HEIGHT ANOMALY CENTERED
AT 43N 81W.

THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE ANALOG AND NEURAL NET
SPECIFICATIONS FROM THE OFFICIAL BLEND, THE CDC PRECIPITATION FORECAST, NEURAL
NET PROBABILITIES FROM THE CANADIAN ENSEMBLE, AND TELECONNECTIONS ON A NEGATIVE
HEIGHT ANOMALY CENTERED AT 43N 81W.

FORECASTER: ARMSTRONG

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 MAY
16.

CLICK HERE FOR A GLOSSARY OF TERMS. 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: 19800509 - 19910425 - 19740511 - 19600501 - 19840430 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 5 DAY PERIODS CENTERED ON THE FOLLOWING DATES: 19800509 - 19600501 - 19910425 - 19740511 - 19840430 6 to 10 day Outlook Table OUTLOOK FOR MAY 20 - 24, 2008 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N B OREGON N B NRN CALIF A B SRN CALIF A B IDAHO B B NEVADA N B W MONTANA B B E MONTANA B B WYOMING B N UTAH B N ARIZONA N B COLORADO B N NEW MEXICO B B N DAKOTA B B S DAKOTA B B NEBRASKA B A KANSAS B A OKLAHOMA B N N TEXAS B B S TEXAS B B W TEXAS B B MINNESOTA B B IOWA B N MISSOURI B A ARKANSAS B N LOUISIANA B N WISCONSIN B B ILLINOIS B A MISSISSIPPI B N MICHIGAN B N INDIANA B A OHIO B A KENTUCKY B A TENNESSEE B A 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 A B AK ALEUTIAN B A AK WESTERN N N AK INT BSN A B AK S INT N A AK SO COAST A A AK PNHDL A A 8 to 14 day Outlook Table OUTLOOK FOR MAY 22 - 28, 2008 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B B OREGON N B NRN CALIF A N SRN CALIF A N IDAHO B B NEVADA N N W MONTANA B B E MONTANA B B WYOMING B N UTAH B N ARIZONA B N COLORADO B A NEW MEXICO B N N DAKOTA B B S DAKOTA B B NEBRASKA B N KANSAS B A OKLAHOMA B A N TEXAS B N S TEXAS N B W TEXAS B B MINNESOTA B B IOWA B B MISSOURI B A ARKANSAS B A LOUISIANA B B WISCONSIN B B ILLINOIS B B MISSISSIPPI B N MICHIGAN B N INDIANA B N OHIO B A KENTUCKY B A TENNESSEE B A 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 N VIRGINIA B A N CAROLINA B N S CAROLINA B N GEORGIA B N FL PNHDL N N FL PENIN A B AK N SLOPE A B AK ALEUTIAN N N AK WESTERN N B AK INT BSN A B AK S INT A N AK SO COAST A N 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.
 
Related Topics:
Prognostic Discussion, Surface Forecasts, 500mb Heights and Anomalies, Time Series of Surface Forecast Skill, Model Guidance Used Our Mission, Who We Are, CPC Information, CPC Web Team
 

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