Aikyam-Lab/Synoptic-Bench huggingface dataset:
Short-fuse models and CAMs continue to show another round of showers and isolated thunderstorms possible this evening across portions of southwest Kansas as a series of H5 vort maxima associated with a +110kt jet core kick out of the southern Colorado Rockies into the high plains. As for temperatures tonight, little change to the general air mass across the high plains and likely increased cloud cover will keep lows dropping much below the 40s(F). Expect highs pushing the lower/mid 70s(F) Monday afternoon. A weak area of high pressure at the surface will be crossing western Kansas early in the day.
254 PM CDT Sun Apr 19 2020 High pressure will drift across the area this evening, with return flow setting up for a brief time overnight into Monday. We'll see a morning trough passage with perhaps some light showers (mainly across the south/east). A cold front will then move through Monday afternoon. The east/southeast portion of the area could escape the low humidity values if clouds/showers are widespread, but there remains uncertainty so a watch was preferred given the potential.
Skies will clear as weak high pressure tries to nudge into the area Monday morning. However, given the decent mid level lapse rates and increasing northwesterly wind fields in the low/mid levels, a stray storm capable of producing some hail or gusty winds may be possible.
The upper level trough will continue to drop south through the period skirting lower portions of our CWA.
Dewpoints could mix down to the lower 30s during the afternoon, with wind gusts up to 35 to 40 mph along/north of I80. Minimum afternoon humidity does drop into the lower 20s, which is just above our red flag warning threshold.
255 PM EDT Sun Apr 19 2020 Mean layer ridging persists across the Caribbean, although zonally squashed and stretching a huge expanse from the Eastern Pacific to the Antilles. The next seven days will feature highly variable wind speeds and directions, a weak push of slightly cooler northerlies, and the beginning of Cuban thunderstorm season. Our breezes will freshen this evening as the low deepens, then turn to the southwest on Monday. Normally, deep southwesterly flow will induce a precipitating cloud line along and in the lee of the Lower Keys in these patterns; however, the low-level thermodynamics will remain hostile.
However, with temps hovering around 32, warm pavement, and strong April insolation, accums have been confined to grassy sfc's on the plains, with light accums on roads in the higher elevations of the Black Hills. Upper level analysis has a broad trof across much of the CONUS with a series of weak trofs from the West Coast into the Southeast. At the surface, high pressure is centered over southern Saskatchewan with weak north to northeast boundary layer flow across the forecast area. Snowfall totals of 2 to 4 inches are expected across Crook County and the higher elevations of the Black Hills, with up to an inch across the plains of northeast Wyoming and the foot hills areas. Ridging builds back into the area early in the week.
The northward progress of the warm front is being hindered by the expanding cold pool to the north.
Warm front has nudged up into far southeast OK, so not out of the question to see a few surface based storms over the next several hours, although large hail will continue to be the primary threat. Have introduce some low PoPs for late Monday afternoon across far northeast OK/northwest AR, with several CAM solutions showing modest SBCAPES ahead of a weak cold front.
The cold front recently cleared the Coastal Bend and will continue making its way offshore. Drier air will filter into the area as high pressure settles in. Temperatures will remain warm with the only exception being tonight temperatures which will be a few degrees cooler after the passage of the front. Tomorrow will be a warm day with partly cloudy skies with temperatures expected to reach the low to high 90s from east to west, respectively.
Northeast winds under lots of insolation still allowing early afternoon temps to reach the middle 60s to lower 70s with high pressure to the north. This activity should exit by early afternoon though a weak trough/cold front will be present over far southern counties around this time.
Dry and pleasant weather is expected for tomorrow with generally clear skies and temperatures rising into the low to mid 60s as weak high pressure briefly builds across the area. Chances for rain return tomorrow night as an upper level low pressure moves through the Great Lakes region.
This area will be closer to the low pressure center and the attendant warm front. Locations along and south of the warm front will see the best chances for severe weather due to better shear (likely characterized by rotating updrafts) and better instability. The question still remains, how far north will this warm front move? At the moment is appears the best answer to that question is points just to the south and southeast of a line extending from about McAlester to Fort Smith. A warm front farther north would promote more surface based storms and thus a better chance for damaging wind gusts.
Additional thunderstorm development is possible through the early evening, primarily along and north of a line from Douglas to Bridgeport. Upper-level ridging begins to set in place Monday with 700 mb temperatures climbing back above the 0C mark. Temperatures will be slightly warmer than Sunday, but highs will mostly remain in the 50s west of the Laramie Range and mid-50s to 60s east.
Chattanooga Airport, TN 53 70 49 71 45 / 100 20 0 10 10 Knoxville McGhee Tyson Airport, TN 50 67 48 68 41 / 100 30 10 10 0 Oak Ridge, TN 50 68 47 68 41 / 100 20 10 10 0 Tri Cities Airport, TN 47 63 44 63 36 / 90 50 10 20 0.
138 PM EDT Sun Apr 19 2020 Persistent troughing in the upper levels will lead to periodic precipitation chances into the middle of the week, along with below normal temperatures. Further dampening chances will be developing subsidence aloft as a trough/low feature moves over the southeast U. With the aforementioned low/trough staying primarily south and east, dry weather is expected Monday as weak high pressure crosses in quasi- zonal mid-level flow.
256 PM MDT Sun Apr 19 2020 Latest upper air analysis shows the long wave trough persisting over the Plains. Within the northwest flow were a couple upper level short wave troughs, with multiple smaller scale troughs. Satellite imagery shows cumulus clouds developing during the afternoon ahead of these troughs. For the rest of the day and tonight, confidence is on the low side regarding precipitation potential for the forecast area. The strongest upper level short wave troughs will move near the northeast and southwest parts of the forecast area late this afternoon and this evening. Monday night a weak upper level short wave trough will move through Southeast Colorado. Most of this trough will be southwest of the forecast area, so confidence of any rainfall for Cheyenne County is low.
Quiet conditions are expected to return on Monday as upper level ridging builds over the west coast.
An upper low northeast of Mt Shasta will weaken into an open trough as it tracks across NV. Today will be around 2-5 degrees warmer than yesterday with highs in the 60s to lower 70s and 50s in the mountains. An elongated but decaying upper level ridge off the coast will shift inland tonight. The ridge will maintain its strength on Monday, and temperatures will climb into the mid 60s to mid 70s for most of the region.
Some previous runs in the various models hinted at a prefrontal trough/bit of upper level energy that could have sparked some morning pcpn, mucking up the atmosphere a bit for any later day convection.
A cold front will move through Monday night with chances for light rain showers.
1123 AM EDT Sun Apr 19 2020 Persistent troughing in the upper levels will lead to periodic precipitation chances into the middle of the week, along with below normal temperatures. Further dampening chances will be developing subsidence aloft as a trough/low feature moves over the southeast U. With the aforementioned low/trough staying primarily south and east, dry weather is expected Monday as weak high pressure crosses in quasi- zonal mid-level flow.
expect modestly cooler temperatures overnight mainly due to the cooling effect of the anticipated shower activity.
1237 PM CDT Sun Apr 19 2020 Cooler temperatures today with highs slightly below average in the 50s.
252 PM EDT Sun Apr 19 2020 A cold front will move through New England tonight with a few showers possible in the north as it moves through. It will be cooler on Monday behind the front.
Meanwhile, a more subtle feature drifting across the high plains may allow a brief shower/storm to develop across portions of southwest/south central KS during peak heating as we remain weakly capped.
Weak high pressure ridge axis over the S FL Peninsula to retreat southward as cold front moves into the N Central Gulf region tonight. Pressure gradient to tighten later tonight ahead of cold front with breezy winds increasing into the SCEC range with building choppy seas towards morning and all day Monday with showers and thunderstorms likely before the front clears the area into Monday night.
Cliff PREVIOUS DISCUSSION: High pressure over the area now will pull away by late this morning. Otherwise, the main story this week is the warming temperatures expected under the building ridge.
The trough will slide across Nevada today and will provide the environment with enough moisture and instability for scattered showers across much of Utah and southwest Wyoming this afternoon, primarily focused over the higher terrain, with a few thunderstorms anticipated. The threat of convection is then expected to be more focused over central and southern Utah this evening as the trough approaches.
217 PM MDT Sun Apr 19 2020 Mean westerly flow expected most of the period as the persistent central NOAM trough finally shifts east. Western NOAM ridge will shift east Monday, with yet another NW flow impulse skirting on the backside of the upper trough over the eastern Dakotas. This will support a warmer but windy day as strong flow above the sfc mixâs out during the day. Warmer and continued dry conds expected Tues and Wed with highs in the 60s and 70s most places. This system will also support a decent chance for showers Thurs, with slightly cooler and unsettled conds expected for the end of the week.
Convection expected to continue moving east across SE GA this afternoon along a warm front, and could have a lull in more robust activity this evening as warm front may push back north. The next round will begin in the overnight period a few hours before dawn, as the cold front reaches the inland SE GA counties, then tracks southeast across SE GA through the morning.
The highest confidence for dense fog will be across southern Missouri and portions of southeastern Kansas. We went very close to the model blend for lows tonight, with most areas bottoming out in the lower to middle 40s. We will then see short wave energy quickly translate southeast across the Corn Belt and central Plains on Monday with a cold front reflected at the surface.
240 PM CDT Sun Apr 19 2020 Northwest flow aloft will persist through the next 24 hours in the wake of a departing upper level trough which is the trigger for thunderstorms across the southeastern USA this afternoon and evening.
Any remaining showers in the mountains today will give way to an expanding area of high pressure over the Northern Rockies.
The HRRR model shows eastward prorogation of new development over southeast Colorado to reach the highway 83 corridor early this evening, perhaps as early as 7 pm. Short-fuse models and CAMs continue to show another round of showers and isolated thunderstorms possible this evening across portions of southwest Kansas as a series of H5 vort maxima associated with a +110kt jet core kick out of the southern Colorado Rockies into the high plains. As for temperatures tonight, little change to the general air mass across the high plains and likely increased cloud cover will keep lows dropping much below the 40s(F). Expect highs pushing the lower/mid 70s(F) Monday afternoon.
Weak cold front early Monday. Precip falling aloft from these thicker cloud decks could result in a few sprinkles reaching the ground, but a significant layer of drier air in the lower levels should result more in the way of virga.
/issued 240 PM CDT Sun Apr 19 2020/ Northwest flow aloft will persist through the next 24 hours in the wake of a departing upper level trough which is the trigger for thunderstorms across the southeastern USA this afternoon and evening.
18Z surface data has high pressure over the Plains while a cold front runs from lower Michigan into Oklahoma. Quiet and dry conditions will be seen through sunrise Monday as high pressure moves quickly through the Midwest. However given the cool temperatures so far this month, seasonal vegetation is not 'yet' susceptible to frost or freezing temperatures. Heating ahead of the approaching cold front will make the atmosphere capable of producing diurnal convection. The cold front looks to enter the highway 20 corridor west of Dubuque in the late afternoon. A potent cold front will arrive Monday evening, and with it, a chance for showers and thunderstorms.
Clearing skies and light winds, along with no discernible dry air advection in the low levels will lead to widespread for potential, and already seeing reduction in vis in areas along north edge of low clouds deck over southeast OK and west central AR. Warm front has nudged up into far southeast OK, so not out of the question to see a few surface based storms over the next several hours, although large hail will continue to be the primary threat. Have introduce some low PoPs for late Monday afternoon across far northeast OK/northwest AR, with several CAM solutions showing modest SBCAPES ahead of a weak cold front.
Convection in the northwest flow aloft is spreading across the higher terrain and over the Palmer Divide.
The next wave will move through the region this afternoon and tonight with snow showers expected over the higher terrain and rain showers across the valley locations with a slight chance of thunderstorms in the stronger storms. The focus will shift south across the San Juan mountains overnight with a few inches possible over the higher terrain before diminishing late tonight. Light accumulations are expected over the higher terrain with snow levels around 8500 feet.
550 PM MDT Sun Apr 19 2020 Latest upper air analysis shows the long wave trough persisting over the Plains. Within the northwest flow were a couple upper level short wave troughs, with multiple smaller scale troughs. Satellite imagery shows cumulus clouds developing during the afternoon ahead of these troughs. For the rest of the day and tonight, confidence is on the low side regarding precipitation potential for the forecast area. The strongest upper level short wave troughs will move near the northeast and southwest parts of the forecast area late this afternoon and this evening. Monday night a weak upper level short wave trough will move through Southeast Colorado. Most of this trough will be southwest of the forecast area, so confidence of any rainfall for Cheyenne County is low.
Upper trough will move off to the east and help bring the cold front across the area overnight, but not expecting too much of an impact in regards to temperatures.
506 PM MDT Sun Apr 19 2020 Mean westerly flow expected most of the period as the persistent central NOAM trough finally shifts east. Western NOAM ridge will shift east Monday, with yet another NW flow impulse skirting on the backside of the upper trough over the eastern Dakotas. This will support a warmer but windy day as strong flow above the sfc mixâs out during the day. Warmer and continued dry conds expected Tues and Wed with highs in the 60s and 70s most places. This system will also support a decent chance for showers Thurs, with slightly cooler and unsettled conds expected for the end of the week.
For 00Z Aviation discussion below High pressure will drift across the area this evening, with return flow setting up for a brief time overnight into Monday. We'll see a morning trough passage with perhaps some light showers (mainly across the south/east). A cold front will then move through Monday afternoon. The east/southeast portion of the area could escape the low humidity values if clouds/showers are widespread, but there remains uncertainty so a watch was preferred given the potential.
4k and Freezing level at 13. Very little in the way of directional shear with moderate speed shear in the lower levels. 0 to 3km helicity values ranging on the lower end south of the lake with values as high as 318 m/s over SW Mississippi.
The forecast is in excellent shape for tonight as high pressure will settle across the region with the northern fringes of the high clouds shifting south of the forecast area as the night progresses. Dry and pleasant weather is expected for tomorrow with generally clear skies and temperatures rising into the low to mid 60s as weak high pressure briefly builds across the area. Chances for rain return tomorrow night as an upper level low pressure moves through the Great Lakes region.
1014 PM EDT Sun Apr 19 2020 A strong low pressure system will bring numerous showers and thunderstorms into and eventually through the region overnight into Monday morning.
652 PM EDT Sun Apr 19 2020 Persistent troughing in the upper levels will lead to periodic precipitation chances into the middle of the week, along with below normal temperatures. Further dampening chances will be developing subsidence aloft as a trough/low feature moves over the southeast U. With the aforementioned low/trough staying primarily south and east, dry weather is expected Monday as weak high pressure crosses in quasi- zonal mid-level flow.
Limited ceilings to OVC012-015 on the low side for KCHA and KTYS and to OVC025 for KTYS where guidance is more mixed on how low ceilings get. CD Chattanooga Airport, TN 52 71 49 72 43 / 100 40 0 10 0 Knoxville McGhee Tyson Airport, TN 49 68 48 68 40 / 90 40 0 20 0 Oak Ridge, TN 50 68 48 68 39 / 80 30 10 10 0 Tri Cities Airport, TN 46 64 45 63 34 / 80 60 10 30 0.
728 PM EDT Sun Apr 19 2020 With high pressure in place and lows dropping to near freezing, frost is possible tonight. Rain showers arrive briefly Monday night as a cold front sweeps through.
Although the rain and thunderstorms will move east of the area after midnight as a cold front moves through, IFR cigs will continue to prevail through 15Z before gradually improving to VFR into the afternoon.
Tonight will become clear, and Monday looks sunny under weak high pressure aloft.
758 PM EDT Sun Apr 19 2020 A strong low pressure system will bring numerous showers and thunderstorms into and eventually through the region overnight into Monday morning.
1043 PM EDT Sun Apr 19 2020 Currently - An Atlantic surface through lower level ridge extends westward across Cuba while a deepening low pressure system marches eastward through the southeast. Short Term Update - Southeast to south winds are expected to freshen soon as the low pressure system moves further eastward, then shift south to southwest later in the night. Proximity of the lower level ridge and ample dr air through much of the depth of the troposphere will keep rain chances slim to none through the overnight. A low moving eastwards towards the Carolina coast and a ridge just to our south will result in freshening southeast to south winds in the next several hours and shifting south to southwest overnight.
337 AM CDT Mon Apr 20 2020 Frontal boundary moving off the lower portions of the Louisiana coastal parishes at 3 am. Dew points have fallen as low as the mid 50s at McComb, and are generally in the lower 60s for most of the rest of the area.
401 AM EDT Mon Apr 20 2020 Low pressure will track off the Carolina coast into the western Atlantic today.
255 AM EDT Mon Apr 20 2020 High pressure will provide dry weather and below-normal temperature today. Persistent troughing in the upper levels will lead to periodic precipitation chances through the week, along with near o below normal temperatures. Lower and mid cloud cover will depart before sunrise, but high clouds will linger until the upper level trough axis passes around midday. Transient low-level ridging in zonal flow aloft will then provide a mostly sunny afternoon. Temperatures will remain below normal in the marginally cooler air mass behind the weak front.
Expect gusty winds across much of north and east Georgia throughout the day tomorrow with wind speeds near 15 mph and gust in the lower 20s.
329 AM CDT Mon Apr 20 2020 A low amplitude upper level ridge axis will move from the southern Rockies today into the southern plains tonight. So western counties are expected to warm a little above normal into the lower 80s, while temperatures should be near normal mid or upper 70s, in the eastern South Plains and Rolling Plains.
Showers will continue early this morning with isentropic ascent ahead of a warm front located to the south.
246 AM CDT Mon Apr 20 2020 At the surface, a cold front extended west southwest from a low pressure centered over western Ontario. Early this morning, this cold front was draped across northern North Dakota and will push south across the state through the day. For minimum relative humidity, basically went with the latest iteration of the RAP as it has been performing pretty well with the lower humidities over the past few days. The duration of the lower humidities looks to be relatively brief this afternoon (anywhere from 1 to 3 hours depending on location), and the timing of the lowest humidity values do not line up perfectly with the highest winds. Overnight lows will generally range from the lower 20s to lower 30s.
121 AM EDT Mon Apr 20 2020 With high pressure in place and lows dropping to near freezing, frost is possible tonight. Rain showers arrive briefly Monday night as a cold front sweeps through.
320 AM CDT Mon Apr 20 2020 Latest surface observations and IR satellite imagery show low pressure system across north central and northeast Alabama. Wrap around moisture to the north and west of the low will continue to bring light rain across the Tennessee Valley until around 10z before ending from west to east. A cold front associated with the aformentioned low pressure system will move through northern Alabama in the early morning hours. Clouds should quickly erode from west to east as cooler and drier air behind a cold front work their way into the area from the northwest. Northerly flow throughout the day will dampen diurnal heating, but mostly sunny skies will warm afternoon temperatures into the lower 70s.
However, as a Canadian low and its associated cold front propagate toward central Indiana, rain chances will increase briefly this evening and tonight.
Portions of the area farther north and west of the fog are currently enjoying clear skies and a cool, crisp morning with lows bottoming out in the low to mid 40s. It should be more mild for today relative to recent days as high temperatures reach into the upper 60s to lower 70s prior to the cold frontal passage.
256 AM EDT Mon Apr 20 2020 A cold front with possibly a few severe thunderstorms will move across the area rapidly this morning.
A gradual warming trend is also expected through the week as high pressure builds near the West Coast. Otherwise, dry conditions will prevail on Monday, as will cooler than normal temperatures. Temperatures today were isothermal across our region, with highs mostly in the lower to mid 60s. After this incoming weak system passes to our east on Monday night, a broad upper ridge centered offshore near 130W is forecast to be our dominant weather feature for the remainder of the week.
208 AM EDT Mon Apr 20 2020 A strong low pressure system will bring numerous showers and thunderstorms into and eventually through the region overnight into Monday morning.