####018013803#### FXUS06 KWBC 041903 PMDMRD Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EDT Tue June 04 2024 6-10 DAY OUTLOOK FOR JUN 10 - 14 2024 The ECENS, GEFS, and Canadian ensemble mean predicted 500-hPa heights are in good agreement with each other for a robust mid-level ridge and trough across the western and eastern contiguous U.S. (CONUS) respectively. A weak shortwave trough is forecast to undercut the ridging in the West. In Alaska, near-normal heights are forecast across much of the state but negative 500-hPa height anomalies shifted east relative to yesterday and are likely to bring more substantial changes to the height pattern over the CONUS during week-2. For Hawaii, slightly above-normal mid-level heights are forecast. During the 6-10 day period, a cold front is forecast to be progressing across the eastern CONUS. This will help to maintain below-normal temperature chances across much of the eastern CONUS. However, the frontal system may not reach the Gulf Coast region where dynamical tools continue to bring strong chances for above-normal temperatures, particularly to South Texas and southern Florida. The GEFS has come into better agreement with the ECENS for the western extent of the below-normal temperature chances across the Plains, bringing it a shade further west relative to prior forecasts. In the West, above-normal temperatures are strongly favored across most of the region. There are slightly reduced temperature chances across Southern California and the Desert Southwest where an undercutting trough may reduce above-normal temperatures. For Alaska, below-normal temperatures remain forecast for southern Alaska. The rest of the Mainland is favored to have near- to above-normal temperatures during the period. In Hawaii, the consolidation tool is less warm than prior forecasts and coming into better agreement with a cooler blend of models forecast, therefore, below-normal temperatures are favored for much of Hawaii. The precipitation forecast across the southeastern CONUS is rather uncertain with fairly different solutions among the model tools. The GEFS based tools are forecasting drier than normal conditions across much of the eastern CONUS. While the ECENS based tools are forecasting above-normal precipitation across the southeastern CONUS along a frontal boundary that is likely to be in the region. The wetter ECENS reforecast tool has been performing better across the Southeast in recent weeks and a slight tilt towards above-normal precipitation is favored. Across the northern tier of the CONUS from the West Coast to the Great Lakes, below-normal precipitation is forecast. A shortwave trough, undercutting the ridge aloft, favors above-normal precipitation from the central Rockies southeastward to the central and southern Great Plains. In the Northeast and Mid-Atlantic, a departing low-pressure system and associated frontal region is likely to bring above-normal precipitation. Above-normal precipitation is favored across much of Alaska, with the best chances of above-normal precipitation favored for parts of southeastern Mainland Alaska. Above-normal precipitation is favored for Hawaii with the consolidation tool forecasting less dry conditions relative to yesterday. The official 6-10 day 500-hPa height blend consists of 40% of Today's 0z GFS Ensemble Mean centered on Day 8, 40% of Today's 0z European Ensemble Mean centered on Day 8, and 20% 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, Good agreement among the dynamical height and temperatures tools is offset by reduced agreement in the precipitation outlook. 8-14 DAY OUTLOOK FOR JUN 12 - 18 2024 The mid-level height pattern for week-2 is transitioning away from a ridge and trough pattern across the western and eastern CONUS, respectively, towards ridging across the Plains and troughing along the coasts. The GEFS is faster in establishing the new regime with troughing along the West Coast by around day 10. The ECENS is a day or two slower relative to the GEFS but there is good agreement for a transition to occur. As a result, the 500-hPa manual blend has a deeper trough along the West Coast and more enhanced ridging across the Plains relative to yesterday. In Alaska, near to above-normal 500-hPa height are forecast with ridging trying to develop across the Gulf of Alaska. In Hawaii, near-normal heights are forecast. Below-normal temperature chances across the eastern CONUS are substantially lower relative to yesterday with above-normal chances developing across the upper Midwest and Northeast. Above-normal temperatures remain forecast during the week-2 period across much of the western CONUS, Rio-Grande Valley, and Gulf Coast. Mid-level ridging looks likely to persist through much of the period across the interior-West. However, along the immediate West Coast, probabilities for above-normal temperature are substantially reduced relative to prior forecasts and the mid-level trough becomes more established by the middle to end of the period. The sub-tropical mid-level high pressure looks likely to remain fairly well established. One concern further east, across Florida, is the potential for a heavy rain event that may limit above-normal temperatures. This reduces confidence in above-normal temperatures relative to what some of the dynamical tools would support. In Alaska, above-normal temperatures are favored in the northern third of the Mainland with near- to below-normal temperatures favored across the southern Mainland, Aleutians and Southeast Alaska. Tools are generally a little warmer across the southern Mainland relative to prior days as some ridging may try to become established across parts of Alaska by the end of the period. In Hawaii, a slight tilt towards below-normal temperatures is favored. There continues to be a large amount of disagreement among the dynamical model tools. The precipitation forecast is quite uncertain across most of the CONUS during week-2 with limited support for above or below-normal precipitation across the country. Above-normal precipitation is favored ahead and at the base of the trough forecast across the eastern CONUS. The region with strongest chances for above-normal is across parts of Florida where a wave of tropical moisture may enhance precipitation amounts. Behind the trough, below-normal precipitation is favored. Across the interior West, above-normal precipitation is slightly favored with good agreement among the tools for a slight tilt among the model tools. However, there is broad disagreement in the raw tools for precipitation in the Pacific Northwest, where near-normal precipitation is favored. In Alaska, a slight tilt towards above-normal precipitation is favored beneath near-normal heights and weak troughing. In Hawaii, above-normal precipitation, consistent with a blend of models forecast. The official 8-14 day 500-hPa height blend consists of: 10% of Today's 0z GFS Ensemble Mean centered on Day 11, 30% of Today's 6z GFS Ensemble Mean centered on Day 11, 40% 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: Below-Average, 2 out of 5, Fair agreement among the dynamical height and temperatures tools is offset by reduced agreement in the precipitation outlook and lower mid-level height anomalies as a pattern transition occurs during the period. FORECASTER: Ryan Bolt 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 1991-2020 base period means as reference in the climate outlooks. The next set of long-lead monthly and seasonal outlooks will be released on June 20. 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: 20030515 - 19880528 - 19550526 - 19730521 - 20010516 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: 20030515 - 19550527 - 19880529 - 19730522 - 19520529 6-10 DAY OUTLOOK TABLE Outlook for Jun 10 - 14 2024 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A B OREGON A B NRN CALIF A N SRN CALIF A N IDAHO A B NEVADA A N W MONTANA A B E MONTANA A B WYOMING A A UTAH A N ARIZONA A N COLORADO A A NEW MEXICO A A N DAKOTA A B S DAKOTA A N NEBRASKA B N KANSAS B A OKLAHOMA B A N TEXAS N A S TEXAS A A W TEXAS A A MINNESOTA B B IOWA B B MISSOURI B N ARKANSAS B N LOUISIANA N A WISCONSIN B N ILLINOIS B B MISSISSIPPI B N MICHIGAN B N INDIANA B N OHIO B N KENTUCKY B B TENNESSEE B B ALABAMA B N NEW YORK B A VERMONT N A NEW HAMP N A MAINE N A MASS N A CONN B A RHODE IS N A PENN B A NEW JERSEY B A W VIRGINIA B N MARYLAND B A DELAWARE B A VIRGINIA B A N CAROLINA B A S CAROLINA N N GEORGIA N N FL PNHDL A A FL PENIN A A AK N SLOPE N N AK ALEUTIAN B N AK WESTERN N N AK INT BSN N A AK S INT B A AK SO COAST B A AK PNHDL B A 8-14 DAY OUTLOOK TABLE Outlook for Jun 12 - 18 2024 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N N OREGON A N NRN CALIF A N SRN CALIF A N IDAHO A N NEVADA A N W MONTANA A A E MONTANA A N WYOMING A A UTAH A A ARIZONA A N COLORADO A A NEW MEXICO A N N DAKOTA A N S DAKOTA A N NEBRASKA A N KANSAS A B OKLAHOMA A B N TEXAS A N S TEXAS A N W TEXAS A N MINNESOTA A N IOWA A N MISSOURI N B ARKANSAS N B LOUISIANA A N WISCONSIN A N ILLINOIS N N MISSISSIPPI N B MICHIGAN N N INDIANA N N OHIO N N KENTUCKY B B TENNESSEE B B ALABAMA N B NEW YORK A A VERMONT A A NEW HAMP A A MAINE A A MASS A A CONN N A RHODE IS N A PENN N N NEW JERSEY N A W VIRGINIA N N MARYLAND N N DELAWARE N N VIRGINIA N N N CAROLINA A N S CAROLINA A B GEORGIA A N FL PNHDL A A FL PENIN A A AK N SLOPE A N AK ALEUTIAN B A AK WESTERN N N AK INT BSN A N AK S INT B N AK SO COAST B N AK PNHDL B 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. $$