36°F
Updated:
3/19/2024
04:58:41am
Forecast Discussion
NWS Omaha/Valley, NE
000 FXUS63 KOAX 190908 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 408 AM CDT Tue Mar 19 2024 .KEY MESSAGES... - High to very high fire danger expected this afternoon between 11 AM and 4 PM, especially across portions of northeast Nebraska - A cold front moving through the region tonight will bring much cooler temperatures into the region, with highs through the end of the forecast period after today in the 40s and low 50s. - A more active weather pattern develops later this week with precipitation chances from Thursday into the weekend. Light wintry mix will be possible across east-central and northeast Nebraska, and southwest Iowa Thursday morning with more widespread rain chances across the entire region Friday morning. - Medium range guidance suggests a strong storm system will impact the region towards the end of the forecast period. The most likely time frame for impacts will be Sunday and Monday with snow becoming increasingly likely across portions of northeast Nebraska and western Iowa. Uncertainty regarding details of system evolution is still high. && .DISCUSSION... Issued at 245 AM CDT Tue Mar 19 2024 ...Today and Tomorrow... Surface analysis this morning shows a surface trough extending from western Nebraska into central Minnesota. Ahead of this feature, southwesterly winds will advect warmer air into the region. Furthermore, regional METAR stations are observing winds ranging from 10 to 20 mph. This will help mix the nocturnal boundary layer limiting the effects of radiative cooling. As such, low temperatures this morning will largely remain near freezing, which is 15 to 20 degrees warmer than yesterday. By 10 AM, the surface trough out west is expected to have moved through the area and into Missouri/Iowa. Behind this, winds will become northwesterly at the surface. The airmass behind the surface trough will be relatively dry with dew points in the upper 20s and low 30s. The dryness of the airmass in conjunction with clear skies and adiabatic compression of air advecting off the High Plains will allow temperatures to rise well above average across the region. Forecast highs today range from the mid 60s across northeast Nebraska and southwest Iowa to near 70 degrees across southeast Nebraska. Forecast soundings also show a deep PBL developing over the course of the day, with the associated inversion reaching heights of 1 to 2 km across short term guidance solutions. This will aid in the downward mixing of higher momentum air aloft and allow winds to strengthen to 15-25 mph this afternoon. Wind gusts as high as 30 mph will be possible, particularly between 11 AM and 4 PM across northeast Nebraska. Due to the low dew points and above average afternoon highs, minimum relative humidities this afternoon will range between 20 and 30 percent. Low relative humidities and gusty winds this afternoon will result in high to very high fire danger across the region, particularly across northeast Nebraska. Further north into Canada, a surface low will track east- southeast across southern Ontario. Behind this system an arctic high pressure will build into the northern Plains and the upper Midwest. Ahead of this high pressure system, a cold front will push south-southwest across the Midwest and central Plains, moving through our region tonight. This will shift winds from northwesterly to out of the northeast. This front is expected to stall out and become a stationary front south of our area, likely extending from southeast Wyoming into northeast Kansas/northwest Missouri. This will bring much cooler high temperatures tomorrow afternoon, ranging from the mid 40s across western Iowa to the low 50s in southeast Nebraska. The baroclinic zone that will set up across the Plains from this stationary front will be an important source of energy for more active weather which is anticipated going into this weekend and next week. ...Thursday and Friday... By Thursday, model guidance suggests ridging is likely across the western CONUS and troughing is likely across the eastern CONUS. Embedded in northwesterly flow aloft, a shortwave trough is expected to eject into the central Plains. Divergence aloft and forcing for ascent ahead of this disturbance will result in surface cyclogenesis in the central High Plains. Most likely location for the surface low to develop is in northeast Colorado/southeast Wyoming. This surface low pressure is expected to remain relatively weak as it traverses east across the central Plains. Nonetheless, flow immediately above the boundary layer across our area (850 to 700 mb) will become south-southwesterly, advecting an elevated layer of warm air into the region. Weak synoptic lift ahead of this disturbance will promote widespread cloud cover and a low potential (15-25 percent chance) of light precipitation Thursday morning, likely after 6 AM. Forecast soundings show temperatures in the boundary layer will largely remain below freezing, as will the vertical temperature profile above the boundary layer at the onset of light precipitation. This will favor flurries/light snow as the dominant precipitation type beginning Thursday morning. Forecast soundings do show a robust dry layer near the surface which will significantly limit the amount of precip that will make it to the ground. Nonetheless, through the morning, flurries/light snow, transitioning to sprinkles/light rain by noon cannot be ruled out, especially along and east of the Missouri river, north of Interstate 80. Late morning (9 AM through noon), ice pellets may mix into the light precipitation as the above freezing layer aloft becomes more robust in the warm air advection ahead of this disturbance. Any light precip that is able to reach the surface should move east of the region by noon. Thursday night into Friday morning, a more robust mid-level disturbance is expected to move across the northern Plains and into the upper Midwest. This will bring a more substantial chance (50-80%) of precipitation across the region Friday morning. At the surface, a reinforcing cold front is expected to move southeast across the region Friday morning. Thursday night ahead of the cold front, temperatures are expected to remain above freezing. Furthermore, the surface front is expected to lag behind the bulk of the precipitation associated with this system. This will likely result in most, if not all precip Friday morning to fall as rain. Between 8 AM and noon, temperatures across far northeast Nebraska will approach and temporarily fall below freezing. This will support a transition from rain to a rain-snow mix late Friday morning. Little to no snow accumulations are expected at this time. Precipitation is expected to move east of the region by 1 PM Friday. Friday night behind the cold front, temperatures are expected to fall into the lower 20s and upper 10s. ...Saturday through Monday... Medium range guidance continues to suggest a deep upper level trough will slowly work its way into the western CONUS by the end of the forecast period. Strong forcing for ascent and PVA that will move into the Great Plains over the strong baroclinic zone along the stationary front is expected to induce strong surface cyclogenesis in the central High Plains. The majority of ensemble and deterministic model solution resolve a surface low with pressure below 990 mb in the central High Plains by Sunday evening. However, there is still substantial uncertainty in the exact position and timing of this system, and where it will track across the Plains by the end of the forecast period. Medium range models also diverge substantially in surface temperature forecasts. Spread amongst models range anywhere from 15-25 degrees for any given location and time across our area Sunday and Monday. As such, will refrain from more detailed discussion on precip type and amounts. Nonetheless, there is enough confidence in saying widespread light to moderate precipitation will be likely (70-90%) across the entire region Sunday into Monday. Snow will also be increasingly likely with northward extent, with the most likely area to see snow being northeast Nebraska and western Iowa along and north of US highway 30. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1030 PM CDT Mon Mar 18 2024 VFR conditions expected through the period with southwest winds overnight at 10 to 15 kts turning clockwise to northwesterly and gusting 20 to 25 kts by Tuesday morning. Winds will begin to weaken and become more northerly by late afternoon/early evening. Otherwise, expect some low level wind shear into the early morning hours, with westerly winds at 45 to 50 kts around 1500 ft agl. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...Darrah AVIATION...CA
NWS OAX Office Area Forecast Discussion
Forecast Discussion
NWS Hastings, NE
000 FXUS63 KGID 190945 AFDGID Area Forecast Discussion National Weather Service Hastings NE 445 AM CDT Tue Mar 19 2024 .KEY MESSAGES... - Highs in the 60s and 70s Today, which will be the warmest day of the forecast period. - A chance (15-45%) for light rain Thursday night for areas mainly northeast of the Tri-Cities - Widespread chances for precipitation (40-75%) this weekend as the next system brings the potential for rain, thunderstorms and snow. Uncertainty still remains on the exact impacts from this system. && .DISCUSSION... Issued at 443 AM CDT Tue Mar 19 2024 Today and Tonight... Today will be the warmest day of the forecast period, with highs in the 60s across south central Nebraska, and portions of north central kansas climbing into the 70s. Winds will become breezy and northerly during the morning hours, but winds will gradually decrease during the afternoon and evening hours. The strongest winds will be mainly northeast of the Tri-Cities. While afternoon relative humidity (RH) values will fall below 25% for most areas, decreasing winds and the lowest RH values being displaced from the highest winds will limit fire weather concerns to being "elevated". Lows tonight will hover around the freezing mark for most areas, with the warmest locations across north central Kansas. Wednesday... A backdoor cold front will lead to a cooler day, with highs in the mid 40s to upper 50s. Temperatures in some locations will be 20 degrees colder than on Tuesday. Winds will be breezy and easterly during the day on Wednesday, with gusts to 25 mph. While winds will be breezy on Wednesday, RH values will be higher than on Tuesday, and the strongest winds will be displaced from the lowest RH values once again, keeping any fire weather concerns low. Thursday through Friday afternoon... Highs on Thursday will be in the 50s, with lows approaching the 60s across eastern portions of the area. A quick moving clipper system will move north of the area Thursday night, bringing the next chance for precipitation (15-45%) to the area. Areas north of I-80 will have the highest chances (25-45%) to see any precipitation from this system. Any rain that does fall Thursday night is expected to remain light. Both the ECMWF and GFS ensembles show a 10% chance or for 0.10 inches or more of precipitation, with the highest chances northeast of the Tri-Cities. Any precipitation will come to an end Friday morning. Friday will be cooler behind the cold frontal passage, with highs in the 40s and 50s. Friday night through Tuesday... An active pattern will continue this weekend as an approaching trough over the west coast will bring multiple chances for precipitation to the area. There remains uncertainty regarding the exact track and development of the system however the general timing of rain/snow is gradually becoming clearer. The highest chances for rain (50-75%) will occur this weekend within the warm sector of the low. A few thunderstorms are possible this weekend as weak instability moves into the area, however at this time any severe thunderstorms are not expected. Snow will be possible along the backside of the system as it departs from the Plains Sunday night into Monday. Model spread increases as the low begins to exit the area, bringing uncertainty on the potential snow impacts. While precipitation chances currently persist from Friday night through Tuesday morning, this will become more refined as the details on the system become clearer. This system will continue to be monitored closely over the coming days to determine the exact impacts it will bring. There remains considerable uncertainty on temperatures this weekend, with the NBM 25-75th percentile temperatures showing a 20+ degree spread in high temperatures on Saturday and Sunday. Temperatures will be cooler as the system departs the area next week. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1235 AM CDT Tue Mar 19 2024 Marginal LLWS will be possible through 12Z. VRF conditions expected through the TAF period. Southwesterly winds will gradually shift to the west overnight, with winds becoming north-northwesterly after sunrise. Wind gusts around 20 MPH will be possible from the mid morning through the mid afternoon hours. Northerly winds will decrease Tuesday afternoon, becoming light and variable overnight. Clear skies are expected through the TAF period. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ DISCUSSION...Davis AVIATION...Davis
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