####018006275#### FXUS21 KWNC 251807 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT April 25 2024 SYNOPSIS: Early in week-2, heavy precipitation remains a concern across the central contiguous U.S. (CONUS) with mid-level low pressure forecast across the West and mid-level high pressure likely across the eastern CONUS. This will allow for a continued active pattern leading to chances for heavy rain and thunderstorms across the Plains and Mississippi Valley. However, the strongest chances have diminished slightly today and dynamical model tools show considerable uncertainty. Heavy rain is also expected in week-1, and additional precipitation in week-2 could cause localized flooding over portions of the Plains, Mississippi Valley, and western Great Lakes. Associated with mid-level low pressure over the West, chances for periodic high winds are possible for much of week-2 over much of the southwestern CONUS, Rockies, and Plains. By the middle of the period the longwave height pattern may break down as more zonal flow is forecast, reducing risks for hazardous weather. Rapid onset drought may become a concern in parts of the Florida peninsula over the next few weeks. HAZARDS Slight risk of heavy precipitation for portions of the Northern Rockies, Plains, Mississippi Valley, and western Great Lakes, Fri-Sun, May 3-5. Slight risk of high winds for much of the Southwest, Rockies, and Great Plains, Fri-Sun, May 3-5. Flooding possible for parts of the eastern Central and Southern Plains, Mississippi Valley, and parts of southwestern Great Lakes. Rapid Onset Drought risk for portions of central Florida. DETAILED SUMMARY FOR SUNDAY APRIL 28 - THURSDAY MAY 02: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR FRIDAY MAY 03 - THURSDAY MAY 09: The GEFS and ECMWF ensemble means are in good agreement indicating a fairly stagnant pattern heading into early week-2, featuring a moderately-amplified mean 500-hPa long-wave trough over or near western North America, and a downstream mid-level ridge with an axis over the eastern CONUS. The western trough looks likely to weaken and diminish by the middle of the week-2 period with more zonal flow pattern taking hold across the CONUS for a period of time. However, a trough across Alaska may help to reestablish negative anomalies across the eastern Pacific Ocean at the end of the period. The persistent mid-level trough in the West favors southerly surface flow bringing unusually moist air northward into the central CONUS, where cyclonically-curved divergent flow aloft is expected. This combination puts a large part of the central CONUS at increased risk for one or more episodes of heavy precipitation and localized thunderstorms. This quasi-stationary pattern is expected to persist through the early part of week-2 before weakening later in the period, prompting a slight risk of heavy precipitation in place through the early part of the period, May 3-5. Probabilistic Extremes Tools (PETs) from the GEFS and the ECENS are in less agreement relative to yesterday. The GEFS has lower precipitation amounts relative to the ECENS and this increases the uncertainty. Raw tools from the GEFS and ECENS are also in more disagreement with the ECENS remaining slightly more robust in its probabilities but the GEFS has further reduced probabilities. Therefore, the moderate risk of heavy precipitation has been discontinued today. The heavy precipitation and thunderstorm activity anticipated during week-2 is not expected to be as intense as conditions in the short-term, but will exacerbate impacts related to excessive precipitation in week-1. The combined effects of two weeks of excessive precipitation support a flooding possible risk near and downstream from areas where the greatest rainfall totals are expected including eastern portions of Kansas and Oklahoma and much of the Mississippi Valley according to the GEFS and ECMWF ensemble means. Runoff from heavy rainfall is expected to enhance the flood risk farther to the south and east (downstream) across the Lower Mississippi Valley. The anticipated long-wave pattern also favors cyclogenesis near or to the lee of the Rockies, with higher surface pressures forecast farther east and west. The timing and strength of any surface low pressure system that forms is uncertain, so a large area from the Southwest and the Rockies eastward through the Great Plains has a slight risk for one or more episodes of high winds for May 3-5 until the mid-level trough across the West weakens by the end of week-2. In the Southeast, above-normal temperatures and near- to below-normal precipitation is forecast during weeks-1 & 2. In parts of the central Florida peninsula and the North Carolina piedmont soil moisture levels are declining due to limited precipitation in recent weeks and months. Recent weeks have seen areas of abnormal dryness (D0) developing and expanding across both of these regions. As we approach the middle of May, increasing sun angles and temperatures in the 80’s to 90’s deg F. could lead to rapid onset drought (ROD) across these regions. Therefore, an area of ROD has been added to parts of central Florida. However, in North Carolina, near-normal precipitation is favored in the week-2 forecast, therefore, no ROD hazard has been posted for this region at this time but interests should remain vigilant and a ROD risk hazard may be added at our next update opportunity on Monday if confidence grows for below-normal precipitation in week-2. Farther north, models generally favor below normal 500-hPa heights across Alaska, with a trough axis near or west of the Mainland that favors stormy weather near the coast of south-central and southeastern Alaska. This pattern may support one or more periods of enhanced precipitation and winds, but conditions are not expected to reach hazardous criteria precluding associated hazards from being designated. FORECASTER: Ryan Bolt $$ ####018003852#### FXCA20 KWBC 251850 PMDCA TROPICAL DISCUSSION - INTERNATIONAL DESKS NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 249 PM EDT THU APR 25 2024 FORECAST BULLETIN 25 APR 2024 AT 1900 UTC: A MID/UPPER TROUGH IS PROPAGATING EASTWARD ACROSS THE WESTERN USA. AS THIS TROUGH PRESSES AGAINST AN UPPER RIDGE CENTERING SOUTH OF MEXICO...A BRANCH OF THE SUBTROPICAL UPPER JET IS BECOMING ENHANCED ACROSS CENTRAL MEXICO. AS THE TROUGH MOVES EASTWARD...EXPECT FAVORABLE DYNAMICS FOR PERIODS OF SEVERE CONVECTION IN NORTHEAST MEXICO. ALTHOUGH THE CORE OF THE EVENT IS EXPECTED TO STAY IN US TERRITORY...THERE IS A SLIGHT RISK FOR ISOLATED SEVERE THUNDERSTORMS IN NORTHERN COAHUILA ON THURSDAY...AND ON FRIDAY TO A LESSER EXTENT. A STATIONARY FRONT EXTENDS FROM THE NORTH ATLANTIC TO THE SOUTHEAST BAHAMAS/EASTERN CUBA ON THURSDAY. ASSOCIATED WITH THIS SYSTEM...A PREFRONTAL TROUGH STRUCTURE EXISTS AHEAD OF THE FRONT EXTENDING TO HISPANIOLA. BY FRIDAY MORNING...THE FRONT IS EXPECTED TO START ADVANCING AS A COLD FRONT AGAIN AS A STRONG UPPER LEVEL TROUGH DRIFTS ACROSS THE EAST COAST OF THE US INTO THE NORTH ATLANTIC. THUS BY FRIDAY EVENING...EXPECT THE FRONT TO EXTEND ACROSS THE SOUTHEAST BAHAMAS WHILE STARTING TO ACCELERATE SOUTHEASTWARD. BY SATURDAY EVENING...EXPECT THE FRONT EXTENDING SOUTH OF THE TURKS AND CAICOS/INAGUA AND INTO SOUTHEAST CUBA. BY SATURDAY...EXPECT A SHEAR LINE TRYING TO ORGANIZE ACROSS THE LEEWARD ISLANDS...ST. CROIX INTO THE CENTRAL CARIBBEAN. BOTH FRONT AND SHEAR LINE ARE FORECAST TO CONTINUE MEANDERING TO THE SOUTHEAST ON SUNDAY. IN TERMS OF RAINFALL ACCUMULATIONS...THE HEAVIEST PRECIPITATION IS EXPECTED ALONG THE PREFRONTAL TROUGH ON THURSDAY. AS THE TROUGH INTERACTS WITH TERRAIN IN HISPANIOLA IN A PRECIPITABLE WATER POOL OF 50-60MM...EXPECT THE POTENTIAL FOR HEAVY RAIN PRODUCING THUNDERSTORMS. THIS INCLUDES A SLIGHT RISK FOR SEVERITY...ESPECIALLY IN ELEVATED TERRAIN AND WESTERN PORTIONS OF THE ISLAND. THROUGH EARLY FRIDAY...EXPECT AMOUNTS OF 25-50MM/DAY AND MAXIMA OF 75-125MM. THE RISK FOR LOCALLY HEAVY PRECIPITATION CONTINUES ON FRIDAY GIVEN THE ARRIVAL OF A MOIST PLUME FROM THE EAST. THIS WILL LIKELY FAVOR 15-20MM/DAY AND MAXIMA OF 40-80MM. ON SATURDAY...EXPECT A CHANGE IN THE LOW-LEVEL WINDS TO NORTHEASTERLIES IN RESPONSE TO THE BUILDING OF A POLAR HIGH OFF THE EAST COAST OF THE USA. AS THE LOW-LEVEL FLOW CHANGES...EXPECT THE MOIST PLUME TO DRIFT SOUTHWARD ACROSS PUERTO RICO INTO THE SOUTHEAST CARIBBEAN. THUS...EXPECT A DECREASE IN AMOUNTS IN HISPANIOLA TO 10-15MM/DAY AND MAXIMA OF 20-35MM. ALSO ON SATURDAY...THE MOIST PLUME WILL FAVOR AN INCREASE IN AMOUNTS IN PUERTO RICO TO SUSTAIN 10-15MM/DAY AND MAXIMA OF 20-35MM. SIMILAR AMOUNTS ARE EXPECTED IN SOUTHEAST CUBA WITH THE FRONT...AS IT INTERACTS WITH NORTHEASTERN SLOPES OF THE SIERRA MAESTRA. REGARDING THE WET SPELL IN SOUTHERN CENTRAL AMERICA...MODELS CONTINUE SHOWING MODERATE RAINFALL AMOUNTS IN COSTA RICA AND PANAMA AS A TROUGH MEANDERS WESTWARD SLOWLY THROUGH THE CYCLE...WHILE INTERACTING WITH THE PANAMANIAN LOW. ON THURSDAY...EXPECT MAXIMA OF 30-60MM IN CENTRAL AND WEST PANAMA. THIS WILL ALSO FAVOR MAXIMA OF 35-70MM IN WESTERN COLOMBIA. ON FRIDAY...EXPECT THE HIGHER ACCUMULATIONS IN WEST PANAMA AND IN EASTERN COSTA RICA...WHERE EXPECT MAXIMA OF 20-45MM. IN EASTERN PANAMA EXPECT MAXIMA OF 20-35MM. ON SATURDAY...EXPECT MAXIMA OF 35-70MM IN THE PACIFIC BASIN OF SOUTHWEST PANAMA...WHILE IN CENTRAL PANAMA EXPECT MAXIMA OF 20-35MM. ALSO OF RELEVANCE...AN EASTERLY WAVE IS PROPAGATING WESTWARD FROM WESTERN VENEZUELA ON THURSDAY TO TO EASTERN PANAMA BY SATURDAY. THIS WILL FAVOR MODERATE TO LOCALLY HEAVY AMOUNTS AS IT MOVES ACROSS THE REGION. GALVEZ/CLARKE/LEDESMA...WPC (USA) $$ ####018011854#### FXUS06 KWBC 251902 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 25 2024 6-10 DAY OUTLOOK FOR MAY 01 - 05 2024 Model solutions depict a persistent longwave pattern into the beginning of May. The GEFS along with the ECMWF and Canadian ensemble means feature a 500-hPa trough of varying amplitude near the West Coast, a broad ridge over the central contiguous U.S. (CONUS), and a trough across the western Atlantic. Positive 500-hPa height anomalies and southerly surface flow support increased above-normal temperature probabilities from the Rockies to the East Coast. 5-day temperatures are expected to be more variable across the Northeast with above-normal temperature probabilities lower in this region. Anomalous mid-level troughing and enhanced onshore flow favor below-normal temperatures across the Pacific Northwest and much of California. The highest forecast confidence in the 6-10 day precipitation outlook exists for the Great Plains and Upper Midwest where above-normal precipitation is favored. This wet start to May is due to the upstream mid-level trough and enhanced low-level moisture from the Gulf of Mexico. Above-normal precipitation probabilities are tempered though due to uncertainty on where the heaviest convective rainfall occurs. Enhanced onshore flow leads to increased above-normal precipitation probabilities from the Pacific Northwest and northern California eastward to the northern Rockies. Near normal precipitation is forecast for the Great Basin and climatological dry areas of the Southwest. A 500-hPa trough over the Bering Sea favors above-normal precipitation for much of Alaska. The uncalibrated model temperature output is colder than the reforecast GEFS and ECMWF tools. The 6-10 day temperature outlook hedged towards the reforecasts, but there is a notable trend the past few days for less coverage of increased above-normal temperature probabilities. Based on the GEFS and ECMWF ensemble means, near normal temperatures and precipitation are favored across much of Hawaii. The official 6-10 day 500-hPa height blend consists of 35% of Today's 6z GFS Ensemble Mean centered on Day 8, 35% 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 a persistent longwave pattern and good agreement among the temperature tools throughout the CONUS. 8-14 DAY OUTLOOK FOR MAY 03 - 09 2024 The GEFS, ECMWF, and Canadian ensemble means maintain the persistent longwave pattern with 500-hPa troughs near both coasts of North America and a broad ridge centered over the central CONUS. The 6-10 and 8-14 day temperature outlooks are quite similar with a majority of the CONUS favored to have above-normal temperatures due to the broad ridge centered over the Mississippi Valley. The Northeast is vulnerable to backdoor cold fronts and cold air damming during the spring and there seems to be an increasing chance for that to occur during early May with an amplified trough over the northwestern Atlantic. A comparison between the manual 500-hPa height blend from the past two days shows the trough over the western Atlantic closer to the East Coast which would increase the potential for a cooler outcome for the Northeast. Although the reforecast tools continue to favor above-normal temperatures across the Northeast, near normal temperatures are forecast for this region due to the colder uncalibrated model output and the analog tool. The 500-hPa trough with negative height anomalies along with enhanced onshore flow favor below-normal temperatures for California and parts of the Desert Southwest and Pacific Northwest. The mid-level longwave trough to ridge pattern from the West Coast to the Mississippi Valley yields a relatively wet (dry) outlook across the western and central (eastern) CONUS. Forecast confidence is not too high though since the reforecast tools indicate weak probabilities overall and the ECMWF ensemble mean predicts a retrogession of the longwave pattern late in week-2. One small change from yesterday’s outlook was a reduction in the coverage of increased below-normal precipitation probabilities across the eastern CONUS. This is based on the GEFS and ECMWF reforecasts and the analog tool derived from the manual 500-hPa blend. These precipitation tools imply the potential for a stationary front to develop across the Southeast or southern Mid-Atlantic which could be a focus for precipitation. A broad 500-hPa trough over the Bering Sea and western Mainland Alaska supports increased above-normal precipitation probabilities nearly statewide for Alaska. Temperature tools continue to differ and a consensus between the GEFS and ECMWF reforecasts favor below (above)-normal temperatures for the North Slope (southeastern Alaska). The GEFS and ECMWF ensemble means feature a mid-level trough, near the West Coast, extending southward to the Central Pacific. This is expected to promote cooler-than-normal temperatures for Hawaii and increased chances of above-normal precipitation except for the Big Island. The official 8-14 day 500-hPa height blend consists of: 35% of Today's 6z GFS Ensemble Mean centered on Day 11, 35% of Today's 0z European Ensemble Mean centered on Day 11, and 30% of Today's 0z Canadian Ensemble Mean centered on Day 11 FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Average, 3 out of 5, with good model agreement on the 500-hPa height pattern offset by uncertainty in the temperature and precipitation outlooks for the eastern CONUS. FORECASTER: Brad Pugh 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 May 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: 19900507 - 19900417 - 19810417 - 19770406 - 20000410 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: 19510404 - 19520404 - 19530404 - 19540404 - 19550404 6-10 DAY OUTLOOK TABLE Outlook for May 01 - 05 2024 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B A OREGON B A NRN CALIF B A SRN CALIF N N IDAHO A A NEVADA A A W MONTANA N A E MONTANA A A WYOMING A N UTAH A N ARIZONA A N COLORADO A N NEW MEXICO A A N DAKOTA A A S DAKOTA A A NEBRASKA A A KANSAS A A OKLAHOMA A A N TEXAS A A S TEXAS A A W TEXAS A A MINNESOTA A A IOWA A A MISSOURI A A ARKANSAS A A LOUISIANA A N WISCONSIN A A ILLINOIS A N MISSISSIPPI A N MICHIGAN A N INDIANA A N OHIO A B KENTUCKY A N TENNESSEE A N ALABAMA A N NEW YORK A B VERMONT A N NEW HAMP A N MAINE A N MASS A B CONN A B RHODE IS A B PENN A B NEW JERSEY A B W VIRGINIA A B MARYLAND A B DELAWARE A B VIRGINIA A B N CAROLINA A B S CAROLINA A B GEORGIA A B FL PNHDL A B FL PENIN A B AK N SLOPE B A AK ALEUTIAN N A AK WESTERN N A AK INT BSN N A AK S INT A A AK SO COAST A A AK PNHDL A A 8-14 DAY OUTLOOK TABLE Outlook for May 03 - 09 2024 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N A OREGON B A NRN CALIF B A SRN CALIF B A IDAHO N A NEVADA N A W MONTANA A A E MONTANA A A WYOMING A N UTAH A A ARIZONA N N COLORADO A N NEW MEXICO A N N DAKOTA A A S DAKOTA A A NEBRASKA A A KANSAS A A OKLAHOMA A A N TEXAS A A S TEXAS A N W TEXAS A A MINNESOTA A A IOWA A A MISSOURI A A ARKANSAS A N LOUISIANA A N WISCONSIN A A ILLINOIS A N MISSISSIPPI A N MICHIGAN A N INDIANA A N OHIO A N KENTUCKY A N TENNESSEE A N ALABAMA A N NEW YORK N B VERMONT N B NEW HAMP N B MAINE N B MASS N B CONN N B RHODE IS N B PENN A B NEW JERSEY N B W VIRGINIA A N MARYLAND A B DELAWARE N B VIRGINIA A N N CAROLINA A N S CAROLINA A N GEORGIA A N FL PNHDL A B FL PENIN A B AK N SLOPE B A AK ALEUTIAN N A AK WESTERN N A AK INT BSN N A AK S INT N A AK SO COAST A A 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. $$ ####018006457#### FXUS02 KWBC 251900 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 300 PM EDT Thu Apr 25 2024 Valid 12Z Sun Apr 28 2024 - 12Z Thu May 02 2024 ***Severe thunderstorms and heavy rain expected west of the lower and Mid-Mississippi Valley on Sunday, moving into the lower Mississippi Valley on Monday*** ...General Overview... The medium-range period will likely begin with a rather active pattern Sunday morning as a low pressure system tracks northeast across the central Plains with severe thunderstorms from the central Plains eastward to the lower to mid-Mississippi Valley into Monday. The upper pattern appears to become more zonal later next week as the central U.S. trough lifts out and a moderately strong trough passes through the Pacific Northwest and reaches into the northern Plains. It appears that a deeper trough will edge into the West Coast by midweek while Gulf moisture will tend to increase and expand across the southern Plains. ...Guidance/Predictability Assessment... The morning model guidance suite features good overall agreement across the U.S. through much of the medium-range period. Models are unanimous in lifting the upper trough and low pressure system northeastward away from the Great Plains early next week but solutions gradually show more diversity afterward as a moderately strong upper trough moves through the Pacific Northwest into the northern Plains. This is due to uncertainty on how fast the upper trough will lift out of the Plains and how much the Pacific Northwest trough will interact with the central U.S. trough. Despite the uncertainty on the trough interactions, the ensemble means are agreeing well that a more zonal pattern will be established across the northern tier states midweek next week while a deeper upper trough will edge toward the West Coast. The WPC medium-range forecast package was based on a general model compromise of 40% from the 00Z ECMWF/EC mean, 40% from the 06Z GFS/GEFS, and 20% from the 00Z CMC/CMC mean, and leaning toward the ensemble means by Days 6 and 7. ...Weather/Hazards Highlights... The overall synoptic environment will be quite conducive for multiple episodes of excessive rainfall across portions of the central and lower Mississippi River Valley. There will likely be multiple mesoscale convective systems to develop from the ArkLaTex region to Missouri, and there is a good chance of training convection given the slow overall progression of the frontal boundary in conjunction with parallel flow to the trailing frontal boundary. For the Day 4 period Sunday, the existing Slight Risk is maintained from eastern Texas north-northeast across Arkansas into southern Missouri where the QPF signal is highest in the model guidance, where a multi-model signal for some 3-5 inch totals is indicated. Storms training over the same areas with locally higher totals are possible. There is still a good chance for a future upgrade to Moderate Risk for portions of this region if these model trends continue. The WPC forecast for QPF remains on the lower end of the guidance spectrum given the influence from the NBM. A Slight Risk area is also maintained on Day 5 centered over northern Louisiana and into portions of adjacent states, generally southeast of the Day 4 outlook area. The convergence boundary is likely to linger across the region on Monday and fire new rounds of convection, followed by an abatement in the coverage and intensity of the convection going in Tuesday over this region. The latest guidance has generally placed the highest QPF farther north. The Slight was kept farther south in favor of the previous ERO for this area. Elsewhere across the U.S., widespread moderate to locally heavy rain is expected from Minnesota to northern Michigan on Sunday as the surface low lifts northeastward, and a Marginal Risk area is planned to account for that on the Day 4 outlook. Colder temperatures moving in across the Intermountain West and the Rockies behind this storm system will likely result in continuing snow showers for the higher mountain ranges of Wyoming and Colorado, although becoming lighter. Rain and mountain snow is also likely to make a return to the Pacific Northwest for the beginning to middle of next week as the next shortwave trough arrives. By Wednesday, showers and storms could once again increase in coverage from Texas to the Central Plains. Temperatures will also be making weather headlines as a major warm-up is expected for a wide expanse of the country east of the Rockies. Highs are expected to rise well into the 80s from the Central/Southern Plains to the Ohio Valley and then reaching the East Coast by Monday, perhaps reaching 90 degrees in some cases. These readings are on the order of 10-20 degrees above normal for late April, and there may be some daily record highs set. Overnight lows will also be summer-like with lows only falling into the 60s for many of these same areas. A modest cool-down is likely by mid- week from the Great Lake to the Ohio Valley and Northeast, and still remaining warm and humid across the south-central U.S. to the Carolinas. The opposite holds true for the Intermountain West on Sunday with readings 5-15 degrees below average, before things moderate going into early next week. Kong/Hamrick Additional 3-7 Day Hazard information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range 500mb heights, surface systems, weather grids, quantitative precipitation forecast (QPF), excessive rainfall outlook (ERO), winter weather outlook (WWO) probabilities, heat indices, and Key Messages can be accessed from: https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml https://www.wpc.ncep.noaa.gov/#page=ero https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml https://www.wpc.ncep.noaa.gov/#page=ovw $$