Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EDT Thu June 25 2020 6-10 DAY OUTLOOK FOR JUL 01 - 05 2020 Today's dynamical models predict a 500-hPa trough over the western Aleutian Islands and a ridge over the Alaska Peninsula. Downstream, all models predict a deamplifying trough over the western CONUS, an amplified ridge over the north-central and northeastern CONUS, and troughing over the East Coast. The predicted 500-hPa height pattern in the manual blend of models indicates positive 500-hPa height anomalies over Alaska and negative 500-hPa height anomalies over the western CONUS. Positive 500-hPa height anomalies are predicted over parts of the central CONUS and Northeast, while weak negative anomalies are predicted over the Southeast. Below normal temperatures are favored over parts of interior Mainland Alaska, consistent with the consolidation forecast, based on the ECMWF and GEFS reforecast tools. Conversely, above normal temperatures are likely over coastal areas of Alaska, under above normal 500-hPa heights and also surrounded by above normal SSTs. Below normal temperatures are likely over most of the western third of the CONUS, due to the predicted troughing over the region. Above normal temperatures are most likely over the Great Lakes and Northeast regions, under predicted positive 500-hPa height anomalies and persistent southerly low-level flow. Above normal temperatures are also likely for the Southern Plains, under persistent low-level southerly flow, and along the Gulf Coast into Florida, consistent with the consolidation forecast. Predicted troughing over the western Bering Sea increases the chances of above normal precipitation for the Aleutians Islands, as well as western and northern Mainland Alaska. Below normal precipitation is likely for southeastern Alaska ahead of a predicted ridge. Forecast troughing over the western CONUS favors near to above normal precipitation for the Pacific Northwest, eastward to the Northern Plains. Above normal precipitation is likely for parts of the Central and Southern Plains, and the southeastern CONUS due to predicted southerly low-level moisture flow from the Gulf of Mexico. Below normal precipitation is likely for parts of the Southern Rockies, Southwest, and southern Texas, as well as the Great Lakes and Northeast regions, under predicted positive 500-hPa height anomalies. The official 6-10 day 500-hPa height blend consists of 30% of Today's 6z GFS Ensemble Mean centered on Day 8, 40% of Today's 0z European Ensemble Mean centered on Day 8, and 30% of Today's 0z Canadian Ensemble Mean centered on Day 8 FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: Above average, 4 out of 5, due to good model agreement on the predicted mid-level height pattern, offset by uncertainty in temperature and precipitation forecast tools for the period. 8-14 DAY OUTLOOK FOR JUL 03 - 09 2020 During the week-2 period, the 500-hPa flow pattern across the forecast domain is similar to the 6-10 day period. However, models indicate further deamplification of the trough and ridge pattern over the CONUS for the 8-14 day period. The manual height blend predicts that a ridge will expand over the Gulf of Alaska, while a trough is forecast downstream over the Pacific Coast of the CONUS. Farther to the east, a mean ridge is predicted to persist over the north-central and northeastern CONUS, while a trough persists in the forecast over the East Coast. Above normal 500-hPa heights are forecast to expand northward across Mainland Alaska and are expected to persist across parts of the north-central CONUS. Near normal 500-hPa heights are predicted over the remainder of the CONUS. As troughing de-amplifies over the West in model forecasts, the area of likely below normal temperatures decreases in parts of the Southwest, while probabilities of above normal temperatures are enhanced for much of Arizona in the week-2 period. Above normal temperatures continue to be likely for much of the Great Plains region, as well as across the northeastern quarter of the CONUS, under predicted persistence of a ridge. The probabilities of below normal temperatures increase over parts of the Gulf Coast region and Southeast, consistent with predicted above normal precipitation and enhanced troughing over the region. The area of likely above normal temperatures expands into interior Mainland Alaska, under the predicted ridge. A forecast of troughing over the Pacific Coast of the CONUS continues to lead to likely above normal precipitation for parts of the Pacific Northwest eastward across the Northern Plains. Predicted southerly low-level moist flow enhances probabilities of above normal precipitation over parts of the Central and Lower Mississippi, Tennessee, and Ohio Valleys, as well as much of the Southeast region. Below normal precipitation probabilities are enhanced over parts of the Southwest, Southern and Central Rockies, and the Southern and Central Plains, as well as for the northern Great Lakes region and parts of the Northeast, consistent with the consolidation forecast. Elevated probabilities of above normal precipitation are indicated over parts of the Aleutians and western Mainland Alaska consistent with predicted troughing to the west early in the 8-14 day period. Below normal precipitation is favored for southeastern Alaska under predicted above normal 500-hPa heights. The official 8-14 day 500-hPa height blend consists of: 30% of Today's 6z GFS Ensemble Mean centered on Day 11, 50% 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: Average, 3 out of 5, due to good agreement on the mid-level height pattern forecast, offset by uncertainty in temperature and precipitation forecasts for the period. FORECASTER: D Collins 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 July 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: 19750611 - 19600612 - 19680625 - 19570625 - 19510612 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: 19750611 - 19600611 - 19680624 - 19510612 - 19770622 6-10 DAY OUTLOOK TABLE Outlook for Jul 01 - 05 2020 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B A OREGON B A NRN CALIF B N SRN CALIF B N IDAHO B A NEVADA B N W MONTANA B A E MONTANA B A WYOMING B A UTAH B N ARIZONA B B COLORADO B B NEW MEXICO A B N DAKOTA A A S DAKOTA A A NEBRASKA A A KANSAS A A OKLAHOMA A A N TEXAS A A S TEXAS A B W TEXAS A N MINNESOTA A A IOWA A A MISSOURI A A ARKANSAS N A LOUISIANA A A WISCONSIN A B ILLINOIS A A MISSISSIPPI N A MICHIGAN A B INDIANA A B OHIO A B KENTUCKY A A TENNESSEE N A ALABAMA N A NEW YORK A B VERMONT A B NEW HAMP A B MAINE A B MASS A B CONN A B RHODE IS A B PENN A B NEW JERSEY A B W VIRGINIA A N MARYLAND A B DELAWARE A B VIRGINIA A N N CAROLINA N A S CAROLINA N A GEORGIA N A FL PNHDL A A FL PENIN A N AK N SLOPE N A AK ALEUTIAN A A AK WESTERN A A AK INT BSN B N AK S INT A B AK SO COAST A B AK PNHDL A B 8-14 DAY OUTLOOK TABLE Outlook for Jul 03 - 09 2020 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B A OREGON B N NRN CALIF B N SRN CALIF B N IDAHO B N NEVADA B N W MONTANA B A E MONTANA A A WYOMING A N UTAH A N ARIZONA A B COLORADO A B NEW MEXICO A B N DAKOTA A A S DAKOTA A A NEBRASKA A N KANSAS A B OKLAHOMA N N N TEXAS N N S TEXAS A N W TEXAS A B MINNESOTA A N IOWA A N MISSOURI A N ARKANSAS N A LOUISIANA B A WISCONSIN A N ILLINOIS A N MISSISSIPPI B A MICHIGAN A N INDIANA A A OHIO A A KENTUCKY N A TENNESSEE N A ALABAMA B A NEW YORK A B VERMONT A B NEW HAMP A B MAINE A B MASS A B CONN A B RHODE IS A B PENN A N NEW JERSEY A N W VIRGINIA A A MARYLAND A N DELAWARE A N VIRGINIA N A N CAROLINA N N S CAROLINA B A GEORGIA B A FL PNHDL N N FL PENIN A N AK N SLOPE A N AK ALEUTIAN A A AK WESTERN A A AK INT BSN A N AK S INT A B AK SO COAST A B AK PNHDL A B 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. $$