Aikyam-Lab/Synoptic-Bench huggingface dataset:
245 AM MDT Fri May 15 2020 08z surface analysis had trough from eastern MT to central WY to southwest NE with low low along it over central WY. Concern then turns toward disposition of main upper low over WA/OR per water vapour. This afternoon through Saturday, WA/OR upper trough moves east/southeast and closes off over southeast MT this evening, sauntering slowly eastward Saturday. shra/isolated TS will continue overnight into Saturday given weak MUCAPE under upper low.
1057 PM MDT Thu May 14 2020 H5 trough continues to move ashore off the Pacific Northwest Coast this afternoon, caught in the quick zonal flow across the northern US. Western and Central WY will start to see the effects from this trough tonight, as diffluence ahead of it spread across the state. Temperatures will remain right around normal for the day tomorrow, while cooler temperatures return Friday night, with most of southern and western WY falling below freezing.
1051 PM MDT Thu May 14 2020 H5 trough continues to move ashore off the Pacific Northwest Coast this afternoon, caught in the quick zonal flow across the northern US. Western and Central WY will start to see the effects from this trough tonight, as diffluence ahead of it spread across the state. Temperatures will remain right around normal for the day tomorrow, while cooler temperatures return Friday night, with most of southern and western WY falling below freezing.
The ops models and most ensembles were consistent and continue to agree well on the upcoming low pressure system to affect all of our cwa Friday into Saturday night. Otherwise, lift from the upper level low pressure trough will begin affecting our cwa Friday spreading east through Friday night.
Based on this imagery and radar the first few cells are starting to form along the cold front. With continued afternoon heating and the cold air aloft with the low, rain showers and scattered thunderstorms will increase along the front as it propagates east into northeast Minnesota late this afternoon and evening, and across western Lake Superior and northwest Wisconsin this evening and tonight. Saturday evening another upper level low moves into our area per the 12 UTC global suite, with another potential round of much needed rain.
252 AM MDT Fri May 15 2020 What is left of the closed upper low over the Pacific Northwest finally progresses eastward today. Also, the passing of the trough axis coincides with peak heating. Slightly drier air works into the area on Saturday as the ridge aloft builds in from the west so most locations should remain dry.
With the clouds and expected precipitation coverage, maximums will be held in the lower 80s for the most part. Slightly drier air in the east will allow minimums to drop into the lower 60s there. This disturbance will develop into an upper closed low as it enters the lower Mississippi River Valley.
06Z surface data has the main cold front running from western Lake Superior into northeast Nebraska. Dew points were in the 50s and 60s ahead of the cold front with 30s and 40s behind the front. The light winds ahead of the approaching cold front in combination with the wet ground will allow fog to develop across the area through mid-morning. Tonight quiet and dry conditions are expected to continue as high pressure quickly moves through the area.
Lingering clouds holding from Warroad to Bemidji at 08z and likely only a slow move east thru the early morning hours as upper level trough near Thunder Bay Ontario moves slowly east. Some cooler air north of the border in associated with a cold front north of Brandon and Winnipeg will try to slip south a bit so Langdon/Cando areas to be the coolest with around 60 or low 60s vs upper 60s elsewhere.
The last few runs of the HRRR attempt to develop isolated showers along the warm front by late afternoon, however with forecast soundings exhibiting a decent EML, have low confidence in storm development for the late afternoon. Cloud cover south of Interstate 70 should inhibit highs to the low 70s with upper 70s in north central Kansas where skies are mostly sunny. For this evening, isentropic lift increases ahead of an incoming upper trough ejecting into the northern plains. Optimal moisture transport with PWAT values seen on forecast soundings suggest north central KS could see the highest rainfall totals overnight.
Today should be a beautiful day with low surface dewpoints, highs in the lower to mid 70s and winds generally under 15 mph.
The southerly flow off the Gulf will keep us unsettled with a weak upper low lifting up over NE TX from the coastal bend late tomorrow and into Saturday. So while heating will be less on Saturday, the arrival of the upper low will bring the best coverage we have seen in a while. The upper low will continue slowly Eastward overnight.
300 AM PDT Fri May 15 2020 Warmer and drier weather briefly returns today and Saturday.
The highest rainfall amounts are likely to reside over the northern half of the CWA tonight and Saturday, therefore WPC has placed this area under a Slight Risk for excessive rainfall. Temperatures will be on the cooler side on Saturday as the rain lingers over along with a thick cloud cover. Highs on Saturday are forecast to range from the lower 80s east to near 90 out west.
A weak upper level ridge will move across the region today, giving most areas across Western Washington a brief break in precipitation.
314 AM MDT Fri May 15 2020 Satellite and 500 mb RAP analysis showed southwest flow aloft across the tri-state region today, with a closed low passing through the northern Plains. Convection is expected to develop along a lee trough in the afternoon and spread eastward into the region through the evening. Normal temperatures for this time of the year range from the low to mid-70s for highs and the mid to upper 40s for lows. A gradual warming trend is expected early in the week as a ridge sets up over the Central High Plains.
The upper low will start to meander from east TX into AR Saturday night.
Saturday will see a return to warm and dry conditions as a high pressure ridge transits the Northern Rockies, but fog may start the day in many valley locations.
The highest chances remain along the South Dakota border while northern locations are expected to remain dry. Ridge builds in the wake of the previous system bringing warming temperatures to start the week.
VFR conditions expected through the period as high pressure off to our east remains in control. Today, high pressure is in place to our east and is situated off the coast off the Carolinas. This provides a southerly flow across our region as we are on the western periphery of the high. Tonight, slight chance POP remains in place across portions of southwest VA as a cold front sags southward out of the Ohio River Valley.
A surface cold front will likely be situated somewhere in the proximity of the I-44 corridor and may provide a trigger for renewed convection if clouds can clear. If clouds can clear, highs in the lower 80s are quite achievable, especially south of that front. By Saturday morning, an upper level trough axis will extend from a closed low across the western Dakotas to another short wave trough across northern Texas.
642 AM CDT Fri May 15 2020 Bulk of area overnight was between convective complex to the south and approach of short wave and associated cold front from the northwest.
An upper low will continue to move across southeastern Washington and northeastern Oregon early this morning and will move into Idaho late this morning. As this happens ridging will build in from the west. The ridging will bring an end to the precipitation, with any rain mainly confined to the eastern Oregon Mountains during the day and should be winding down by mid-afternoon Dry weather is expected tonight.
Today will be dry and milder as weak upper ridging builds over the area. Upper ridging quickly moves east tonight and a cold front will march east towards the coast by Saturday morning.
647 AM EDT Fri May 15 2020 Low pressure system will track across the Great Lakes today bringing a front into the Ohio Valley.
404 AM CDT Fri May 15 2020 Weak surface ridging will bring dry weather today with near-normal highs around 70 degrees. This suggests mesocyclone development if storms develop.
538 AM MDT Fri May 15 2020 08z surface analysis had trough from eastern MT to central WY to southwest NE with low low along it over central WY. Concern then turns toward disposition of main upper low over WA/OR per water vapour. This afternoon through Saturday, WA/OR upper trough moves east/southeast and closes off over southeast MT this evening, sauntering slowly eastward Saturday. shra/isolated TS will continue overnight into Saturday given weak MUCAPE under upper low.
For 12Z Aviation discussion below Weak surface ridging will bring dry weather today with near-normal highs around 70 degrees. This suggests mesocyclone development if storms develop.
Highs today will be in the upper 80s and lower 90s, with lows tonight mainly in the lower 60s.
Bulk of area overnight was between convective complex to the south and approach of short wave and associated cold front from the northwest.
This will support organized severe convection and CAMs including the HRRR and NAM Nest show a line of intense storms developing along a Cheyenne-Chadron line by early afternoon, along the pre-frontal trough.
The highest amounts will in the far south and the central interior counties. Low pressure tracking east through the Florida Straits today will maintain exercise caution conditions on the waters for much of today. As the low approaches the Bahamas and begins a northeasterly track the winds start to diminish and become more northeast to north.
Mostly dry and warmer today as a dying weather system moves east. A quick moving ridge of high pressure will sit over Nevada through Saturday.
455 AM MDT Fri May 15 2020 What is left of the closed upper low over the Pacific Northwest finally progresses eastward today. Also, the passing of the trough axis coincides with peak heating. Slightly drier air works into the area on Saturday as the ridge aloft builds in from the west so most locations should remain dry.
It will become a warm front and begin to slowly lift northward towards the forecast area late tonight. On Saturday the warm front will slide northward through the region in response to the approaching upper level system from the west and backing flow aloft. Expect scattered showers and a few storms during the morning hours with this boundary, then focus then shifts to warm sector south of the warm front. Saturday night, main cold front will begin to slide through region with showers and thunderstorms likely across the region. Highs on Saturday will be warmer, in the mid 70s to low 80s, then lows Saturday night will be in the upper 50s to mid 60s.
/issued 306 AM CDT Fri May 15 2020/ Weak high pressure is in place over our area and will persist through Saturday. Saturday, a low pressure system is expected to move toward our area from the Western US.
Temperatures ranged from the lower 60s to lower 70s. On Saturday, a deepening low pressure system will move towards the area from Northern Plains. As the low pressure area moves through the region on Saturday night, the 850 mb moisture transport will gradually increase and preciptable water values will climb into the 1 to 1.
In the lower levels, low clouds associated with convergence along the stationary front that is sitting roughly along I-70 will likely linger through the evening. The stationary front should begin to lift northward as a warm front late tonight with it moving north of the area by late tomorrow morning. With no focus it's difficult to say one area has a better chance than any other area until the evening when a cold front moves through the area.
This will bring us cooler, drier air that will help skies clear tonight as reflected in the NBM. Northwesterly flow aloft keeping us cool will shift to southwesterly ahead of another mid-level trough, transporting warm air and moisture from the south that will lead to higher temperatures and cloud cover on Saturday.
We kept the highest PoPs confined to the far southwest into the west central given the slow eastward progression depicted by the CAMS and expected from the mean flow. The highest chances remain along the South Dakota border while northern locations are expected to remain dry. Ridge builds in the wake of the previous system bringing warming temperatures to start the week.
The w-central ID mountains will see lingering showers today on the backside of the exiting trough.
1206 PM MDT Fri May 15 2020 What is left of the closed upper low over the Pacific Northwest finally progresses eastward today. Also, the passing of the trough axis coincides with peak heating. Slightly drier air works into the area on Saturday as the ridge aloft builds in from the west so most locations should remain dry.
As precip begins to wane later tonight and winds slow shift to NW, have introduced some fog, but will have to be watched for areal coverage as the speed of the ridge could prolong light winds and with ample moisture, could give many areas persistent fog into the morning hrs Saturday. With the ridge building in behind the exiting system, low level clouds could linger thru the morning hrs before giving way to more sunshine as upper ridging will aid in drying the area out under NW flow aloft/sfc. Cooler air on NNW flow Saturday night will bring lower and mid 40s to the CWA.
08z surface analysis had trough from eastern MT to central WY to southwest NE with low low along it over central WY. Concern then turns toward disposition of main upper low over WA/OR per water vapour. This afternoon through Saturday, WA/OR upper trough moves east/southeast and closes off over southeast MT this evening, sauntering slowly eastward Saturday. shra/isolated TS will continue overnight into Saturday given weak MUCAPE under upper low.
Outflow from an MCS across Oklahoma this afternoon is pushing westward toward the High Plains and should get a boost in its progress from this evening's South/Rolling Plains storms. A cooler but moist air mass and proximity to cooler mid level temperatures near an exiting short wave trough could lead to a few showers/thunderstorms across the Rolling Plains during the day Saturday. By Saturday evening an upper level low will be located across northeastern Texas as it lifts away from our forecast area.
253 PM CDT Fri May 15 2020 A cold front will stall out in the Ohio Valley tonight and then return northward on Saturday ahead of a low pressure system that will be approaching along the boundary.
Temperatures and dewpoints behind the precip have remained in the low/mid 60s and have not had much chance to recover under the cloud cover. Additional thunderstorm chances are forecast Saturday as a compact upper low lifts northeast to around the Red River Saturday afternoon/evening. The greater storm potential looks to be across Southeast Oklahoma into Northwest Arkansas as the upper low moves into the region.
336 PM EDT Fri May 15 2020 A broad area of low pressure remains in the eastern Florida Straits but has been slowly moving to the northeast this afternoon. With the shower coverage dwindling, the Middle Keys managed to rebound into the lower 80s with the Lower Keys reaching into the mid 80s.
Dry conditions are expected across much of south central Alabama and the western Florida Panhandle on Saturday as drier/more subsident conditions are expected under the influence of a mid-level ridge nosing westward from the western Atlantic. Otherwise, lows will be in the low 60s inland to mid/upper 60s along the coast. Highs on Saturday will be slightly warmer, with mid 80s west of the Alabama River and along the coast, and in the upper 80s to lower 90s to the east of the river.
This should allow for a warm night with lows only dropping into the low to mid 60s. Kept only 20 pop in the forecast given better lift along an approaching cold front will remain over Texas and Arkansas much of the day. Models continue to be slow moving with the front as the upper low over Texas phases with it.
The trough, combined with some mid and upper level moisture and instability, has resulted in some elevated scattered showers/isolated thunderstorms early this afternoon. As the trough continues to move east into our region late this afternoon and tonight, hi-res models are in good agreement that the initial discrete cells along the dry-line west of our region will transition to two strong lines of thunderstorms. Storms should be quickly diminishing after midnight, and just our eastern counties will have small chances for additional thunderstorms Saturday as the trough moves east of us. With some cooler northeasterly surface winds Saturday, cooler higher in the upper 70s to low 80s will be possible in the Big Country and Heartland, while elsewhere highs will be in the mid to upper 80s.
258 PM EDT Fri May 15 2020 Low pressure over upstate New York will track across southern New Hampshire and the southern tip of Maine spawning widespread showers and thunderstorms this evening. Along and south of the low track will be the area most likely to see thunderstorms containing large hail, damaging winds and heavy rainfall. The low will race offshore tonight with high pressure and drier air to follow for Saturday and Saturday night.
By by the weekend a low pressure system situated over central Texas, a southeastward moving cold front will increase rain and thunderstorm potential to the Mid-South. As the upper trough deepens and approaches the area by Saturday and low level flow will continue to carry warm, moist, Gulf air into the area, showers and thunderstorms will develop across the area.
Further north the more substantial cold front has pushed to near Interstate 44 and marks the northward extent of any stronger storm potential.
More diurnally forced convection ahead of a stronger closed low to our southwest will be possible on Saturday afternoon as well.
Showers and a few thunderstorms are expected again on Saturday as the upper low slowly crosses the forecast area. The precipitation chances will end early on Saturday evening as the upper low moves off to the east and an upper ridge builds over the area from the west.
LW Chattanooga Airport, TN 62 86 63 87 66 / 0 10 0 20 40 Knoxville McGhee Tyson Airport, TN 60 84 62 86 65 / 0 20 10 20 40 Oak Ridge, TN 60 85 62 86 64 / 10 20 10 20 50 Tri Cities Airport, TN 57 83 58 84 61 / 10 30 10 30 40.
With high pressure just to our west, we still expect drying conditions to accompany this area of high pressure as it shifts over the Northern Rockies tonight into Saturday.
A few diurnally driven showers are possible mainly west of the Highway 83 corridor Saturday afternoon. An upper level ridge builds over the area in the wake of the exiting SD upper wave, bringing warming temperatures to start the week.
301 PM EDT Fri May 15 2020 High pressure offshore the Carolinas will slowly shift east tonight.
Moving into Saturday, models show a slow moving trough coming out of the Rockies and digging south into east Texas. By doing so, ridging aloft will expand and increase subsidence.
243 PM CDT Fri May 15 2020 Surface analysis shows a weak ridge of high pressure extending south from Canada into the area today. There may be a bit of a gap (or at least a lightening of precipitation) in things across the central portion of the area where subidence may be enhanced north of convection and in the downward side of the low level frontogenetic circulation.
Models didn't have a good handle on the low clouds hanging on this morning, but areas that cleared out warmed up quickly.
Fairly tranquil currently between upper systems and with surface ridging over the area. The upper low will exit into southern MN Saturday night, with all but our far southeastern edge seeing showers tapering off.
For 18Z Aviation Discussion Below Weak surface ridging will bring dry weather today with near-normal highs around 70 degrees. This suggests mesocyclone development if storms develop.
An initial lead short wave trough in western sd this afternoon was bringing showers and storms which were moving into central sd. Otherwise, the main upper level low pressure area will be moving across the region later tonight through Saturday night with rain overspreading most of the region by Saturday morning.
Despite a modest amount of frontogenesis in the 800 to 600 hPa layer, light rain showers west of I-29 will initially have a difficult time reaching the surface, given a deep dry layer in the lowest 7000 ft of the atmosphere. Afternoon high temperatures will be cooler thanks to the abundant clouds and rain, with highs about 5 degrees below seasonal normals.
Mid-level temperatures were a little cooler as well, with 700mb temps +5 to +6C across much of far western Kansas. Earlier this morning, there were some hints that a small inverted trough axis along/west of U83 might be enough to support a couple late afternoon storms, but it does not seem like that will be happening now.
This trough will pass east overnight with high pressure building in behind it.
1138 AM EDT Fri May 15 2020 Currently - A broad area of low pressure remains over the Florida Straits and continues to bring periods of showers across the Florida Keys. Where there is more sunshine, temperatures have warmed into the lower 80s across the Lower Keys. Precipitation chances have been scaled back to 40 percent for the Lower Keys, while maintaining higher PoPs in the Middle and Upper Keys. Otherwise, broad area of low pressure in the distant Florida Straits will slowly meander northeast towards the Bahamas over the next 24-36 hours.
An upper ridge will build over eastern Montana in its wake as a large upper low gradually presses toward northern California this weekend.
Aloft, short wave disturbance moving through the Great Lakes region will drag a surface cold front over the Midwest to about the Ohio River by early Saturday morning. Thereafter short wave ridging will transit the Ohio Valley Saturday before yielding to a pair of phasing closed lows at the end of the short term window.
The deeper into the cooler air, the lower the risk of major severe weather. Another cold front is expected to move into Oklahoma tomorrow, joining an MCV that is likely to be over southern Oklahoma during the day.
959 PM EDT Fri May 15 2020 Low pressure over upstate New York will track across southern New Hampshire and the southern tip of Maine spawning widespread showers and thunderstorms this evening. Along and south of the low track will be the area most likely to see thunderstorms containing large hail, damaging winds and heavy rainfall. The low will race offshore tonight with high pressure and drier air to follow for Saturday and Saturday night.
Expect an increase in activity late this afternoon and early this evening as the trough closes on the area and the region reaches peak heating. Models depicted a shallow transitory ridge over the region Saturday through Saturday night and, as a result, eastern Utah and western Colorado should be quiet with respect to both wind and precipitation.
No impacts expected tonight with temperatures remaining above freezing due to increasing high clouds and slightly warmer/moister airmass compared with last night (although still light winds expected). Fairly tranquil currently between upper systems and with surface ridging over the area. The upper low will exit into southern MN Saturday night, with all but our far southeastern edge seeing showers tapering off.
658 PM CDT Fri May 15 2020 Surface analysis shows a weak ridge of high pressure extending south from Canada into the area today. There may be a bit of a gap (or at least a lightening of precipitation) in things across the central portion of the area where subsidence may be enhanced north of convection and in the downward side of the low level frontogenetic circulation.
856 PM CDT Fri May 15 2020 A cold front will stall out in the Ohio Valley tonight and then return northward on Saturday ahead of a low pressure system that will be approaching along the boundary.