PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EDT THU AUG 09 2007 6-10 DAY OUTLOOK VALID FOR AUG 15 - 19 2007 TODAYS MODEL GUIDANCE IS IN REASONABLY GOOD AGREEMENT INDICATING A SLIGHTLY PROGRESSIVE FLOW PATTERN OVER THE EASTERN PACIFIC AND WESTERN NORTH AMERICA AND AN AMPLIFICATION TO THE LONGWAVE PATTERN OVER THE NORTH ATLANTIC. THE GFS–BASED AND 12Z ECMWF ENSEMBLE MEAN SOLUTIONS SHIFT THE EAST PACIFIC TROUGH ONTO THE WEST COAST AND BUILD THE WEST-CENTRAL RIDGE TOWARDS THE EAST COAST. HOWEVER... MODEL GUIDANCE INDICATES A STRONG VORTEX OVER EASTERN QUEBEC THAT WILL LIKELY INFLUENCE THE TEMPERATURE FORECAST FOR THE NORTHEAST AND MID-ATLANTIC. ACROSS EASTERN QUEBEC... THE 6Z GFS ENSEMBLE MEAN SOLUTION FORECASTS A 500-HPA HEIGHT ANOMALY TO EXCEED -150 METERS WHILE THE 0Z GFS AND 12Z ECMWF ENSEMBLE MEAN SOLUTIONS ARE MORE MODEST WITH THE NEGATIVE 500-HPA HEIGHT ANOMALY. A LARGE TEMPERATURE GRADIENT WILL LIKELY DEVELOP BETWEEN THE SOUTHERN MID-ATLANTIC AND NEW ENGLAND. THEREFORE... THE TEMPERATURE FORECAST FOR THE NORTHEAST AND THE MID-ATLANTIC REMAINS UNCERTAIN TODAY. THE OFFICIAL BLENDED HEIGHT FIELD FOR 500-HPA INDICATES ABOVE NORMAL HEIGHTS ACROSS MUCH OF THE CONUS WITH BELOW NORMAL HEIGHTS ACROSS THE NORTHEAST... WEST COAST... AND ALASKAN PANHANDLE. A LARGE NEGATIVE 500-HPA HEIGHT ANOMALY OF 120 METERS IS CENTERED OVER EASTERN QUEBEC. RIDGING ALOFT WILL SUPPORT ABOVE NORMAL TEMPERATURES FROM THE PLAINS AND MISSISSIPPI VALLEY INTO THE SOUTHEAST. AS THE EAST PACIFIC TROUGH MOVES ONSHORE... A COOLING TREND IS EXPECTED FOR THE WEST. BELOW NORMAL 500-HPA HEIGHTS WILL FAVOR BELOW NORMAL TEMPERATURES IN THE NORTHEAST AND ALONG THE WEST COAST. MOST OF ALASKA CAN EXPECT TEMPERATURES TO AVERAGE NEAR OR ABOVE NORMAL WITH BELOW NORMAL TEMPERATURES LIKELY FOR THE ALASKAN PANHANDLE. THE LARGE SUBTROPICAL RIDGE WILL LIKELY LEAD TO BELOW NORMAL RAINFALL FOR THE CENTRAL AND SOUTHERN PLAINS ALONG WITH THE SOUTHEAST. HOWEVER... SHORTWAVE TROUGHS TRACKING ACROSS SOUTHERN CANADA COMBINED WITH NORTHWEST FLOW ALOFT WILL INITIATE CONVECTIVE COMPLEXES. THE MOST LIKELY AREA FOR THESE CONVECTIVE COMPLEXES AND THUS ABOVE NORMAL RAINFALL IS THE UPPER MISSISSIPPI VALLEY AND GREAT LAKES. MODEL GUIDANCE SHOWS AN INCREASE IN EASTERLY WAVES TRACKING ACROSS THE LOWER LATITUDES AND BRINGING ABOVE NORMAL RAINFALL TO SOUTH FLORIDA AND TEXAS. THE POSITION OF THE RIDGE ALOFT SHOULD STEER MOISTURE INTO THE SOUTHWEST AND CENTRAL ROCKIES WHERE NEAR NORMAL MONSOON CONDITIONS ARE EXPECTED. ELSEWHERE... MOIST WEST TO SOUTHWEST FLOW WILL PROMOTE ABOVE NORMAL PRECIPITATION FROM ALASKA INTO THE PACIFIC NORTHWEST. TODAYS OFFICIAL 500-HPA BLEND CONSISTS OF 30 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...25 PERCENT OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 8...AND 25 PERCENT OF TODAY'S EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 7. MODEL(S) OF THE DAY: 0Z GFS ENSEMBLE MEAN FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD IS ABOVE AVERAGE... 4 ON A SCALE OF 1 TO 5... DUE TO REASONABLY GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS. THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE KLEIN... NEURAL NET... AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLENDED HEIGHT FIELD... THE CPC AUTO FORECAST... TEMPERATURE PROBABILITIES FROM THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM... AND THE CDC TEMPERATURE FORECAST TOOL. THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE ANALOG SPECIFICATIONS FROM THE OFFICIAL BLENDED HEIGHT FIELD... ANALONG SPECIFICATIONS FROM THE GFS... THE CPC AUTO FORECAST... AND THE CDC PRECIPITATION FORECAST TOOL. IT IS ALSO HEAVILY BASED ON DAILY PRECIPITATION FORECASTS FROM THE MODELS AND PATTERN RECOGNITION. 8-14 DAY OUTLOOK FOR AUG 17 - 23 2007: FOR WEEK 2 THE GFS ENSEMBLE MEAN SOLUTIONS CONTINUE THE SLIGHT PROGRESSION AND DEAMPLIFICATION OF THE CIRCULATION PATTERN OVER NORTH AMERICA. THE MODERATELY STRONG TROUGH OVER THE EAST PACIFIC PUSHES FARTHER INLAND INTO THE WEST... WHILE THE RIDGE OVER THE CENTRAL CONUS WEAKENS. ALL GFS ENSEMBLE MEAN SOLUTIONS INDICATE THAT THE NEGATIVE 500-HPA HEIGHT ANOMALY LOCATED OVER EASTERN CANADA IS SMALLER. FOR THE SECOND CONSECUTIVE DAY... A WEAKNESS WITHIN THE LARGE-SCALE RIDGE IS EVIDENT OVER THE SOUTHERN PLAINS. THE EXPECTED LONGWAVE PATTERN WILL LIKELY MAINTAIN ABOVE NORMAL TEMPERATURES FOR THE NORTHERN AND CENTRAL PLAINS... MISSISSIPPI VALLEY... AND SOUTHEAST. BELOW NORMAL TEMPERATURES ARE FORECAST FOR NORTHERN NEW ENGLAND AND SOUTH TEXAS. FOR ALASKA... TEMPERATURE TOOLS FROM THE OFFICIAL BLENDED 500-HPA HEIGHT FIELD FORECAST DIFFER WITH THE CPC AUTO FORECAST AND THE CDC TEMPERATURE FORECAST TOOL. NORTHERLY FLOW SHOULD RESULT IN BELOW NORMAL TEMPERATURES FOR NORTHWEST ALASKA WITH ABOVE NORMAL TEMPERATURES PERSISTING FOR THE ALEUTIANS AND SOUTHERN ALASKA. PRECIPITATION TOOLS ARE SUGGESTING THAT THE PATTERN WILL BECOME WETTER FOR MUCH OF THE CONUS. HOWEVER... WITH NEARLY ZONAL FLOW... DEFINING AREAS OF ABOVE NORMAL RAINFALL IS A CHALLENGE. THE GREATEST LIKELIHOOD FOR ABOVE NORMAL RAINFALL EXISTS ACROSS THE WESTERN GULF REGION ASSOCIATED WITH THE WEAKNESS WITHIN THE RIDGE AND IN THE UPPER MISSISSIPPI VALLEY CLOSE TO STRONG MID-LEVEL FLOW. ABOVE NORMAL PRECIPITATION IS ALSO FORECAST FOR SOUTHEAST ALASKA AND THE ALASKAN PANHANDLE. ABOVE NORMAL 500-HPA HEIGHTS AND PERSISTENCE FAVORS BELOW NORMAL RAINFALL FROM THE TENNESSEE VALLEY INTO THE SOUTHERN MID-ATLANTIC. THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 25 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...25 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...AND 50 PERCENT OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11. FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS AVERAGE... 3 ON A SCALE OF 1 TO 5 DUE TO A LESS AMPLIFIED FLOW PATTERN AND UNCERTAINTY IN THE PRECIPITATION FORECAST. THE 8-14 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLENDED HEIGHT FIELD... THE CPC AUTO FORECAST... TEMPERATURE PROBABILITIES FROM THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM... AND THE CDC TEMPERATURE FORECAST TOOL. THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE ANALOG AND NEURAL NET SPECIFICATIONS FROM THE OFFICIAL BLENDED HEIGHT FIELD... THE CDC PRECIPITATION FORECAST TOOL... AND THE CPC AUTO FORECAST. FORECASTER: PUGH 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 AUGUST 16. 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. 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: 19520723 - 19780819 - 19590818 - 19990725 - 19520813 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: 19520724 - 19780819 - 19590818 - 19990725 - 19870812 6 to 10 day Outlook Table OUTLOOK FOR AUG 15 - 19, 2007 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B A OREGON N A NRN CALIF N N SRN CALIF A B IDAHO A A NEVADA A N W MONTANA A A E MONTANA A N WYOMING A N UTAH A N ARIZONA A N COLORADO A B NEW MEXICO A B N DAKOTA A A S DAKOTA A N NEBRASKA A B KANSAS A B OKLAHOMA A B N TEXAS A N S TEXAS N A W TEXAS N N MINNESOTA A A IOWA A N MISSOURI A B ARKANSAS A B LOUISIANA A N WISCONSIN A A ILLINOIS A N MISSISSIPPI A B MICHIGAN N A INDIANA A N OHIO A A KENTUCKY A B TENNESSEE A B ALABAMA A B NEW YORK B N VERMONT B N NEW HAMP B N MAINE B N MASS B N CONN B N RHODE IS B N PENN N N NEW JERSEY B N W VIRGINIA A B MARYLAND A N DELAWARE N B VIRGINIA A B N CAROLINA A B S CAROLINA A B GEORGIA A B FL PNHDL A B FL PENIN A N AK N SLOPE N 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 N A 8 to 14 day Outlook Table OUTLOOK FOR AUG 17 - 23, 2007 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N N OREGON N B NRN CALIF N B SRN CALIF N B IDAHO N N NEVADA N B W MONTANA N N E MONTANA A N WYOMING A N UTAH N N ARIZONA A N COLORADO A N NEW MEXICO A A N DAKOTA A A S DAKOTA A N NEBRASKA A N KANSAS A N OKLAHOMA N A N TEXAS N A S TEXAS B A W TEXAS N A MINNESOTA A A IOWA A A MISSOURI A N ARKANSAS A A LOUISIANA A A WISCONSIN A A ILLINOIS A N MISSISSIPPI A A MICHIGAN A N INDIANA A N OHIO A N KENTUCKY A B TENNESSEE A B ALABAMA A N NEW YORK A N VERMONT N N NEW HAMP N N MAINE B N MASS N N CONN N N RHODE IS N N PENN A N NEW JERSEY A N W VIRGINIA A B MARYLAND A B DELAWARE A B VIRGINIA A B N CAROLINA A B S CAROLINA A B GEORGIA A N FL PNHDL A N FL PENIN A N AK N SLOPE B B AK ALEUTIAN A N AK WESTERN B N AK INT BSN N N AK S INT A A AK SO COAST A A AK PNHDL B 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. $$