FXUS06 KWBC 031902 PMDMRD Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks NWS Climate Prediction Center College Park, MD 300 PM EDT Thu April 03 2025 6-10 DAY OUTLOOK FOR APR 09 - 13 2025 The 0z GEFS, ECENS, and CMCE are in good agreement regarding an amplified 500-hPa height pattern across North America. Weak troughing is forecast over the eastern contiguous U.S. (CONUS), with ridging becoming established across the west-central CONUS. Troughing initially forecast across central Alaska is predicted to weaken, with ridging and positive height anomalies expanding over the state by the end of the period. Today’s manual 6-10 day 500-hPa height blend depicts above normal heights across much of the western CONUS, and below normal heights over the southeastern quadrant of the CONUS. Near normal heights are favored across the northeastern CONUS. Near- to slightly below normal heights are depicted over much of Mainland Alaska and the Alaska Peninsula, with above normal heights forecast over the western Aleutians, far eastern Mainland, and Southeast Alaska. Probabilities for below normal temperatures are increased over much of the eastern CONUS behind a frontal boundary predicted to move through at the outset of the period, with the highest chances (greater than 70 percent) across parts of the Southeast. There are concerns for frosts or freezes across some areas as relatively colder temperatures coincide with emerging vegetation. Ridging forecast across the West favors elevated probabilities of above normal temperatures. Troughing predicted over central Mainland Alaska supports increased chances for above normal temperatures over the southern and eastern parts of the state due to enhanced southerly flow. Conversely, below normal temperature chances are increased on the backside of the mean trough axis across western Mainland. Increasing mid-level heights over the Aleutians support enhanced near to above normal temperature chances. Above normal temperatures continue to be favored across Hawaii. A broad area of enhanced below normal precipitation probabilities are forecast across much of the western CONUS and building into the Great Plains, Midwest, and Southeast as surface high pressure becomes established. A coastal storm is forecast to develop on the eastern seaboard during the period, this may bring a period of unsettled weather to parts of the East Coast, slightly elevating chances for above normal precipitation. Elevated probabilities for above normal precipitation are favored in Southeast Alaska due to enhanced onshore flow ahead of mid-level troughing. Near to below normal precipitation chances are increased across the southwestern Mainland and the Aleutians underneath a more northerly mid-level flow pattern with near normal precipitation favored over the remainder of Mainland Alaska. Above normal precipitation is forecast across Hawaii supported by the consolidation forecast tool. The official 6-10 day 500-hPa height blend consists of 10% of Today's 0z GFS Ensemble Mean centered on Day 8, 20% 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 agreement in the model height pattern. 8-14 DAY OUTLOOK FOR APR 11 - 17 2025 The 500-hPa height pattern predicted during week-2 is less amplified to that of the 6-10 day period, with some eastward progression of the features. The dynamical models remain in agreement regarding ridging across the central CONUS and weak troughing across the East Coast and in the Pacific Northwest for the period mean. Weakly above normal heights are depicted across Alaska underneath a weak trough persisting across the central Mainland. Larger positive height anomalies are forecast across the Aleutians and the far western Mainland associated with ridging centered across eastern Russia and the Bering Sea. Below normal temperature probabilities remain slightly favored in parts of the Southeast with near normal otherwise favored for most areas east of the Mississippi. Enhanced probabilities of above normal temperatures are indicated across the West, especially the Four Corners (>70%), under the forecast positive 500-hPa height departures. Warming temperatures are forecast across the Plains and Mississippi Valley resulting in an eastward expansion of the enhanced above normal temperature probabilities to include these areas. Chances for above normal temperatures persist across southern Alaska due to continued southerly flow. A slight tilt toward below normal temperatures is favored over the western Mainland. Increased probabilities for above normal temperatures remain forecast across Hawaii. Ridging over the West, combined with surface high pressure over the East, favors increased chances for below normal precipitation over much of the CONUS. The strongest probabilities are across parts of the southwestern CONUS and in the Great Lakes, the Ohio, Tennessee, and Middle and Lower Mississippi Valleys, and the Southeast. An area of surface low pressure development along the Mid-Atlantic and Northeast Coast is possible during the week-2 period, increasing chances for near to above normal precipitation for this region. A slight tilt toward below normal precipitation remains favored across for southwestern Mainland Alaska underneath slightly enhanced northerly mid-level flow. Near normal precipitation is favored for much of the rest of the mainland associated with weak troughing across the Central Mainland. Above normal precipitation chances are increased across Hawaii. The official 8-14 day 500-hPa height blend consists of: 10% of Today's 0z GFS Ensemble Mean centered on Day 11, 25% of Today's 6z GFS Ensemble Mean centered on Day 11, 40% of Today's 0z European Ensemble Mean centered on Day 11, and 25% of Today's 0z Canadian Ensemble Mean centered on Day 11 FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: About Average, 3 out of 5, due to good agreement among the dynamical guidance offset by a progressive pattern. 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 April 17. 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: 19630403 - 19650417 - 19670314 - 19540323 - 19960328 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: 19630404 - 19650415 - 20030331 - 19670313 - 19540322 6-10 DAY OUTLOOK TABLE Outlook for Apr 09 - 13 2025 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A A OREGON A N NRN CALIF A B SRN CALIF A B IDAHO A B NEVADA A B W MONTANA A N E MONTANA A B WYOMING A B UTAH A B ARIZONA A B COLORADO A B NEW MEXICO A B N DAKOTA A B S DAKOTA A B NEBRASKA A B KANSAS A B OKLAHOMA A B N TEXAS A B S TEXAS N B W TEXAS A B MINNESOTA A B IOWA A B MISSOURI A B ARKANSAS B B LOUISIANA B B WISCONSIN A B ILLINOIS B B MISSISSIPPI B B MICHIGAN B B INDIANA B B OHIO B N KENTUCKY B N TENNESSEE B N ALABAMA B B NEW YORK B N VERMONT B N NEW HAMP B N MAINE B N MASS B A CONN B A RHODE IS B A PENN B N NEW JERSEY B A W VIRGINIA B N MARYLAND B A DELAWARE B A VIRGINIA B A N CAROLINA B A S CAROLINA B N GEORGIA B B FL PNHDL B B FL PENIN B N AK N SLOPE B N AK ALEUTIAN B B AK WESTERN B B AK INT BSN B N AK S INT N N AK SO COAST A N AK PNHDL A A 8-14 DAY OUTLOOK TABLE Outlook for Apr 11 - 17 2025 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N A OREGON N N NRN CALIF A B SRN CALIF A B IDAHO A B NEVADA A B W MONTANA A A E MONTANA A N WYOMING A B UTAH A B ARIZONA A B COLORADO A B NEW MEXICO A B N DAKOTA A N S DAKOTA A N NEBRASKA A B KANSAS A B OKLAHOMA A B N TEXAS A B S TEXAS A B W TEXAS A B MINNESOTA A N IOWA A B MISSOURI A B ARKANSAS A B LOUISIANA A B WISCONSIN A B ILLINOIS A B MISSISSIPPI N B MICHIGAN N B INDIANA N B OHIO N B KENTUCKY N B TENNESSEE N B ALABAMA N B NEW YORK N N VERMONT N N NEW HAMP N N MAINE N N MASS N A CONN N A RHODE IS N A PENN N N NEW JERSEY N A W VIRGINIA N B MARYLAND N N DELAWARE N A VIRGINIA N N N CAROLINA N N S CAROLINA B B GEORGIA N B FL PNHDL B B FL PENIN B B AK N SLOPE N N AK ALEUTIAN A B AK WESTERN N B AK INT BSN N N AK S INT A N AK SO COAST A N AK PNHDL A 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. $$