Aikyam-Lab/Synoptic-Bench huggingface dataset:
451 AM EST Fri Dec 27 2019 Cold frontal zone/boundary continues to drop southeastward towards the Ohio River this morning. Guidance suggest CIGS should rebound back up into VFR categories by the end of the forecast period as low pressure developing to our west over the Plains lifts this boundary back to the north.
This will be followed by dry and a little warmer weather through the weekend.
Some improvement in conditions to VFR continues to be supported by most guidance after 20z, with IFR conditions developing again and shower chances increasing after 00z as a warm front lifts north. /Issued 245 AM CST Fri Dec 27 2019/ Areas of patchy fog/drizzle will continue this morning as shallow cold front stalls in the higher terrain of southeast Oklahoma and northwest Arkansas. Warm front will begin to lift back north through the area tonight in response to approaching storm system moving through the central /southern Rockies. Precipitation chances will continue to increase through the day Saturday as Pacific cold front moves into eastern Oklahoma by late afternoon.
Ridge of high pressure north of the area will maintain an onshore flow pattern for our area Today and Tonight. The activity across se GA is expected to gradually diminish through dawn, with latest guidance showing a developing coastal trough later Today and Tonight, with an area of showers developing along the east coast of central FL later Today, spreading northward along the FL east coast to our southern counties this evening, further north later Tonight. Southwesterly flow will exist aloft, given upper ridging off the SE coast, supporting above normal high temperatures Today in the mid-upper 70s inland, around 70 coast.
345 AM CST Fri Dec 27 2019 (Today and Tonight) An upper level trough is currently located across the Desert Southwest. The better chance of showers and thunderstorms will late tonight into the early morning hours Saturday, as the aforementioned upper level trough approaches and a Pacific front sweeps across the region.
332 AM MST Fri Dec 27 2019 Water vapor imagery shows an upper trough across the western CONUS. and small scale upper ridging over the central Plains just preceding the trough. Surface analysis shows high pressure across the northern Plains into the upper Midwest. Through the day, the upper trough will swing east/northeastward, crossing the Four Corners region, then the central Rockies tonight, strengthening as an upper low.
908 AM EST Fri Dec 27 2019 The synoptic pattern continues to show the high pressure center off the New England coastline with ridging extending over the southeast U. Broad high pressure off the New England states extends along the eastern seaboard, over Florida and into the Gulf of Mexico.
417 AM MST Fri Dec 27 2019 Water vapor imagery shows an upper trough across the western CONUS. and small scale upper ridging over the central Plains just preceding the trough. Surface analysis shows high pressure across the northern Plains into the upper Midwest. Through the day, the upper trough will swing east/northeastward, crossing the Four Corners region, then the central Rockies tonight, strengthening as an upper low.
If light rainfall can develop before 15Z over northwestern OK, it will be of the freezing type. More widespread rainfall will begin to develop later this evening and into Saturday as the main mid to upper trough crosses the Rockies and a Pacific cold front accompanies it.
Low stratus will continue to dominate the region early this morning with low clouds likely pushing out by the early afternoon as high pressure pushes into southern Wisconsin.
/issued 419 AM EST Fri Dec 27 2019/ High pressure will ridge across the area through the weekend with easterly flow remaining in place through Saturday.
A split upper trough will move east across the western US the next few days. Montana will see the drier northern stream trough tonight and Saturday. The wetter southern trough in the 4 corners area of the SW US lifts NE over the weekend and brings a major winter storm to the Northern Plains and Upper Midwest over the weekend but the snow from this system is expected to stay east of the forecast area although skies will remain cloudy over the eastern half of the forecast area while high pressure keeps skies clear to partly cloudy in the west.
248 PM CST Fri Dec 27 2019 Moisture has been rampant across the region today, streaming in from the Pacific (as seen on water vapor imagery) and from the Gulf as a warm front was slowly working its way northward. As the warm front continues to lift northward during the evening, a Pacific front will be approaching from the west compliments of a tightly wound upper level low spinning over south- central AZ this afternoon. As the main lift, that being the upper low that will be opening, pulls through the region tomorrow, we'll see gusty westerly winds with patchy blowing dust possible on the Caprock.
A strengthened onshore flow as the pressure gradient tightens downstream of an approaching weekend cold front will be the saving grace from overnight dense inland fog. The approach and passage of a pre-frontal trough leading a main Central Texas cold front will introduce far northern air field scattered (light) showers tomorrow morning.
Better chance of this will be tonight into Saturday morning as an upper level trough and a pacific cold front move across the area.
Thus, skies will remain mostly cloudy today but warm air advection should allow much of the region to reach the lower and middle 60s. Chattanooga Airport, TN 64 48 66 58 / 0 0 10 70 Knoxville McGhee Tyson Airport, TN 62 44 65 54 / 0 0 10 50 Oak Ridge, TN 61 45 63 55 / 0 0 10 60 Tri Cities Airport, TN 60 42 66 49 / 0 0 10 40.
/issued 908 AM EST Fri Dec 27 2019/ The synoptic pattern continues to show the high pressure center off the New England coastline with ridging extending over the southeast U. Broad high pressure off the New England states extends along the eastern seaboard, over Florida and into the Gulf of Mexico.
1046 AM MST Fri Dec 27 2019 Water vapor imagery shows an upper trough across the western CONUS. and small scale upper ridging over the central Plains just preceding the trough. Surface analysis shows high pressure across the northern Plains into the upper Midwest. Through the day, the upper trough will swing east/northeastward, crossing the Four Corners region, then the central Rockies tonight, strengthening as an upper low.
A weak upper trough will bring light snow showers to the north (Baker County and central Idaho), with flurries possible east and south of Mountain Home. Accumulations will be minor in the north, with less than an inch expected in the higher elevations. Starting late Saturday night scattered snow showers over the higher terrain and isolated snow showers at lower elevations. Short wave trough will pass through today and should break up the low clouds even more. The trough will bring scattered snow showers to northern mountains. A Pacific warm front will bring a chance of light snow Saturday night.
An upper level impulse builds across the Southern Appalachian region overnight while weakening, as amplified ridging develops ahead of a strong late weekend storm system. In this pattern, a warm front lifts north through the mid Mississippi and Lower Ohio Valley region. Low pressure system over the western plains will eventually swing through the central/northern plains and slowly head towards the Great Lakes region.
A few sites were still in the 50s but most of the area has warmed into the lower 60s. Temperatures were on track to top out warmer than normal and from the mid 60s northeast to the lower 70s south. Expect the highest chances for -SHRA after 27/19-23Z.
1143 AM CST Fri Dec 27 2019 Updated for 18Z aviation discussion 18Z TAF discussion: The lower Cigs have not developed this morning and VFR conditions were observed at all TAF site at 1730Z. A few sites were still in the 50s but most of the area has warmed into the lower 60s. Temperatures were on track to top out warmer than normal and from the mid 60s northeast to the lower 70s south.
These should break up a bit across far southeast Kentucky tonight with this trend continuing north Saturday morning as broad zonal to southwest flow further backs downstream of a potent upper level low in the Desert Southwest. Backing southeast/east surface winds will accompany a warm frontal passage early Saturday, allowing warm/moist advection to spill into eastern Kentucky.
932 AM CST Fri Dec 27 2019 Cold front boundary was settling southward through the Rolling Plains, and perhaps can jump onto the Caprock though initial cold surge is fairly shallow. Updated both for the cooler temperatures and wind shift, as well as to include a Dense Fog Advisory, initially for the southern Texas Panhandle, northern South Plains, and northern Rolling Plains. /issued 524 AM CST Fri Dec 27 2019/ Poor flying conditions continue across all terminals, and will through most of the TAF period until around 0900 UTC for KLBB and KPVW, and 1100 UTC for KCDS as a cold front will move through the region during that time.
1231 PM EST Fri Dec 27 2019 Cooler air overspreads the area through tonight behind a cold front.
Meanwhile, the warm front has started its retreat bringing warmer air from the south (so, many locations will see warming temperatures overnight). As the upper level low moves toward our forecast area, widespread showers are expected to develop over the panhandles and shift eastward toward our area overnight into Saturday morning. Saturday will be warmer as southerly flow briefly returns. Showers will clear west to east Saturday afternoon ahead of a stronger cold front. Day After the Saturday cold front passes through our forecast area, and showers depart to our east Saturday evening, a long period of benign weather will begin. The cooler air will be relatively close to the seasonal average temperatures, with little day-to-day change.
The first round will be fueled mostly by isentropic lift in the broad warm sector, and will occur prior to the arrival of the highest moisture; thus rain rates will be light to briefly moderate and precipitation totals through Saturday morning should only amount to a few tenths of an inch. Forcing for precipitation will increase dramatically Saturday as the upper low lifts northward and the upper jet positions over central and eastern Kansas, and will combine with the anomalous moisture to intensify rainfall rates and coverage. In addition, warm-air advection from ~900-850 hPa coincident with falling temperatures in the midlevel trough will result in lapse rates supportive of elevated convection Saturday afternoon and evening, furthering the potential for moderate to heavy rainfall.
Highs tomorrow will once again top out in the lower to middle 60s. A deep upper level trough over the Rockies will bring a very wet weekend to the area as it ejects out into the region in a couple of waves.
Despite the clouds, warm air advection alone should still bring temperatures into the lower to middle 60s this afternoon.
1028 AM CST Fri Dec 27 2019 Cold front is stalling in the higher terrain of southeast Oklahoma this morning. Most of the area will remain north of the front Today before it returns to the north as a warm front Tonight.
256 PM EST Fri Dec 27 2019 Drier weather is moving into the region from the west this afternoon as a weak cold front pushed through.
246 PM EST Fri Dec 27 2019 Drier weather is moving into the region from the west this afternoon as a weak cold front pushed through.
/Issued 1028 AM CST Fri Dec 27 2019/ Cold front is stalling in the higher terrain of southeast Oklahoma this morning. Most of the area will remain north of the front Today before it returns to the north as a warm front Tonight.
839 AM PST Fri Dec 27 2019 A weak ridge aloft will keep the weather fair and the days a little warmer through the weekend, but the nights will remain chilly.
The arrival of a cold front around 15Z will bring prevailing -SHRA to KAUS/KSAT/KSSF.
1023 AM EST Fri Dec 27 2019 A broad 500 mb ridge is centered over the southeast Bahamas this morning, with the 12z KEY and MFL soundings observing a 500 mb height of 589 and 588 decameters respectively.
Snowcover and valleys will keep the cold best over the north, while the southern zones will be 10 to 15 degrees warmer. A split upper trough will move east across the western US the next few days. Montana will see the drier northern stream trough tonight and Saturday. The wetter southern trough in the 4 corners area of the SW US lifts NE over the weekend and brings a major winter storm to the Northern Plains and Upper Midwest over the weekend but the snow from this system is expected to stay east of the forecast area although skies will remain cloudy over the eastern half of the forecast area while high pressure keeps skies clear to partly cloudy in the west.
1233 PM EST Fri Dec 27 2019 Expect spotty light rain and drizzle over the mountains today, but high pressure should dry things up for tonight and Saturday.
130 PM CST Fri Dec 27 2019 A closed low over AZ this morning and its associated trough will move east reaching the Rockies early Saturday.
200 PM EST Fri Dec 27 2019 Cooler air overspreads the area through tonight behind a cold front.
206 PM MST Fri Dec 27 2019 Split upper flow over the western states will bring an upper trough in over the area that will bring in some clouds but we should stay dry. The main impact from the trough will be to grab a cut-off low over the four-corners area and pull it north into the northern Plains.
System will lift stalled frontal boundary back north as a warm front tonight. Also, with the high PWs, could see rainfall up to an inch possible.
A slowly-moving warm front will stay south of these areas until near the time a front moves into western Oklahoma with widespread rain early Saturday. Meanwhile, the warm front has started its retreat bringing warmer air from the south (so, many locations will see warming temperatures overnight). As the upper level low moves toward our forecast area, widespread showers are expected to develop over the panhandles and shift eastward toward our area overnight into Saturday morning. Saturday will be warmer as southerly flow briefly returns. Showers will clear west to east Saturday afternoon ahead of a stronger cold front. Day After the Saturday cold front passes through our forecast area, and showers depart to our east Saturday evening, a long period of benign weather will begin. The cooler air will be relatively close to the seasonal average temperatures, with little day-to-day change.
707 PM EST Fri Dec 27 2019 Drier weather is moving into the region from the west this afternoon as a weak cold front pushed through.
Much drier air moves in behind the cold front, scouring out the low ceilings and fog, but there is still a fair amount of uncertainty to when we'll transition back to VFR tomorrow. /issued 248 PM CST Fri Dec 27 2019/ Moisture has been rampant across the region today, streaming in from the Pacific (as seen on water vapor imagery) and from the Gulf as a warm front was slowly working its way northward. As the warm front continues to lift northward during the evening, a Pacific front will be approaching from the west compliments of a tightly wound upper level low spinning over south- central AZ this afternoon. As the main lift, that being the upper low that will be opening, pulls through the region tomorrow, we'll see gusty westerly winds with patchy blowing dust possible on the Caprock.
Satellite imagery this afternoon shows a southwest flow in place across the Plains, ahead of a large trough in the Desert Southwest. The warm air and moisture advection on top of the high have already resulted a few showers across eastern Kansas and northern Missouri, but in general the widespread rain expected from this coming event wont arrive till after midnight, early Saturday morning. However, the parent trough driving this system will lift north quickly Saturday night, taking the rain with it as a dry slot punches in under the trough.
822 PM EST Fri Dec 27 2019 Low level ESE/SE below H7 has strengthened around the Atlantic ridge allowing deep low level moisture and scattered to numerous showers to move across east central FL into this evening.
Weak high pressure and generally dry air mass will return Saturday.
Chattanooga Airport, TN 48 66 58 68 / 30 10 60 80 Knoxville McGhee Tyson Airport, TN 44 65 53 69 / 20 10 30 80 Oak Ridge, TN 44 65 52 68 / 10 10 40 80 Tri Cities Airport, TN 43 65 51 66 / 0 0 30 70.
The initial phase of our precipitation event began earlier today as a cold rain and even freezing rain event across mainly far southwest Kansas bordering Oklahoma. Rain showers will continue to expand in coverage as the main upper level low draws near through the night.
/Issued 356 PM CST Fri Dec 27 2019/ Warm front is arching from northwest Texas into southeast Oklahoma this afternoon with stratocu deck still locked into portions of the area northwest of I-44. Warm front will continue to lift north overnight making for difficult overnight low forecast as temperatures gradually rise but likely not until some stratus and patchy fog redevelops late this evening. As the trough axis lifts through the area late Saturday afternoon into the evening the best chance of convection will occur with with isolated to scattered storms developing near the US 75 corridor.
934 PM EST Fri Dec 27 2019 Drier weather is moving into the region from the west this afternoon as a weak cold front pushed through.
Patchy fog and low clouds are developing as the low level cloud deck from earlier has cleared out. A few scattered showers will be around during early morning hours and late afternoon hours with CKV having the highest likelihood of being impacted.
Taking a look at satellite imagery, we can see what appears to be a closed upper level low in water vapor imagery moving through Arizona. Tonight, elevated thunderstorms are expected to become linear in nature based on the uniform wind column parallel to a weak pacific cold front. These threat should be limited in areal coverage and perhaps on the higher end of threats. Another cold front will pass through Saturday resulting in breezy wind speeds across the area. Temperatures behind the cold front will be on the chilly side with lows in the teens to low 20s Saturday night.
356 PM CST Fri Dec 27 2019 Warm front is arching from northwest Texas into southeast Oklahoma this afternoon with stratocu deck still locked into portions of the area northwest of I-44. Warm front will continue to lift north overnight making for difficult overnight low forecast as temperatures gradually rise but likely not until some stratus and patchy fog redevelops late this evening. As the trough axis lifts through the area late Saturday afternoon into the evening the best chance of convection will occur with with isolated to scattered storms developing near the US 75 corridor.
A warm front will be pushed northward tonight bringing relatively warm, moist air over a relatively cold airmass across northeast Oklahoma. The thinking is this moist air will condense over the cooler airmass resulting in patchy dense fog to be observed after midnight tonight.
Precipitation chances will continue to increase today, especially into the afternoon hours as strong 150 kt upper jet streak lifts into the region ahead of main upper trough axis. In addition, a brief tornado or two can not be ruled out given the low LCL heights with 0-1 km helicity in excess of 300 (m/s)2.
Continuing the slow grind in getting away from the ridging toward the well-anticipated wet storm system due in Sunday and Sunday night.
The exception is around Deer Park, Coeur d'Alene, and Rathdrum where pockets of clearing this evening have allowed temperatures to drop to 19-22F which may allow for patchy freezing fog to develop. Models show snow showers decreasing overnight as a short wave ridge noses into the region.
A secondary surge of cold air is expected Sunday AM as a shrtwv trof moves thru the mid-level trof. There could be enough cold air aloft in assocn with the shrtwv trof for a few -SHRA/-SHSN in the far nw CWFA Sunday AM. Surface ridging will temper the warm-up into Mon, possibly Tue. Models still insist that a closed upper low will drop into Baja region and phase with a nrn stream mid/upper trof Thur amplifying the flow with a Pacific front moving thru. Baja trof still looks to be too far s for anything other than a few passing -SHRA across far reaches of the Trans Pecos and will attempt to downplay PoPs generated by NBM. Warmer temps seem most likely Fri/Sat.
252 AM CST Sat Dec 28 2019 A rather sharp UL trough is positioned from NRN MB/SK into Chihuahua this morning.
The closed low along the southern stream is starting to transition to more of an open-wave trough as it heads towards the Four Corners region. The airmass will start to stabilize tomorrow, but this will trap cold air at the lower levels. Temperatures are expected to be cooler across most areas tomorrow.
The exception is around Deer Park, Coeur d'Alene, and Rathdrum where pockets of clearing this evening have allowed temperatures to drop to 19-22F which may allow for patchy freezing fog to develop. Models show snow showers decreasing overnight as a short wave ridge noses into the region. KPUW/KGEG have the better chances for visibility restrictions given the higher elevation of these TAF sites with the stratus layer getting closer to ground level.
In fact, temperatures will continue to warm as the morning wears on as a warm front lifts northward through the area, also returning dewpoints back into the 50s by afternoon. The primary impacts from this approaching weather system is expected late this afternoon into the evening as a cold front moves through the forecast area. Dry weather is expected for the end of 2019 with cooler temperatures closer to seasonal averages for this time of year.
The deep occluded cyclone will pull northeastward away from the region Saturday night with dwindling PoPs. While mainly colder and blustery, could see some snow flurries/snow showers under the upper trof during the day.
1031 PM EST Fri Dec 27 2019 Currently - A high cell over the eastern United States and another one off the mid Atlantic Coast is effectively acting as a ridge axis to our north. Expect gentle to moderate east breezes across the Keys with the highest rain chances and stronger breezes in and around the Upper Keys. A ridge to our north will maintain mostly moderate east breezes across Keys waters. A couple nuances will be winds will tend lighter over the cooler gulf and bay waters.
Patchy fog and low clouds are developing as the low level cloud deck from earlier has cleared out.
/issued 130 PM CST Fri Dec 27 2019/ A closed low over AZ this morning and its associated trough will move east reaching the Rockies early Saturday. As the low lifts NE a secondary trough will rotate down into the area Sunday.
1150 PM EST Fri Dec 27 2019 Drier weather is moving into the region from the west this afternoon as a weak cold front pushed through.
Likewise, as the rain moves east, higher elevation areas west of the clearing line will likely experience widespread, dense fog and locally freezing fog possible in the Syracuse and Scott City areas.
An upper trough along the Rockies will continue to move to northeast during this period. A trailing cold front will approach the mid south by late Saturday night, and will provide additional forcing for convection.
/issued 252 AM CST Sat Dec 28 2019/ A rather sharp UL trough is positioned from NRN MB/SK into Chihuahua this morning.
413 AM MST Sat Dec 28 2019 The high amplitude upper trough is now crossing the Four Corners region, with deep southwesterly flow ahead of the trough across the Great Plains. KUDX radar shows snowfall spreading across western SD, with the strongest band located from Faith to Wall to Pine Ridge. Current temps are hovering right around freezing, so some minor icing may occur, but it will be hard to get anything more than a light glaze at those temperatures. The trough will finish cutting off this afternoon, then swing northeastward into the central and northern Plains tonight into Sunday morning.